From d35fd87e643656a43e1ec19e18ead85839886679 Mon Sep 17 00:00:00 2001
From: George Hazan <ghazan@miranda.im>
Date: Thu, 2 Jul 2020 19:37:06 +0300
Subject: fixes #2472 (Update liblua to 5.4)

---
 libs/liblua/docs/readme.html |  117 ++-
 libs/liblua/liblua.vcxproj   |    2 +-
 libs/liblua/src/lapi.c       |  644 +++++++++-------
 libs/liblua/src/lapi.h       |   27 +-
 libs/liblua/src/lauxlib.c    |  352 ++++-----
 libs/liblua/src/lauxlib.h    |   54 +-
 libs/liblua/src/lbaselib.c   |  139 ++--
 libs/liblua/src/lcode.c      | 1131 ++++++++++++++++++++-------
 libs/liblua/src/lcode.h      |   34 +-
 libs/liblua/src/lcorolib.c   |   84 +-
 libs/liblua/src/lctype.c     |   43 +-
 libs/liblua/src/lctype.h     |    4 +-
 libs/liblua/src/ldblib.c     |   73 +-
 libs/liblua/src/ldebug.c     |  428 +++++++----
 libs/liblua/src/ldebug.h     |   18 +-
 libs/liblua/src/ldo.c        |  506 ++++++------
 libs/liblua/src/ldo.h        |   35 +-
 libs/liblua/src/ldump.c      |  197 ++---
 libs/liblua/src/lfunc.c      |  222 +++++-
 libs/liblua/src/lfunc.h      |   50 +-
 libs/liblua/src/lgc.c        | 1219 +++++++++++++++++++----------
 libs/liblua/src/lgc.h        |  103 ++-
 libs/liblua/src/linit.c      |    7 +-
 libs/liblua/src/liolib.c     |  112 ++-
 libs/liblua/src/ljumptab.h   |  112 +++
 libs/liblua/src/llex.c       |   75 +-
 libs/liblua/src/llex.h       |    4 +-
 libs/liblua/src/llimits.h    |  108 ++-
 libs/liblua/src/lmathlib.c   |  433 ++++++++++-
 libs/liblua/src/lmem.c       |  178 ++++-
 libs/liblua/src/lmem.h       |   72 +-
 libs/liblua/src/loadlib.c    |  261 +++----
 libs/liblua/src/lobject.c    |  311 +++++---
 libs/liblua/src/lobject.h    |  734 ++++++++++++------
 libs/liblua/src/lopcodes.c   |  190 +++--
 libs/liblua/src/lopcodes.h   |  401 ++++++----
 libs/liblua/src/lopnames.h   |  103 +++
 libs/liblua/src/loslib.c     |   85 ++-
 libs/liblua/src/lparser.c    | 1000 ++++++++++++++++--------
 libs/liblua/src/lparser.h    |   77 +-
 libs/liblua/src/lprefix.h    |    4 +-
 libs/liblua/src/lstate.c     |  242 ++++--
 libs/liblua/src/lstate.h     |  195 ++++-
 libs/liblua/src/lstring.c    |  141 ++--
 libs/liblua/src/lstring.h    |   25 +-
 libs/liblua/src/lstrlib.c    |  483 ++++++++----
 libs/liblua/src/ltable.c     |  672 ++++++++++------
 libs/liblua/src/ltable.h     |   19 +-
 libs/liblua/src/ltablib.c    |   52 +-
 libs/liblua/src/ltm.c        |  173 ++++-
 libs/liblua/src/ltm.h        |   28 +-
 libs/liblua/src/lua.h        |   65 +-
 libs/liblua/src/luaconf.h    |  260 +++----
 libs/liblua/src/lualib.h     |    5 +-
 libs/liblua/src/lundump.c    |  266 ++++---
 libs/liblua/src/lundump.h    |    8 +-
 libs/liblua/src/lutf8lib.c   |  117 ++-
 libs/liblua/src/lvm.c        | 1732 +++++++++++++++++++++++++++---------------
 libs/liblua/src/lvm.h        |   91 ++-
 libs/liblua/src/lzio.c       |    2 +-
 libs/liblua/src/lzio.h       |    2 +-
 61 files changed, 9482 insertions(+), 4845 deletions(-)
 create mode 100644 libs/liblua/src/ljumptab.h
 create mode 100644 libs/liblua/src/lopnames.h

(limited to 'libs/liblua')
diff --git a/libs/liblua/docs/readme.html b/libs/liblua/docs/readme.html
index b118f7b02d..eebd34025c 100644
--- a/libs/liblua/docs/readme.html
+++ b/libs/liblua/docs/readme.html
@@ -1,7 +1,7 @@
 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 <HTML>
 <HEAD>
-<TITLE>Lua 5.3 readme</TITLE>
+<TITLE>Lua 5.4 readme</TITLE>
 <LINK REL="stylesheet" TYPE="text/css" HREF="lua.css">
 <META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1">
 <STYLE TYPE="text/css">
@@ -30,7 +30,7 @@ tt, kbd, code {
 
 <H1>
 <A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua"></A>
-Welcome to Lua 5.3
+Welcome to Lua 5.4
 </H1>
 
 <DIV CLASS="menubar">
@@ -47,7 +47,7 @@ Welcome to Lua 5.3
 
 <H2><A NAME="about">About Lua</A></H2>
 <P>
-Lua is a powerful, fast, lightweight, embeddable scripting language
+Lua is a powerful, efficient, lightweight, embeddable scripting language
 developed by a
 <A HREF="http://www.lua.org/authors.html">team</A>
 at
@@ -55,7 +55,9 @@ at
 the Pontifical Catholic University of Rio de Janeiro in Brazil.
 Lua is
 <A HREF="#license">free software</A>
-used in many products and projects around the world.
+used in
+<A HREF="http://www.lua.org/uses.html">many products and projects</A>
+around the world.
 
 <P>
 Lua's
@@ -69,7 +71,7 @@ and
 updated
 <A HREF="http://www.lua.org/docs.html">documentation</A>,
 especially the
-<A HREF="http://www.lua.org/manual/5.3/">reference manual</A>,
+<A HREF="http://www.lua.org/manual/5.4/">reference manual</A>,
 which may differ slightly from the
 <A HREF="contents.html">local copy</A>
 distributed in this package.
@@ -85,7 +87,8 @@ because
 Lua is implemented in pure ANSI C and compiles unmodified in all known
 platforms that have an ANSI C compiler.
 Lua also compiles unmodified as C++.
-The instructions given below for building Lua are for Unix-like platforms.
+The instructions given below for building Lua are for Unix-like platforms,
+such as Linux and Mac OS X.
 See also
 <A HREF="#other">instructions for other systems</A>
 and
@@ -101,21 +104,24 @@ a multi-platform distribution of Lua that includes batteries.
 
 <H3>Building Lua</H3>
 <P>
-In most Unix-like platforms, simply do "<KBD>make</KBD>" with a suitable target.
+In most common Unix-like platforms, simply do "<KBD>make</KBD>".
 Here are the details.
 
 <OL>
 <LI>
 Open a terminal window and move to
-the top-level directory, which is named <TT>lua-5.3.5</TT>.
+the top-level directory, which is named <TT>lua-5.4.0</TT>.
 The <TT>Makefile</TT> there controls both the build process and the installation process.
 <P>
 <LI>
-  Do "<KBD>make</KBD>" and see if your platform is listed.
+  Do "<KBD>make</KBD>". The <TT>Makefile</TT> will guess your platform and build Lua for it.
+<P>
+<LI>
+  If the guess failed, do "<KBD>make help</KBD>" and see if your platform is listed.
   The platforms currently supported are:
 <P>
 <P CLASS="display">
-   aix bsd c89 freebsd generic linux macosx mingw posix solaris
+   guess aix bsd c89 freebsd generic linux linux-readline macosx mingw posix solaris
 </P>
 <P>
   If your platform is listed, just do "<KBD>make xxx</KBD>", where xxx
@@ -136,25 +142,27 @@ and liblua.a (the library).
   after building Lua. This will run the interpreter and print its version.
 </OL>
 <P>
-If you're running Linux and get compilation errors,
+If you're running Linux, try "<KBD>make linux-readline</KBD>" to build the interactive Lua interpreter with handy line-editing and history capabilities.
+If you get compilation errors,
 make sure you have installed the <TT>readline</TT> development package
 (which is probably named <TT>libreadline-dev</TT> or <TT>readline-devel</TT>).
 If you get link errors after that,
-then try "<KBD>make linux MYLIBS=-ltermcap</KBD>".
+then try "<KBD>make linux-readline MYLIBS=-ltermcap</KBD>".
 
 <H3>Installing Lua</H3>
 <P>
   Once you have built Lua, you may want to install it in an official
   place in your system. In this case, do "<KBD>make install</KBD>". The official
   place and the way to install files are defined in the <TT>Makefile</TT>. You'll
-  probably need the right permissions to install files.
+  probably need the right permissions to install files, and so may need to do "<KBD>sudo make install</KBD>".
 
 <P>
-  To build and install Lua in one step, do "<KBD>make xxx install</KBD>",
+  To build and install Lua in one step, do "<KBD>make all install</KBD>",
+  or "<KBD>make xxx install</KBD>",
   where xxx is your platform name.
 
 <P>
-  To install Lua locally, do "<KBD>make local</KBD>".
+  To install Lua locally after building it, do "<KBD>make local</KBD>".
   This will create a directory <TT>install</TT> with subdirectories
   <TT>bin</TT>, <TT>include</TT>, <TT>lib</TT>, <TT>man</TT>, <TT>share</TT>,
   and install Lua as listed below.
@@ -223,11 +231,8 @@ then try "<KBD>make linux MYLIBS=-ltermcap</KBD>".
 <DT>
 library:
 <DD>
-lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c
-lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c ltable.c
-ltm.c lundump.c lvm.c lzio.c
-lauxlib.c lbaselib.c lbitlib.c lcorolib.c ldblib.c liolib.c
-lmathlib.c loslib.c lstrlib.c ltablib.c lutf8lib.c loadlib.c linit.c
+lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c ltable.c ltm.c lundump.c lvm.c lzio.c
+lauxlib.c lbaselib.c lcorolib.c ldblib.c liolib.c lmathlib.c loadlib.c loslib.c lstrlib.c ltablib.c lutf8lib.c linit.c
 <DT>
 interpreter:
 <DD>
@@ -239,9 +244,9 @@ compiler:
 </DL>
 
 <P>
-  To use Lua as a library in your own programs you'll need to know how to
+  To use Lua as a library in your own programs, you'll need to know how to
   create and use libraries with your compiler. Moreover, to dynamically load
-  C libraries for Lua you'll need to know how to create dynamic libraries
+  C libraries for Lua, you'll need to know how to create dynamic libraries
   and you'll need to make sure that the Lua API functions are accessible to
   those dynamic libraries &mdash; but <EM>don't</EM> link the Lua library
   into each dynamic library. For Unix, we recommend that the Lua library
@@ -254,9 +259,9 @@ compiler:
   As mentioned above, you may edit <TT>src/luaconf.h</TT> to customize
   some features before building Lua.
 
-<H2><A NAME="changes">Changes since Lua 5.2</A></H2>
+<H2><A NAME="changes">Changes since Lua 5.3</A></H2>
 <P>
-Here are the main changes introduced in Lua 5.3.
+Here are the main changes introduced in Lua 5.4.
 The
 <A HREF="contents.html">reference manual</A>
 lists the
@@ -264,50 +269,20 @@ lists the
 
 <H3>Main changes</H3>
 <UL>
-<LI> integers (64-bit by default)
-<LI> official support for 32-bit numbers
-<LI> bitwise operators
-<LI> basic utf-8 support
-<LI> functions for packing and unpacking values
-
-</UL>
-
-Here are the other changes introduced in Lua 5.3:
-<H3>Language</H3>
-<UL>
-<LI> userdata can have any Lua value as uservalue
-<LI> floor division
-<LI> more flexible rules for some metamethods
-</UL>
-
-<H3>Libraries</H3>
-<UL>
-<LI> <CODE>ipairs</CODE> and the table library respect metamethods
-<LI> strip option in <CODE>string.dump</CODE>
-<LI> table library respects metamethods
-<LI> new function <CODE>table.move</CODE>
-<LI> new function <CODE>string.pack</CODE>
-<LI> new function <CODE>string.unpack</CODE>
-<LI> new function <CODE>string.packsize</CODE>
-</UL>
-
-<H3>C API</H3>
-<UL>
-<LI> simpler API for continuation functions in C
-<LI> <CODE>lua_gettable</CODE> and similar functions return type of resulted value
-<LI> strip option in <CODE>lua_dump</CODE>
-<LI> new function: <CODE>lua_geti</CODE>
-<LI> new function: <CODE>lua_seti</CODE>
-<LI> new function: <CODE>lua_isyieldable</CODE>
-<LI> new function: <CODE>lua_numbertointeger</CODE>
-<LI> new function: <CODE>lua_rotate</CODE>
-<LI> new function: <CODE>lua_stringtonumber</CODE>
-</UL>
-
-<H3>Lua standalone interpreter</H3>
-<UL>
-<LI> can be used as calculator; no need to prefix with '='
-<LI> <CODE>arg</CODE> table available to all code
+<LI> new generational mode for garbage collection
+<LI> to-be-closed variables
+<LI> const variables
+<LI> userdata can have multiple user values
+<LI> new implementation for math.random
+<LI> warning system
+<LI> debug information about function arguments and returns
+<LI> new semantics for the integer 'for' loop
+<LI> optional 'init' argument to 'string.gmatch'
+<LI> new functions 'lua_resetthread' and 'coroutine.close'
+<LI> string-to-number coercions moved to the string library
+<LI> allocation function allowed to fail when shrinking a memory block
+<LI> new format '%p' in 'string.format'
+<LI> utf8 library accepts codepoints up to 2^31
 </UL>
 
 <H2><A NAME="license">License</A></H2>
@@ -328,7 +303,7 @@ For details, see
 <A HREF="http://www.lua.org/license.html">this</A>.
 
 <BLOCKQUOTE STYLE="padding-bottom: 0em">
-Copyright &copy; 1994&ndash;2017 Lua.org, PUC-Rio.
+Copyright &copy; 1994&ndash;2020 Lua.org, PUC-Rio.
 
 <P>
 Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -355,10 +330,10 @@ THE SOFTWARE.
 
 <P CLASS="footer">
 Last update:
-Mon Jun 18 22:57:33 -03 2018
+Fri May  1 19:33:31 UTC 2020
 </P>
 <!--
-Last change: revised for Lua 5.3.5
+Last change: revised for Lua 5.4.0 (final)
 -->
 
 </BODY>
diff --git a/libs/liblua/liblua.vcxproj b/libs/liblua/liblua.vcxproj
index 09ffc2ea06..c733282048 100644
--- a/libs/liblua/liblua.vcxproj
+++ b/libs/liblua/liblua.vcxproj
@@ -21,7 +21,7 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{BD291BF0-D804-4818-8311-DE871E6BCEAA}</ProjectGuid>
     <ProjectName>liblua</ProjectName>
-    <TargetName>lua53</TargetName>
+    <TargetName>lua54</TargetName>
   </PropertyGroup>
   <PropertyGroup>
     <GenerateManifest>false</GenerateManifest>
diff --git a/libs/liblua/src/lapi.c b/libs/liblua/src/lapi.c
index 02b7fab7ea..3e24781e0e 100644
--- a/libs/liblua/src/lapi.c
+++ b/libs/liblua/src/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.259.1.2 2017/12/06 18:35:12 roberto Exp $
+** $Id: lapi.c $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -10,6 +10,7 @@
 #include "lprefix.h"
 
 
+#include <limits.h>
 #include <stdarg.h>
 #include <string.h>
 
@@ -36,11 +37,14 @@ const char lua_ident[] =
   "$LuaAuthors: " LUA_AUTHORS " $";
 
 
-/* value at a non-valid index */
-#define NONVALIDVALUE		cast(TValue *, luaO_nilobject)
 
-/* corresponding test */
-#define isvalid(o)	((o) != luaO_nilobject)
+/*
+** Test for a valid index.
+** '!ttisnil(o)' implies 'o != &G(L)->nilvalue', so it is not needed.
+** However, it covers the most common cases in a faster way.
+*/
+#define isvalid(L, o)	(!ttisnil(o) || o != &G(L)->nilvalue)
+
 
 /* test for pseudo index */
 #define ispseudo(i)		((i) <= LUA_REGISTRYINDEX)
@@ -48,49 +52,46 @@ const char lua_ident[] =
 /* test for upvalue */
 #define isupvalue(i)		((i) < LUA_REGISTRYINDEX)
 
-/* test for valid but not pseudo index */
-#define isstackindex(i, o)	(isvalid(o) && !ispseudo(i))
-
-#define api_checkvalidindex(l,o)  api_check(l, isvalid(o), "invalid index")
-
-#define api_checkstackindex(l, i, o)  \
-	api_check(l, isstackindex(i, o), "index not in the stack")
 
-
-static TValue *index2addr (lua_State *L, int idx) {
+static TValue *index2value (lua_State *L, int idx) {
   CallInfo *ci = L->ci;
   if (idx > 0) {
-    TValue *o = ci->func + idx;
-    api_check(L, idx <= ci->top - (ci->func + 1), "unacceptable index");
-    if (o >= L->top) return NONVALIDVALUE;
-    else return o;
+    StkId o = ci->func + idx;
+    api_check(L, idx <= L->ci->top - (ci->func + 1), "unacceptable index");
+    if (o >= L->top) return &G(L)->nilvalue;
+    else return s2v(o);
   }
   else if (!ispseudo(idx)) {  /* negative index */
     api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
-    return L->top + idx;
+    return s2v(L->top + idx);
   }
   else if (idx == LUA_REGISTRYINDEX)
     return &G(L)->l_registry;
   else {  /* upvalues */
     idx = LUA_REGISTRYINDEX - idx;
     api_check(L, idx <= MAXUPVAL + 1, "upvalue index too large");
-    if (ttislcf(ci->func))  /* light C function? */
-      return NONVALIDVALUE;  /* it has no upvalues */
+    if (ttislcf(s2v(ci->func)))  /* light C function? */
+      return &G(L)->nilvalue;  /* it has no upvalues */
     else {
-      CClosure *func = clCvalue(ci->func);
-      return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE;
+      CClosure *func = clCvalue(s2v(ci->func));
+      return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : &G(L)->nilvalue;
     }
   }
 }
 
 
-/*
-** to be called by 'lua_checkstack' in protected mode, to grow stack
-** capturing memory errors
-*/
-static void growstack (lua_State *L, void *ud) {
-  int size = *(int *)ud;
-  luaD_growstack(L, size);
+static StkId index2stack (lua_State *L, int idx) {
+  CallInfo *ci = L->ci;
+  if (idx > 0) {
+    StkId o = ci->func + idx;
+    api_check(L, o < L->top, "unacceptable index");
+    return o;
+  }
+  else {    /* non-positive index */
+    api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
+    api_check(L, !ispseudo(idx), "invalid index");
+    return L->top + idx;
+  }
 }
 
 
@@ -106,7 +107,7 @@ LUA_API int lua_checkstack (lua_State *L, int n) {
     if (inuse > LUAI_MAXSTACK - n)  /* can grow without overflow? */
       res = 0;  /* no */
     else  /* try to grow stack */
-      res = (luaD_rawrunprotected(L, &growstack, &n) == LUA_OK);
+      res = luaD_growstack(L, n, 0);
   }
   if (res && ci->top < L->top + n)
     ci->top = L->top + n;  /* adjust frame top */
@@ -124,7 +125,7 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
   api_check(from, to->ci->top - to->top >= n, "stack overflow");
   from->top -= n;
   for (i = 0; i < n; i++) {
-    setobj2s(to, to->top, from->top + i);
+    setobjs2s(to, to->top, from->top + i);
     to->top++;  /* stack already checked by previous 'api_check' */
   }
   lua_unlock(to);
@@ -141,10 +142,9 @@ LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
 }
 
 
-LUA_API const lua_Number *lua_version (lua_State *L) {
-  static const lua_Number version = LUA_VERSION_NUM;
-  if (L == NULL) return &version;
-  else return G(L)->version;
+LUA_API lua_Number lua_version (lua_State *L) {
+  UNUSED(L);
+  return LUA_VERSION_NUM;
 }
 
 
@@ -170,18 +170,23 @@ LUA_API int lua_gettop (lua_State *L) {
 
 
 LUA_API void lua_settop (lua_State *L, int idx) {
-  StkId func = L->ci->func;
+  CallInfo *ci = L->ci;
+  StkId func = ci->func;
+  ptrdiff_t diff;  /* difference for new top */
   lua_lock(L);
   if (idx >= 0) {
-    api_check(L, idx <= L->stack_last - (func + 1), "new top too large");
-    while (L->top < (func + 1) + idx)
-      setnilvalue(L->top++);
-    L->top = (func + 1) + idx;
+    api_check(L, idx <= ci->top - (func + 1), "new top too large");
+    diff = ((func + 1) + idx) - L->top;
+    for (; diff > 0; diff--)
+      setnilvalue(s2v(L->top++));  /* clear new slots */
   }
   else {
     api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
-    L->top += idx+1;  /* 'subtract' index (index is negative) */
+    diff = idx + 1;  /* will "subtract" index (as it is negative) */
   }
+  if (diff < 0 && hastocloseCfunc(ci->nresults))
+    luaF_close(L, L->top + diff, LUA_OK);
+  L->top += diff;  /* correct top only after closing any upvalue */
   lua_unlock(L);
 }
 
@@ -189,11 +194,13 @@ LUA_API void lua_settop (lua_State *L, int idx) {
 /*
 ** Reverse the stack segment from 'from' to 'to'
 ** (auxiliary to 'lua_rotate')
+** Note that we move(copy) only the value inside the stack.
+** (We do not move additional fields that may exist.)
 */
 static void reverse (lua_State *L, StkId from, StkId to) {
   for (; from < to; from++, to--) {
     TValue temp;
-    setobj(L, &temp, from);
+    setobj(L, &temp, s2v(from));
     setobjs2s(L, from, to);
     setobj2s(L, to, &temp);
   }
@@ -208,8 +215,7 @@ LUA_API void lua_rotate (lua_State *L, int idx, int n) {
   StkId p, t, m;
   lua_lock(L);
   t = L->top - 1;  /* end of stack segment being rotated */
-  p = index2addr(L, idx);  /* start of segment */
-  api_checkstackindex(L, idx, p);
+  p = index2stack(L, idx);  /* start of segment */
   api_check(L, (n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'");
   m = (n >= 0 ? t - n : p - n - 1);  /* end of prefix */
   reverse(L, p, m);  /* reverse the prefix with length 'n' */
@@ -222,12 +228,12 @@ LUA_API void lua_rotate (lua_State *L, int idx, int n) {
 LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
   TValue *fr, *to;
   lua_lock(L);
-  fr = index2addr(L, fromidx);
-  to = index2addr(L, toidx);
-  api_checkvalidindex(L, to);
+  fr = index2value(L, fromidx);
+  to = index2value(L, toidx);
+  api_check(L, isvalid(L, to), "invalid index");
   setobj(L, to, fr);
   if (isupvalue(toidx))  /* function upvalue? */
-    luaC_barrier(L, clCvalue(L->ci->func), fr);
+    luaC_barrier(L, clCvalue(s2v(L->ci->func)), fr);
   /* LUA_REGISTRYINDEX does not need gc barrier
      (collector revisits it before finishing collection) */
   lua_unlock(L);
@@ -236,7 +242,7 @@ LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
 
 LUA_API void lua_pushvalue (lua_State *L, int idx) {
   lua_lock(L);
-  setobj2s(L, L->top, index2addr(L, idx));
+  setobj2s(L, L->top, index2value(L, idx));
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -249,53 +255,53 @@ LUA_API void lua_pushvalue (lua_State *L, int idx) {
 
 
 LUA_API int lua_type (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
-  return (isvalid(o) ? ttnov(o) : LUA_TNONE);
+  const TValue *o = index2value(L, idx);
+  return (isvalid(L, o) ? ttype(o) : LUA_TNONE);
 }
 
 
 LUA_API const char *lua_typename (lua_State *L, int t) {
   UNUSED(L);
-  api_check(L, LUA_TNONE <= t && t < LUA_NUMTAGS, "invalid tag");
+  api_check(L, LUA_TNONE <= t && t < LUA_NUMTYPES, "invalid type");
   return ttypename(t);
 }
 
 
 LUA_API int lua_iscfunction (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return (ttislcf(o) || (ttisCclosure(o)));
 }
 
 
 LUA_API int lua_isinteger (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return ttisinteger(o);
 }
 
 
 LUA_API int lua_isnumber (lua_State *L, int idx) {
   lua_Number n;
-  const TValue *o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return tonumber(o, &n);
 }
 
 
 LUA_API int lua_isstring (lua_State *L, int idx) {
-  const TValue *o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return (ttisstring(o) || cvt2str(o));
 }
 
 
 LUA_API int lua_isuserdata (lua_State *L, int idx) {
-  const TValue *o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return (ttisfulluserdata(o) || ttislightuserdata(o));
 }
 
 
 LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
-  StkId o1 = index2addr(L, index1);
-  StkId o2 = index2addr(L, index2);
-  return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0;
+  const TValue *o1 = index2value(L, index1);
+  const TValue *o2 = index2value(L, index2);
+  return (isvalid(L, o1) && isvalid(L, o2)) ? luaV_rawequalobj(o1, o2) : 0;
 }
 
 
@@ -309,19 +315,20 @@ LUA_API void lua_arith (lua_State *L, int op) {
     api_incr_top(L);
   }
   /* first operand at top - 2, second at top - 1; result go to top - 2 */
-  luaO_arith(L, op, L->top - 2, L->top - 1, L->top - 2);
+  luaO_arith(L, op, s2v(L->top - 2), s2v(L->top - 1), L->top - 2);
   L->top--;  /* remove second operand */
   lua_unlock(L);
 }
 
 
 LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
-  StkId o1, o2;
+  const TValue *o1;
+  const TValue *o2;
   int i = 0;
   lua_lock(L);  /* may call tag method */
-  o1 = index2addr(L, index1);
-  o2 = index2addr(L, index2);
-  if (isvalid(o1) && isvalid(o2)) {
+  o1 = index2value(L, index1);
+  o2 = index2value(L, index2);
+  if (isvalid(L, o1) && isvalid(L, o2)) {
     switch (op) {
       case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break;
       case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
@@ -335,7 +342,7 @@ LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
 
 
 LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) {
-  size_t sz = luaO_str2num(s, L->top);
+  size_t sz = luaO_str2num(s, s2v(L->top));
   if (sz != 0)
     api_incr_top(L);
   return sz;
@@ -343,35 +350,33 @@ LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) {
 
 
 LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) {
-  lua_Number n;
-  const TValue *o = index2addr(L, idx);
+  lua_Number n = 0;
+  const TValue *o = index2value(L, idx);
   int isnum = tonumber(o, &n);
-  if (!isnum)
-    n = 0;  /* call to 'tonumber' may change 'n' even if it fails */
-  if (pisnum) *pisnum = isnum;
+  if (pisnum)
+    *pisnum = isnum;
   return n;
 }
 
 
 LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum) {
-  lua_Integer res;
-  const TValue *o = index2addr(L, idx);
+  lua_Integer res = 0;
+  const TValue *o = index2value(L, idx);
   int isnum = tointeger(o, &res);
-  if (!isnum)
-    res = 0;  /* call to 'tointeger' may change 'n' even if it fails */
-  if (pisnum) *pisnum = isnum;
+  if (pisnum)
+    *pisnum = isnum;
   return res;
 }
 
 
 LUA_API int lua_toboolean (lua_State *L, int idx) {
-  const TValue *o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return !l_isfalse(o);
 }
 
 
 LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
-  StkId o = index2addr(L, idx);
+  TValue *o = index2value(L, idx);
   if (!ttisstring(o)) {
     if (!cvt2str(o)) {  /* not convertible? */
       if (len != NULL) *len = 0;
@@ -380,7 +385,7 @@ LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
     lua_lock(L);  /* 'luaO_tostring' may create a new string */
     luaO_tostring(L, o);
     luaC_checkGC(L);
-    o = index2addr(L, idx);  /* previous call may reallocate the stack */
+    o = index2value(L, idx);  /* previous call may reallocate the stack */
     lua_unlock(L);
   }
   if (len != NULL)
@@ -389,20 +394,20 @@ LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
 }
 
 
-LUA_API size_t lua_rawlen (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
-  switch (ttype(o)) {
-    case LUA_TSHRSTR: return tsvalue(o)->shrlen;
-    case LUA_TLNGSTR: return tsvalue(o)->u.lnglen;
-    case LUA_TUSERDATA: return uvalue(o)->len;
-    case LUA_TTABLE: return luaH_getn(hvalue(o));
+LUA_API lua_Unsigned lua_rawlen (lua_State *L, int idx) {
+  const TValue *o = index2value(L, idx);
+  switch (ttypetag(o)) {
+    case LUA_VSHRSTR: return tsvalue(o)->shrlen;
+    case LUA_VLNGSTR: return tsvalue(o)->u.lnglen;
+    case LUA_VUSERDATA: return uvalue(o)->len;
+    case LUA_VTABLE: return luaH_getn(hvalue(o));
     default: return 0;
   }
 }
 
 
 LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   if (ttislcf(o)) return fvalue(o);
   else if (ttisCclosure(o))
     return clCvalue(o)->f;
@@ -410,9 +415,8 @@ LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
 }
 
 
-LUA_API void *lua_touserdata (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
-  switch (ttnov(o)) {
+static void *touserdata (const TValue *o) {
+  switch (ttype(o)) {
     case LUA_TUSERDATA: return getudatamem(uvalue(o));
     case LUA_TLIGHTUSERDATA: return pvalue(o);
     default: return NULL;
@@ -420,23 +424,37 @@ LUA_API void *lua_touserdata (lua_State *L, int idx) {
 }
 
 
+LUA_API void *lua_touserdata (lua_State *L, int idx) {
+  const TValue *o = index2value(L, idx);
+  return touserdata(o);
+}
+
+
 LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
+  const TValue *o = index2value(L, idx);
   return (!ttisthread(o)) ? NULL : thvalue(o);
 }
 
 
+/*
+** Returns a pointer to the internal representation of an object.
+** Note that ANSI C does not allow the conversion of a pointer to
+** function to a 'void*', so the conversion here goes through
+** a 'size_t'. (As the returned pointer is only informative, this
+** conversion should not be a problem.)
+*/
 LUA_API const void *lua_topointer (lua_State *L, int idx) {
-  StkId o = index2addr(L, idx);
-  switch (ttype(o)) {
-    case LUA_TTABLE: return hvalue(o);
-    case LUA_TLCL: return clLvalue(o);
-    case LUA_TCCL: return clCvalue(o);
-    case LUA_TLCF: return cast(void *, cast(size_t, fvalue(o)));
-    case LUA_TTHREAD: return thvalue(o);
-    case LUA_TUSERDATA: return getudatamem(uvalue(o));
-    case LUA_TLIGHTUSERDATA: return pvalue(o);
-    default: return NULL;
+  const TValue *o = index2value(L, idx);
+  switch (ttypetag(o)) {
+    case LUA_VLCF: return cast_voidp(cast_sizet(fvalue(o)));
+    case LUA_VUSERDATA: case LUA_VLIGHTUSERDATA:
+      return touserdata(o);
+    default: {
+      if (iscollectable(o))
+        return gcvalue(o);
+      else
+        return NULL;
+    }
   }
 }
 
@@ -449,7 +467,7 @@ LUA_API const void *lua_topointer (lua_State *L, int idx) {
 
 LUA_API void lua_pushnil (lua_State *L) {
   lua_lock(L);
-  setnilvalue(L->top);
+  setnilvalue(s2v(L->top));
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -457,7 +475,7 @@ LUA_API void lua_pushnil (lua_State *L) {
 
 LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
   lua_lock(L);
-  setfltvalue(L->top, n);
+  setfltvalue(s2v(L->top), n);
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -465,7 +483,7 @@ LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
 
 LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
   lua_lock(L);
-  setivalue(L->top, n);
+  setivalue(s2v(L->top), n);
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -491,7 +509,7 @@ LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
 LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
   lua_lock(L);
   if (s == NULL)
-    setnilvalue(L->top);
+    setnilvalue(s2v(L->top));
   else {
     TString *ts;
     ts = luaS_new(L, s);
@@ -532,7 +550,7 @@ LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
 LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
   lua_lock(L);
   if (n == 0) {
-    setfvalue(L->top, fn);
+    setfvalue(s2v(L->top), fn);
     api_incr_top(L);
   }
   else {
@@ -543,10 +561,10 @@ LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
     cl->f = fn;
     L->top -= n;
     while (n--) {
-      setobj2n(L, &cl->upvalue[n], L->top + n);
+      setobj2n(L, &cl->upvalue[n], s2v(L->top + n));
       /* does not need barrier because closure is white */
     }
-    setclCvalue(L, L->top, cl);
+    setclCvalue(L, s2v(L->top), cl);
     api_incr_top(L);
     luaC_checkGC(L);
   }
@@ -556,7 +574,10 @@ LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
 
 LUA_API void lua_pushboolean (lua_State *L, int b) {
   lua_lock(L);
-  setbvalue(L->top, (b != 0));  /* ensure that true is 1 */
+  if (b)
+    setbtvalue(s2v(L->top));
+  else
+    setbfvalue(s2v(L->top));
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -564,7 +585,7 @@ LUA_API void lua_pushboolean (lua_State *L, int b) {
 
 LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
   lua_lock(L);
-  setpvalue(L->top, p);
+  setpvalue(s2v(L->top), p);
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -572,7 +593,7 @@ LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
 
 LUA_API int lua_pushthread (lua_State *L) {
   lua_lock(L);
-  setthvalue(L, L->top, L);
+  setthvalue(L, s2v(L->top), L);
   api_incr_top(L);
   lua_unlock(L);
   return (G(L)->mainthread == L);
@@ -595,10 +616,10 @@ static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
   else {
     setsvalue2s(L, L->top, str);
     api_incr_top(L);
-    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
+    luaV_finishget(L, t, s2v(L->top - 1), L->top - 1, slot);
   }
   lua_unlock(L);
-  return ttnov(L->top - 1);
+  return ttype(s2v(L->top - 1));
 }
 
 
@@ -610,74 +631,90 @@ LUA_API int lua_getglobal (lua_State *L, const char *name) {
 
 
 LUA_API int lua_gettable (lua_State *L, int idx) {
-  StkId t;
+  const TValue *slot;
+  TValue *t;
   lua_lock(L);
-  t = index2addr(L, idx);
-  luaV_gettable(L, t, L->top - 1, L->top - 1);
+  t = index2value(L, idx);
+  if (luaV_fastget(L, t, s2v(L->top - 1), slot, luaH_get)) {
+    setobj2s(L, L->top - 1, slot);
+  }
+  else
+    luaV_finishget(L, t, s2v(L->top - 1), L->top - 1, slot);
   lua_unlock(L);
-  return ttnov(L->top - 1);
+  return ttype(s2v(L->top - 1));
 }
 
 
 LUA_API int lua_getfield (lua_State *L, int idx, const char *k) {
   lua_lock(L);
-  return auxgetstr(L, index2addr(L, idx), k);
+  return auxgetstr(L, index2value(L, idx), k);
 }
 
 
 LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
-  StkId t;
+  TValue *t;
   const TValue *slot;
   lua_lock(L);
-  t = index2addr(L, idx);
-  if (luaV_fastget(L, t, n, slot, luaH_getint)) {
+  t = index2value(L, idx);
+  if (luaV_fastgeti(L, t, n, slot)) {
     setobj2s(L, L->top, slot);
-    api_incr_top(L);
   }
   else {
-    setivalue(L->top, n);
-    api_incr_top(L);
-    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
+    TValue aux;
+    setivalue(&aux, n);
+    luaV_finishget(L, t, &aux, L->top, slot);
   }
+  api_incr_top(L);
   lua_unlock(L);
-  return ttnov(L->top - 1);
+  return ttype(s2v(L->top - 1));
+}
+
+
+static int finishrawget (lua_State *L, const TValue *val) {
+  if (isempty(val))  /* avoid copying empty items to the stack */
+    setnilvalue(s2v(L->top));
+  else
+    setobj2s(L, L->top, val);
+  api_incr_top(L);
+  lua_unlock(L);
+  return ttype(s2v(L->top - 1));
+}
+
+
+static Table *gettable (lua_State *L, int idx) {
+  TValue *t = index2value(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  return hvalue(t);
 }
 
 
 LUA_API int lua_rawget (lua_State *L, int idx) {
-  StkId t;
+  Table *t;
+  const TValue *val;
   lua_lock(L);
-  t = index2addr(L, idx);
-  api_check(L, ttistable(t), "table expected");
-  setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
-  lua_unlock(L);
-  return ttnov(L->top - 1);
+  api_checknelems(L, 1);
+  t = gettable(L, idx);
+  val = luaH_get(t, s2v(L->top - 1));
+  L->top--;  /* remove key */
+  return finishrawget(L, val);
 }
 
 
 LUA_API int lua_rawgeti (lua_State *L, int idx, lua_Integer n) {
-  StkId t;
+  Table *t;
   lua_lock(L);
-  t = index2addr(L, idx);
-  api_check(L, ttistable(t), "table expected");
-  setobj2s(L, L->top, luaH_getint(hvalue(t), n));
-  api_incr_top(L);
-  lua_unlock(L);
-  return ttnov(L->top - 1);
+  t = gettable(L, idx);
+  return finishrawget(L, luaH_getint(t, n));
 }
 
 
 LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
-  StkId t;
+  Table *t;
   TValue k;
   lua_lock(L);
-  t = index2addr(L, idx);
-  api_check(L, ttistable(t), "table expected");
-  setpvalue(&k, cast(void *, p));
-  setobj2s(L, L->top, luaH_get(hvalue(t), &k));
-  api_incr_top(L);
-  lua_unlock(L);
-  return ttnov(L->top - 1);
+  t = gettable(L, idx);
+  setpvalue(&k, cast_voidp(p));
+  return finishrawget(L, luaH_get(t, &k));
 }
 
 
@@ -685,7 +722,7 @@ LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
   Table *t;
   lua_lock(L);
   t = luaH_new(L);
-  sethvalue(L, L->top, t);
+  sethvalue2s(L, L->top, t);
   api_incr_top(L);
   if (narray > 0 || nrec > 0)
     luaH_resize(L, t, narray, nrec);
@@ -699,8 +736,8 @@ LUA_API int lua_getmetatable (lua_State *L, int objindex) {
   Table *mt;
   int res = 0;
   lua_lock(L);
-  obj = index2addr(L, objindex);
-  switch (ttnov(obj)) {
+  obj = index2value(L, objindex);
+  switch (ttype(obj)) {
     case LUA_TTABLE:
       mt = hvalue(obj)->metatable;
       break;
@@ -708,11 +745,11 @@ LUA_API int lua_getmetatable (lua_State *L, int objindex) {
       mt = uvalue(obj)->metatable;
       break;
     default:
-      mt = G(L)->mt[ttnov(obj)];
+      mt = G(L)->mt[ttype(obj)];
       break;
   }
   if (mt != NULL) {
-    sethvalue(L, L->top, mt);
+    sethvalue2s(L, L->top, mt);
     api_incr_top(L);
     res = 1;
   }
@@ -721,15 +758,23 @@ LUA_API int lua_getmetatable (lua_State *L, int objindex) {
 }
 
 
-LUA_API int lua_getuservalue (lua_State *L, int idx) {
-  StkId o;
+LUA_API int lua_getiuservalue (lua_State *L, int idx, int n) {
+  TValue *o;
+  int t;
   lua_lock(L);
-  o = index2addr(L, idx);
+  o = index2value(L, idx);
   api_check(L, ttisfulluserdata(o), "full userdata expected");
-  getuservalue(L, uvalue(o), L->top);
+  if (n <= 0 || n > uvalue(o)->nuvalue) {
+    setnilvalue(s2v(L->top));
+    t = LUA_TNONE;
+  }
+  else {
+    setobj2s(L, L->top, &uvalue(o)->uv[n - 1].uv);
+    t = ttype(s2v(L->top));
+  }
   api_incr_top(L);
   lua_unlock(L);
-  return ttnov(L->top - 1);
+  return t;
 }
 
 
@@ -744,12 +789,14 @@ static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
   const TValue *slot;
   TString *str = luaS_new(L, k);
   api_checknelems(L, 1);
-  if (luaV_fastset(L, t, str, slot, luaH_getstr, L->top - 1))
+  if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
+    luaV_finishfastset(L, t, slot, s2v(L->top - 1));
     L->top--;  /* pop value */
+  }
   else {
     setsvalue2s(L, L->top, str);  /* push 'str' (to make it a TValue) */
     api_incr_top(L);
-    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
+    luaV_finishset(L, t, s2v(L->top - 1), s2v(L->top - 2), slot);
     L->top -= 2;  /* pop value and key */
   }
   lua_unlock(L);  /* lock done by caller */
@@ -764,11 +811,16 @@ LUA_API void lua_setglobal (lua_State *L, const char *name) {
 
 
 LUA_API void lua_settable (lua_State *L, int idx) {
-  StkId t;
+  TValue *t;
+  const TValue *slot;
   lua_lock(L);
   api_checknelems(L, 2);
-  t = index2addr(L, idx);
-  luaV_settable(L, t, L->top - 2, L->top - 1);
+  t = index2value(L, idx);
+  if (luaV_fastget(L, t, s2v(L->top - 2), slot, luaH_get)) {
+    luaV_finishfastset(L, t, slot, s2v(L->top - 1));
+  }
+  else
+    luaV_finishset(L, t, s2v(L->top - 2), s2v(L->top - 1), slot);
   L->top -= 2;  /* pop index and value */
   lua_unlock(L);
 }
@@ -776,68 +828,63 @@ LUA_API void lua_settable (lua_State *L, int idx) {
 
 LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
   lua_lock(L);  /* unlock done in 'auxsetstr' */
-  auxsetstr(L, index2addr(L, idx), k);
+  auxsetstr(L, index2value(L, idx), k);
 }
 
 
 LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
-  StkId t;
+  TValue *t;
   const TValue *slot;
   lua_lock(L);
   api_checknelems(L, 1);
-  t = index2addr(L, idx);
-  if (luaV_fastset(L, t, n, slot, luaH_getint, L->top - 1))
-    L->top--;  /* pop value */
+  t = index2value(L, idx);
+  if (luaV_fastgeti(L, t, n, slot)) {
+    luaV_finishfastset(L, t, slot, s2v(L->top - 1));
+  }
   else {
-    setivalue(L->top, n);
-    api_incr_top(L);
-    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
-    L->top -= 2;  /* pop value and key */
+    TValue aux;
+    setivalue(&aux, n);
+    luaV_finishset(L, t, &aux, s2v(L->top - 1), slot);
   }
+  L->top--;  /* pop value */
   lua_unlock(L);
 }
 
 
-LUA_API void lua_rawset (lua_State *L, int idx) {
-  StkId o;
+static void aux_rawset (lua_State *L, int idx, TValue *key, int n) {
+  Table *t;
   TValue *slot;
   lua_lock(L);
-  api_checknelems(L, 2);
-  o = index2addr(L, idx);
-  api_check(L, ttistable(o), "table expected");
-  slot = luaH_set(L, hvalue(o), L->top - 2);
-  setobj2t(L, slot, L->top - 1);
-  invalidateTMcache(hvalue(o));
-  luaC_barrierback(L, hvalue(o), L->top-1);
-  L->top -= 2;
+  api_checknelems(L, n);
+  t = gettable(L, idx);
+  slot = luaH_set(L, t, key);
+  setobj2t(L, slot, s2v(L->top - 1));
+  invalidateTMcache(t);
+  luaC_barrierback(L, obj2gco(t), s2v(L->top - 1));
+  L->top -= n;
   lua_unlock(L);
 }
 
 
-LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
-  StkId o;
-  lua_lock(L);
-  api_checknelems(L, 1);
-  o = index2addr(L, idx);
-  api_check(L, ttistable(o), "table expected");
-  luaH_setint(L, hvalue(o), n, L->top - 1);
-  luaC_barrierback(L, hvalue(o), L->top-1);
-  L->top--;
-  lua_unlock(L);
+LUA_API void lua_rawset (lua_State *L, int idx) {
+  aux_rawset(L, idx, s2v(L->top - 2), 2);
 }
 
 
 LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
-  StkId o;
-  TValue k, *slot;
+  TValue k;
+  setpvalue(&k, cast_voidp(p));
+  aux_rawset(L, idx, &k, 1);
+}
+
+
+LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
+  Table *t;
   lua_lock(L);
   api_checknelems(L, 1);
-  o = index2addr(L, idx);
-  api_check(L, ttistable(o), "table expected");
-  setpvalue(&k, cast(void *, p));
-  slot = luaH_set(L, hvalue(o), &k);
-  setobj2t(L, slot, L->top - 1);
-  luaC_barrierback(L, hvalue(o), L->top - 1);
+  t = gettable(L, idx);
+  luaH_setint(L, t, n, s2v(L->top - 1));
+  luaC_barrierback(L, obj2gco(t), s2v(L->top - 1));
   L->top--;
   lua_unlock(L);
 }
@@ -848,14 +895,14 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
   Table *mt;
   lua_lock(L);
   api_checknelems(L, 1);
-  obj = index2addr(L, objindex);
-  if (ttisnil(L->top - 1))
+  obj = index2value(L, objindex);
+  if (ttisnil(s2v(L->top - 1)))
     mt = NULL;
   else {
-    api_check(L, ttistable(L->top - 1), "table expected");
-    mt = hvalue(L->top - 1);
+    api_check(L, ttistable(s2v(L->top - 1)), "table expected");
+    mt = hvalue(s2v(L->top - 1));
   }
-  switch (ttnov(obj)) {
+  switch (ttype(obj)) {
     case LUA_TTABLE: {
       hvalue(obj)->metatable = mt;
       if (mt) {
@@ -873,7 +920,7 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
       break;
     }
     default: {
-      G(L)->mt[ttnov(obj)] = mt;
+      G(L)->mt[ttype(obj)] = mt;
       break;
     }
   }
@@ -883,16 +930,23 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
 }
 
 
-LUA_API void lua_setuservalue (lua_State *L, int idx) {
-  StkId o;
+LUA_API int lua_setiuservalue (lua_State *L, int idx, int n) {
+  TValue *o;
+  int res;
   lua_lock(L);
   api_checknelems(L, 1);
-  o = index2addr(L, idx);
+  o = index2value(L, idx);
   api_check(L, ttisfulluserdata(o), "full userdata expected");
-  setuservalue(L, uvalue(o), L->top - 1);
-  luaC_barrier(L, gcvalue(o), L->top - 1);
+  if (!(cast_uint(n) - 1u < cast_uint(uvalue(o)->nuvalue)))
+    res = 0;  /* 'n' not in [1, uvalue(o)->nuvalue] */
+  else {
+    setobj(L, &uvalue(o)->uv[n - 1].uv, s2v(L->top - 1));
+    luaC_barrierback(L, gcvalue(o), s2v(L->top - 1));
+    res = 1;
+  }
   L->top--;
   lua_unlock(L);
+  return res;
 }
 
 
@@ -916,7 +970,7 @@ LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
   checkresults(L, nargs, nresults);
   func = L->top - (nargs+1);
-  if (k != NULL && L->nny == 0) {  /* need to prepare continuation? */
+  if (k != NULL && yieldable(L)) {  /* need to prepare continuation? */
     L->ci->u.c.k = k;  /* save continuation */
     L->ci->u.c.ctx = ctx;  /* save context */
     luaD_call(L, func, nresults);  /* do the call */
@@ -959,12 +1013,12 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
   if (errfunc == 0)
     func = 0;
   else {
-    StkId o = index2addr(L, errfunc);
-    api_checkstackindex(L, errfunc, o);
+    StkId o = index2stack(L, errfunc);
+    api_check(L, ttisfunction(s2v(o)), "error handler must be a function");
     func = savestack(L, o);
   }
   c.func = L->top - (nargs+1);  /* function to be called */
-  if (k == NULL || L->nny > 0) {  /* no continuation or no yieldable? */
+  if (k == NULL || !yieldable(L)) {  /* no continuation or no yieldable? */
     c.nresults = nresults;  /* do a 'conventional' protected call */
     status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
   }
@@ -973,7 +1027,7 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
     ci->u.c.k = k;  /* save continuation */
     ci->u.c.ctx = ctx;  /* save context */
     /* save information for error recovery */
-    ci->extra = savestack(L, c.func);
+    ci->u2.funcidx = cast_int(savestack(L, c.func));
     ci->u.c.old_errfunc = L->errfunc;
     L->errfunc = func;
     setoah(ci->callstatus, L->allowhook);  /* save value of 'allowhook' */
@@ -998,14 +1052,14 @@ LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
   luaZ_init(L, &z, reader, data);
   status = luaD_protectedparser(L, &z, chunkname, mode);
   if (status == LUA_OK) {  /* no errors? */
-    LClosure *f = clLvalue(L->top - 1);  /* get newly created function */
+    LClosure *f = clLvalue(s2v(L->top - 1));  /* get newly created function */
     if (f->nupvalues >= 1) {  /* does it have an upvalue? */
       /* get global table from registry */
       Table *reg = hvalue(&G(L)->l_registry);
       const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
       /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
       setobj(L, f->upvals[0]->v, gt);
-      luaC_upvalbarrier(L, f->upvals[0]);
+      luaC_barrier(L, f->upvals[0], gt);
     }
   }
   lua_unlock(L);
@@ -1018,7 +1072,7 @@ LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) {
   TValue *o;
   lua_lock(L);
   api_checknelems(L, 1);
-  o = L->top - 1;
+  o = s2v(L->top - 1);
   if (isLfunction(o))
     status = luaU_dump(L, getproto(o), writer, data, strip);
   else
@@ -1036,12 +1090,12 @@ LUA_API int lua_status (lua_State *L) {
 /*
 ** Garbage-collection function
 */
-
-LUA_API int lua_gc (lua_State *L, int what, int data) {
+LUA_API int lua_gc (lua_State *L, int what, ...) {
+  va_list argp;
   int res = 0;
-  global_State *g;
+  global_State *g = G(L);
   lua_lock(L);
-  g = G(L);
+  va_start(argp, what);
   switch (what) {
     case LUA_GCSTOP: {
       g->gcrunning = 0;
@@ -1066,11 +1120,12 @@ LUA_API int lua_gc (lua_State *L, int what, int data) {
       break;
     }
     case LUA_GCSTEP: {
+      int data = va_arg(argp, int);
       l_mem debt = 1;  /* =1 to signal that it did an actual step */
       lu_byte oldrunning = g->gcrunning;
       g->gcrunning = 1;  /* allow GC to run */
       if (data == 0) {
-        luaE_setdebt(g, -GCSTEPSIZE);  /* to do a "small" step */
+        luaE_setdebt(g, 0);  /* do a basic step */
         luaC_step(L);
       }
       else {  /* add 'data' to total debt */
@@ -1084,22 +1139,49 @@ LUA_API int lua_gc (lua_State *L, int what, int data) {
       break;
     }
     case LUA_GCSETPAUSE: {
-      res = g->gcpause;
-      g->gcpause = data;
+      int data = va_arg(argp, int);
+      res = getgcparam(g->gcpause);
+      setgcparam(g->gcpause, data);
       break;
     }
     case LUA_GCSETSTEPMUL: {
-      res = g->gcstepmul;
-      if (data < 40) data = 40;  /* avoid ridiculous low values (and 0) */
-      g->gcstepmul = data;
+      int data = va_arg(argp, int);
+      res = getgcparam(g->gcstepmul);
+      setgcparam(g->gcstepmul, data);
       break;
     }
     case LUA_GCISRUNNING: {
       res = g->gcrunning;
       break;
     }
+    case LUA_GCGEN: {
+      int minormul = va_arg(argp, int);
+      int majormul = va_arg(argp, int);
+      res = isdecGCmodegen(g) ? LUA_GCGEN : LUA_GCINC;
+      if (minormul != 0)
+        g->genminormul = minormul;
+      if (majormul != 0)
+        setgcparam(g->genmajormul, majormul);
+      luaC_changemode(L, KGC_GEN);
+      break;
+    }
+    case LUA_GCINC: {
+      int pause = va_arg(argp, int);
+      int stepmul = va_arg(argp, int);
+      int stepsize = va_arg(argp, int);
+      res = isdecGCmodegen(g) ? LUA_GCGEN : LUA_GCINC;
+      if (pause != 0)
+        setgcparam(g->gcpause, pause);
+      if (stepmul != 0)
+        setgcparam(g->gcstepmul, stepmul);
+      if (stepsize != 0)
+        g->gcstepsize = stepsize;
+      luaC_changemode(L, KGC_INC);
+      break;
+    }
     default: res = -1;  /* invalid option */
   }
+  va_end(argp);
   lua_unlock(L);
   return res;
 }
@@ -1121,12 +1203,12 @@ LUA_API int lua_error (lua_State *L) {
 
 
 LUA_API int lua_next (lua_State *L, int idx) {
-  StkId t;
+  Table *t;
   int more;
   lua_lock(L);
-  t = index2addr(L, idx);
-  api_check(L, ttistable(t), "table expected");
-  more = luaH_next(L, hvalue(t), L->top - 1);
+  api_checknelems(L, 1);
+  t = gettable(L, idx);
+  more = luaH_next(L, t, L->top - 1);
   if (more) {
     api_incr_top(L);
   }
@@ -1137,6 +1219,22 @@ LUA_API int lua_next (lua_State *L, int idx) {
 }
 
 
+LUA_API void lua_toclose (lua_State *L, int idx) {
+  int nresults;
+  StkId o;
+  lua_lock(L);
+  o = index2stack(L, idx);
+  nresults = L->ci->nresults;
+  api_check(L, L->openupval == NULL || uplevel(L->openupval) <= o,
+               "marked index below or equal new one");
+  luaF_newtbcupval(L, o);  /* create new to-be-closed upvalue */
+  if (!hastocloseCfunc(nresults))  /* function not marked yet? */
+    L->ci->nresults = codeNresults(nresults);  /* mark it */
+  lua_assert(hastocloseCfunc(L->ci->nresults));
+  lua_unlock(L);
+}
+
+
 LUA_API void lua_concat (lua_State *L, int n) {
   lua_lock(L);
   api_checknelems(L, n);
@@ -1154,9 +1252,9 @@ LUA_API void lua_concat (lua_State *L, int n) {
 
 
 LUA_API void lua_len (lua_State *L, int idx) {
-  StkId t;
+  TValue *t;
   lua_lock(L);
-  t = index2addr(L, idx);
+  t = index2value(L, idx);
   luaV_objlen(L, L->top, t);
   api_incr_top(L);
   lua_unlock(L);
@@ -1181,11 +1279,28 @@ LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
 }
 
 
-LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
+void lua_setwarnf (lua_State *L, lua_WarnFunction f, void *ud) {
+  lua_lock(L);
+  G(L)->ud_warn = ud;
+  G(L)->warnf = f;
+  lua_unlock(L);
+}
+
+
+void lua_warning (lua_State *L, const char *msg, int tocont) {
+  lua_lock(L);
+  luaE_warning(L, msg, tocont);
+  lua_unlock(L);
+}
+
+
+
+LUA_API void *lua_newuserdatauv (lua_State *L, size_t size, int nuvalue) {
   Udata *u;
   lua_lock(L);
-  u = luaS_newudata(L, size);
-  setuvalue(L, L->top, u);
+  api_check(L, 0 <= nuvalue && nuvalue < USHRT_MAX, "invalid value");
+  u = luaS_newudata(L, size, nuvalue);
+  setuvalue(L, s2v(L->top), u);
   api_incr_top(L);
   luaC_checkGC(L);
   lua_unlock(L);
@@ -1194,25 +1309,27 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
 
 
 
-static const char *aux_upvalue (StkId fi, int n, TValue **val,
-                                CClosure **owner, UpVal **uv) {
-  switch (ttype(fi)) {
-    case LUA_TCCL: {  /* C closure */
+static const char *aux_upvalue (TValue *fi, int n, TValue **val,
+                                GCObject **owner) {
+  switch (ttypetag(fi)) {
+    case LUA_VCCL: {  /* C closure */
       CClosure *f = clCvalue(fi);
-      if (!(1 <= n && n <= f->nupvalues)) return NULL;
+      if (!(cast_uint(n) - 1u < cast_uint(f->nupvalues)))
+        return NULL;  /* 'n' not in [1, f->nupvalues] */
       *val = &f->upvalue[n-1];
-      if (owner) *owner = f;
+      if (owner) *owner = obj2gco(f);
       return "";
     }
-    case LUA_TLCL: {  /* Lua closure */
+    case LUA_VLCL: {  /* Lua closure */
       LClosure *f = clLvalue(fi);
       TString *name;
       Proto *p = f->p;
-      if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
+      if (!(cast_uint(n) - 1u  < cast_uint(p->sizeupvalues)))
+        return NULL;  /* 'n' not in [1, p->sizeupvalues] */
       *val = f->upvals[n-1]->v;
-      if (uv) *uv = f->upvals[n - 1];
+      if (owner) *owner = obj2gco(f->upvals[n - 1]);
       name = p->upvalues[n-1].name;
-      return (name == NULL) ? "(*no name)" : getstr(name);
+      return (name == NULL) ? "(no name)" : getstr(name);
     }
     default: return NULL;  /* not a closure */
   }
@@ -1223,7 +1340,7 @@ LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
   const char *name;
   TValue *val = NULL;  /* to avoid warnings */
   lua_lock(L);
-  name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL, NULL);
+  name = aux_upvalue(index2value(L, funcindex), n, &val, NULL);
   if (name) {
     setobj2s(L, L->top, val);
     api_incr_top(L);
@@ -1236,18 +1353,16 @@ LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
 LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
   const char *name;
   TValue *val = NULL;  /* to avoid warnings */
-  CClosure *owner = NULL;
-  UpVal *uv = NULL;
-  StkId fi;
+  GCObject *owner = NULL;  /* to avoid warnings */
+  TValue *fi;
   lua_lock(L);
-  fi = index2addr(L, funcindex);
+  fi = index2value(L, funcindex);
   api_checknelems(L, 1);
-  name = aux_upvalue(fi, n, &val, &owner, &uv);
+  name = aux_upvalue(fi, n, &val, &owner);
   if (name) {
     L->top--;
-    setobj(L, val, L->top);
-    if (owner) { luaC_barrier(L, owner, L->top); }
-    else if (uv) { luaC_upvalbarrier(L, uv); }
+    setobj(L, val, s2v(L->top));
+    luaC_barrier(L, owner, val);
   }
   lua_unlock(L);
   return name;
@@ -1256,7 +1371,7 @@ LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
 
 static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
   LClosure *f;
-  StkId fi = index2addr(L, fidx);
+  TValue *fi = index2value(L, fidx);
   api_check(L, ttisLclosure(fi), "Lua function expected");
   f = clLvalue(fi);
   api_check(L, (1 <= n && n <= f->p->sizeupvalues), "invalid upvalue index");
@@ -1266,12 +1381,12 @@ static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
 
 
 LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
-  StkId fi = index2addr(L, fidx);
-  switch (ttype(fi)) {
-    case LUA_TLCL: {  /* lua closure */
+  TValue *fi = index2value(L, fidx);
+  switch (ttypetag(fi)) {
+    case LUA_VLCL: {  /* lua closure */
       return *getupvalref(L, fidx, n, NULL);
     }
-    case LUA_TCCL: {  /* C closure */
+    case LUA_VCCL: {  /* C closure */
       CClosure *f = clCvalue(fi);
       api_check(L, 1 <= n && n <= f->nupvalues, "invalid upvalue index");
       return &f->upvalue[n - 1];
@@ -1289,11 +1404,8 @@ LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
   LClosure *f1;
   UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
   UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
-  luaC_upvdeccount(L, *up1);
   *up1 = *up2;
-  (*up1)->refcount++;
-  if (upisopen(*up1)) (*up1)->u.open.touched = 1;
-  luaC_upvalbarrier(L, *up1);
+  luaC_objbarrier(L, f1, *up1);
 }
 
 
diff --git a/libs/liblua/src/lapi.h b/libs/liblua/src/lapi.h
index 8e16ad53d9..41216b2709 100644
--- a/libs/liblua/src/lapi.h
+++ b/libs/liblua/src/lapi.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.h,v 2.9.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lapi.h $
 ** Auxiliary functions from Lua API
 ** See Copyright Notice in lua.h
 */
@@ -11,14 +11,37 @@
 #include "llimits.h"
 #include "lstate.h"
 
+
+/* Increments 'L->top', checking for stack overflows */
 #define api_incr_top(L)   {L->top++; api_check(L, L->top <= L->ci->top, \
 				"stack overflow");}
 
+
+/*
+** If a call returns too many multiple returns, the callee may not have
+** stack space to accommodate all results. In this case, this macro
+** increases its stack space ('L->ci->top').
+*/
 #define adjustresults(L,nres) \
-    { if ((nres) == LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; }
+    { if ((nres) <= LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; }
+
 
+/* Ensure the stack has at least 'n' elements */
 #define api_checknelems(L,n)	api_check(L, (n) < (L->top - L->ci->func), \
 				  "not enough elements in the stack")
 
 
+/*
+** To reduce the overhead of returning from C functions, the presence of
+** to-be-closed variables in these functions is coded in the CallInfo's
+** field 'nresults', in a way that functions with no to-be-closed variables
+** with zero, one, or "all" wanted results have no overhead. Functions
+** with other number of wanted results, as well as functions with
+** variables to be closed, have an extra check.
+*/
+
+#define hastocloseCfunc(n)	((n) < LUA_MULTRET)
+
+#define codeNresults(n)		(-(n) - 3)
+
 #endif
diff --git a/libs/liblua/src/lauxlib.c b/libs/liblua/src/lauxlib.c
index 8bdada50a7..e3d9be37f0 100644
--- a/libs/liblua/src/lauxlib.c
+++ b/libs/liblua/src/lauxlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.c,v 1.289.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lauxlib.c $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -27,6 +27,12 @@
 #include "lauxlib.h"
 
 
+#if !defined(MAX_SIZET)
+/* maximum value for size_t */
+#define MAX_SIZET	((size_t)(~(size_t)0))
+#endif
+
+
 /*
 ** {======================================================
 ** Traceback
@@ -40,8 +46,8 @@
 
 
 /*
-** search for 'objidx' in table at index -1.
-** return 1 + string at top if find a good name.
+** Search for 'objidx' in table at index -1. ('objidx' must be an
+** absolute index.) Return 1 + string at top if it found a good name.
 */
 static int findfield (lua_State *L, int objidx, int level) {
   if (level == 0 || !lua_istable(L, -1))
@@ -54,10 +60,10 @@ static int findfield (lua_State *L, int objidx, int level) {
         return 1;
       }
       else if (findfield(L, objidx, level - 1)) {  /* try recursively */
-        lua_remove(L, -2);  /* remove table (but keep name) */
-        lua_pushliteral(L, ".");
-        lua_insert(L, -2);  /* place '.' between the two names */
-        lua_concat(L, 3);
+        /* stack: lib_name, lib_table, field_name (top) */
+        lua_pushliteral(L, ".");  /* place '.' between the two names */
+        lua_replace(L, -3);  /* (in the slot occupied by table) */
+        lua_concat(L, 3);  /* lib_name.field_name */
         return 1;
       }
     }
@@ -76,12 +82,12 @@ static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
   lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
   if (findfield(L, top + 1, 2)) {
     const char *name = lua_tostring(L, -1);
-    if (strncmp(name, "_G.", 3) == 0) {  /* name start with '_G.'? */
+    if (strncmp(name, LUA_GNAME ".", 3) == 0) {  /* name start with '_G.'? */
       lua_pushstring(L, name + 3);  /* push name without prefix */
       lua_remove(L, -2);  /* remove original name */
     }
-    lua_copy(L, -1, top + 1);  /* move name to proper place */
-    lua_pop(L, 2);  /* remove pushed values */
+    lua_copy(L, -1, top + 1);  /* copy name to proper place */
+    lua_settop(L, top + 1);  /* remove table "loaded" and name copy */
     return 1;
   }
   else {
@@ -124,32 +130,37 @@ static int lastlevel (lua_State *L) {
 
 LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
                                 const char *msg, int level) {
+  luaL_Buffer b;
   lua_Debug ar;
-  int top = lua_gettop(L);
   int last = lastlevel(L1);
-  int n1 = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
-  if (msg)
-    lua_pushfstring(L, "%s\n", msg);
-  luaL_checkstack(L, 10, NULL);
-  lua_pushliteral(L, "stack traceback:");
+  int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
+  luaL_buffinit(L, &b);
+  if (msg) {
+    luaL_addstring(&b, msg);
+    luaL_addchar(&b, '\n');
+  }
+  luaL_addstring(&b, "stack traceback:");
   while (lua_getstack(L1, level++, &ar)) {
-    if (n1-- == 0) {  /* too many levels? */
-      lua_pushliteral(L, "\n\t...");  /* add a '...' */
-      level = last - LEVELS2 + 1;  /* and skip to last ones */
+    if (limit2show-- == 0) {  /* too many levels? */
+      int n = last - level - LEVELS2 + 1;  /* number of levels to skip */
+      lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n);
+      luaL_addvalue(&b);  /* add warning about skip */
+      level += n;  /* and skip to last levels */
     }
     else {
       lua_getinfo(L1, "Slnt", &ar);
-      lua_pushfstring(L, "\n\t%s:", ar.short_src);
-      if (ar.currentline > 0)
-        lua_pushfstring(L, "%d:", ar.currentline);
-      lua_pushliteral(L, " in ");
+      if (ar.currentline <= 0)
+        lua_pushfstring(L, "\n\t%s: in ", ar.short_src);
+      else
+        lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline);
+      luaL_addvalue(&b);
       pushfuncname(L, &ar);
+      luaL_addvalue(&b);
       if (ar.istailcall)
-        lua_pushliteral(L, "\n\t(...tail calls...)");
-      lua_concat(L, lua_gettop(L) - top);
+        luaL_addstring(&b, "\n\t(...tail calls...)");
     }
   }
-  lua_concat(L, lua_gettop(L) - top);
+  luaL_pushresult(&b);
 }
 
 /* }====================================================== */
@@ -179,7 +190,7 @@ LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {
 }
 
 
-static int typeerror (lua_State *L, int arg, const char *tname) {
+int luaL_typeerror (lua_State *L, int arg, const char *tname) {
   const char *msg;
   const char *typearg;  /* name for the type of the actual argument */
   if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
@@ -194,7 +205,7 @@ static int typeerror (lua_State *L, int arg, const char *tname) {
 
 
 static void tag_error (lua_State *L, int arg, int tag) {
-  typeerror(L, arg, lua_typename(L, tag));
+  luaL_typeerror(L, arg, lua_typename(L, tag));
 }
 
 
@@ -238,7 +249,7 @@ LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
     return 1;
   }
   else {
-    lua_pushnil(L);
+    luaL_pushfail(L);
     if (fname)
       lua_pushfstring(L, "%s: %s", fname, strerror(en));
     else
@@ -273,23 +284,24 @@ LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
 
 LUALIB_API int luaL_execresult (lua_State *L, int stat) {
   const char *what = "exit";  /* type of termination */
-  if (stat == -1)  /* error? */
+  if (stat != 0 && errno != 0)  /* error with an 'errno'? */
     return luaL_fileresult(L, 0, NULL);
   else {
     l_inspectstat(stat, what);  /* interpret result */
     if (*what == 'e' && stat == 0)  /* successful termination? */
       lua_pushboolean(L, 1);
     else
-      lua_pushnil(L);
+      luaL_pushfail(L);
     lua_pushstring(L, what);
     lua_pushinteger(L, stat);
-    return 3;  /* return true/nil,what,code */
+    return 3;  /* return true/fail,what,code */
   }
 }
 
 /* }====================================================== */
 
 
+
 /*
 ** {======================================================
 ** Userdata's metatable manipulation
@@ -332,7 +344,7 @@ LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) {
 
 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
   void *p = luaL_testudata(L, ud, tname);
-  if (p == NULL) typeerror(L, ud, tname);
+  luaL_argexpected(L, p != NULL, ud, tname);
   return p;
 }
 
@@ -463,10 +475,8 @@ static void *resizebox (lua_State *L, int idx, size_t newsize) {
   lua_Alloc allocf = lua_getallocf(L, &ud);
   UBox *box = (UBox *)lua_touserdata(L, idx);
   void *temp = allocf(ud, box->box, box->bsize, newsize);
-  if (temp == NULL && newsize > 0) {  /* allocation error? */
-    resizebox(L, idx, 0);  /* free buffer */
-    luaL_error(L, "not enough memory for buffer allocation");
-  }
+  if (temp == NULL && newsize > 0)  /* allocation error? */
+    luaL_error(L, "not enough memory");
   box->box = temp;
   box->bsize = newsize;
   return temp;
@@ -479,16 +489,20 @@ static int boxgc (lua_State *L) {
 }
 
 
-static void *newbox (lua_State *L, size_t newsize) {
-  UBox *box = (UBox *)lua_newuserdata(L, sizeof(UBox));
+static const luaL_Reg boxmt[] = {  /* box metamethods */
+  {"__gc", boxgc},
+  {"__close", boxgc},
+  {NULL, NULL}
+};
+
+
+static void newbox (lua_State *L) {
+  UBox *box = (UBox *)lua_newuserdatauv(L, sizeof(UBox), 0);
   box->box = NULL;
   box->bsize = 0;
-  if (luaL_newmetatable(L, "LUABOX")) {  /* creating metatable? */
-    lua_pushcfunction(L, boxgc);
-    lua_setfield(L, -2, "__gc");  /* metatable.__gc = boxgc */
-  }
+  if (luaL_newmetatable(L, "_UBOX*"))  /* creating metatable? */
+    luaL_setfuncs(L, boxmt, 0);  /* set its metamethods */
   lua_setmetatable(L, -2);
-  return resizebox(L, -1, newsize);
 }
 
 
@@ -496,38 +510,64 @@ static void *newbox (lua_State *L, size_t newsize) {
 ** check whether buffer is using a userdata on the stack as a temporary
 ** buffer
 */
-#define buffonstack(B)	((B)->b != (B)->initb)
+#define buffonstack(B)	((B)->b != (B)->init.b)
 
 
 /*
-** returns a pointer to a free area with at least 'sz' bytes
+** Compute new size for buffer 'B', enough to accommodate extra 'sz'
+** bytes.
 */
-LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
-  lua_State *L = B->L;
-  if (B->size - B->n < sz) {  /* not enough space? */
+static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
+  size_t newsize = B->size * 2;  /* double buffer size */
+  if (MAX_SIZET - sz < B->n)  /* overflow in (B->n + sz)? */
+    return luaL_error(B->L, "buffer too large");
+  if (newsize < B->n + sz)  /* double is not big enough? */
+    newsize = B->n + sz;
+  return newsize;
+}
+
+
+/*
+** Returns a pointer to a free area with at least 'sz' bytes in buffer
+** 'B'. 'boxidx' is the relative position in the stack where the
+** buffer's box is or should be.
+*/
+static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {
+  if (B->size - B->n >= sz)  /* enough space? */
+    return B->b + B->n;
+  else {
+    lua_State *L = B->L;
     char *newbuff;
-    size_t newsize = B->size * 2;  /* double buffer size */
-    if (newsize - B->n < sz)  /* not big enough? */
-      newsize = B->n + sz;
-    if (newsize < B->n || newsize - B->n < sz)
-      luaL_error(L, "buffer too large");
+    size_t newsize = newbuffsize(B, sz);
     /* create larger buffer */
-    if (buffonstack(B))
-      newbuff = (char *)resizebox(L, -1, newsize);
-    else {  /* no buffer yet */
-      newbuff = (char *)newbox(L, newsize);
+    if (buffonstack(B))  /* buffer already has a box? */
+      newbuff = (char *)resizebox(L, boxidx, newsize);  /* resize it */
+    else {  /* no box yet */
+      lua_pushnil(L);  /* reserve slot for final result */
+      newbox(L);  /* create a new box */
+      /* move box (and slot) to its intended position */
+      lua_rotate(L, boxidx - 1, 2);
+      lua_toclose(L, boxidx);
+      newbuff = (char *)resizebox(L, boxidx, newsize);
       memcpy(newbuff, B->b, B->n * sizeof(char));  /* copy original content */
     }
     B->b = newbuff;
     B->size = newsize;
+    return newbuff + B->n;
   }
-  return &B->b[B->n];
+}
+
+/*
+** returns a pointer to a free area with at least 'sz' bytes
+*/
+LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
+  return prepbuffsize(B, sz, -1);
 }
 
 
 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
   if (l > 0) {  /* avoid 'memcpy' when 's' can be NULL */
-    char *b = luaL_prepbuffsize(B, l);
+    char *b = prepbuffsize(B, l, -1);
     memcpy(b, s, l * sizeof(char));
     luaL_addsize(B, l);
   }
@@ -543,8 +583,8 @@ LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
   lua_State *L = B->L;
   lua_pushlstring(L, B->b, B->n);
   if (buffonstack(B)) {
-    resizebox(L, -2, 0);  /* delete old buffer */
-    lua_remove(L, -2);  /* remove its header from the stack */
+    lua_copy(L, -1, -3);  /* move string to reserved slot */
+    lua_pop(L, 2);  /* pop string and box (closing the box) */
   }
 }
 
@@ -555,20 +595,29 @@ LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
 }
 
 
+/*
+** 'luaL_addvalue' is the only function in the Buffer system where the
+** box (if existent) is not on the top of the stack. So, instead of
+** calling 'luaL_addlstring', it replicates the code using -2 as the
+** last argument to 'prepbuffsize', signaling that the box is (or will
+** be) bellow the string being added to the buffer. (Box creation can
+** trigger an emergency GC, so we should not remove the string from the
+** stack before we have the space guaranteed.)
+*/
 LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
   lua_State *L = B->L;
-  size_t l;
-  const char *s = lua_tolstring(L, -1, &l);
-  if (buffonstack(B))
-    lua_insert(L, -2);  /* put value below buffer */
-  luaL_addlstring(B, s, l);
-  lua_remove(L, (buffonstack(B)) ? -2 : -1);  /* remove value */
+  size_t len;
+  const char *s = lua_tolstring(L, -1, &len);
+  char *b = prepbuffsize(B, len, -2);
+  memcpy(b, s, len * sizeof(char));
+  luaL_addsize(B, len);
+  lua_pop(L, 1);  /* pop string */
 }
 
 
 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
   B->L = L;
-  B->b = B->initb;
+  B->b = B->init.b;
   B->n = 0;
   B->size = LUAL_BUFFERSIZE;
 }
@@ -576,7 +625,7 @@ LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
 
 LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
   luaL_buffinit(L, B);
-  return luaL_prepbuffsize(B, sz);
+  return prepbuffsize(B, sz, -1);
 }
 
 /* }====================================================== */
@@ -845,87 +894,6 @@ LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
 }
 
 
-/*
-** {======================================================
-** Compatibility with 5.1 module functions
-** =======================================================
-*/
-#if defined(LUA_COMPAT_MODULE)
-
-static const char *luaL_findtable (lua_State *L, int idx,
-                                   const char *fname, int szhint) {
-  const char *e;
-  if (idx) lua_pushvalue(L, idx);
-  do {
-    e = strchr(fname, '.');
-    if (e == NULL) e = fname + strlen(fname);
-    lua_pushlstring(L, fname, e - fname);
-    if (lua_rawget(L, -2) == LUA_TNIL) {  /* no such field? */
-      lua_pop(L, 1);  /* remove this nil */
-      lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
-      lua_pushlstring(L, fname, e - fname);
-      lua_pushvalue(L, -2);
-      lua_settable(L, -4);  /* set new table into field */
-    }
-    else if (!lua_istable(L, -1)) {  /* field has a non-table value? */
-      lua_pop(L, 2);  /* remove table and value */
-      return fname;  /* return problematic part of the name */
-    }
-    lua_remove(L, -2);  /* remove previous table */
-    fname = e + 1;
-  } while (*e == '.');
-  return NULL;
-}
-
-
-/*
-** Count number of elements in a luaL_Reg list.
-*/
-static int libsize (const luaL_Reg *l) {
-  int size = 0;
-  for (; l && l->name; l++) size++;
-  return size;
-}
-
-
-/*
-** Find or create a module table with a given name. The function
-** first looks at the LOADED table and, if that fails, try a
-** global variable with that name. In any case, leaves on the stack
-** the module table.
-*/
-LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname,
-                                 int sizehint) {
-  luaL_findtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE, 1);
-  if (lua_getfield(L, -1, modname) != LUA_TTABLE) {  /* no LOADED[modname]? */
-    lua_pop(L, 1);  /* remove previous result */
-    /* try global variable (and create one if it does not exist) */
-    lua_pushglobaltable(L);
-    if (luaL_findtable(L, 0, modname, sizehint) != NULL)
-      luaL_error(L, "name conflict for module '%s'", modname);
-    lua_pushvalue(L, -1);
-    lua_setfield(L, -3, modname);  /* LOADED[modname] = new table */
-  }
-  lua_remove(L, -2);  /* remove LOADED table */
-}
-
-
-LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
-                               const luaL_Reg *l, int nup) {
-  luaL_checkversion(L);
-  if (libname) {
-    luaL_pushmodule(L, libname, libsize(l));  /* get/create library table */
-    lua_insert(L, -(nup + 1));  /* move library table to below upvalues */
-  }
-  if (l)
-    luaL_setfuncs(L, l, nup);
-  else
-    lua_pop(L, nup);  /* remove upvalues */
-}
-
-#endif
-/* }====================================================== */
-
 /*
 ** set functions from list 'l' into table at top - 'nup'; each
 ** function gets the 'nup' elements at the top as upvalues.
@@ -934,10 +902,14 @@ LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
   luaL_checkstack(L, nup, "too many upvalues");
   for (; l->name != NULL; l++) {  /* fill the table with given functions */
-    int i;
-    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
-      lua_pushvalue(L, -nup);
-    lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    if (l->func == NULL)  /* place holder? */
+      lua_pushboolean(L, 0);
+    else {
+      int i;
+      for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+        lua_pushvalue(L, -nup);
+      lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    }
     lua_setfield(L, -(nup + 2), l->name);
   }
   lua_pop(L, nup);  /* remove upvalues */
@@ -988,18 +960,24 @@ LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
 }
 
 
-LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
-                                                               const char *r) {
+LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s,
+                                     const char *p, const char *r) {
   const char *wild;
   size_t l = strlen(p);
-  luaL_Buffer b;
-  luaL_buffinit(L, &b);
   while ((wild = strstr(s, p)) != NULL) {
-    luaL_addlstring(&b, s, wild - s);  /* push prefix */
-    luaL_addstring(&b, r);  /* push replacement in place of pattern */
+    luaL_addlstring(b, s, wild - s);  /* push prefix */
+    luaL_addstring(b, r);  /* push replacement in place of pattern */
     s = wild + l;  /* continue after 'p' */
   }
-  luaL_addstring(&b, s);  /* push last suffix */
+  luaL_addstring(b, s);  /* push last suffix */
+}
+
+
+LUALIB_API const char *luaL_gsub (lua_State *L, const char *s,
+                                  const char *p, const char *r) {
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  luaL_addgsub(&b, s, p, r);
   luaL_pushresult(&b);
   return lua_tostring(L, -1);
 }
@@ -1017,27 +995,63 @@ static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
 
 
 static int panic (lua_State *L) {
+  const char *msg = lua_tostring(L, -1);
+  if (msg == NULL) msg = "error object is not a string";
   lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
-                        lua_tostring(L, -1));
+                        msg);
   return 0;  /* return to Lua to abort */
 }
 
 
+/*
+** Emit a warning. '*warnstate' means:
+** 0 - warning system is off;
+** 1 - ready to start a new message;
+** 2 - previous message is to be continued.
+*/
+static void warnf (void *ud, const char *message, int tocont) {
+  int *warnstate = (int *)ud;
+  if (*warnstate != 2 && !tocont && *message == '@') {  /* control message? */
+    if (strcmp(message, "@off") == 0)
+      *warnstate = 0;
+    else if (strcmp(message, "@on") == 0)
+      *warnstate = 1;
+    return;
+  }
+  else if (*warnstate == 0)  /* warnings off? */
+    return;
+  if (*warnstate == 1)  /* previous message was the last? */
+    lua_writestringerror("%s", "Lua warning: ");  /* start a new warning */
+  lua_writestringerror("%s", message);  /* write message */
+  if (tocont)  /* not the last part? */
+    *warnstate = 2;  /* to be continued */
+  else {  /* last part */
+    lua_writestringerror("%s", "\n");  /* finish message with end-of-line */
+    *warnstate = 1;  /* ready to start a new message */
+  }
+}
+
+
 LUALIB_API lua_State *luaL_newstate (void) {
   lua_State *L = lua_newstate(l_alloc, NULL);
-  if (L) lua_atpanic(L, &panic);
+  if (L) {
+    int *warnstate;  /* space for warning state */
+    lua_atpanic(L, &panic);
+    warnstate = (int *)lua_newuserdatauv(L, sizeof(int), 0);
+    luaL_ref(L, LUA_REGISTRYINDEX);  /* make sure it won't be collected */
+    *warnstate = 0;  /* default is warnings off */
+    lua_setwarnf(L, warnf, warnstate);
+  }
   return L;
 }
 
 
 LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
-  const lua_Number *v = lua_version(L);
+  lua_Number v = lua_version(L);
   if (sz != LUAL_NUMSIZES)  /* check numeric types */
     luaL_error(L, "core and library have incompatible numeric types");
-  if (v != lua_version(NULL))
-    luaL_error(L, "multiple Lua VMs detected");
-  else if (*v != ver)
+  else if (v != ver)
     luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
-                  (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)*v);
+                  (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)v);
 }
 
diff --git a/libs/liblua/src/lauxlib.h b/libs/liblua/src/lauxlib.h
index 9857d3a835..59fef6af13 100644
--- a/libs/liblua/src/lauxlib.h
+++ b/libs/liblua/src/lauxlib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.h,v 1.131.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lauxlib.h $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -15,6 +15,12 @@
 #include "lua.h"
 
 
+/* global table */
+#define LUA_GNAME	"_G"
+
+
+typedef struct luaL_Buffer luaL_Buffer;
+
 
 /* extra error code for 'luaL_loadfilex' */
 #define LUA_ERRFILE     (LUA_ERRERR+1)
@@ -44,6 +50,7 @@ LUALIB_API int (luaL_getmetafield) (lua_State *L, int obj, const char *e);
 LUALIB_API int (luaL_callmeta) (lua_State *L, int obj, const char *e);
 LUALIB_API const char *(luaL_tolstring) (lua_State *L, int idx, size_t *len);
 LUALIB_API int (luaL_argerror) (lua_State *L, int arg, const char *extramsg);
+LUALIB_API int (luaL_typeerror) (lua_State *L, int arg, const char *tname);
 LUALIB_API const char *(luaL_checklstring) (lua_State *L, int arg,
                                                           size_t *l);
 LUALIB_API const char *(luaL_optlstring) (lua_State *L, int arg,
@@ -73,6 +80,7 @@ LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def,
 LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname);
 LUALIB_API int (luaL_execresult) (lua_State *L, int stat);
 
+
 /* predefined references */
 #define LUA_NOREF       (-2)
 #define LUA_REFNIL      (-1)
@@ -93,8 +101,10 @@ LUALIB_API lua_State *(luaL_newstate) (void);
 
 LUALIB_API lua_Integer (luaL_len) (lua_State *L, int idx);
 
-LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s, const char *p,
-                                                  const char *r);
+LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s,
+                                     const char *p, const char *r);
+LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s,
+                                    const char *p, const char *r);
 
 LUALIB_API void (luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup);
 
@@ -121,6 +131,10 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
 
 #define luaL_argcheck(L, cond,arg,extramsg)	\
 		((void)((cond) || luaL_argerror(L, (arg), (extramsg))))
+
+#define luaL_argexpected(L,cond,arg,tname)	\
+		((void)((cond) || luaL_typeerror(L, (arg), (tname))))
+
 #define luaL_checkstring(L,n)	(luaL_checklstring(L, (n), NULL))
 #define luaL_optstring(L,n,d)	(luaL_optlstring(L, (n), (d), NULL))
 
@@ -139,19 +153,30 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
 #define luaL_loadbuffer(L,s,sz,n)	luaL_loadbufferx(L,s,sz,n,NULL)
 
 
+/* push the value used to represent failure/error */
+#define luaL_pushfail(L)	lua_pushnil(L)
+
+
 /*
 ** {======================================================
 ** Generic Buffer manipulation
 ** =======================================================
 */
 
-typedef struct luaL_Buffer {
+struct luaL_Buffer {
   char *b;  /* buffer address */
   size_t size;  /* buffer size */
   size_t n;  /* number of characters in buffer */
   lua_State *L;
-  char initb[LUAL_BUFFERSIZE];  /* initial buffer */
-} luaL_Buffer;
+  union {
+    LUAI_MAXALIGN;  /* ensure maximum alignment for buffer */
+    char b[LUAL_BUFFERSIZE];  /* initial buffer */
+  } init;
+};
+
+
+#define luaL_bufflen(bf)	((bf)->n)
+#define luaL_buffaddr(bf)	((bf)->b)
 
 
 #define luaL_addchar(B,c) \
@@ -160,6 +185,8 @@ typedef struct luaL_Buffer {
 
 #define luaL_addsize(B,s)	((B)->n += (s))
 
+#define luaL_buffsub(B,s)	((B)->n -= (s))
+
 LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B);
 LUALIB_API char *(luaL_prepbuffsize) (luaL_Buffer *B, size_t sz);
 LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l);
@@ -197,21 +224,6 @@ typedef struct luaL_Stream {
 
 /* }====================================================== */
 
-
-
-/* compatibility with old module system */
-#if defined(LUA_COMPAT_MODULE)
-
-LUALIB_API void (luaL_pushmodule) (lua_State *L, const char *modname,
-                                   int sizehint);
-LUALIB_API void (luaL_openlib) (lua_State *L, const char *libname,
-                                const luaL_Reg *l, int nup);
-
-#define luaL_register(L,n,l)	(luaL_openlib(L,(n),(l),0))
-
-#endif
-
-
 /*
 ** {==================================================================
 ** "Abstraction Layer" for basic report of messages and errors
diff --git a/libs/liblua/src/lbaselib.c b/libs/liblua/src/lbaselib.c
index 6460e4f8d4..747fd45a2f 100644
--- a/libs/liblua/src/lbaselib.c
+++ b/libs/liblua/src/lbaselib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.314.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lbaselib.c $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -24,18 +24,12 @@
 static int luaB_print (lua_State *L) {
   int n = lua_gettop(L);  /* number of arguments */
   int i;
-  lua_getglobal(L, "tostring");
-  for (i=1; i<=n; i++) {
-    const char *s;
+  for (i = 1; i <= n; i++) {  /* for each argument */
     size_t l;
-    lua_pushvalue(L, -1);  /* function to be called */
-    lua_pushvalue(L, i);   /* value to print */
-    lua_call(L, 1, 1);
-    s = lua_tolstring(L, -1, &l);  /* get result */
-    if (s == NULL)
-      return luaL_error(L, "'tostring' must return a string to 'print'");
-    if (i>1) lua_writestring("\t", 1);
-    lua_writestring(s, l);
+    const char *s = luaL_tolstring(L, i, &l);  /* convert it to string */
+    if (i > 1)  /* not the first element? */
+      lua_writestring("\t", 1);  /* add a tab before it */
+    lua_writestring(s, l);  /* print it */
     lua_pop(L, 1);  /* pop result */
   }
   lua_writeline();
@@ -43,13 +37,31 @@ static int luaB_print (lua_State *L) {
 }
 
 
+/*
+** Creates a warning with all given arguments.
+** Check first for errors; otherwise an error may interrupt
+** the composition of a warning, leaving it unfinished.
+*/
+static int luaB_warn (lua_State *L) {
+  int n = lua_gettop(L);  /* number of arguments */
+  int i;
+  luaL_checkstring(L, 1);  /* at least one argument */
+  for (i = 2; i <= n; i++)
+    luaL_checkstring(L, i);  /* make sure all arguments are strings */
+  for (i = 1; i < n; i++)  /* compose warning */
+    lua_warning(L, lua_tostring(L, i), 1);
+  lua_warning(L, lua_tostring(L, n), 0);  /* close warning */
+  return 0;
+}
+
+
 #define SPACECHARS	" \f\n\r\t\v"
 
 static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
   lua_Unsigned n = 0;
   int neg = 0;
   s += strspn(s, SPACECHARS);  /* skip initial spaces */
-  if (*s == '-') { s++; neg = 1; }  /* handle signal */
+  if (*s == '-') { s++; neg = 1; }  /* handle sign */
   else if (*s == '+') s++;
   if (!isalnum((unsigned char)*s))  /* no digit? */
     return NULL;
@@ -68,7 +80,6 @@ static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
 
 static int luaB_tonumber (lua_State *L) {
   if (lua_isnoneornil(L, 2)) {  /* standard conversion? */
-    luaL_checkany(L, 1);
     if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */
       lua_settop(L, 1);  /* yes; return it */
       return 1;
@@ -79,6 +90,7 @@ static int luaB_tonumber (lua_State *L) {
       if (s != NULL && lua_stringtonumber(L, s) == l + 1)
         return 1;  /* successful conversion to number */
       /* else not a number */
+      luaL_checkany(L, 1);  /* (but there must be some parameter) */
     }
   }
   else {
@@ -94,7 +106,7 @@ static int luaB_tonumber (lua_State *L) {
       return 1;
     }  /* else not a number */
   }  /* else not a number */
-  lua_pushnil(L);  /* not a number */
+  luaL_pushfail(L);  /* not a number */
   return 1;
 }
 
@@ -125,8 +137,7 @@ static int luaB_getmetatable (lua_State *L) {
 static int luaB_setmetatable (lua_State *L) {
   int t = lua_type(L, 2);
   luaL_checktype(L, 1, LUA_TTABLE);
-  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
-                    "nil or table expected");
+  luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
   if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
     return luaL_error(L, "cannot change a protected metatable");
   lua_settop(L, 2);
@@ -145,8 +156,8 @@ static int luaB_rawequal (lua_State *L) {
 
 static int luaB_rawlen (lua_State *L) {
   int t = lua_type(L, 1);
-  luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
-                   "table or string expected");
+  luaL_argexpected(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
+                      "table or string");
   lua_pushinteger(L, lua_rawlen(L, 1));
   return 1;
 }
@@ -170,27 +181,58 @@ static int luaB_rawset (lua_State *L) {
 }
 
 
+static int pushmode (lua_State *L, int oldmode) {
+  lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental" : "generational");
+  return 1;
+}
+
+
 static int luaB_collectgarbage (lua_State *L) {
   static const char *const opts[] = {"stop", "restart", "collect",
     "count", "step", "setpause", "setstepmul",
-    "isrunning", NULL};
+    "isrunning", "generational", "incremental", NULL};
   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
-    LUA_GCISRUNNING};
+    LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
   int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
-  int ex = (int)luaL_optinteger(L, 2, 0);
-  int res = lua_gc(L, o, ex);
   switch (o) {
     case LUA_GCCOUNT: {
-      int b = lua_gc(L, LUA_GCCOUNTB, 0);
-      lua_pushnumber(L, (lua_Number)res + ((lua_Number)b/1024));
+      int k = lua_gc(L, o);
+      int b = lua_gc(L, LUA_GCCOUNTB);
+      lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));
+      return 1;
+    }
+    case LUA_GCSTEP: {
+      int step = (int)luaL_optinteger(L, 2, 0);
+      int res = lua_gc(L, o, step);
+      lua_pushboolean(L, res);
+      return 1;
+    }
+    case LUA_GCSETPAUSE:
+    case LUA_GCSETSTEPMUL: {
+      int p = (int)luaL_optinteger(L, 2, 0);
+      int previous = lua_gc(L, o, p);
+      lua_pushinteger(L, previous);
       return 1;
     }
-    case LUA_GCSTEP: case LUA_GCISRUNNING: {
+    case LUA_GCISRUNNING: {
+      int res = lua_gc(L, o);
       lua_pushboolean(L, res);
       return 1;
     }
+    case LUA_GCGEN: {
+      int minormul = (int)luaL_optinteger(L, 2, 0);
+      int majormul = (int)luaL_optinteger(L, 3, 0);
+      return pushmode(L, lua_gc(L, o, minormul, majormul));
+    }
+    case LUA_GCINC: {
+      int pause = (int)luaL_optinteger(L, 2, 0);
+      int stepmul = (int)luaL_optinteger(L, 3, 0);
+      int stepsize = (int)luaL_optinteger(L, 4, 0);
+      return pushmode(L, lua_gc(L, o, pause, stepmul, stepsize));
+    }
     default: {
+      int res = lua_gc(L, o);
       lua_pushinteger(L, res);
       return 1;
     }
@@ -206,23 +248,6 @@ static int luaB_type (lua_State *L) {
 }
 
 
-static int pairsmeta (lua_State *L, const char *method, int iszero,
-                      lua_CFunction iter) {
-  luaL_checkany(L, 1);
-  if (luaL_getmetafield(L, 1, method) == LUA_TNIL) {  /* no metamethod? */
-    lua_pushcfunction(L, iter);  /* will return generator, */
-    lua_pushvalue(L, 1);  /* state, */
-    if (iszero) lua_pushinteger(L, 0);  /* and initial value */
-    else lua_pushnil(L);
-  }
-  else {
-    lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
-    lua_call(L, 1, 3);  /* get 3 values from metamethod */
-  }
-  return 3;
-}
-
-
 static int luaB_next (lua_State *L) {
   luaL_checktype(L, 1, LUA_TTABLE);
   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
@@ -236,7 +261,17 @@ static int luaB_next (lua_State *L) {
 
 
 static int luaB_pairs (lua_State *L) {
-  return pairsmeta(L, "__pairs", 0, luaB_next);
+  luaL_checkany(L, 1);
+  if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) {  /* no metamethod? */
+    lua_pushcfunction(L, luaB_next);  /* will return generator, */
+    lua_pushvalue(L, 1);  /* state, */
+    lua_pushnil(L);  /* and initial value */
+  }
+  else {
+    lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
+    lua_call(L, 1, 3);  /* get 3 values from metamethod */
+  }
+  return 3;
 }
 
 
@@ -255,15 +290,11 @@ static int ipairsaux (lua_State *L) {
 ** (The given "table" may not be a table.)
 */
 static int luaB_ipairs (lua_State *L) {
-#if defined(LUA_COMPAT_IPAIRS)
-  return pairsmeta(L, "__ipairs", 1, ipairsaux);
-#else
   luaL_checkany(L, 1);
   lua_pushcfunction(L, ipairsaux);  /* iteration function */
   lua_pushvalue(L, 1);  /* state */
   lua_pushinteger(L, 0);  /* initial value */
   return 3;
-#endif
 }
 
 
@@ -277,9 +308,9 @@ static int load_aux (lua_State *L, int status, int envidx) {
     return 1;
   }
   else {  /* error (message is on top of the stack) */
-    lua_pushnil(L);
+    luaL_pushfail(L);
     lua_insert(L, -2);  /* put before error message */
-    return 2;  /* return nil plus error message */
+    return 2;  /* return fail plus error message */
   }
 }
 
@@ -459,13 +490,11 @@ static const luaL_Reg base_funcs[] = {
   {"ipairs", luaB_ipairs},
   {"loadfile", luaB_loadfile},
   {"load", luaB_load},
-#if defined(LUA_COMPAT_LOADSTRING)
-  {"loadstring", luaB_load},
-#endif
   {"next", luaB_next},
   {"pairs", luaB_pairs},
   {"pcall", luaB_pcall},
   {"print", luaB_print},
+  {"warn", luaB_warn},
   {"rawequal", luaB_rawequal},
   {"rawlen", luaB_rawlen},
   {"rawget", luaB_rawget},
@@ -477,7 +506,7 @@ static const luaL_Reg base_funcs[] = {
   {"type", luaB_type},
   {"xpcall", luaB_xpcall},
   /* placeholders */
-  {"_G", NULL},
+  {LUA_GNAME, NULL},
   {"_VERSION", NULL},
   {NULL, NULL}
 };
@@ -489,7 +518,7 @@ LUAMOD_API int luaopen_base (lua_State *L) {
   luaL_setfuncs(L, base_funcs, 0);
   /* set global _G */
   lua_pushvalue(L, -1);
-  lua_setfield(L, -2, "_G");
+  lua_setfield(L, -2, LUA_GNAME);
   /* set global _VERSION */
   lua_pushliteral(L, LUA_VERSION);
   lua_setfield(L, -2, "_VERSION");
diff --git a/libs/liblua/src/lcode.c b/libs/liblua/src/lcode.c
index 12619f54a0..6f241c9476 100644
--- a/libs/liblua/src/lcode.c
+++ b/libs/liblua/src/lcode.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 2.112.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lcode.c $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -10,6 +10,7 @@
 #include "lprefix.h"
 
 
+#include <limits.h>
 #include <math.h>
 #include <stdlib.h>
 
@@ -36,11 +37,22 @@
 #define hasjumps(e)	((e)->t != (e)->f)
 
 
+static int codesJ (FuncState *fs, OpCode o, int sj, int k);
+
+
+
+/* semantic error */
+l_noret luaK_semerror (LexState *ls, const char *msg) {
+  ls->t.token = 0;  /* remove "near <token>" from final message */
+  luaX_syntaxerror(ls, msg);
+}
+
+
 /*
 ** If expression is a numeric constant, fills 'v' with its value
 ** and returns 1. Otherwise, returns 0.
 */
-static int tonumeral(const expdesc *e, TValue *v) {
+static int tonumeral (const expdesc *e, TValue *v) {
   if (hasjumps(e))
     return 0;  /* not a numeral */
   switch (e->k) {
@@ -55,6 +67,60 @@ static int tonumeral(const expdesc *e, TValue *v) {
 }
 
 
+/*
+** Get the constant value from a constant expression
+*/
+static TValue *const2val (FuncState *fs, const expdesc *e) {
+  lua_assert(e->k == VCONST);
+  return &fs->ls->dyd->actvar.arr[e->u.info].k;
+}
+
+
+/*
+** If expression is a constant, fills 'v' with its value
+** and returns 1. Otherwise, returns 0.
+*/
+int luaK_exp2const (FuncState *fs, const expdesc *e, TValue *v) {
+  if (hasjumps(e))
+    return 0;  /* not a constant */
+  switch (e->k) {
+    case VFALSE:
+      setbfvalue(v);
+      return 1;
+    case VTRUE:
+      setbtvalue(v);
+      return 1;
+    case VNIL:
+      setnilvalue(v);
+      return 1;
+    case VKSTR: {
+      setsvalue(fs->ls->L, v, e->u.strval);
+      return 1;
+    }
+    case VCONST: {
+      setobj(fs->ls->L, v, const2val(fs, e));
+      return 1;
+    }
+    default: return tonumeral(e, v);
+  }
+}
+
+
+/*
+** Return the previous instruction of the current code. If there
+** may be a jump target between the current instruction and the
+** previous one, return an invalid instruction (to avoid wrong
+** optimizations).
+*/
+static Instruction *previousinstruction (FuncState *fs) {
+  static const Instruction invalidinstruction = ~(Instruction)0;
+  if (fs->pc > fs->lasttarget)
+    return &fs->f->code[fs->pc - 1];  /* previous instruction */
+  else
+    return cast(Instruction*, &invalidinstruction);
+}
+
+
 /*
 ** Create a OP_LOADNIL instruction, but try to optimize: if the previous
 ** instruction is also OP_LOADNIL and ranges are compatible, adjust
@@ -62,21 +128,18 @@ static int tonumeral(const expdesc *e, TValue *v) {
 ** instance, 'local a; local b' will generate a single opcode.)
 */
 void luaK_nil (FuncState *fs, int from, int n) {
-  Instruction *previous;
   int l = from + n - 1;  /* last register to set nil */
-  if (fs->pc > fs->lasttarget) {  /* no jumps to current position? */
-    previous = &fs->f->code[fs->pc-1];
-    if (GET_OPCODE(*previous) == OP_LOADNIL) {  /* previous is LOADNIL? */
-      int pfrom = GETARG_A(*previous);  /* get previous range */
-      int pl = pfrom + GETARG_B(*previous);
-      if ((pfrom <= from && from <= pl + 1) ||
-          (from <= pfrom && pfrom <= l + 1)) {  /* can connect both? */
-        if (pfrom < from) from = pfrom;  /* from = min(from, pfrom) */
-        if (pl > l) l = pl;  /* l = max(l, pl) */
-        SETARG_A(*previous, from);
-        SETARG_B(*previous, l - from);
-        return;
-      }
+  Instruction *previous = previousinstruction(fs);
+  if (GET_OPCODE(*previous) == OP_LOADNIL) {  /* previous is LOADNIL? */
+    int pfrom = GETARG_A(*previous);  /* get previous range */
+    int pl = pfrom + GETARG_B(*previous);
+    if ((pfrom <= from && from <= pl + 1) ||
+        (from <= pfrom && pfrom <= l + 1)) {  /* can connect both? */
+      if (pfrom < from) from = pfrom;  /* from = min(from, pfrom) */
+      if (pl > l) l = pl;  /* l = max(l, pl) */
+      SETARG_A(*previous, from);
+      SETARG_B(*previous, l - from);
+      return;
     }  /* else go through */
   }
   luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0);  /* else no optimization */
@@ -88,7 +151,7 @@ void luaK_nil (FuncState *fs, int from, int n) {
 ** a list of jumps.
 */
 static int getjump (FuncState *fs, int pc) {
-  int offset = GETARG_sBx(fs->f->code[pc]);
+  int offset = GETARG_sJ(fs->f->code[pc]);
   if (offset == NO_JUMP)  /* point to itself represents end of list */
     return NO_JUMP;  /* end of list */
   else
@@ -104,9 +167,10 @@ static void fixjump (FuncState *fs, int pc, int dest) {
   Instruction *jmp = &fs->f->code[pc];
   int offset = dest - (pc + 1);
   lua_assert(dest != NO_JUMP);
-  if (abs(offset) > MAXARG_sBx)
+  if (!(-OFFSET_sJ <= offset && offset <= MAXARG_sJ - OFFSET_sJ))
     luaX_syntaxerror(fs->ls, "control structure too long");
-  SETARG_sBx(*jmp, offset);
+  lua_assert(GET_OPCODE(*jmp) == OP_JMP);
+  SETARG_sJ(*jmp, offset);
 }
 
 
@@ -129,17 +193,10 @@ void luaK_concat (FuncState *fs, int *l1, int l2) {
 
 /*
 ** Create a jump instruction and return its position, so its destination
-** can be fixed later (with 'fixjump'). If there are jumps to
-** this position (kept in 'jpc'), link them all together so that
-** 'patchlistaux' will fix all them directly to the final destination.
+** can be fixed later (with 'fixjump').
 */
 int luaK_jump (FuncState *fs) {
-  int jpc = fs->jpc;  /* save list of jumps to here */
-  int j;
-  fs->jpc = NO_JUMP;  /* no more jumps to here */
-  j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
-  luaK_concat(fs, &j, jpc);  /* keep them on hold */
-  return j;
+  return codesJ(fs, OP_JMP, NO_JUMP, 0);
 }
 
 
@@ -147,7 +204,13 @@ int luaK_jump (FuncState *fs) {
 ** Code a 'return' instruction
 */
 void luaK_ret (FuncState *fs, int first, int nret) {
-  luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
+  OpCode op;
+  switch (nret) {
+    case 0: op = OP_RETURN0; break;
+    case 1: op = OP_RETURN1; break;
+    default: op = OP_RETURN; break;
+  }
+  luaK_codeABC(fs, op, first, nret + 1, 0);
 }
 
 
@@ -155,8 +218,8 @@ void luaK_ret (FuncState *fs, int first, int nret) {
 ** Code a "conditional jump", that is, a test or comparison opcode
 ** followed by a jump. Return jump position.
 */
-static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
-  luaK_codeABC(fs, op, A, B, C);
+static int condjump (FuncState *fs, OpCode op, int A, int B, int C, int k) {
+  luaK_codeABCk(fs, op, A, B, C, k);
   return luaK_jump(fs);
 }
 
@@ -201,7 +264,7 @@ static int patchtestreg (FuncState *fs, int node, int reg) {
   else {
      /* no register to put value or register already has the value;
         change instruction to simple test */
-    *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
+    *i = CREATE_ABCk(OP_TEST, GETARG_B(*i), 0, 0, GETARG_k(*i));
   }
   return 1;
 }
@@ -235,73 +298,103 @@ static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
 
 
 /*
-** Ensure all pending jumps to current position are fixed (jumping
-** to current position with no values) and reset list of pending
-** jumps
+** Path all jumps in 'list' to jump to 'target'.
+** (The assert means that we cannot fix a jump to a forward address
+** because we only know addresses once code is generated.)
 */
-static void dischargejpc (FuncState *fs) {
-  patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
-  fs->jpc = NO_JUMP;
+void luaK_patchlist (FuncState *fs, int list, int target) {
+  lua_assert(target <= fs->pc);
+  patchlistaux(fs, list, target, NO_REG, target);
 }
 
 
-/*
-** Add elements in 'list' to list of pending jumps to "here"
-** (current position)
-*/
 void luaK_patchtohere (FuncState *fs, int list) {
-  luaK_getlabel(fs);  /* mark "here" as a jump target */
-  luaK_concat(fs, &fs->jpc, list);
+  int hr = luaK_getlabel(fs);  /* mark "here" as a jump target */
+  luaK_patchlist(fs, list, hr);
 }
 
 
 /*
-** Path all jumps in 'list' to jump to 'target'.
-** (The assert means that we cannot fix a jump to a forward address
-** because we only know addresses once code is generated.)
+** MAXimum number of successive Instructions WiTHout ABSolute line
+** information.
 */
-void luaK_patchlist (FuncState *fs, int list, int target) {
-  if (target == fs->pc)  /* 'target' is current position? */
-    luaK_patchtohere(fs, list);  /* add list to pending jumps */
-  else {
-    lua_assert(target < fs->pc);
-    patchlistaux(fs, list, target, NO_REG, target);
+#if !defined(MAXIWTHABS)
+#define MAXIWTHABS	120
+#endif
+
+
+/* limit for difference between lines in relative line info. */
+#define LIMLINEDIFF	0x80
+
+
+/*
+** Save line info for a new instruction. If difference from last line
+** does not fit in a byte, of after that many instructions, save a new
+** absolute line info; (in that case, the special value 'ABSLINEINFO'
+** in 'lineinfo' signals the existence of this absolute information.)
+** Otherwise, store the difference from last line in 'lineinfo'.
+*/
+static void savelineinfo (FuncState *fs, Proto *f, int line) {
+  int linedif = line - fs->previousline;
+  int pc = fs->pc - 1;  /* last instruction coded */
+  if (abs(linedif) >= LIMLINEDIFF || fs->iwthabs++ > MAXIWTHABS) {
+    luaM_growvector(fs->ls->L, f->abslineinfo, fs->nabslineinfo,
+                    f->sizeabslineinfo, AbsLineInfo, MAX_INT, "lines");
+    f->abslineinfo[fs->nabslineinfo].pc = pc;
+    f->abslineinfo[fs->nabslineinfo++].line = line;
+    linedif = ABSLINEINFO;  /* signal that there is absolute information */
+    fs->iwthabs = 0;  /* restart counter */
   }
+  luaM_growvector(fs->ls->L, f->lineinfo, pc, f->sizelineinfo, ls_byte,
+                  MAX_INT, "opcodes");
+  f->lineinfo[pc] = linedif;
+  fs->previousline = line;  /* last line saved */
 }
 
 
 /*
-** Path all jumps in 'list' to close upvalues up to given 'level'
-** (The assertion checks that jumps either were closing nothing
-** or were closing higher levels, from inner blocks.)
+** Remove line information from the last instruction.
+** If line information for that instruction is absolute, set 'iwthabs'
+** above its max to force the new (replacing) instruction to have
+** absolute line info, too.
 */
-void luaK_patchclose (FuncState *fs, int list, int level) {
-  level++;  /* argument is +1 to reserve 0 as non-op */
-  for (; list != NO_JUMP; list = getjump(fs, list)) {
-    lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP &&
-                (GETARG_A(fs->f->code[list]) == 0 ||
-                 GETARG_A(fs->f->code[list]) >= level));
-    SETARG_A(fs->f->code[list], level);
+static void removelastlineinfo (FuncState *fs) {
+  Proto *f = fs->f;
+  int pc = fs->pc - 1;  /* last instruction coded */
+  if (f->lineinfo[pc] != ABSLINEINFO) {  /* relative line info? */
+    fs->previousline -= f->lineinfo[pc];  /* correct last line saved */
+    fs->iwthabs--;  /* undo previous increment */
+  }
+  else {  /* absolute line information */
+    lua_assert(f->abslineinfo[fs->nabslineinfo - 1].pc == pc);
+    fs->nabslineinfo--;  /* remove it */
+    fs->iwthabs = MAXIWTHABS + 1;  /* force next line info to be absolute */
   }
 }
 
 
+/*
+** Remove the last instruction created, correcting line information
+** accordingly.
+*/
+static void removelastinstruction (FuncState *fs) {
+  removelastlineinfo(fs);
+  fs->pc--;
+}
+
+
 /*
 ** Emit instruction 'i', checking for array sizes and saving also its
 ** line information. Return 'i' position.
 */
-static int luaK_code (FuncState *fs, Instruction i) {
+int luaK_code (FuncState *fs, Instruction i) {
   Proto *f = fs->f;
-  dischargejpc(fs);  /* 'pc' will change */
   /* put new instruction in code array */
   luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction,
                   MAX_INT, "opcodes");
-  f->code[fs->pc] = i;
-  /* save corresponding line information */
-  luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
-                  MAX_INT, "opcodes");
-  f->lineinfo[fs->pc] = fs->ls->lastline;
-  return fs->pc++;
+  f->code[fs->pc++] = i;
+  savelineinfo(fs, f, fs->ls->lastline);
+  return fs->pc - 1;  /* index of new instruction */
 }
 
 
@@ -309,12 +402,11 @@ static int luaK_code (FuncState *fs, Instruction i) {
 ** Format and emit an 'iABC' instruction. (Assertions check consistency
 ** of parameters versus opcode.)
 */
-int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
+int luaK_codeABCk (FuncState *fs, OpCode o, int a, int b, int c, int k) {
   lua_assert(getOpMode(o) == iABC);
-  lua_assert(getBMode(o) != OpArgN || b == 0);
-  lua_assert(getCMode(o) != OpArgN || c == 0);
-  lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C);
-  return luaK_code(fs, CREATE_ABC(o, a, b, c));
+  lua_assert(a <= MAXARG_A && b <= MAXARG_B &&
+             c <= MAXARG_C && (k & ~1) == 0);
+  return luaK_code(fs, CREATE_ABCk(o, a, b, c, k));
 }
 
 
@@ -322,13 +414,34 @@ int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
 ** Format and emit an 'iABx' instruction.
 */
 int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
-  lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
-  lua_assert(getCMode(o) == OpArgN);
+  lua_assert(getOpMode(o) == iABx);
   lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx);
   return luaK_code(fs, CREATE_ABx(o, a, bc));
 }
 
 
+/*
+** Format and emit an 'iAsBx' instruction.
+*/
+int luaK_codeAsBx (FuncState *fs, OpCode o, int a, int bc) {
+  unsigned int b = bc + OFFSET_sBx;
+  lua_assert(getOpMode(o) == iAsBx);
+  lua_assert(a <= MAXARG_A && b <= MAXARG_Bx);
+  return luaK_code(fs, CREATE_ABx(o, a, b));
+}
+
+
+/*
+** Format and emit an 'isJ' instruction.
+*/
+static int codesJ (FuncState *fs, OpCode o, int sj, int k) {
+  unsigned int j = sj + OFFSET_sJ;
+  lua_assert(getOpMode(o) == isJ);
+  lua_assert(j <= MAXARG_sJ && (k & ~1) == 0);
+  return luaK_code(fs, CREATE_sJ(o, j, k));
+}
+
+
 /*
 ** Emit an "extra argument" instruction (format 'iAx')
 */
@@ -343,7 +456,7 @@ static int codeextraarg (FuncState *fs, int a) {
 ** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX'
 ** instruction with "extra argument".
 */
-int luaK_codek (FuncState *fs, int reg, int k) {
+static int luaK_codek (FuncState *fs, int reg, int k) {
   if (k <= MAXARG_Bx)
     return luaK_codeABx(fs, OP_LOADK, reg, k);
   else {
@@ -384,13 +497,28 @@ void luaK_reserveregs (FuncState *fs, int n) {
 )
 */
 static void freereg (FuncState *fs, int reg) {
-  if (!ISK(reg) && reg >= fs->nactvar) {
+  if (reg >= luaY_nvarstack(fs)) {
     fs->freereg--;
     lua_assert(reg == fs->freereg);
   }
 }
 
 
+/*
+** Free two registers in proper order
+*/
+static void freeregs (FuncState *fs, int r1, int r2) {
+  if (r1 > r2) {
+    freereg(fs, r1);
+    freereg(fs, r2);
+  }
+  else {
+    freereg(fs, r2);
+    freereg(fs, r1);
+  }
+}
+
+
 /*
 ** Free register used by expression 'e' (if any)
 */
@@ -407,14 +535,7 @@ static void freeexp (FuncState *fs, expdesc *e) {
 static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) {
   int r1 = (e1->k == VNONRELOC) ? e1->u.info : -1;
   int r2 = (e2->k == VNONRELOC) ? e2->u.info : -1;
-  if (r1 > r2) {
-    freereg(fs, r1);
-    freereg(fs, r2);
-  }
-  else {
-    freereg(fs, r2);
-    freereg(fs, r1);
-  }
+  freeregs(fs, r1, r2);
 }
 
 
@@ -433,7 +554,7 @@ static int addk (FuncState *fs, TValue *key, TValue *v) {
   if (ttisinteger(idx)) {  /* is there an index there? */
     k = cast_int(ivalue(idx));
     /* correct value? (warning: must distinguish floats from integers!) */
-    if (k < fs->nk && ttype(&f->k[k]) == ttype(v) &&
+    if (k < fs->nk && ttypetag(&f->k[k]) == ttypetag(v) &&
                       luaV_rawequalobj(&f->k[k], v))
       return k;  /* reuse index */
   }
@@ -455,7 +576,7 @@ static int addk (FuncState *fs, TValue *key, TValue *v) {
 /*
 ** Add a string to list of constants and return its index.
 */
-int luaK_stringK (FuncState *fs, TString *s) {
+static int stringK (FuncState *fs, TString *s) {
   TValue o;
   setsvalue(fs->ls->L, &o, s);
   return addk(fs, &o, &o);  /* use string itself as key */
@@ -468,9 +589,9 @@ int luaK_stringK (FuncState *fs, TString *s) {
 ** same value; conversion to 'void*' is used only for hashing, so there
 ** are no "precision" problems.
 */
-int luaK_intK (FuncState *fs, lua_Integer n) {
+static int luaK_intK (FuncState *fs, lua_Integer n) {
   TValue k, o;
-  setpvalue(&k, cast(void*, cast(size_t, n)));
+  setpvalue(&k, cast_voidp(cast_sizet(n)));
   setivalue(&o, n);
   return addk(fs, &k, &o);
 }
@@ -486,11 +607,21 @@ static int luaK_numberK (FuncState *fs, lua_Number r) {
 
 
 /*
-** Add a boolean to list of constants and return its index.
+** Add a false to list of constants and return its index.
+*/
+static int boolF (FuncState *fs) {
+  TValue o;
+  setbfvalue(&o);
+  return addk(fs, &o, &o);  /* use boolean itself as key */
+}
+
+
+/*
+** Add a true to list of constants and return its index.
 */
-static int boolK (FuncState *fs, int b) {
+static int boolT (FuncState *fs) {
   TValue o;
-  setbvalue(&o, b);
+  setbtvalue(&o);
   return addk(fs, &o, &o);  /* use boolean itself as key */
 }
 
@@ -507,22 +638,93 @@ static int nilK (FuncState *fs) {
 }
 
 
+/*
+** Check whether 'i' can be stored in an 'sC' operand. Equivalent to
+** (0 <= int2sC(i) && int2sC(i) <= MAXARG_C) but without risk of
+** overflows in the hidden addition inside 'int2sC'.
+*/
+static int fitsC (lua_Integer i) {
+  return (l_castS2U(i) + OFFSET_sC <= cast_uint(MAXARG_C));
+}
+
+
+/*
+** Check whether 'i' can be stored in an 'sBx' operand.
+*/
+static int fitsBx (lua_Integer i) {
+  return (-OFFSET_sBx <= i && i <= MAXARG_Bx - OFFSET_sBx);
+}
+
+
+void luaK_int (FuncState *fs, int reg, lua_Integer i) {
+  if (fitsBx(i))
+    luaK_codeAsBx(fs, OP_LOADI, reg, cast_int(i));
+  else
+    luaK_codek(fs, reg, luaK_intK(fs, i));
+}
+
+
+static void luaK_float (FuncState *fs, int reg, lua_Number f) {
+  lua_Integer fi;
+  if (luaV_flttointeger(f, &fi, F2Ieq) && fitsBx(fi))
+    luaK_codeAsBx(fs, OP_LOADF, reg, cast_int(fi));
+  else
+    luaK_codek(fs, reg, luaK_numberK(fs, f));
+}
+
+
+/*
+** Convert a constant in 'v' into an expression description 'e'
+*/
+static void const2exp (TValue *v, expdesc *e) {
+  switch (ttypetag(v)) {
+    case LUA_VNUMINT:
+      e->k = VKINT; e->u.ival = ivalue(v);
+      break;
+    case LUA_VNUMFLT:
+      e->k = VKFLT; e->u.nval = fltvalue(v);
+      break;
+    case LUA_VFALSE:
+      e->k = VFALSE;
+      break;
+    case LUA_VTRUE:
+      e->k = VTRUE;
+      break;
+    case LUA_VNIL:
+      e->k = VNIL;
+      break;
+    case LUA_VSHRSTR:  case LUA_VLNGSTR:
+      e->k = VKSTR; e->u.strval = tsvalue(v);
+      break;
+    default: lua_assert(0);
+  }
+}
+
+
 /*
 ** Fix an expression to return the number of results 'nresults'.
-** Either 'e' is a multi-ret expression (function call or vararg)
-** or 'nresults' is LUA_MULTRET (as any expression can satisfy that).
+** 'e' must be a multi-ret expression (function call or vararg).
 */
 void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
-  if (e->k == VCALL) {  /* expression is an open function call? */
-    SETARG_C(getinstruction(fs, e), nresults + 1);
-  }
-  else if (e->k == VVARARG) {
-    Instruction *pc = &getinstruction(fs, e);
-    SETARG_B(*pc, nresults + 1);
+  Instruction *pc = &getinstruction(fs, e);
+  if (e->k == VCALL)  /* expression is an open function call? */
+    SETARG_C(*pc, nresults + 1);
+  else {
+    lua_assert(e->k == VVARARG);
+    SETARG_C(*pc, nresults + 1);
     SETARG_A(*pc, fs->freereg);
     luaK_reserveregs(fs, 1);
   }
-  else lua_assert(nresults == LUA_MULTRET);
+}
+
+
+/*
+** Convert a VKSTR to a VK
+*/
+static void str2K (FuncState *fs, expdesc *e) {
+  lua_assert(e->k == VKSTR);
+  e->u.info = stringK(fs, e->u.strval);
+  e->k = VK;
 }
 
 
@@ -532,7 +734,7 @@ void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
 ** vararg), it already returns one result, so nothing needs to be done.
 ** Function calls become VNONRELOC expressions (as its result comes
 ** fixed in the base register of the call), while vararg expressions
-** become VRELOCABLE (as OP_VARARG puts its results where it wants).
+** become VRELOC (as OP_VARARG puts its results where it wants).
 ** (Calls are created returning one result, so that does not need
 ** to be fixed.)
 */
@@ -544,39 +746,53 @@ void luaK_setoneret (FuncState *fs, expdesc *e) {
     e->u.info = GETARG_A(getinstruction(fs, e));
   }
   else if (e->k == VVARARG) {
-    SETARG_B(getinstruction(fs, e), 2);
-    e->k = VRELOCABLE;  /* can relocate its simple result */
+    SETARG_C(getinstruction(fs, e), 2);
+    e->k = VRELOC;  /* can relocate its simple result */
   }
 }
 
 
 /*
-** Ensure that expression 'e' is not a variable.
+** Ensure that expression 'e' is not a variable (nor a constant).
+** (Expression still may have jump lists.)
 */
 void luaK_dischargevars (FuncState *fs, expdesc *e) {
   switch (e->k) {
+    case VCONST: {
+      const2exp(const2val(fs, e), e);
+      break;
+    }
     case VLOCAL: {  /* already in a register */
+      e->u.info = e->u.var.sidx;
       e->k = VNONRELOC;  /* becomes a non-relocatable value */
       break;
     }
     case VUPVAL: {  /* move value to some (pending) register */
       e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);
-      e->k = VRELOCABLE;
+      e->k = VRELOC;
+      break;
+    }
+    case VINDEXUP: {
+      e->u.info = luaK_codeABC(fs, OP_GETTABUP, 0, e->u.ind.t, e->u.ind.idx);
+      e->k = VRELOC;
+      break;
+    }
+    case VINDEXI: {
+      freereg(fs, e->u.ind.t);
+      e->u.info = luaK_codeABC(fs, OP_GETI, 0, e->u.ind.t, e->u.ind.idx);
+      e->k = VRELOC;
+      break;
+    }
+    case VINDEXSTR: {
+      freereg(fs, e->u.ind.t);
+      e->u.info = luaK_codeABC(fs, OP_GETFIELD, 0, e->u.ind.t, e->u.ind.idx);
+      e->k = VRELOC;
       break;
     }
     case VINDEXED: {
-      OpCode op;
-      freereg(fs, e->u.ind.idx);
-      if (e->u.ind.vt == VLOCAL) {  /* is 't' in a register? */
-        freereg(fs, e->u.ind.t);
-        op = OP_GETTABLE;
-      }
-      else {
-        lua_assert(e->u.ind.vt == VUPVAL);
-        op = OP_GETTABUP;  /* 't' is in an upvalue */
-      }
-      e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx);
-      e->k = VRELOCABLE;
+      freeregs(fs, e->u.ind.t, e->u.ind.idx);
+      e->u.info = luaK_codeABC(fs, OP_GETTABLE, 0, e->u.ind.t, e->u.ind.idx);
+      e->k = VRELOC;
       break;
     }
     case VVARARG: case VCALL: {
@@ -591,6 +807,7 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
 /*
 ** Ensures expression value is in register 'reg' (and therefore
 ** 'e' will become a non-relocatable expression).
+** (Expression still may have jump lists.)
 */
 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
   luaK_dischargevars(fs, e);
@@ -599,23 +816,30 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
       luaK_nil(fs, reg, 1);
       break;
     }
-    case VFALSE: case VTRUE: {
-      luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
+    case VFALSE: {
+      luaK_codeABC(fs, OP_LOADFALSE, reg, 0, 0);
       break;
     }
+    case VTRUE: {
+      luaK_codeABC(fs, OP_LOADTRUE, reg, 0, 0);
+      break;
+    }
+    case VKSTR: {
+      str2K(fs, e);
+    }  /* FALLTHROUGH */
     case VK: {
       luaK_codek(fs, reg, e->u.info);
       break;
     }
     case VKFLT: {
-      luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval));
+      luaK_float(fs, reg, e->u.nval);
       break;
     }
     case VKINT: {
-      luaK_codek(fs, reg, luaK_intK(fs, e->u.ival));
+      luaK_int(fs, reg, e->u.ival);
       break;
     }
-    case VRELOCABLE: {
+    case VRELOC: {
       Instruction *pc = &getinstruction(fs, e);
       SETARG_A(*pc, reg);  /* instruction will put result in 'reg' */
       break;
@@ -637,6 +861,7 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
 
 /*
 ** Ensures expression value is in any register.
+** (Expression still may have jump lists.)
 */
 static void discharge2anyreg (FuncState *fs, expdesc *e) {
   if (e->k != VNONRELOC) {  /* no fixed register yet? */
@@ -646,9 +871,9 @@ static void discharge2anyreg (FuncState *fs, expdesc *e) {
 }
 
 
-static int code_loadbool (FuncState *fs, int A, int b, int jump) {
+static int code_loadbool (FuncState *fs, int A, OpCode op) {
   luaK_getlabel(fs);  /* those instructions may be jump targets */
-  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
+  return luaK_codeABC(fs, op, A, 0, 0);
 }
 
 
@@ -666,8 +891,8 @@ static int need_value (FuncState *fs, int list) {
 
 
 /*
-** Ensures final expression result (including results from its jump
-** lists) is in register 'reg'.
+** Ensures final expression result (which includes results from its
+** jump lists) is in register 'reg'.
 ** If expression has jumps, need to patch these jumps either to
 ** its final position or to "load" instructions (for those tests
 ** that do not produce values).
@@ -682,8 +907,9 @@ static void exp2reg (FuncState *fs, expdesc *e, int reg) {
     int p_t = NO_JUMP;  /* position of an eventual LOAD true */
     if (need_value(fs, e->t) || need_value(fs, e->f)) {
       int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
-      p_f = code_loadbool(fs, reg, 0, 1);
-      p_t = code_loadbool(fs, reg, 1, 0);
+      p_f = code_loadbool(fs, reg, OP_LFALSESKIP);  /* skip next inst. */
+      p_t = code_loadbool(fs, reg, OP_LOADTRUE);
+      /* jump around these booleans if 'e' is not a test */
       luaK_patchtohere(fs, fj);
     }
     final = luaK_getlabel(fs);
@@ -697,8 +923,7 @@ static void exp2reg (FuncState *fs, expdesc *e, int reg) {
 
 
 /*
-** Ensures final expression result (including results from its jump
-** lists) is in next available register.
+** Ensures final expression result is in next available register.
 */
 void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
   luaK_dischargevars(fs, e);
@@ -709,15 +934,15 @@ void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
 
 
 /*
-** Ensures final expression result (including results from its jump
-** lists) is in some (any) register and return that register.
+** Ensures final expression result is in some (any) register
+** and return that register.
 */
 int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
   luaK_dischargevars(fs, e);
   if (e->k == VNONRELOC) {  /* expression already has a register? */
     if (!hasjumps(e))  /* no jumps? */
       return e->u.info;  /* result is already in a register */
-    if (e->u.info >= fs->nactvar) {  /* reg. is not a local? */
+    if (e->u.info >= luaY_nvarstack(fs)) {  /* reg. is not a local? */
       exp2reg(fs, e, e->u.info);  /* put final result in it */
       return e->u.info;
     }
@@ -728,8 +953,8 @@ int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
 
 
 /*
-** Ensures final expression result is either in a register or in an
-** upvalue.
+** Ensures final expression result is either in a register
+** or in an upvalue.
 */
 void luaK_exp2anyregup (FuncState *fs, expdesc *e) {
   if (e->k != VUPVAL || hasjumps(e))
@@ -738,8 +963,8 @@ void luaK_exp2anyregup (FuncState *fs, expdesc *e) {
 
 
 /*
-** Ensures final expression result is either in a register or it is
-** a constant.
+** Ensures final expression result is either in a register
+** or it is a constant.
 */
 void luaK_exp2val (FuncState *fs, expdesc *e) {
   if (hasjumps(e))
@@ -749,30 +974,54 @@ void luaK_exp2val (FuncState *fs, expdesc *e) {
 }
 
 
+/*
+** Try to make 'e' a K expression with an index in the range of R/K
+** indices. Return true iff succeeded.
+*/
+static int luaK_exp2K (FuncState *fs, expdesc *e) {
+  if (!hasjumps(e)) {
+    int info;
+    switch (e->k) {  /* move constants to 'k' */
+      case VTRUE: info = boolT(fs); break;
+      case VFALSE: info = boolF(fs); break;
+      case VNIL: info = nilK(fs); break;
+      case VKINT: info = luaK_intK(fs, e->u.ival); break;
+      case VKFLT: info = luaK_numberK(fs, e->u.nval); break;
+      case VKSTR: info = stringK(fs, e->u.strval); break;
+      case VK: info = e->u.info; break;
+      default: return 0;  /* not a constant */
+    }
+    if (info <= MAXINDEXRK) {  /* does constant fit in 'argC'? */
+      e->k = VK;  /* make expression a 'K' expression */
+      e->u.info = info;
+      return 1;
+    }
+  }
+  /* else, expression doesn't fit; leave it unchanged */
+  return 0;
+}
+
+
 /*
 ** Ensures final expression result is in a valid R/K index
 ** (that is, it is either in a register or in 'k' with an index
 ** in the range of R/K indices).
-** Returns R/K index.
+** Returns 1 iff expression is K.
 */
 int luaK_exp2RK (FuncState *fs, expdesc *e) {
-  luaK_exp2val(fs, e);
-  switch (e->k) {  /* move constants to 'k' */
-    case VTRUE: e->u.info = boolK(fs, 1); goto vk;
-    case VFALSE: e->u.info = boolK(fs, 0); goto vk;
-    case VNIL: e->u.info = nilK(fs); goto vk;
-    case VKINT: e->u.info = luaK_intK(fs, e->u.ival); goto vk;
-    case VKFLT: e->u.info = luaK_numberK(fs, e->u.nval); goto vk;
-    case VK:
-     vk:
-      e->k = VK;
-      if (e->u.info <= MAXINDEXRK)  /* constant fits in 'argC'? */
-        return RKASK(e->u.info);
-      else break;
-    default: break;
+  if (luaK_exp2K(fs, e))
+    return 1;
+  else {  /* not a constant in the right range: put it in a register */
+    luaK_exp2anyreg(fs, e);
+    return 0;
   }
-  /* not a constant in the right range: put it in a register */
-  return luaK_exp2anyreg(fs, e);
+}
+
+
+static void codeABRK (FuncState *fs, OpCode o, int a, int b,
+                      expdesc *ec) {
+  int k = luaK_exp2RK(fs, ec);
+  luaK_codeABCk(fs, o, a, b, ec->u.info, k);
 }
 
 
@@ -783,7 +1032,7 @@ void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
   switch (var->k) {
     case VLOCAL: {
       freeexp(fs, ex);
-      exp2reg(fs, ex, var->u.info);  /* compute 'ex' into proper place */
+      exp2reg(fs, ex, var->u.var.sidx);  /* compute 'ex' into proper place */
       return;
     }
     case VUPVAL: {
@@ -791,10 +1040,20 @@ void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
       luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0);
       break;
     }
+    case VINDEXUP: {
+      codeABRK(fs, OP_SETTABUP, var->u.ind.t, var->u.ind.idx, ex);
+      break;
+    }
+    case VINDEXI: {
+      codeABRK(fs, OP_SETI, var->u.ind.t, var->u.ind.idx, ex);
+      break;
+    }
+    case VINDEXSTR: {
+      codeABRK(fs, OP_SETFIELD, var->u.ind.t, var->u.ind.idx, ex);
+      break;
+    }
     case VINDEXED: {
-      OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP;
-      int e = luaK_exp2RK(fs, ex);
-      luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e);
+      codeABRK(fs, OP_SETTABLE, var->u.ind.t, var->u.ind.idx, ex);
       break;
     }
     default: lua_assert(0);  /* invalid var kind to store */
@@ -814,7 +1073,7 @@ void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
   e->u.info = fs->freereg;  /* base register for op_self */
   e->k = VNONRELOC;  /* self expression has a fixed register */
   luaK_reserveregs(fs, 2);  /* function and 'self' produced by op_self */
-  luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key));
+  codeABRK(fs, OP_SELF, e->u.info, ereg, key);
   freeexp(fs, key);
 }
 
@@ -826,7 +1085,7 @@ static void negatecondition (FuncState *fs, expdesc *e) {
   Instruction *pc = getjumpcontrol(fs, e->u.info);
   lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
                                            GET_OPCODE(*pc) != OP_TEST);
-  SETARG_A(*pc, !(GETARG_A(*pc)));
+  SETARG_k(*pc, (GETARG_k(*pc) ^ 1));
 }
 
 
@@ -837,17 +1096,17 @@ static void negatecondition (FuncState *fs, expdesc *e) {
 ** and removing the 'not'.
 */
 static int jumponcond (FuncState *fs, expdesc *e, int cond) {
-  if (e->k == VRELOCABLE) {
+  if (e->k == VRELOC) {
     Instruction ie = getinstruction(fs, e);
     if (GET_OPCODE(ie) == OP_NOT) {
-      fs->pc--;  /* remove previous OP_NOT */
-      return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
+      removelastinstruction(fs);  /* remove previous OP_NOT */
+      return condjump(fs, OP_TEST, GETARG_B(ie), 0, 0, !cond);
     }
     /* else go through */
   }
   discharge2anyreg(fs, e);
   freeexp(fs, e);
-  return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond);
+  return condjump(fs, OP_TESTSET, NO_REG, e->u.info, 0, cond);
 }
 
 
@@ -863,7 +1122,7 @@ void luaK_goiftrue (FuncState *fs, expdesc *e) {
       pc = e->u.info;  /* save jump position */
       break;
     }
-    case VK: case VKFLT: case VKINT: case VTRUE: {
+    case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: {
       pc = NO_JUMP;  /* always true; do nothing */
       break;
     }
@@ -908,13 +1167,12 @@ void luaK_goiffalse (FuncState *fs, expdesc *e) {
 ** Code 'not e', doing constant folding.
 */
 static void codenot (FuncState *fs, expdesc *e) {
-  luaK_dischargevars(fs, e);
   switch (e->k) {
     case VNIL: case VFALSE: {
       e->k = VTRUE;  /* true == not nil == not false */
       break;
     }
-    case VK: case VKFLT: case VKINT: case VTRUE: {
+    case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: {
       e->k = VFALSE;  /* false == not "x" == not 0.5 == not 1 == not true */
       break;
     }
@@ -922,12 +1180,12 @@ static void codenot (FuncState *fs, expdesc *e) {
       negatecondition(fs, e);
       break;
     }
-    case VRELOCABLE:
+    case VRELOC:
     case VNONRELOC: {
       discharge2anyreg(fs, e);
       freeexp(fs, e);
       e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0);
-      e->k = VRELOCABLE;
+      e->k = VRELOC;
       break;
     }
     default: lua_assert(0);  /* cannot happen */
@@ -939,16 +1197,95 @@ static void codenot (FuncState *fs, expdesc *e) {
 }
 
 
+/*
+** Check whether expression 'e' is a small literal string
+*/
+static int isKstr (FuncState *fs, expdesc *e) {
+  return (e->k == VK && !hasjumps(e) && e->u.info <= MAXARG_B &&
+          ttisshrstring(&fs->f->k[e->u.info]));
+}
+
+/*
+** Check whether expression 'e' is a literal integer.
+*/
+int luaK_isKint (expdesc *e) {
+  return (e->k == VKINT && !hasjumps(e));
+}
+
+
+/*
+** Check whether expression 'e' is a literal integer in
+** proper range to fit in register C
+*/
+static int isCint (expdesc *e) {
+  return luaK_isKint(e) && (l_castS2U(e->u.ival) <= l_castS2U(MAXARG_C));
+}
+
+
+/*
+** Check whether expression 'e' is a literal integer in
+** proper range to fit in register sC
+*/
+static int isSCint (expdesc *e) {
+  return luaK_isKint(e) && fitsC(e->u.ival);
+}
+
+
+/*
+** Check whether expression 'e' is a literal integer or float in
+** proper range to fit in a register (sB or sC).
+*/
+static int isSCnumber (expdesc *e, int *pi, int *isfloat) {
+  lua_Integer i;
+  if (e->k == VKINT)
+    i = e->u.ival;
+  else if (e->k == VKFLT && luaV_flttointeger(e->u.nval, &i, F2Ieq))
+    *isfloat = 1;
+  else
+    return 0;  /* not a number */
+  if (!hasjumps(e) && fitsC(i)) {
+    *pi = int2sC(cast_int(i));
+    return 1;
+  }
+  else
+    return 0;
+}
+
+
 /*
 ** Create expression 't[k]'. 't' must have its final result already in a
-** register or upvalue.
+** register or upvalue. Upvalues can only be indexed by literal strings.
+** Keys can be literal strings in the constant table or arbitrary
+** values in registers.
 */
 void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
-  lua_assert(!hasjumps(t) && (vkisinreg(t->k) || t->k == VUPVAL));
-  t->u.ind.t = t->u.info;  /* register or upvalue index */
-  t->u.ind.idx = luaK_exp2RK(fs, k);  /* R/K index for key */
-  t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL : VLOCAL;
-  t->k = VINDEXED;
+  if (k->k == VKSTR)
+    str2K(fs, k);
+  lua_assert(!hasjumps(t) &&
+             (t->k == VLOCAL || t->k == VNONRELOC || t->k == VUPVAL));
+  if (t->k == VUPVAL && !isKstr(fs, k))  /* upvalue indexed by non 'Kstr'? */
+    luaK_exp2anyreg(fs, t);  /* put it in a register */
+  if (t->k == VUPVAL) {
+    t->u.ind.t = t->u.info;  /* upvalue index */
+    t->u.ind.idx = k->u.info;  /* literal string */
+    t->k = VINDEXUP;
+  }
+  else {
+    /* register index of the table */
+    t->u.ind.t = (t->k == VLOCAL) ? t->u.var.sidx: t->u.info;
+    if (isKstr(fs, k)) {
+      t->u.ind.idx = k->u.info;  /* literal string */
+      t->k = VINDEXSTR;
+    }
+    else if (isCint(k)) {
+      t->u.ind.idx = cast_int(k->u.ival);  /* int. constant in proper range */
+      t->k = VINDEXI;
+    }
+    else {
+      t->u.ind.idx = luaK_exp2anyreg(fs, k);  /* register */
+      t->k = VINDEXED;
+    }
+  }
 }
 
 
@@ -962,7 +1299,7 @@ static int validop (int op, TValue *v1, TValue *v2) {
     case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
     case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: {  /* conversion errors */
       lua_Integer i;
-      return (tointeger(v1, &i) && tointeger(v2, &i));
+      return (tointegerns(v1, &i) && tointegerns(v2, &i));
     }
     case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD:  /* division by 0 */
       return (nvalue(v2) != 0);
@@ -976,11 +1313,11 @@ static int validop (int op, TValue *v1, TValue *v2) {
 ** (In this case, 'e1' has the final result.)
 */
 static int constfolding (FuncState *fs, int op, expdesc *e1,
-                                                const expdesc *e2) {
+                                        const expdesc *e2) {
   TValue v1, v2, res;
   if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2))
     return 0;  /* non-numeric operands or not safe to fold */
-  luaO_arith(fs->ls->L, op, &v1, &v2, &res);  /* does operation */
+  luaO_rawarith(fs->ls->L, op, &v1, &v2, &res);  /* does operation */
   if (ttisinteger(&res)) {
     e1->k = VKINT;
     e1->u.ival = ivalue(&res);
@@ -1005,7 +1342,7 @@ static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) {
   int r = luaK_exp2anyreg(fs, e);  /* opcodes operate only on registers */
   freeexp(fs, e);
   e->u.info = luaK_codeABC(fs, op, 0, r, 0);  /* generate opcode */
-  e->k = VRELOCABLE;  /* all those operations are relocatable */
+  e->k = VRELOC;  /* all those operations are relocatable */
   luaK_fixline(fs, line);
 }
 
@@ -1015,61 +1352,212 @@ static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) {
 ** (everything but logical operators 'and'/'or' and comparison
 ** operators).
 ** Expression to produce final result will be encoded in 'e1'.
-** Because 'luaK_exp2RK' can free registers, its calls must be
-** in "stack order" (that is, first on 'e2', which may have more
-** recent registers to be released).
 */
-static void codebinexpval (FuncState *fs, OpCode op,
-                           expdesc *e1, expdesc *e2, int line) {
-  int rk2 = luaK_exp2RK(fs, e2);  /* both operands are "RK" */
-  int rk1 = luaK_exp2RK(fs, e1);
+static void finishbinexpval (FuncState *fs, expdesc *e1, expdesc *e2,
+                             OpCode op, int v2, int flip, int line,
+                             OpCode mmop, TMS event) {
+  int v1 = luaK_exp2anyreg(fs, e1);
+  int pc = luaK_codeABCk(fs, op, 0, v1, v2, 0);
   freeexps(fs, e1, e2);
-  e1->u.info = luaK_codeABC(fs, op, 0, rk1, rk2);  /* generate opcode */
-  e1->k = VRELOCABLE;  /* all those operations are relocatable */
+  e1->u.info = pc;
+  e1->k = VRELOC;  /* all those operations are relocatable */
+  luaK_fixline(fs, line);
+  luaK_codeABCk(fs, mmop, v1, v2, event, flip);  /* to call metamethod */
   luaK_fixline(fs, line);
 }
 
 
 /*
-** Emit code for comparisons.
-** 'e1' was already put in R/K form by 'luaK_infix'.
+** Emit code for binary expressions that "produce values" over
+** two registers.
 */
-static void codecomp (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
-  int rk1 = (e1->k == VK) ? RKASK(e1->u.info)
-                          : check_exp(e1->k == VNONRELOC, e1->u.info);
-  int rk2 = luaK_exp2RK(fs, e2);
-  freeexps(fs, e1, e2);
-  switch (opr) {
-    case OPR_NE: {  /* '(a ~= b)' ==> 'not (a == b)' */
-      e1->u.info = condjump(fs, OP_EQ, 0, rk1, rk2);
-      break;
-    }
-    case OPR_GT: case OPR_GE: {
-      /* '(a > b)' ==> '(b < a)';  '(a >= b)' ==> '(b <= a)' */
-      OpCode op = cast(OpCode, (opr - OPR_NE) + OP_EQ);
-      e1->u.info = condjump(fs, op, 1, rk2, rk1);  /* invert operands */
-      break;
-    }
-    default: {  /* '==', '<', '<=' use their own opcodes */
-      OpCode op = cast(OpCode, (opr - OPR_EQ) + OP_EQ);
-      e1->u.info = condjump(fs, op, 1, rk1, rk2);
-      break;
+static void codebinexpval (FuncState *fs, OpCode op,
+                           expdesc *e1, expdesc *e2, int line) {
+  int v2 = luaK_exp2anyreg(fs, e2);  /* both operands are in registers */
+  lua_assert(OP_ADD <= op && op <= OP_SHR);
+  finishbinexpval(fs, e1, e2, op, v2, 0, line, OP_MMBIN,
+                  cast(TMS, (op - OP_ADD) + TM_ADD));
+}
+
+
+/*
+** Code binary operators with immediate operands.
+*/
+static void codebini (FuncState *fs, OpCode op,
+                       expdesc *e1, expdesc *e2, int flip, int line,
+                       TMS event) {
+  int v2 = int2sC(cast_int(e2->u.ival));  /* immediate operand */
+  lua_assert(e2->k == VKINT);
+  finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINI, event);
+}
+
+
+/* Try to code a binary operator negating its second operand.
+** For the metamethod, 2nd operand must keep its original value.
+*/
+static int finishbinexpneg (FuncState *fs, expdesc *e1, expdesc *e2,
+                             OpCode op, int line, TMS event) {
+  if (!luaK_isKint(e2))
+    return 0;  /* not an integer constant */
+  else {
+    lua_Integer i2 = e2->u.ival;
+    if (!(fitsC(i2) && fitsC(-i2)))
+      return 0;  /* not in the proper range */
+    else {  /* operating a small integer constant */
+      int v2 = cast_int(i2);
+      finishbinexpval(fs, e1, e2, op, int2sC(-v2), 0, line, OP_MMBINI, event);
+      /* correct metamethod argument */
+      SETARG_B(fs->f->code[fs->pc - 1], int2sC(v2));
+      return 1;  /* successfully coded */
     }
   }
+}
+
+
+static void swapexps (expdesc *e1, expdesc *e2) {
+  expdesc temp = *e1; *e1 = *e2; *e2 = temp;  /* swap 'e1' and 'e2' */
+}
+
+
+/*
+** Code arithmetic operators ('+', '-', ...). If second operand is a
+** constant in the proper range, use variant opcodes with K operands.
+*/
+static void codearith (FuncState *fs, BinOpr opr,
+                       expdesc *e1, expdesc *e2, int flip, int line) {
+  TMS event = cast(TMS, opr + TM_ADD);
+  if (tonumeral(e2, NULL) && luaK_exp2K(fs, e2)) {  /* K operand? */
+    int v2 = e2->u.info;  /* K index */
+    OpCode op = cast(OpCode, opr + OP_ADDK);
+    finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINK, event);
+  }
+  else {  /* 'e2' is neither an immediate nor a K operand */
+    OpCode op = cast(OpCode, opr + OP_ADD);
+    if (flip)
+      swapexps(e1, e2);  /* back to original order */
+    codebinexpval(fs, op, e1, e2, line);  /* use standard operators */
+  }
+}
+
+
+/*
+** Code commutative operators ('+', '*'). If first operand is a
+** numeric constant, change order of operands to try to use an
+** immediate or K operator.
+*/
+static void codecommutative (FuncState *fs, BinOpr op,
+                             expdesc *e1, expdesc *e2, int line) {
+  int flip = 0;
+  if (tonumeral(e1, NULL)) {  /* is first operand a numeric constant? */
+    swapexps(e1, e2);  /* change order */
+    flip = 1;
+  }
+  if (op == OPR_ADD && isSCint(e2))  /* immediate operand? */
+    codebini(fs, cast(OpCode, OP_ADDI), e1, e2, flip, line, TM_ADD);
+  else
+    codearith(fs, op, e1, e2, flip, line);
+}
+
+
+/*
+** Code bitwise operations; they are all associative, so the function
+** tries to put an integer constant as the 2nd operand (a K operand).
+*/
+static void codebitwise (FuncState *fs, BinOpr opr,
+                         expdesc *e1, expdesc *e2, int line) {
+  int flip = 0;
+  int v2;
+  OpCode op;
+  if (e1->k == VKINT && luaK_exp2RK(fs, e1)) {
+    swapexps(e1, e2);  /* 'e2' will be the constant operand */
+    flip = 1;
+  }
+  else if (!(e2->k == VKINT && luaK_exp2RK(fs, e2))) {  /* no constants? */
+    op = cast(OpCode, opr + OP_ADD);
+    codebinexpval(fs, op, e1, e2, line);  /* all-register opcodes */
+    return;
+  }
+  v2 = e2->u.info;  /* index in K array */
+  op = cast(OpCode, opr + OP_ADDK);
+  lua_assert(ttisinteger(&fs->f->k[v2]));
+  finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINK,
+                  cast(TMS, opr + TM_ADD));
+}
+
+
+/*
+** Emit code for order comparisons. When using an immediate operand,
+** 'isfloat' tells whether the original value was a float.
+*/
+static void codeorder (FuncState *fs, OpCode op, expdesc *e1, expdesc *e2) {
+  int r1, r2;
+  int im;
+  int isfloat = 0;
+  if (isSCnumber(e2, &im, &isfloat)) {
+    /* use immediate operand */
+    r1 = luaK_exp2anyreg(fs, e1);
+    r2 = im;
+    op = cast(OpCode, (op - OP_LT) + OP_LTI);
+  }
+  else if (isSCnumber(e1, &im, &isfloat)) {
+    /* transform (A < B) to (B > A) and (A <= B) to (B >= A) */
+    r1 = luaK_exp2anyreg(fs, e2);
+    r2 = im;
+    op = (op == OP_LT) ? OP_GTI : OP_GEI;
+  }
+  else {  /* regular case, compare two registers */
+    r1 = luaK_exp2anyreg(fs, e1);
+    r2 = luaK_exp2anyreg(fs, e2);
+  }
+  freeexps(fs, e1, e2);
+  e1->u.info = condjump(fs, op, r1, r2, isfloat, 1);
   e1->k = VJMP;
 }
 
 
 /*
-** Aplly prefix operation 'op' to expression 'e'.
+** Emit code for equality comparisons ('==', '~=').
+** 'e1' was already put as RK by 'luaK_infix'.
+*/
+static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
+  int r1, r2;
+  int im;
+  int isfloat = 0;  /* not needed here, but kept for symmetry */
+  OpCode op;
+  if (e1->k != VNONRELOC) {
+    lua_assert(e1->k == VK || e1->k == VKINT || e1->k == VKFLT);
+    swapexps(e1, e2);
+  }
+  r1 = luaK_exp2anyreg(fs, e1);  /* 1st expression must be in register */
+  if (isSCnumber(e2, &im, &isfloat)) {
+    op = OP_EQI;
+    r2 = im;  /* immediate operand */
+  }
+  else if (luaK_exp2RK(fs, e2)) {  /* 1st expression is constant? */
+    op = OP_EQK;
+    r2 = e2->u.info;  /* constant index */
+  }
+  else {
+    op = OP_EQ;  /* will compare two registers */
+    r2 = luaK_exp2anyreg(fs, e2);
+  }
+  freeexps(fs, e1, e2);
+  e1->u.info = condjump(fs, op, r1, r2, isfloat, (opr == OPR_EQ));
+  e1->k = VJMP;
+}
+
+
+/*
+** Apply prefix operation 'op' to expression 'e'.
 */
 void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {
   static const expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP};
+  luaK_dischargevars(fs, e);
   switch (op) {
     case OPR_MINUS: case OPR_BNOT:  /* use 'ef' as fake 2nd operand */
       if (constfolding(fs, op + LUA_OPUNM, e, &ef))
         break;
-      /* FALLTHROUGH */
+      /* else */ /* FALLTHROUGH */
     case OPR_LEN:
       codeunexpval(fs, cast(OpCode, op + OP_UNM), e, line);
       break;
@@ -1084,6 +1572,7 @@ void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {
 ** 2nd operand.
 */
 void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
+  luaK_dischargevars(fs, v);
   switch (op) {
     case OPR_AND: {
       luaK_goiftrue(fs, v);  /* go ahead only if 'v' is true */
@@ -1094,7 +1583,7 @@ void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
       break;
     }
     case OPR_CONCAT: {
-      luaK_exp2nextreg(fs, v);  /* operand must be on the 'stack' */
+      luaK_exp2nextreg(fs, v);  /* operand must be on the stack */
       break;
     }
     case OPR_ADD: case OPR_SUB:
@@ -1103,67 +1592,126 @@ void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
     case OPR_BAND: case OPR_BOR: case OPR_BXOR:
     case OPR_SHL: case OPR_SHR: {
       if (!tonumeral(v, NULL))
-        luaK_exp2RK(fs, v);
+        luaK_exp2anyreg(fs, v);
       /* else keep numeral, which may be folded with 2nd operand */
       break;
     }
-    default: {
-      luaK_exp2RK(fs, v);
+    case OPR_EQ: case OPR_NE: {
+      if (!tonumeral(v, NULL))
+        luaK_exp2RK(fs, v);
+      /* else keep numeral, which may be an immediate operand */
+      break;
+    }
+    case OPR_LT: case OPR_LE:
+    case OPR_GT: case OPR_GE: {
+      int dummy, dummy2;
+      if (!isSCnumber(v, &dummy, &dummy2))
+        luaK_exp2anyreg(fs, v);
+      /* else keep numeral, which may be an immediate operand */
       break;
     }
+    default: lua_assert(0);
+  }
+}
+
+/*
+** Create code for '(e1 .. e2)'.
+** For '(e1 .. e2.1 .. e2.2)' (which is '(e1 .. (e2.1 .. e2.2))',
+** because concatenation is right associative), merge both CONCATs.
+*/
+static void codeconcat (FuncState *fs, expdesc *e1, expdesc *e2, int line) {
+  Instruction *ie2 = previousinstruction(fs);
+  if (GET_OPCODE(*ie2) == OP_CONCAT) {  /* is 'e2' a concatenation? */
+    int n = GETARG_B(*ie2);  /* # of elements concatenated in 'e2' */
+    lua_assert(e1->u.info + 1 == GETARG_A(*ie2));
+    freeexp(fs, e2);
+    SETARG_A(*ie2, e1->u.info);  /* correct first element ('e1') */
+    SETARG_B(*ie2, n + 1);  /* will concatenate one more element */
+  }
+  else {  /* 'e2' is not a concatenation */
+    luaK_codeABC(fs, OP_CONCAT, e1->u.info, 2, 0);  /* new concat opcode */
+    freeexp(fs, e2);
+    luaK_fixline(fs, line);
   }
 }
 
 
 /*
 ** Finalize code for binary operation, after reading 2nd operand.
-** For '(a .. b .. c)' (which is '(a .. (b .. c))', because
-** concatenation is right associative), merge second CONCAT into first
-** one.
 */
-void luaK_posfix (FuncState *fs, BinOpr op,
+void luaK_posfix (FuncState *fs, BinOpr opr,
                   expdesc *e1, expdesc *e2, int line) {
-  switch (op) {
+  luaK_dischargevars(fs, e2);
+  if (foldbinop(opr) && constfolding(fs, opr + LUA_OPADD, e1, e2))
+    return;  /* done by folding */
+  switch (opr) {
     case OPR_AND: {
-      lua_assert(e1->t == NO_JUMP);  /* list closed by 'luK_infix' */
-      luaK_dischargevars(fs, e2);
+      lua_assert(e1->t == NO_JUMP);  /* list closed by 'luaK_infix' */
       luaK_concat(fs, &e2->f, e1->f);
       *e1 = *e2;
       break;
     }
     case OPR_OR: {
-      lua_assert(e1->f == NO_JUMP);  /* list closed by 'luK_infix' */
-      luaK_dischargevars(fs, e2);
+      lua_assert(e1->f == NO_JUMP);  /* list closed by 'luaK_infix' */
       luaK_concat(fs, &e2->t, e1->t);
       *e1 = *e2;
       break;
     }
-    case OPR_CONCAT: {
-      luaK_exp2val(fs, e2);
-      if (e2->k == VRELOCABLE &&
-          GET_OPCODE(getinstruction(fs, e2)) == OP_CONCAT) {
-        lua_assert(e1->u.info == GETARG_B(getinstruction(fs, e2))-1);
-        freeexp(fs, e1);
-        SETARG_B(getinstruction(fs, e2), e1->u.info);
-        e1->k = VRELOCABLE; e1->u.info = e2->u.info;
+    case OPR_CONCAT: {  /* e1 .. e2 */
+      luaK_exp2nextreg(fs, e2);
+      codeconcat(fs, e1, e2, line);
+      break;
+    }
+    case OPR_ADD: case OPR_MUL: {
+      codecommutative(fs, opr, e1, e2, line);
+      break;
+    }
+    case OPR_SUB: {
+      if (finishbinexpneg(fs, e1, e2, OP_ADDI, line, TM_SUB))
+        break; /* coded as (r1 + -I) */
+      /* ELSE */
+    }  /* FALLTHROUGH */
+    case OPR_DIV: case OPR_IDIV: case OPR_MOD: case OPR_POW: {
+      codearith(fs, opr, e1, e2, 0, line);
+      break;
+    }
+    case OPR_BAND: case OPR_BOR: case OPR_BXOR: {
+      codebitwise(fs, opr, e1, e2, line);
+      break;
+    }
+    case OPR_SHL: {
+      if (isSCint(e1)) {
+        swapexps(e1, e2);
+        codebini(fs, OP_SHLI, e1, e2, 1, line, TM_SHL);  /* I << r2 */
       }
-      else {
-        luaK_exp2nextreg(fs, e2);  /* operand must be on the 'stack' */
-        codebinexpval(fs, OP_CONCAT, e1, e2, line);
+      else if (finishbinexpneg(fs, e1, e2, OP_SHRI, line, TM_SHL)) {
+        /* coded as (r1 >> -I) */;
       }
+      else  /* regular case (two registers) */
+       codebinexpval(fs, OP_SHL, e1, e2, line);
       break;
     }
-    case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
-    case OPR_IDIV: case OPR_MOD: case OPR_POW:
-    case OPR_BAND: case OPR_BOR: case OPR_BXOR:
-    case OPR_SHL: case OPR_SHR: {
-      if (!constfolding(fs, op + LUA_OPADD, e1, e2))
-        codebinexpval(fs, cast(OpCode, op + OP_ADD), e1, e2, line);
+    case OPR_SHR: {
+      if (isSCint(e2))
+        codebini(fs, OP_SHRI, e1, e2, 0, line, TM_SHR);  /* r1 >> I */
+      else  /* regular case (two registers) */
+        codebinexpval(fs, OP_SHR, e1, e2, line);
       break;
     }
-    case OPR_EQ: case OPR_LT: case OPR_LE:
-    case OPR_NE: case OPR_GT: case OPR_GE: {
-      codecomp(fs, op, e1, e2);
+    case OPR_EQ: case OPR_NE: {
+      codeeq(fs, opr, e1, e2);
+      break;
+    }
+    case OPR_LT: case OPR_LE: {
+      OpCode op = cast(OpCode, (opr - OPR_EQ) + OP_EQ);
+      codeorder(fs, op, e1, e2);
+      break;
+    }
+    case OPR_GT: case OPR_GE: {
+      /* '(a > b)' <=> '(b < a)';  '(a >= b)' <=> '(b <= a)' */
+      OpCode op = cast(OpCode, (opr - OPR_NE) + OP_EQ);
+      swapexps(e1, e2);
+      codeorder(fs, op, e1, e2);
       break;
     }
     default: lua_assert(0);
@@ -1172,10 +1720,23 @@ void luaK_posfix (FuncState *fs, BinOpr op,
 
 
 /*
-** Change line information associated with current position.
+** Change line information associated with current position, by removing
+** previous info and adding it again with new line.
 */
 void luaK_fixline (FuncState *fs, int line) {
-  fs->f->lineinfo[fs->pc - 1] = line;
+  removelastlineinfo(fs);
+  savelineinfo(fs, fs->f, line);
+}
+
+
+void luaK_settablesize (FuncState *fs, int pc, int ra, int asize, int hsize) {
+  Instruction *inst = &fs->f->code[pc];
+  int rb = (hsize != 0) ? luaO_ceillog2(hsize) + 1 : 0;  /* hash size */
+  int extra = asize / (MAXARG_C + 1);  /* higher bits of array size */
+  int rc = asize % (MAXARG_C + 1);  /* lower bits of array size */
+  int k = (extra > 0);  /* true iff needs extra argument */
+  *inst = CREATE_ABCk(OP_NEWTABLE, ra, rb, rc, k);
+  *(inst + 1) = CREATE_Ax(OP_EXTRAARG, extra);
 }
 
 
@@ -1187,17 +1748,67 @@ void luaK_fixline (FuncState *fs, int line) {
 ** table (or LUA_MULTRET to add up to stack top).
 */
 void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
-  int c =  (nelems - 1)/LFIELDS_PER_FLUSH + 1;
-  int b = (tostore == LUA_MULTRET) ? 0 : tostore;
   lua_assert(tostore != 0 && tostore <= LFIELDS_PER_FLUSH);
-  if (c <= MAXARG_C)
-    luaK_codeABC(fs, OP_SETLIST, base, b, c);
-  else if (c <= MAXARG_Ax) {
-    luaK_codeABC(fs, OP_SETLIST, base, b, 0);
-    codeextraarg(fs, c);
+  if (tostore == LUA_MULTRET)
+    tostore = 0;
+  if (nelems <= MAXARG_C)
+    luaK_codeABC(fs, OP_SETLIST, base, tostore, nelems);
+  else {
+    int extra = nelems / (MAXARG_C + 1);
+    nelems %= (MAXARG_C + 1);
+    luaK_codeABCk(fs, OP_SETLIST, base, tostore, nelems, 1);
+    codeextraarg(fs, extra);
   }
-  else
-    luaX_syntaxerror(fs->ls, "constructor too long");
   fs->freereg = base + 1;  /* free registers with list values */
 }
 
+
+/*
+** return the final target of a jump (skipping jumps to jumps)
+*/
+static int finaltarget (Instruction *code, int i) {
+  int count;
+  for (count = 0; count < 100; count++) {  /* avoid infinite loops */
+    Instruction pc = code[i];
+    if (GET_OPCODE(pc) != OP_JMP)
+      break;
+     else
+       i += GETARG_sJ(pc) + 1;
+  }
+  return i;
+}
+
+
+/*
+** Do a final pass over the code of a function, doing small peephole
+** optimizations and adjustments.
+*/
+void luaK_finish (FuncState *fs) {
+  int i;
+  Proto *p = fs->f;
+  for (i = 0; i < fs->pc; i++) {
+    Instruction *pc = &p->code[i];
+    lua_assert(i == 0 || isOT(*(pc - 1)) == isIT(*pc));
+    switch (GET_OPCODE(*pc)) {
+      case OP_RETURN0: case OP_RETURN1: {
+        if (!(fs->needclose || p->is_vararg))
+          break;  /* no extra work */
+        /* else use OP_RETURN to do the extra work */
+        SET_OPCODE(*pc, OP_RETURN);
+      }  /* FALLTHROUGH */
+      case OP_RETURN: case OP_TAILCALL: {
+        if (fs->needclose)
+          SETARG_k(*pc, 1);  /* signal that it needs to close */
+        if (p->is_vararg)
+          SETARG_C(*pc, p->numparams + 1);  /* signal that it is vararg */
+        break;
+      }
+      case OP_JMP: {
+        int target = finaltarget(p->code, i);
+        fixjump(fs, i, target);
+        break;
+      }
+      default: break;
+    }
+  }
+}
diff --git a/libs/liblua/src/lcode.h b/libs/liblua/src/lcode.h
index 882dc9c156..3265824452 100644
--- a/libs/liblua/src/lcode.h
+++ b/libs/liblua/src/lcode.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.h,v 1.64.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lcode.h $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -24,40 +24,53 @@
 ** grep "ORDER OPR" if you change these enums  (ORDER OP)
 */
 typedef enum BinOpr {
+  /* arithmetic operators */
   OPR_ADD, OPR_SUB, OPR_MUL, OPR_MOD, OPR_POW,
-  OPR_DIV,
-  OPR_IDIV,
+  OPR_DIV, OPR_IDIV,
+  /* bitwise operators */
   OPR_BAND, OPR_BOR, OPR_BXOR,
   OPR_SHL, OPR_SHR,
+  /* string operator */
   OPR_CONCAT,
+  /* comparison operators */
   OPR_EQ, OPR_LT, OPR_LE,
   OPR_NE, OPR_GT, OPR_GE,
+  /* logical operators */
   OPR_AND, OPR_OR,
   OPR_NOBINOPR
 } BinOpr;
 
 
+/* true if operation is foldable (that is, it is arithmetic or bitwise) */
+#define foldbinop(op)	((op) <= OPR_SHR)
+
+
+#define luaK_codeABC(fs,o,a,b,c)	luaK_codeABCk(fs,o,a,b,c,0)
+
+
 typedef enum UnOpr { OPR_MINUS, OPR_BNOT, OPR_NOT, OPR_LEN, OPR_NOUNOPR } UnOpr;
 
 
 /* get (pointer to) instruction of given 'expdesc' */
 #define getinstruction(fs,e)	((fs)->f->code[(e)->u.info])
 
-#define luaK_codeAsBx(fs,o,A,sBx)	luaK_codeABx(fs,o,A,(sBx)+MAXARG_sBx)
 
 #define luaK_setmultret(fs,e)	luaK_setreturns(fs, e, LUA_MULTRET)
 
 #define luaK_jumpto(fs,t)	luaK_patchlist(fs, luaK_jump(fs), t)
 
+LUAI_FUNC int luaK_code (FuncState *fs, Instruction i);
 LUAI_FUNC int luaK_codeABx (FuncState *fs, OpCode o, int A, unsigned int Bx);
-LUAI_FUNC int luaK_codeABC (FuncState *fs, OpCode o, int A, int B, int C);
-LUAI_FUNC int luaK_codek (FuncState *fs, int reg, int k);
+LUAI_FUNC int luaK_codeAsBx (FuncState *fs, OpCode o, int A, int Bx);
+LUAI_FUNC int luaK_codeABCk (FuncState *fs, OpCode o, int A,
+                                            int B, int C, int k);
+LUAI_FUNC int luaK_isKint (expdesc *e);
+LUAI_FUNC int luaK_exp2const (FuncState *fs, const expdesc *e, TValue *v);
 LUAI_FUNC void luaK_fixline (FuncState *fs, int line);
 LUAI_FUNC void luaK_nil (FuncState *fs, int from, int n);
 LUAI_FUNC void luaK_reserveregs (FuncState *fs, int n);
 LUAI_FUNC void luaK_checkstack (FuncState *fs, int n);
-LUAI_FUNC int luaK_stringK (FuncState *fs, TString *s);
-LUAI_FUNC int luaK_intK (FuncState *fs, lua_Integer n);
+LUAI_FUNC void luaK_int (FuncState *fs, int reg, lua_Integer n);
 LUAI_FUNC void luaK_dischargevars (FuncState *fs, expdesc *e);
 LUAI_FUNC int luaK_exp2anyreg (FuncState *fs, expdesc *e);
 LUAI_FUNC void luaK_exp2anyregup (FuncState *fs, expdesc *e);
@@ -75,14 +88,17 @@ LUAI_FUNC int luaK_jump (FuncState *fs);
 LUAI_FUNC void luaK_ret (FuncState *fs, int first, int nret);
 LUAI_FUNC void luaK_patchlist (FuncState *fs, int list, int target);
 LUAI_FUNC void luaK_patchtohere (FuncState *fs, int list);
-LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level);
 LUAI_FUNC void luaK_concat (FuncState *fs, int *l1, int l2);
 LUAI_FUNC int luaK_getlabel (FuncState *fs);
 LUAI_FUNC void luaK_prefix (FuncState *fs, UnOpr op, expdesc *v, int line);
 LUAI_FUNC void luaK_infix (FuncState *fs, BinOpr op, expdesc *v);
 LUAI_FUNC void luaK_posfix (FuncState *fs, BinOpr op, expdesc *v1,
                             expdesc *v2, int line);
+LUAI_FUNC void luaK_settablesize (FuncState *fs, int pc,
+                                  int ra, int asize, int hsize);
 LUAI_FUNC void luaK_setlist (FuncState *fs, int base, int nelems, int tostore);
+LUAI_FUNC void luaK_finish (FuncState *fs);
+LUAI_FUNC l_noret luaK_semerror (LexState *ls, const char *msg);
 
 
 #endif
diff --git a/libs/liblua/src/lcorolib.c b/libs/liblua/src/lcorolib.c
index 0b17af9e34..7d6e585b1d 100644
--- a/libs/liblua/src/lcorolib.c
+++ b/libs/liblua/src/lcorolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcorolib.c,v 1.10.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lcorolib.c $
 ** Coroutine Library
 ** See Copyright Notice in lua.h
 */
@@ -20,25 +20,24 @@
 
 static lua_State *getco (lua_State *L) {
   lua_State *co = lua_tothread(L, 1);
-  luaL_argcheck(L, co, 1, "thread expected");
+  luaL_argexpected(L, co, 1, "thread");
   return co;
 }
 
 
+/*
+** Resumes a coroutine. Returns the number of results for non-error
+** cases or -1 for errors.
+*/
 static int auxresume (lua_State *L, lua_State *co, int narg) {
-  int status;
+  int status, nres;
   if (!lua_checkstack(co, narg)) {
     lua_pushliteral(L, "too many arguments to resume");
     return -1;  /* error flag */
   }
-  if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
-    lua_pushliteral(L, "cannot resume dead coroutine");
-    return -1;  /* error flag */
-  }
   lua_xmove(L, co, narg);
-  status = lua_resume(co, L, narg);
+  status = lua_resume(co, L, narg, &nres);
   if (status == LUA_OK || status == LUA_YIELD) {
-    int nres = lua_gettop(co);
     if (!lua_checkstack(L, nres + 1)) {
       lua_pop(co, nres);  /* remove results anyway */
       lua_pushliteral(L, "too many results to resume");
@@ -75,8 +74,11 @@ static int luaB_auxwrap (lua_State *L) {
   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
   int r = auxresume(L, co, lua_gettop(L));
   if (r < 0) {
+    int stat = lua_status(co);
+    if (stat != LUA_OK && stat != LUA_YIELD)
+      lua_resetthread(co);  /* close variables in case of errors */
     if (lua_type(L, -1) == LUA_TSTRING) {  /* error object is a string? */
-      luaL_where(L, 1);  /* add extra info */
+      luaL_where(L, 1);  /* add extra info, if available */
       lua_insert(L, -2);
       lua_concat(L, 2);
     }
@@ -108,35 +110,48 @@ static int luaB_yield (lua_State *L) {
 }
 
 
-static int luaB_costatus (lua_State *L) {
-  lua_State *co = getco(L);
-  if (L == co) lua_pushliteral(L, "running");
+#define COS_RUN		0
+#define COS_DEAD	1
+#define COS_YIELD	2
+#define COS_NORM	3
+
+
+static const char *const statname[] =
+  {"running", "dead", "suspended", "normal"};
+
+
+static int auxstatus (lua_State *L, lua_State *co) {
+  if (L == co) return COS_RUN;
   else {
     switch (lua_status(co)) {
       case LUA_YIELD:
-        lua_pushliteral(L, "suspended");
-        break;
+        return COS_YIELD;
       case LUA_OK: {
         lua_Debug ar;
-        if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
-          lua_pushliteral(L, "normal");  /* it is running */
+        if (lua_getstack(co, 0, &ar))  /* does it have frames? */
+          return COS_NORM;  /* it is running */
         else if (lua_gettop(co) == 0)
-            lua_pushliteral(L, "dead");
+            return COS_DEAD;
         else
-          lua_pushliteral(L, "suspended");  /* initial state */
-        break;
+          return COS_YIELD;  /* initial state */
       }
       default:  /* some error occurred */
-        lua_pushliteral(L, "dead");
-        break;
+        return COS_DEAD;
     }
   }
+}
+
+
+static int luaB_costatus (lua_State *L) {
+  lua_State *co = getco(L);
+  lua_pushstring(L, statname[auxstatus(L, co)]);
   return 1;
 }
 
 
 static int luaB_yieldable (lua_State *L) {
-  lua_pushboolean(L, lua_isyieldable(L));
+  lua_State *co = lua_isnone(L, 1) ? L : getco(L);
+  lua_pushboolean(L, lua_isyieldable(co));
   return 1;
 }
 
@@ -148,6 +163,28 @@ static int luaB_corunning (lua_State *L) {
 }
 
 
+static int luaB_close (lua_State *L) {
+  lua_State *co = getco(L);
+  int status = auxstatus(L, co);
+  switch (status) {
+    case COS_DEAD: case COS_YIELD: {
+      status = lua_resetthread(co);
+      if (status == LUA_OK) {
+        lua_pushboolean(L, 1);
+        return 1;
+      }
+      else {
+        lua_pushboolean(L, 0);
+        lua_xmove(co, L, 1);  /* copy error message */
+        return 2;
+      }
+    }
+    default:  /* normal or running coroutine */
+      return luaL_error(L, "cannot close a %s coroutine", statname[status]);
+  }
+}
+
+
 static const luaL_Reg co_funcs[] = {
   {"create", luaB_cocreate},
   {"resume", luaB_coresume},
@@ -156,6 +193,7 @@ static const luaL_Reg co_funcs[] = {
   {"wrap", luaB_cowrap},
   {"yield", luaB_yield},
   {"isyieldable", luaB_yieldable},
+  {"close", luaB_close},
   {NULL, NULL}
 };
 
diff --git a/libs/liblua/src/lctype.c b/libs/liblua/src/lctype.c
index f8ad7a2edf..9542280942 100644
--- a/libs/liblua/src/lctype.c
+++ b/libs/liblua/src/lctype.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lctype.c,v 1.12.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lctype.c $
 ** 'ctype' functions for Lua
 ** See Copyright Notice in lua.h
 */
@@ -16,6 +16,15 @@
 
 #include <limits.h>
 
+
+#if defined (LUA_UCID)		/* accept UniCode IDentifiers? */
+/* consider all non-ascii codepoints to be alphabetic */
+#define NONA		0x01
+#else
+#define NONA		0x00	/* default */
+#endif
+
+
 LUAI_DDEF const lu_byte luai_ctype_[UCHAR_MAX + 2] = {
   0x00,  /* EOZ */
   0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 0. */
@@ -34,22 +43,22 @@ LUAI_DDEF const lu_byte luai_ctype_[UCHAR_MAX + 2] = {
   0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,
   0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,  0x05,	/* 7. */
   0x05,  0x05,  0x05,  0x04,  0x04,  0x04,  0x04,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 8. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* 9. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* a. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* b. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* c. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* d. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* e. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,	/* f. */
-  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* 8. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* 9. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* a. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* b. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  0x00,  0x00,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* c. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* d. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,	/* e. */
+  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,  NONA,
+  NONA,  NONA,  NONA,  NONA,  NONA,  0x00,  0x00,  0x00,	/* f. */
+  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00,  0x00
 };
 
 #endif			/* } */
diff --git a/libs/liblua/src/lctype.h b/libs/liblua/src/lctype.h
index b09b21a337..cbff4d7e19 100644
--- a/libs/liblua/src/lctype.h
+++ b/libs/liblua/src/lctype.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lctype.h,v 1.12.1.1 2013/04/12 18:48:47 roberto Exp $
+** $Id: lctype.h $
 ** 'ctype' functions for Lua
 ** See Copyright Notice in lua.h
 */
@@ -68,7 +68,7 @@
 
 
 /* two more entries for 0 and -1 (EOZ) */
-LUAI_DDEC const lu_byte luai_ctype_[UCHAR_MAX + 2];
+LUAI_DDEC(const lu_byte luai_ctype_[UCHAR_MAX + 2];)
 
 
 #else			/* }{ */
diff --git a/libs/liblua/src/ldblib.c b/libs/liblua/src/ldblib.c
index 9d29afb0a8..59eb8f0ea7 100644
--- a/libs/liblua/src/ldblib.c
+++ b/libs/liblua/src/ldblib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldblib.c,v 1.151.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ldblib.c $
 ** Interface from Lua to its debug API
 ** See Copyright Notice in lua.h
 */
@@ -21,10 +21,10 @@
 
 
 /*
-** The hook table at registry[&HOOKKEY] maps threads to their current
-** hook function. (We only need the unique address of 'HOOKKEY'.)
+** The hook table at registry[HOOKKEY] maps threads to their current
+** hook function.
 */
-static const int HOOKKEY = 0;
+static const char *const HOOKKEY = "_HOOKKEY";
 
 
 /*
@@ -55,8 +55,7 @@ static int db_getmetatable (lua_State *L) {
 
 static int db_setmetatable (lua_State *L) {
   int t = lua_type(L, 2);
-  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
-                    "nil or table expected");
+  luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
   lua_settop(L, 2);
   lua_setmetatable(L, 1);
   return 1;  /* return 1st argument */
@@ -64,19 +63,24 @@ static int db_setmetatable (lua_State *L) {
 
 
 static int db_getuservalue (lua_State *L) {
+  int n = (int)luaL_optinteger(L, 2, 1);
   if (lua_type(L, 1) != LUA_TUSERDATA)
-    lua_pushnil(L);
-  else
-    lua_getuservalue(L, 1);
+    luaL_pushfail(L);
+  else if (lua_getiuservalue(L, 1, n) != LUA_TNONE) {
+    lua_pushboolean(L, 1);
+    return 2;
+  }
   return 1;
 }
 
 
 static int db_setuservalue (lua_State *L) {
+  int n = (int)luaL_optinteger(L, 3, 1);
   luaL_checktype(L, 1, LUA_TUSERDATA);
   luaL_checkany(L, 2);
   lua_settop(L, 2);
-  lua_setuservalue(L, 1);
+  if (!lua_setiuservalue(L, 1, n))
+    luaL_pushfail(L);
   return 1;
 }
 
@@ -146,7 +150,7 @@ static int db_getinfo (lua_State *L) {
   lua_Debug ar;
   int arg;
   lua_State *L1 = getthread(L, &arg);
-  const char *options = luaL_optstring(L, arg+2, "flnStu");
+  const char *options = luaL_optstring(L, arg+2, "flnSrtu");
   checkstack(L, L1, 3);
   if (lua_isfunction(L, arg + 1)) {  /* info about a function? */
     options = lua_pushfstring(L, ">%s", options);  /* add '>' to 'options' */
@@ -155,7 +159,7 @@ static int db_getinfo (lua_State *L) {
   }
   else {  /* stack level */
     if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) {
-      lua_pushnil(L);  /* level out of range */
+      luaL_pushfail(L);  /* level out of range */
       return 1;
     }
   }
@@ -163,7 +167,8 @@ static int db_getinfo (lua_State *L) {
     return luaL_argerror(L, arg+2, "invalid option");
   lua_newtable(L);  /* table to collect results */
   if (strchr(options, 'S')) {
-    settabss(L, "source", ar.source);
+    lua_pushlstring(L, ar.source, ar.srclen);
+    lua_setfield(L, -2, "source");
     settabss(L, "short_src", ar.short_src);
     settabsi(L, "linedefined", ar.linedefined);
     settabsi(L, "lastlinedefined", ar.lastlinedefined);
@@ -180,6 +185,10 @@ static int db_getinfo (lua_State *L) {
     settabss(L, "name", ar.name);
     settabss(L, "namewhat", ar.namewhat);
   }
+  if (strchr(options, 'r')) {
+    settabsi(L, "ftransfer", ar.ftransfer);
+    settabsi(L, "ntransfer", ar.ntransfer);
+  }
   if (strchr(options, 't'))
     settabsb(L, "istailcall", ar.istailcall);
   if (strchr(options, 'L'))
@@ -193,8 +202,6 @@ static int db_getinfo (lua_State *L) {
 static int db_getlocal (lua_State *L) {
   int arg;
   lua_State *L1 = getthread(L, &arg);
-  lua_Debug ar;
-  const char *name;
   int nvar = (int)luaL_checkinteger(L, arg + 2);  /* local-variable index */
   if (lua_isfunction(L, arg + 1)) {  /* function argument? */
     lua_pushvalue(L, arg + 1);  /* push function */
@@ -202,6 +209,8 @@ static int db_getlocal (lua_State *L) {
     return 1;  /* return only name (there is no value) */
   }
   else {  /* stack-level argument */
+    lua_Debug ar;
+    const char *name;
     int level = (int)luaL_checkinteger(L, arg + 1);
     if (!lua_getstack(L1, level, &ar))  /* out of range? */
       return luaL_argerror(L, arg+1, "level out of range");
@@ -214,7 +223,7 @@ static int db_getlocal (lua_State *L) {
       return 2;
     }
     else {
-      lua_pushnil(L);  /* no name (nor value) */
+      luaL_pushfail(L);  /* no name (nor value) */
       return 1;
     }
   }
@@ -305,7 +314,7 @@ static int db_upvaluejoin (lua_State *L) {
 static void hookf (lua_State *L, lua_Debug *ar) {
   static const char *const hooknames[] =
     {"call", "return", "line", "count", "tail call"};
-  lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
+  lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY);
   lua_pushthread(L);
   if (lua_rawget(L, -2) == LUA_TFUNCTION) {  /* is there a hook function? */
     lua_pushstring(L, hooknames[(int)ar->event]);  /* push event name */
@@ -358,14 +367,12 @@ static int db_sethook (lua_State *L) {
     count = (int)luaL_optinteger(L, arg + 3, 0);
     func = hookf; mask = makemask(smask, count);
   }
-  if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) {
-    lua_createtable(L, 0, 2);  /* create a hook table */
-    lua_pushvalue(L, -1);
-    lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY);  /* set it in position */
+  if (!luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)) {
+    /* table just created; initialize it */
     lua_pushstring(L, "k");
     lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */
     lua_pushvalue(L, -1);
-    lua_setmetatable(L, -2);  /* setmetatable(hooktable) = hooktable */
+    lua_setmetatable(L, -2);  /* metatable(hooktable) = hooktable */
   }
   checkstack(L, L1, 1);
   lua_pushthread(L1); lua_xmove(L1, L, 1);  /* key (thread) */
@@ -382,12 +389,14 @@ static int db_gethook (lua_State *L) {
   char buff[5];
   int mask = lua_gethookmask(L1);
   lua_Hook hook = lua_gethook(L1);
-  if (hook == NULL)  /* no hook? */
-    lua_pushnil(L);
+  if (hook == NULL) {  /* no hook? */
+    luaL_pushfail(L);
+    return 1;
+  }
   else if (hook != hookf)  /* external hook? */
     lua_pushliteral(L, "external hook");
   else {  /* hook table must exist */
-    lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
+    lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY);
     checkstack(L, L1, 1);
     lua_pushthread(L1); lua_xmove(L1, L, 1);
     lua_rawget(L, -2);   /* 1st result = hooktable[L1] */
@@ -408,7 +417,7 @@ static int db_debug (lua_State *L) {
       return 0;
     if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
         lua_pcall(L, 0, 0, 0))
-      lua_writestringerror("%s\n", lua_tostring(L, -1));
+      lua_writestringerror("%s\n", luaL_tolstring(L, -1, NULL));
     lua_settop(L, 0);  /* remove eventual returns */
   }
 }
@@ -428,6 +437,17 @@ static int db_traceback (lua_State *L) {
 }
 
 
+static int db_setcstacklimit (lua_State *L) {
+  int limit = (int)luaL_checkinteger(L, 1);
+  int res = lua_setcstacklimit(L, limit);
+  if (res == 0)
+    lua_pushboolean(L, 0);
+  else
+    lua_pushinteger(L, res);
+  return 1;
+}
+
+
 static const luaL_Reg dblib[] = {
   {"debug", db_debug},
   {"getuservalue", db_getuservalue},
@@ -445,6 +465,7 @@ static const luaL_Reg dblib[] = {
   {"setmetatable", db_setmetatable},
   {"setupvalue", db_setupvalue},
   {"traceback", db_traceback},
+  {"setcstacklimit", db_setcstacklimit},
   {NULL, NULL}
 };
 
diff --git a/libs/liblua/src/ldebug.c b/libs/liblua/src/ldebug.c
index e1389296e9..afdc2b74ab 100644
--- a/libs/liblua/src/ldebug.c
+++ b/libs/liblua/src/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.121.1.2 2017/07/10 17:21:50 roberto Exp $
+** $Id: ldebug.c $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -31,11 +31,11 @@
 
 
 
-#define noLuaClosure(f)		((f) == NULL || (f)->c.tt == LUA_TCCL)
+#define noLuaClosure(f)		((f) == NULL || (f)->c.tt == LUA_VCCL)
 
 
 /* Active Lua function (given call info) */
-#define ci_func(ci)		(clLvalue((ci)->func))
+#define ci_func(ci)		(clLvalue(s2v((ci)->func)))
 
 
 static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
@@ -48,29 +48,85 @@ static int currentpc (CallInfo *ci) {
 }
 
 
-static int currentline (CallInfo *ci) {
-  return getfuncline(ci_func(ci)->p, currentpc(ci));
+/*
+** Get a "base line" to find the line corresponding to an instruction.
+** For that, search the array of absolute line info for the largest saved
+** instruction smaller or equal to the wanted instruction. A special
+** case is when there is no absolute info or the instruction is before
+** the first absolute one.
+*/
+static int getbaseline (const Proto *f, int pc, int *basepc) {
+  if (f->sizeabslineinfo == 0 || pc < f->abslineinfo[0].pc) {
+    *basepc = -1;  /* start from the beginning */
+    return f->linedefined;
+  }
+  else {
+    unsigned int i;
+    if (pc >= f->abslineinfo[f->sizeabslineinfo - 1].pc)
+      i = f->sizeabslineinfo - 1;  /* instruction is after last saved one */
+    else {  /* binary search */
+      unsigned int j = f->sizeabslineinfo - 1;  /* pc < anchorlines[j] */
+      i = 0;  /* abslineinfo[i] <= pc */
+      while (i < j - 1) {
+        unsigned int m = (j + i) / 2;
+        if (pc >= f->abslineinfo[m].pc)
+          i = m;
+        else
+          j = m;
+      }
+    }
+    *basepc = f->abslineinfo[i].pc;
+    return f->abslineinfo[i].line;
+  }
 }
 
 
 /*
-** If function yielded, its 'func' can be in the 'extra' field. The
-** next function restores 'func' to its correct value for debugging
-** purposes. (It exchanges 'func' and 'extra'; so, when called again,
-** after debugging, it also "re-restores" ** 'func' to its altered value.
+** Get the line corresponding to instruction 'pc' in function 'f';
+** first gets a base line and from there does the increments until
+** the desired instruction.
 */
-static void swapextra (lua_State *L) {
-  if (L->status == LUA_YIELD) {
-    CallInfo *ci = L->ci;  /* get function that yielded */
-    StkId temp = ci->func;  /* exchange its 'func' and 'extra' values */
-    ci->func = restorestack(L, ci->extra);
-    ci->extra = savestack(L, temp);
+int luaG_getfuncline (const Proto *f, int pc) {
+  if (f->lineinfo == NULL)  /* no debug information? */
+    return -1;
+  else {
+    int basepc;
+    int baseline = getbaseline(f, pc, &basepc);
+    while (basepc++ < pc) {  /* walk until given instruction */
+      lua_assert(f->lineinfo[basepc] != ABSLINEINFO);
+      baseline += f->lineinfo[basepc];  /* correct line */
+    }
+    return baseline;
   }
 }
 
 
+static int getcurrentline (CallInfo *ci) {
+  return luaG_getfuncline(ci_func(ci)->p, currentpc(ci));
+}
+
+
 /*
-** This function can be called asynchronously (e.g. during a signal).
+** Set 'trap' for all active Lua frames.
+** This function can be called during a signal, under "reasonable"
+** assumptions. A new 'ci' is completely linked in the list before it
+** becomes part of the "active" list, and we assume that pointers are
+** atomic; see comment in next function.
+** (A compiler doing interprocedural optimizations could, theoretically,
+** reorder memory writes in such a way that the list could be
+** temporarily broken while inserting a new element. We simply assume it
+** has no good reasons to do that.)
+*/
+static void settraps (CallInfo *ci) {
+  for (; ci != NULL; ci = ci->previous)
+    if (isLua(ci))
+      ci->u.l.trap = 1;
+}
+
+
+/*
+** This function can be called during a signal, under "reasonable"
+** assumptions.
 ** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
 ** 'resethookcount') are for debug only, and it is no problem if they
 ** get arbitrary values (causes at most one wrong hook call). 'hookmask'
@@ -89,6 +145,8 @@ LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
   L->basehookcount = count;
   resethookcount(L);
   L->hookmask = cast_byte(mask);
+  if (mask)
+    settraps(L->ci);  /* to trace inside 'luaV_execute' */
 }
 
 
@@ -124,7 +182,7 @@ LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
 }
 
 
-static const char *upvalname (Proto *p, int uv) {
+static const char *upvalname (const Proto *p, int uv) {
   TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
   if (s == NULL) return "?";
   else return getstr(s);
@@ -132,38 +190,37 @@ static const char *upvalname (Proto *p, int uv) {
 
 
 static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
-  int nparams = clLvalue(ci->func)->p->numparams;
-  if (n >= cast_int(ci->u.l.base - ci->func) - nparams)
-    return NULL;  /* no such vararg */
-  else {
-    *pos = ci->func + nparams + n;
-    return "(*vararg)";  /* generic name for any vararg */
+  if (clLvalue(s2v(ci->func))->p->is_vararg) {
+    int nextra = ci->u.l.nextraargs;
+    if (n <= nextra) {
+      *pos = ci->func - nextra + (n - 1);
+      return "(vararg)";  /* generic name for any vararg */
+    }
   }
+  return NULL;  /* no such vararg */
 }
 
 
-static const char *findlocal (lua_State *L, CallInfo *ci, int n,
-                              StkId *pos) {
+const char *luaG_findlocal (lua_State *L, CallInfo *ci, int n, StkId *pos) {
+  StkId base = ci->func + 1;
   const char *name = NULL;
-  StkId base;
   if (isLua(ci)) {
     if (n < 0)  /* access to vararg values? */
       return findvararg(ci, -n, pos);
-    else {
-      base = ci->u.l.base;
+    else
       name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
-    }
   }
-  else
-    base = ci->func + 1;
   if (name == NULL) {  /* no 'standard' name? */
     StkId limit = (ci == L->ci) ? L->top : ci->next->func;
-    if (limit - base >= n && n > 0)  /* is 'n' inside 'ci' stack? */
-      name = "(*temporary)";  /* generic name for any valid slot */
+    if (limit - base >= n && n > 0) {  /* is 'n' inside 'ci' stack? */
+      /* generic name for any valid slot */
+      name = isLua(ci) ? "(temporary)" : "(C temporary)";
+    }
     else
       return NULL;  /* no name */
   }
-  *pos = base + (n - 1);
+  if (pos)
+    *pos = base + (n - 1);
   return name;
 }
 
@@ -171,22 +228,20 @@ static const char *findlocal (lua_State *L, CallInfo *ci, int n,
 LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
   const char *name;
   lua_lock(L);
-  swapextra(L);
   if (ar == NULL) {  /* information about non-active function? */
-    if (!isLfunction(L->top - 1))  /* not a Lua function? */
+    if (!isLfunction(s2v(L->top - 1)))  /* not a Lua function? */
       name = NULL;
     else  /* consider live variables at function start (parameters) */
-      name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
+      name = luaF_getlocalname(clLvalue(s2v(L->top - 1))->p, n, 0);
   }
   else {  /* active function; get information through 'ar' */
     StkId pos = NULL;  /* to avoid warnings */
-    name = findlocal(L, ar->i_ci, n, &pos);
+    name = luaG_findlocal(L, ar->i_ci, n, &pos);
     if (name) {
-      setobj2s(L, L->top, pos);
+      setobjs2s(L, L->top, pos);
       api_incr_top(L);
     }
   }
-  swapextra(L);
   lua_unlock(L);
   return name;
 }
@@ -196,13 +251,11 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
   StkId pos = NULL;  /* to avoid warnings */
   const char *name;
   lua_lock(L);
-  swapextra(L);
-  name = findlocal(L, ar->i_ci, n, &pos);
+  name = luaG_findlocal(L, ar->i_ci, n, &pos);
   if (name) {
     setobjs2s(L, pos, L->top - 1);
     L->top--;  /* pop value */
   }
-  swapextra(L);
   lua_unlock(L);
   return name;
 }
@@ -211,36 +264,55 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
 static void funcinfo (lua_Debug *ar, Closure *cl) {
   if (noLuaClosure(cl)) {
     ar->source = "=[C]";
+    ar->srclen = LL("=[C]");
     ar->linedefined = -1;
     ar->lastlinedefined = -1;
     ar->what = "C";
   }
   else {
-    Proto *p = cl->l.p;
-    ar->source = p->source ? getstr(p->source) : "=?";
+    const Proto *p = cl->l.p;
+    if (p->source) {
+      ar->source = getstr(p->source);
+      ar->srclen = tsslen(p->source);
+    }
+    else {
+      ar->source = "=?";
+      ar->srclen = LL("=?");
+    }
     ar->linedefined = p->linedefined;
     ar->lastlinedefined = p->lastlinedefined;
     ar->what = (ar->linedefined == 0) ? "main" : "Lua";
   }
-  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
+  luaO_chunkid(ar->short_src, ar->source, ar->srclen);
+}
+
+
+static int nextline (const Proto *p, int currentline, int pc) {
+  if (p->lineinfo[pc] != ABSLINEINFO)
+    return currentline + p->lineinfo[pc];
+  else
+    return luaG_getfuncline(p, pc);
 }
 
 
 static void collectvalidlines (lua_State *L, Closure *f) {
   if (noLuaClosure(f)) {
-    setnilvalue(L->top);
+    setnilvalue(s2v(L->top));
     api_incr_top(L);
   }
   else {
     int i;
     TValue v;
-    int *lineinfo = f->l.p->lineinfo;
+    const Proto *p = f->l.p;
+    int currentline = p->linedefined;
     Table *t = luaH_new(L);  /* new table to store active lines */
-    sethvalue(L, L->top, t);  /* push it on stack */
+    sethvalue2s(L, L->top, t);  /* push it on stack */
     api_incr_top(L);
-    setbvalue(&v, 1);  /* boolean 'true' to be the value of all indices */
-    for (i = 0; i < f->l.p->sizelineinfo; i++)  /* for all lines with code */
-      luaH_setint(L, t, lineinfo[i], &v);  /* table[line] = true */
+    setbtvalue(&v);  /* boolean 'true' to be the value of all indices */
+    for (i = 0; i < p->sizelineinfo; i++) {  /* for all lines with code */
+      currentline = nextline(p, currentline, i);
+      luaH_setint(L, t, currentline, &v);  /* table[line] = true */
+    }
   }
 }
 
@@ -269,7 +341,7 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
         break;
       }
       case 'l': {
-        ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
+        ar->currentline = (ci && isLua(ci)) ? getcurrentline(ci) : -1;
         break;
       }
       case 'u': {
@@ -296,6 +368,15 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
         }
         break;
       }
+      case 'r': {
+        if (ci == NULL || !(ci->callstatus & CIST_TRAN))
+          ar->ftransfer = ar->ntransfer = 0;
+        else {
+          ar->ftransfer = ci->u2.transferinfo.ftransfer;
+          ar->ntransfer = ci->u2.transferinfo.ntransfer;
+        }
+        break;
+      }
       case 'L':
       case 'f':  /* handled by lua_getinfo */
         break;
@@ -310,28 +391,26 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
   int status;
   Closure *cl;
   CallInfo *ci;
-  StkId func;
+  TValue *func;
   lua_lock(L);
-  swapextra(L);
   if (*what == '>') {
     ci = NULL;
-    func = L->top - 1;
+    func = s2v(L->top - 1);
     api_check(L, ttisfunction(func), "function expected");
     what++;  /* skip the '>' */
     L->top--;  /* pop function */
   }
   else {
     ci = ar->i_ci;
-    func = ci->func;
-    lua_assert(ttisfunction(ci->func));
+    func = s2v(ci->func);
+    lua_assert(ttisfunction(func));
   }
   cl = ttisclosure(func) ? clvalue(func) : NULL;
   status = auxgetinfo(L, what, ar, cl, ci);
   if (strchr(what, 'f')) {
-    setobjs2s(L, L->top, func);
+    setobj2s(L, L->top, func);
     api_incr_top(L);
   }
-  swapextra(L);  /* correct before option 'L', which can raise a mem. error */
   if (strchr(what, 'L'))
     collectvalidlines(L, cl);
   lua_unlock(L);
@@ -345,30 +424,38 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
 ** =======================================================
 */
 
-static const char *getobjname (Proto *p, int lastpc, int reg,
+static const char *getobjname (const Proto *p, int lastpc, int reg,
                                const char **name);
 
 
 /*
-** find a "name" for the RK value 'c'
+** Find a "name" for the constant 'c'.
 */
-static void kname (Proto *p, int pc, int c, const char **name) {
-  if (ISK(c)) {  /* is 'c' a constant? */
-    TValue *kvalue = &p->k[INDEXK(c)];
-    if (ttisstring(kvalue)) {  /* literal constant? */
-      *name = svalue(kvalue);  /* it is its own name */
-      return;
-    }
-    /* else no reasonable name found */
-  }
-  else {  /* 'c' is a register */
-    const char *what = getobjname(p, pc, c, name); /* search for 'c' */
-    if (what && *what == 'c') {  /* found a constant name? */
-      return;  /* 'name' already filled */
-    }
-    /* else no reasonable name found */
-  }
-  *name = "?";  /* no reasonable name found */
+static void kname (const Proto *p, int c, const char **name) {
+  TValue *kvalue = &p->k[c];
+  *name = (ttisstring(kvalue)) ? svalue(kvalue) : "?";
+}
+
+
+/*
+** Find a "name" for the register 'c'.
+*/
+static void rname (const Proto *p, int pc, int c, const char **name) {
+  const char *what = getobjname(p, pc, c, name); /* search for 'c' */
+  if (!(what && *what == 'c'))  /* did not find a constant name? */
+    *name = "?";
+}
+
+
+/*
+** Find a "name" for a 'C' value in an RK instruction.
+*/
+static void rkname (const Proto *p, int pc, Instruction i, const char **name) {
+  int c = GETARG_C(i);  /* key index */
+  if (GETARG_k(i))  /* is 'c' a constant? */
+    kname(p, c, name);
+  else  /* 'c' is a register */
+    rname(p, pc, c, name);
 }
 
 
@@ -380,55 +467,70 @@ static int filterpc (int pc, int jmptarget) {
 
 
 /*
-** try to find last instruction before 'lastpc' that modified register 'reg'
+** Try to find last instruction before 'lastpc' that modified register 'reg'.
 */
-static int findsetreg (Proto *p, int lastpc, int reg) {
+static int findsetreg (const Proto *p, int lastpc, int reg) {
   int pc;
   int setreg = -1;  /* keep last instruction that changed 'reg' */
   int jmptarget = 0;  /* any code before this address is conditional */
+  if (testMMMode(GET_OPCODE(p->code[lastpc])))
+    lastpc--;  /* previous instruction was not actually executed */
   for (pc = 0; pc < lastpc; pc++) {
     Instruction i = p->code[pc];
     OpCode op = GET_OPCODE(i);
     int a = GETARG_A(i);
+    int change;  /* true if current instruction changed 'reg' */
     switch (op) {
-      case OP_LOADNIL: {
+      case OP_LOADNIL: {  /* set registers from 'a' to 'a+b' */
         int b = GETARG_B(i);
-        if (a <= reg && reg <= a + b)  /* set registers from 'a' to 'a+b' */
-          setreg = filterpc(pc, jmptarget);
+        change = (a <= reg && reg <= a + b);
         break;
       }
-      case OP_TFORCALL: {
-        if (reg >= a + 2)  /* affect all regs above its base */
-          setreg = filterpc(pc, jmptarget);
+      case OP_TFORCALL: {  /* affect all regs above its base */
+        change = (reg >= a + 2);
         break;
       }
       case OP_CALL:
-      case OP_TAILCALL: {
-        if (reg >= a)  /* affect all registers above base */
-          setreg = filterpc(pc, jmptarget);
+      case OP_TAILCALL: {  /* affect all registers above base */
+        change = (reg >= a);
         break;
       }
-      case OP_JMP: {
-        int b = GETARG_sBx(i);
+      case OP_JMP: {  /* doesn't change registers, but changes 'jmptarget' */
+        int b = GETARG_sJ(i);
         int dest = pc + 1 + b;
-        /* jump is forward and do not skip 'lastpc'? */
-        if (pc < dest && dest <= lastpc) {
-          if (dest > jmptarget)
-            jmptarget = dest;  /* update 'jmptarget' */
-        }
+        /* jump does not skip 'lastpc' and is larger than current one? */
+        if (dest <= lastpc && dest > jmptarget)
+          jmptarget = dest;  /* update 'jmptarget' */
+        change = 0;
         break;
       }
-      default:
-        if (testAMode(op) && reg == a)  /* any instruction that set A */
-          setreg = filterpc(pc, jmptarget);
+      default:  /* any instruction that sets A */
+        change = (testAMode(op) && reg == a);
         break;
     }
+    if (change)
+      setreg = filterpc(pc, jmptarget);
   }
   return setreg;
 }
 
 
-static const char *getobjname (Proto *p, int lastpc, int reg,
+/*
+** Check whether table being indexed by instruction 'i' is the
+** environment '_ENV'
+*/
+static const char *gxf (const Proto *p, int pc, Instruction i, int isup) {
+  int t = GETARG_B(i);  /* table index */
+  const char *name;  /* name of indexed variable */
+  if (isup)  /* is an upvalue? */
+    name = upvalname(p, t);
+  else
+    getobjname(p, pc, t, &name);
+  return (name && strcmp(name, LUA_ENV) == 0) ? "global" : "field";
+}
+
+
+static const char *getobjname (const Proto *p, int lastpc, int reg,
                                const char **name) {
   int pc;
   *name = luaF_getlocalname(p, reg + 1, lastpc);
@@ -446,15 +548,24 @@ static const char *getobjname (Proto *p, int lastpc, int reg,
           return getobjname(p, pc, b, name);  /* get name for 'b' */
         break;
       }
-      case OP_GETTABUP:
+      case OP_GETTABUP: {
+        int k = GETARG_C(i);  /* key index */
+        kname(p, k, name);
+        return gxf(p, pc, i, 1);
+      }
       case OP_GETTABLE: {
         int k = GETARG_C(i);  /* key index */
-        int t = GETARG_B(i);  /* table index */
-        const char *vn = (op == OP_GETTABLE)  /* name of indexed variable */
-                         ? luaF_getlocalname(p, t + 1, pc)
-                         : upvalname(p, t);
-        kname(p, pc, k, name);
-        return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
+        rname(p, pc, k, name);
+        return gxf(p, pc, i, 0);
+      }
+      case OP_GETI: {
+        *name = "integer index";
+        return "field";
+      }
+      case OP_GETFIELD: {
+        int k = GETARG_C(i);  /* key index */
+        kname(p, k, name);
+        return gxf(p, pc, i, 0);
       }
       case OP_GETUPVAL: {
         *name = upvalname(p, GETARG_B(i));
@@ -471,8 +582,7 @@ static const char *getobjname (Proto *p, int lastpc, int reg,
         break;
       }
       case OP_SELF: {
-        int k = GETARG_C(i);  /* key index */
-        kname(p, pc, k, name);
+        rkname(p, pc, i, name);
         return "method";
       }
       default: break;  /* go through to return NULL */
@@ -491,7 +601,7 @@ static const char *getobjname (Proto *p, int lastpc, int reg,
 static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
                                      const char **name) {
   TMS tm = (TMS)0;  /* (initial value avoids warnings) */
-  Proto *p = ci_func(ci)->p;  /* calling function */
+  const Proto *p = ci_func(ci)->p;  /* calling function */
   int pc = currentpc(ci);  /* calling instruction index */
   Instruction i = p->code[pc];  /* calling instruction */
   if (ci->callstatus & CIST_HOOKED) {  /* was it called inside a hook? */
@@ -508,16 +618,14 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
     }
     /* other instructions can do calls through metamethods */
     case OP_SELF: case OP_GETTABUP: case OP_GETTABLE:
+    case OP_GETI: case OP_GETFIELD:
       tm = TM_INDEX;
       break;
-    case OP_SETTABUP: case OP_SETTABLE:
+    case OP_SETTABUP: case OP_SETTABLE: case OP_SETI: case OP_SETFIELD:
       tm = TM_NEWINDEX;
       break;
-    case OP_ADD: case OP_SUB: case OP_MUL: case OP_MOD:
-    case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND:
-    case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: {
-      int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD);  /* ORDER OP */
-      tm = cast(TMS, offset + cast_int(TM_ADD));  /* ORDER TM */
+    case OP_MMBIN: case OP_MMBINI: case OP_MMBINK: {
+      tm = cast(TMS, GETARG_C(i));
       break;
     }
     case OP_UNM: tm = TM_UNM; break;
@@ -525,12 +633,16 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
     case OP_LEN: tm = TM_LEN; break;
     case OP_CONCAT: tm = TM_CONCAT; break;
     case OP_EQ: tm = TM_EQ; break;
-    case OP_LT: tm = TM_LT; break;
-    case OP_LE: tm = TM_LE; break;
+    case OP_LT: case OP_LE: case OP_LTI: case OP_LEI:
+      *name = "order";  /* '<=' can call '__lt', etc. */
+      return "metamethod";
+    case OP_CLOSE: case OP_RETURN:
+      *name = "close";
+      return "metamethod";
     default:
       return NULL;  /* cannot find a reasonable name */
   }
-  *name = getstr(G(L)->tmname[tm]);
+  *name = getstr(G(L)->tmname[tm]) + 2;
   return "metamethod";
 }
 
@@ -544,8 +656,9 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
 ** checks are ISO C and ensure a correct result.
 */
 static int isinstack (CallInfo *ci, const TValue *o) {
-  ptrdiff_t i = o - ci->u.l.base;
-  return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o);
+  StkId base = ci->func + 1;
+  ptrdiff_t i = cast(StkId, o) - base;
+  return (0 <= i && i < (ci->top - base) && s2v(base + i) == o);
 }
 
 
@@ -576,7 +689,7 @@ static const char *varinfo (lua_State *L, const TValue *o) {
     kind = getupvalname(ci, o, &name);  /* check whether 'o' is an upvalue */
     if (!kind && isinstack(ci, o))  /* no? try a register */
       kind = getobjname(ci_func(ci)->p, currentpc(ci),
-                        cast_int(o - ci->u.l.base), &name);
+                        cast_int(cast(StkId, o) - (ci->func + 1)), &name);
   }
   return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : "";
 }
@@ -588,6 +701,12 @@ l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
 }
 
 
+l_noret luaG_forerror (lua_State *L, const TValue *o, const char *what) {
+  luaG_runerror(L, "bad 'for' %s (number expected, got %s)",
+                   what, luaT_objtypename(L, o));
+}
+
+
 l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
   if (ttisstring(p1) || cvt2str(p1)) p1 = p2;
   luaG_typeerror(L, p1, "concatenate");
@@ -596,8 +715,7 @@ l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
 
 l_noret luaG_opinterror (lua_State *L, const TValue *p1,
                          const TValue *p2, const char *msg) {
-  lua_Number temp;
-  if (!tonumber(p1, &temp))  /* first operand is wrong? */
+  if (!ttisnumber(p1))  /* first operand is wrong? */
     p2 = p1;  /* now second is wrong */
   luaG_typeerror(L, p2, msg);
 }
@@ -608,7 +726,7 @@ l_noret luaG_opinterror (lua_State *L, const TValue *p1,
 */
 l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
   lua_Integer temp;
-  if (!tointeger(p1, &temp))
+  if (!tointegerns(p1, &temp))
     p2 = p1;
   luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
 }
@@ -629,7 +747,7 @@ const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
                                         int line) {
   char buff[LUA_IDSIZE];
   if (src)
-    luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
+    luaO_chunkid(buff, getstr(src), tsslen(src));
   else {  /* no source available; use "?" instead */
     buff[0] = '?'; buff[1] = '\0';
   }
@@ -640,6 +758,7 @@ const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
 l_noret luaG_errormsg (lua_State *L) {
   if (L->errfunc != 0) {  /* is there an error handling function? */
     StkId errfunc = restorestack(L, L->errfunc);
+    lua_assert(ttisfunction(s2v(errfunc)));
     setobjs2s(L, L->top, L->top - 1);  /* move argument */
     setobjs2s(L, L->top - 1, errfunc);  /* push function */
     L->top++;  /* assume EXTRA_STACK */
@@ -658,42 +777,65 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
   msg = luaO_pushvfstring(L, fmt, argp);  /* format message */
   va_end(argp);
   if (isLua(ci))  /* if Lua function, add source:line information */
-    luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci));
+    luaG_addinfo(L, msg, ci_func(ci)->p->source, getcurrentline(ci));
   luaG_errormsg(L);
 }
 
 
-void luaG_traceexec (lua_State *L) {
+/*
+** Check whether new instruction 'newpc' is in a different line from
+** previous instruction 'oldpc'.
+*/
+static int changedline (const Proto *p, int oldpc, int newpc) {
+  while (oldpc++ < newpc) {
+    if (p->lineinfo[oldpc] != 0)
+      return (luaG_getfuncline(p, oldpc - 1) != luaG_getfuncline(p, newpc));
+  }
+  return 0;  /* no line changes in the way */
+}
+
+
+int luaG_traceexec (lua_State *L, const Instruction *pc) {
   CallInfo *ci = L->ci;
   lu_byte mask = L->hookmask;
-  int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
+  int counthook;
+  if (!(mask & (LUA_MASKLINE | LUA_MASKCOUNT))) {  /* no hooks? */
+    ci->u.l.trap = 0;  /* don't need to stop again */
+    return 0;  /* turn off 'trap' */
+  }
+  pc++;  /* reference is always next instruction */
+  ci->u.l.savedpc = pc;  /* save 'pc' */
+  counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
   if (counthook)
     resethookcount(L);  /* reset count */
   else if (!(mask & LUA_MASKLINE))
-    return;  /* no line hook and count != 0; nothing to be done */
+    return 1;  /* no line hook and count != 0; nothing to be done now */
   if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
     ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
-    return;  /* do not call hook again (VM yielded, so it did not move) */
+    return 1;  /* do not call hook again (VM yielded, so it did not move) */
   }
+  if (!isIT(*(ci->u.l.savedpc - 1)))
+    L->top = ci->top;  /* prepare top */
   if (counthook)
-    luaD_hook(L, LUA_HOOKCOUNT, -1);  /* call count hook */
+    luaD_hook(L, LUA_HOOKCOUNT, -1, 0, 0);  /* call count hook */
   if (mask & LUA_MASKLINE) {
-    Proto *p = ci_func(ci)->p;
-    int npc = pcRel(ci->u.l.savedpc, p);
-    int newline = getfuncline(p, npc);
-    if (npc == 0 ||  /* call linehook when enter a new function, */
-        ci->u.l.savedpc <= L->oldpc ||  /* when jump back (loop), or when */
-        newline != getfuncline(p, pcRel(L->oldpc, p)))  /* enter a new line */
-      luaD_hook(L, LUA_HOOKLINE, newline);  /* call line hook */
-  }
-  L->oldpc = ci->u.l.savedpc;
+    const Proto *p = ci_func(ci)->p;
+    int npci = pcRel(pc, p);
+    if (npci == 0 ||  /* call linehook when enter a new function, */
+        pc <= L->oldpc ||  /* when jump back (loop), or when */
+        changedline(p, pcRel(L->oldpc, p), npci)) {  /* enter new line */
+      int newline = luaG_getfuncline(p, npci);
+      luaD_hook(L, LUA_HOOKLINE, newline, 0, 0);  /* call line hook */
+    }
+    L->oldpc = pc;  /* 'pc' of last call to line hook */
+  }
   if (L->status == LUA_YIELD) {  /* did hook yield? */
     if (counthook)
       L->hookcount = 1;  /* undo decrement to zero */
     ci->u.l.savedpc--;  /* undo increment (resume will increment it again) */
     ci->callstatus |= CIST_HOOKYIELD;  /* mark that it yielded */
-    ci->func = L->top - 1;  /* protect stack below results */
     luaD_throw(L, LUA_YIELD);
   }
+  return 1;  /* keep 'trap' on */
 }
 
diff --git a/libs/liblua/src/ldebug.h b/libs/liblua/src/ldebug.h
index 8cea0ee0a7..1fe0efab08 100644
--- a/libs/liblua/src/ldebug.h
+++ b/libs/liblua/src/ldebug.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.h,v 2.14.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ldebug.h $
 ** Auxiliary functions from Debug Interface module
 ** See Copyright Notice in lua.h
 */
@@ -11,15 +11,23 @@
 #include "lstate.h"
 
 
-#define pcRel(pc, p)	(cast(int, (pc) - (p)->code) - 1)
-
-#define getfuncline(f,pc)	(((f)->lineinfo) ? (f)->lineinfo[pc] : -1)
+#define pcRel(pc, p)	(cast_int((pc) - (p)->code) - 1)
 
 #define resethookcount(L)	(L->hookcount = L->basehookcount)
 
+/*
+** mark for entries in 'lineinfo' array that has absolute information in
+** 'abslineinfo' array
+*/
+#define ABSLINEINFO	(-0x80)
 
+LUAI_FUNC int luaG_getfuncline (const Proto *f, int pc);
+LUAI_FUNC const char *luaG_findlocal (lua_State *L, CallInfo *ci, int n,
+                                                    StkId *pos);
 LUAI_FUNC l_noret luaG_typeerror (lua_State *L, const TValue *o,
                                                 const char *opname);
+LUAI_FUNC l_noret luaG_forerror (lua_State *L, const TValue *o,
+                                               const char *what);
 LUAI_FUNC l_noret luaG_concaterror (lua_State *L, const TValue *p1,
                                                   const TValue *p2);
 LUAI_FUNC l_noret luaG_opinterror (lua_State *L, const TValue *p1,
@@ -33,7 +41,7 @@ LUAI_FUNC l_noret luaG_runerror (lua_State *L, const char *fmt, ...);
 LUAI_FUNC const char *luaG_addinfo (lua_State *L, const char *msg,
                                                   TString *src, int line);
 LUAI_FUNC l_noret luaG_errormsg (lua_State *L);
-LUAI_FUNC void luaG_traceexec (lua_State *L);
+LUAI_FUNC int luaG_traceexec (lua_State *L, const Instruction *pc);
 
 
 #endif
diff --git a/libs/liblua/src/ldo.c b/libs/liblua/src/ldo.c
index 316e45c8fe..c563b1d9b3 100644
--- a/libs/liblua/src/ldo.c
+++ b/libs/liblua/src/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.157.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ldo.c $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -88,7 +88,7 @@ struct lua_longjmp {
 };
 
 
-static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
+void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
   switch (errcode) {
     case LUA_ERRMEM: {  /* memory error? */
       setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */
@@ -98,6 +98,10 @@ static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
       setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
       break;
     }
+    case CLOSEPROTECT: {
+      setnilvalue(s2v(oldtop));  /* no error message */
+      break;
+    }
     default: {
       setobjs2s(L, oldtop, L->top - 1);  /* error message on current top */
       break;
@@ -114,6 +118,7 @@ l_noret luaD_throw (lua_State *L, int errcode) {
   }
   else {  /* thread has no error handler */
     global_State *g = G(L);
+    errcode = luaF_close(L, L->stack, errcode);  /* close all upvalues */
     L->status = cast_byte(errcode);  /* mark it as dead */
     if (g->mainthread->errorJmp) {  /* main thread has a handler? */
       setobjs2s(L, g->mainthread->top++, L->top - 1);  /* copy error obj. */
@@ -121,7 +126,7 @@ l_noret luaD_throw (lua_State *L, int errcode) {
     }
     else {  /* no handler at all; abort */
       if (g->panic) {  /* panic function? */
-        seterrorobj(L, errcode, L->top);  /* assume EXTRA_STACK */
+        luaD_seterrorobj(L, errcode, L->top);  /* assume EXTRA_STACK */
         if (L->ci->top < L->top)
           L->ci->top = L->top;  /* pushing msg. can break this invariant */
         lua_unlock(L);
@@ -134,7 +139,8 @@ l_noret luaD_throw (lua_State *L, int errcode) {
 
 
 int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
-  unsigned short oldnCcalls = L->nCcalls;
+  global_State *g = G(L);
+  l_uint32 oldnCcalls = g->Cstacklimit - (L->nCcalls + L->nci);
   struct lua_longjmp lj;
   lj.status = LUA_OK;
   lj.previous = L->errorJmp;  /* chain new error handler */
@@ -143,7 +149,7 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
     (*f)(L, ud);
   );
   L->errorJmp = lj.previous;  /* restore old error handler */
-  L->nCcalls = oldnCcalls;
+  L->nCcalls = g->Cstacklimit - oldnCcalls - L->nci;
   return lj.status;
 }
 
@@ -155,17 +161,19 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
 ** Stack reallocation
 ** ===================================================================
 */
-static void correctstack (lua_State *L, TValue *oldstack) {
+static void correctstack (lua_State *L, StkId oldstack, StkId newstack) {
   CallInfo *ci;
   UpVal *up;
-  L->top = (L->top - oldstack) + L->stack;
+  if (oldstack == newstack)
+    return;  /* stack address did not change */
+  L->top = (L->top - oldstack) + newstack;
   for (up = L->openupval; up != NULL; up = up->u.open.next)
-    up->v = (up->v - oldstack) + L->stack;
+    up->v = s2v((uplevel(up) - oldstack) + newstack);
   for (ci = L->ci; ci != NULL; ci = ci->previous) {
-    ci->top = (ci->top - oldstack) + L->stack;
-    ci->func = (ci->func - oldstack) + L->stack;
+    ci->top = (ci->top - oldstack) + newstack;
+    ci->func = (ci->func - oldstack) + newstack;
     if (isLua(ci))
-      ci->u.l.base = (ci->u.l.base - oldstack) + L->stack;
+      ci->u.l.trap = 1;  /* signal to update 'trap' in 'luaV_execute' */
   }
 }
 
@@ -174,36 +182,53 @@ static void correctstack (lua_State *L, TValue *oldstack) {
 #define ERRORSTACKSIZE	(LUAI_MAXSTACK + 200)
 
 
-void luaD_reallocstack (lua_State *L, int newsize) {
-  TValue *oldstack = L->stack;
+int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
   int lim = L->stacksize;
+  StkId newstack = luaM_reallocvector(L, L->stack, lim, newsize, StackValue);
   lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
   lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK);
-  luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue);
+  if (unlikely(newstack == NULL)) {  /* reallocation failed? */
+    if (raiseerror)
+      luaM_error(L);
+    else return 0;  /* do not raise an error */
+  }
   for (; lim < newsize; lim++)
-    setnilvalue(L->stack + lim); /* erase new segment */
+    setnilvalue(s2v(newstack + lim)); /* erase new segment */
+  correctstack(L, L->stack, newstack);
+  L->stack = newstack;
   L->stacksize = newsize;
   L->stack_last = L->stack + newsize - EXTRA_STACK;
-  correctstack(L, oldstack);
+  return 1;
 }
 
 
-void luaD_growstack (lua_State *L, int n) {
+/*
+** Try to grow the stack by at least 'n' elements. when 'raiseerror'
+** is true, raises any error; otherwise, return 0 in case of errors.
+*/
+int luaD_growstack (lua_State *L, int n, int raiseerror) {
   int size = L->stacksize;
-  if (size > LUAI_MAXSTACK)  /* error after extra size? */
-    luaD_throw(L, LUA_ERRERR);
+  int newsize = 2 * size;  /* tentative new size */
+  if (unlikely(size > LUAI_MAXSTACK)) {  /* need more space after extra size? */
+    if (raiseerror)
+      luaD_throw(L, LUA_ERRERR);  /* error inside message handler */
+    else return 0;
+  }
   else {
     int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK;
-    int newsize = 2 * size;
-    if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK;
-    if (newsize < needed) newsize = needed;
-    if (newsize > LUAI_MAXSTACK) {  /* stack overflow? */
-      luaD_reallocstack(L, ERRORSTACKSIZE);
-      luaG_runerror(L, "stack overflow");
+    if (newsize > LUAI_MAXSTACK)  /* cannot cross the limit */
+      newsize = LUAI_MAXSTACK;
+    if (newsize < needed)  /* but must respect what was asked for */
+      newsize = needed;
+    if (unlikely(newsize > LUAI_MAXSTACK)) {  /* stack overflow? */
+      /* add extra size to be able to handle the error message */
+      luaD_reallocstack(L, ERRORSTACKSIZE, raiseerror);
+      if (raiseerror)
+        luaG_runerror(L, "stack overflow");
+      else return 0;
     }
-    else
-      luaD_reallocstack(L, newsize);
-  }
+  }  /* else no errors */
+  return luaD_reallocstack(L, newsize, raiseerror);
 }
 
 
@@ -223,17 +248,14 @@ void luaD_shrinkstack (lua_State *L) {
   int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
   if (goodsize > LUAI_MAXSTACK)
     goodsize = LUAI_MAXSTACK;  /* respect stack limit */
-  if (L->stacksize > LUAI_MAXSTACK)  /* had been handling stack overflow? */
-    luaE_freeCI(L);  /* free all CIs (list grew because of an error) */
-  else
-    luaE_shrinkCI(L);  /* shrink list */
   /* if thread is currently not handling a stack overflow and its
      good size is smaller than current size, shrink its stack */
   if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) &&
       goodsize < L->stacksize)
-    luaD_reallocstack(L, goodsize);
+    luaD_reallocstack(L, goodsize, 0);  /* ok if that fails */
   else  /* don't change stack */
     condmovestack(L,{},{});  /* (change only for debugging) */
+  luaE_shrinkCI(L);  /* shrink CI list */
 }
 
 
@@ -247,12 +269,14 @@ void luaD_inctop (lua_State *L) {
 
 /*
 ** Call a hook for the given event. Make sure there is a hook to be
-** called. (Both 'L->hook' and 'L->hookmask', which triggers this
+** called. (Both 'L->hook' and 'L->hookmask', which trigger this
 ** function, can be changed asynchronously by signals.)
 */
-void luaD_hook (lua_State *L, int event, int line) {
+void luaD_hook (lua_State *L, int event, int line,
+                              int ftransfer, int ntransfer) {
   lua_Hook hook = L->hook;
   if (hook && L->allowhook) {  /* make sure there is a hook */
+    int mask = CIST_HOOKED;
     CallInfo *ci = L->ci;
     ptrdiff_t top = savestack(L, L->top);
     ptrdiff_t ci_top = savestack(L, ci->top);
@@ -260,11 +284,16 @@ void luaD_hook (lua_State *L, int event, int line) {
     ar.event = event;
     ar.currentline = line;
     ar.i_ci = ci;
+    if (ntransfer != 0) {
+      mask |= CIST_TRAN;  /* 'ci' has transfer information */
+      ci->u2.transferinfo.ftransfer = ftransfer;
+      ci->u2.transferinfo.ntransfer = ntransfer;
+    }
     luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-    ci->top = L->top + LUA_MINSTACK;
-    lua_assert(ci->top <= L->stack_last);
+    if (L->top + LUA_MINSTACK > ci->top)
+      ci->top = L->top + LUA_MINSTACK;
     L->allowhook = 0;  /* cannot call hooks inside a hook */
-    ci->callstatus |= CIST_HOOKED;
+    ci->callstatus |= mask;
     lua_unlock(L);
     (*hook)(L, &ar);
     lua_lock(L);
@@ -272,56 +301,66 @@ void luaD_hook (lua_State *L, int event, int line) {
     L->allowhook = 1;
     ci->top = restorestack(L, ci_top);
     L->top = restorestack(L, top);
-    ci->callstatus &= ~CIST_HOOKED;
+    ci->callstatus &= ~mask;
   }
 }
 
 
-static void callhook (lua_State *L, CallInfo *ci) {
-  int hook = LUA_HOOKCALL;
+/*
+** Executes a call hook for Lua functions. This function is called
+** whenever 'hookmask' is not zero, so it checks whether call hooks are
+** active.
+*/
+void luaD_hookcall (lua_State *L, CallInfo *ci) {
+  int hook = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL : LUA_HOOKCALL;
+  Proto *p;
+  if (!(L->hookmask & LUA_MASKCALL))  /* some other hook? */
+    return;  /* don't call hook */
+  p = clLvalue(s2v(ci->func))->p;
+  L->top = ci->top;  /* prepare top */
   ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
-  if (isLua(ci->previous) &&
-      GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
-    ci->callstatus |= CIST_TAIL;
-    hook = LUA_HOOKTAILCALL;
-  }
-  luaD_hook(L, hook, -1);
+  luaD_hook(L, hook, -1, 1, p->numparams);
   ci->u.l.savedpc--;  /* correct 'pc' */
 }
 
 
-static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
-  int i;
-  int nfixargs = p->numparams;
-  StkId base, fixed;
-  /* move fixed parameters to final position */
-  fixed = L->top - actual;  /* first fixed argument */
-  base = L->top;  /* final position of first argument */
-  for (i = 0; i < nfixargs && i < actual; i++) {
-    setobjs2s(L, L->top++, fixed + i);
-    setnilvalue(fixed + i);  /* erase original copy (for GC) */
+static StkId rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) {
+  ptrdiff_t oldtop = savestack(L, L->top);  /* hook may change top */
+  int delta = 0;
+  if (isLuacode(ci)) {
+    Proto *p = clLvalue(s2v(ci->func))->p;
+    if (p->is_vararg)
+      delta = ci->u.l.nextraargs + p->numparams + 1;
+    if (L->top < ci->top)
+      L->top = ci->top;  /* correct top to run hook */
   }
-  for (; i < nfixargs; i++)
-    setnilvalue(L->top++);  /* complete missing arguments */
-  return base;
+  if (L->hookmask & LUA_MASKRET) {  /* is return hook on? */
+    int ftransfer;
+    ci->func += delta;  /* if vararg, back to virtual 'func' */
+    ftransfer = cast(unsigned short, firstres - ci->func);
+    luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres);  /* call it */
+    ci->func -= delta;
+  }
+  if (isLua(ci->previous))
+    L->oldpc = ci->previous->u.l.savedpc;  /* update 'oldpc' */
+  return restorestack(L, oldtop);
 }
 
 
 /*
-** Check whether __call metafield of 'func' is a function. If so, put
-** it in stack below original 'func' so that 'luaD_precall' can call
-** it. Raise an error if __call metafield is not a function.
+** Check whether 'func' has a '__call' metafield. If so, put it in the
+** stack, below original 'func', so that 'luaD_call' can call it. Raise
+** an error if there is no '__call' metafield.
 */
-static void tryfuncTM (lua_State *L, StkId func) {
-  const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL);
+void luaD_tryfuncTM (lua_State *L, StkId func) {
+  const TValue *tm = luaT_gettmbyobj(L, s2v(func), TM_CALL);
   StkId p;
-  if (!ttisfunction(tm))
-    luaG_typeerror(L, func, "call");
-  /* Open a hole inside the stack at 'func' */
-  for (p = L->top; p > func; p--)
+  if (unlikely(ttisnil(tm)))
+    luaG_typeerror(L, s2v(func), "call");  /* nothing to call */
+  for (p = L->top; p > func; p--)  /* open space for metamethod */
     setobjs2s(L, p, p-1);
-  L->top++;  /* slot ensured by caller */
-  setobj2s(L, func, tm);  /* tag method is the new function to be called */
+  L->top++;  /* stack space pre-allocated by the caller */
+  setobj2s(L, func, tm);  /* metamethod is the new function to be called */
 }
 
 
@@ -331,183 +370,161 @@ static void tryfuncTM (lua_State *L, StkId func) {
 ** expressions, multiple results for tail calls/single parameters)
 ** separated.
 */
-static int moveresults (lua_State *L, const TValue *firstResult, StkId res,
-                                      int nres, int wanted) {
+static void moveresults (lua_State *L, StkId res, int nres, int wanted) {
+  StkId firstresult;
+  int i;
   switch (wanted) {  /* handle typical cases separately */
-    case 0: break;  /* nothing to move */
-    case 1: {  /* one result needed */
+    case 0:  /* no values needed */
+      L->top = res;
+      return;
+    case 1:  /* one value needed */
       if (nres == 0)   /* no results? */
-        firstResult = luaO_nilobject;  /* adjust with nil */
-      setobjs2s(L, res, firstResult);  /* move it to proper place */
+        setnilvalue(s2v(res));  /* adjust with nil */
+      else
+        setobjs2s(L, res, L->top - nres);  /* move it to proper place */
+      L->top = res + 1;
+      return;
+    case LUA_MULTRET:
+      wanted = nres;  /* we want all results */
       break;
-    }
-    case LUA_MULTRET: {
-      int i;
-      for (i = 0; i < nres; i++)  /* move all results to correct place */
-        setobjs2s(L, res + i, firstResult + i);
-      L->top = res + nres;
-      return 0;  /* wanted == LUA_MULTRET */
-    }
-    default: {
-      int i;
-      if (wanted <= nres) {  /* enough results? */
-        for (i = 0; i < wanted; i++)  /* move wanted results to correct place */
-          setobjs2s(L, res + i, firstResult + i);
-      }
-      else {  /* not enough results; use all of them plus nils */
-        for (i = 0; i < nres; i++)  /* move all results to correct place */
-          setobjs2s(L, res + i, firstResult + i);
-        for (; i < wanted; i++)  /* complete wanted number of results */
-          setnilvalue(res + i);
+    default:  /* multiple results (or to-be-closed variables) */
+      if (hastocloseCfunc(wanted)) {  /* to-be-closed variables? */
+        ptrdiff_t savedres = savestack(L, res);
+        luaF_close(L, res, LUA_OK);  /* may change the stack */
+        res = restorestack(L, savedres);
+        wanted = codeNresults(wanted);  /* correct value */
+        if (wanted == LUA_MULTRET)
+          wanted = nres;
       }
       break;
-    }
   }
+  firstresult = L->top - nres;  /* index of first result */
+  /* move all results to correct place */
+  for (i = 0; i < nres && i < wanted; i++)
+    setobjs2s(L, res + i, firstresult + i);
+  for (; i < wanted; i++)  /* complete wanted number of results */
+    setnilvalue(s2v(res + i));
   L->top = res + wanted;  /* top points after the last result */
-  return 1;
 }
 
 
 /*
 ** Finishes a function call: calls hook if necessary, removes CallInfo,
-** moves current number of results to proper place; returns 0 iff call
-** wanted multiple (variable number of) results.
+** moves current number of results to proper place.
 */
-int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
-  StkId res;
-  int wanted = ci->nresults;
-  if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
-    if (L->hookmask & LUA_MASKRET) {
-      ptrdiff_t fr = savestack(L, firstResult);  /* hook may change stack */
-      luaD_hook(L, LUA_HOOKRET, -1);
-      firstResult = restorestack(L, fr);
-    }
-    L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
-  }
-  res = ci->func;  /* res == final position of 1st result */
+void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
+  if (L->hookmask)
+    L->top = rethook(L, ci, L->top - nres, nres);
   L->ci = ci->previous;  /* back to caller */
   /* move results to proper place */
-  return moveresults(L, firstResult, res, nres, wanted);
+  moveresults(L, ci->func, nres, ci->nresults);
 }
 
 
 
-#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
+#define next_ci(L)  (L->ci->next ? L->ci->next : luaE_extendCI(L))
 
 
-/* macro to check stack size, preserving 'p' */
-#define checkstackp(L,n,p)  \
-  luaD_checkstackaux(L, n, \
-    ptrdiff_t t__ = savestack(L, p);  /* save 'p' */ \
-    luaC_checkGC(L),  /* stack grow uses memory */ \
-    p = restorestack(L, t__))  /* 'pos' part: restore 'p' */
+/*
+** Prepare a function for a tail call, building its call info on top
+** of the current call info. 'narg1' is the number of arguments plus 1
+** (so that it includes the function itself).
+*/
+void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int narg1) {
+  Proto *p = clLvalue(s2v(func))->p;
+  int fsize = p->maxstacksize;  /* frame size */
+  int nfixparams = p->numparams;
+  int i;
+  for (i = 0; i < narg1; i++)  /* move down function and arguments */
+    setobjs2s(L, ci->func + i, func + i);
+  checkstackGC(L, fsize);
+  func = ci->func;  /* moved-down function */
+  for (; narg1 <= nfixparams; narg1++)
+    setnilvalue(s2v(func + narg1));  /* complete missing arguments */
+  ci->top = func + 1 + fsize;  /* top for new function */
+  lua_assert(ci->top <= L->stack_last);
+  ci->u.l.savedpc = p->code;  /* starting point */
+  ci->callstatus |= CIST_TAIL;
+  L->top = func + narg1;  /* set top */
+}
 
 
 /*
-** Prepares a function call: checks the stack, creates a new CallInfo
-** entry, fills in the relevant information, calls hook if needed.
-** If function is a C function, does the call, too. (Otherwise, leave
-** the execution ('luaV_execute') to the caller, to allow stackless
-** calls.) Returns true iff function has been executed (C function).
+** Call a function (C or Lua). The function to be called is at *func.
+** The arguments are on the stack, right after the function.
+** When returns, all the results are on the stack, starting at the original
+** function position.
 */
-int luaD_precall (lua_State *L, StkId func, int nresults) {
+void luaD_call (lua_State *L, StkId func, int nresults) {
   lua_CFunction f;
-  CallInfo *ci;
-  switch (ttype(func)) {
-    case LUA_TCCL:  /* C closure */
-      f = clCvalue(func)->f;
+ retry:
+  switch (ttypetag(s2v(func))) {
+    case LUA_VCCL:  /* C closure */
+      f = clCvalue(s2v(func))->f;
       goto Cfunc;
-    case LUA_TLCF:  /* light C function */
-      f = fvalue(func);
+    case LUA_VLCF:  /* light C function */
+      f = fvalue(s2v(func));
      Cfunc: {
       int n;  /* number of returns */
+      CallInfo *ci = next_ci(L);
       checkstackp(L, LUA_MINSTACK, func);  /* ensure minimum stack size */
-      ci = next_ci(L);  /* now 'enter' new function */
       ci->nresults = nresults;
-      ci->func = func;
+      ci->callstatus = CIST_C;
       ci->top = L->top + LUA_MINSTACK;
+      ci->func = func;
+      L->ci = ci;
       lua_assert(ci->top <= L->stack_last);
-      ci->callstatus = 0;
-      if (L->hookmask & LUA_MASKCALL)
-        luaD_hook(L, LUA_HOOKCALL, -1);
+      if (L->hookmask & LUA_MASKCALL) {
+        int narg = cast_int(L->top - func) - 1;
+        luaD_hook(L, LUA_HOOKCALL, -1, 1, narg);
+      }
       lua_unlock(L);
       n = (*f)(L);  /* do the actual call */
       lua_lock(L);
       api_checknelems(L, n);
-      luaD_poscall(L, ci, L->top - n, n);
-      return 1;
+      luaD_poscall(L, ci, n);
+      break;
     }
-    case LUA_TLCL: {  /* Lua function: prepare its call */
-      StkId base;
-      Proto *p = clLvalue(func)->p;
-      int n = cast_int(L->top - func) - 1;  /* number of real arguments */
+    case LUA_VLCL: {  /* Lua function */
+      CallInfo *ci = next_ci(L);
+      Proto *p = clLvalue(s2v(func))->p;
+      int narg = cast_int(L->top - func) - 1;  /* number of real arguments */
+      int nfixparams = p->numparams;
       int fsize = p->maxstacksize;  /* frame size */
       checkstackp(L, fsize, func);
-      if (p->is_vararg)
-        base = adjust_varargs(L, p, n);
-      else {  /* non vararg function */
-        for (; n < p->numparams; n++)
-          setnilvalue(L->top++);  /* complete missing arguments */
-        base = func + 1;
-      }
-      ci = next_ci(L);  /* now 'enter' new function */
       ci->nresults = nresults;
+      ci->u.l.savedpc = p->code;  /* starting point */
+      ci->callstatus = 0;
+      ci->top = func + 1 + fsize;
       ci->func = func;
-      ci->u.l.base = base;
-      L->top = ci->top = base + fsize;
+      L->ci = ci;
+      for (; narg < nfixparams; narg++)
+        setnilvalue(s2v(L->top++));  /* complete missing arguments */
       lua_assert(ci->top <= L->stack_last);
-      ci->u.l.savedpc = p->code;  /* starting point */
-      ci->callstatus = CIST_LUA;
-      if (L->hookmask & LUA_MASKCALL)
-        callhook(L, ci);
-      return 0;
+      luaV_execute(L, ci);  /* run the function */
+      break;
     }
     default: {  /* not a function */
-      checkstackp(L, 1, func);  /* ensure space for metamethod */
-      tryfuncTM(L, func);  /* try to get '__call' metamethod */
-      return luaD_precall(L, func, nresults);  /* now it must be a function */
+      checkstackp(L, 1, func);  /* space for metamethod */
+      luaD_tryfuncTM(L, func);  /* try to get '__call' metamethod */
+      goto retry;  /* try again with metamethod */
     }
   }
 }
 
 
 /*
-** Check appropriate error for stack overflow ("regular" overflow or
-** overflow while handling stack overflow). If 'nCalls' is larger than
-** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
-** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to
-** allow overflow handling to work)
-*/
-static void stackerror (lua_State *L) {
-  if (L->nCcalls == LUAI_MAXCCALLS)
-    luaG_runerror(L, "C stack overflow");
-  else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3)))
-    luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
-}
-
-
-/*
-** Call a function (C or Lua). The function to be called is at *func.
-** The arguments are on the stack, right after the function.
-** When returns, all the results are on the stack, starting at the original
-** function position.
-*/
-void luaD_call (lua_State *L, StkId func, int nResults) {
-  if (++L->nCcalls >= LUAI_MAXCCALLS)
-    stackerror(L);
-  if (!luaD_precall(L, func, nResults))  /* is a Lua function? */
-    luaV_execute(L);  /* call it */
-  L->nCcalls--;
-}
-
-
-/*
-** Similar to 'luaD_call', but does not allow yields during the call
+** Similar to 'luaD_call', but does not allow yields during the call.
+** If there is a stack overflow, freeing all CI structures will
+** force the subsequent call to invoke 'luaE_extendCI', which then
+** will raise any errors.
 */
 void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
-  L->nny++;
+  incXCcalls(L);
+  if (getCcalls(L) <= CSTACKERR)  /* possible stack overflow? */
+    luaE_freeCI(L);
   luaD_call(L, func, nResults);
-  L->nny--;
+  decXCcalls(L);
 }
 
 
@@ -519,7 +536,7 @@ static void finishCcall (lua_State *L, int status) {
   CallInfo *ci = L->ci;
   int n;
   /* must have a continuation and must be able to call it */
-  lua_assert(ci->u.c.k != NULL && L->nny == 0);
+  lua_assert(ci->u.c.k != NULL && yieldable(L));
   /* error status can only happen in a protected call */
   lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
   if (ci->callstatus & CIST_YPCALL) {  /* was inside a pcall? */
@@ -533,7 +550,7 @@ static void finishCcall (lua_State *L, int status) {
   n = (*ci->u.c.k)(L, status, ci->u.c.ctx);  /* call continuation function */
   lua_lock(L);
   api_checknelems(L, n);
-  luaD_poscall(L, ci, L->top - n, n);  /* finish 'luaD_precall' */
+  luaD_poscall(L, ci, n);  /* finish 'luaD_call' */
 }
 
 
@@ -546,14 +563,15 @@ static void finishCcall (lua_State *L, int status) {
 ** status is LUA_YIELD).
 */
 static void unroll (lua_State *L, void *ud) {
+  CallInfo *ci;
   if (ud != NULL)  /* error status? */
     finishCcall(L, *(int *)ud);  /* finish 'lua_pcallk' callee */
-  while (L->ci != &L->base_ci) {  /* something in the stack */
-    if (!isLua(L->ci))  /* C function? */
+  while ((ci = L->ci) != &L->base_ci) {  /* something in the stack */
+    if (!isLua(ci))  /* C function? */
       finishCcall(L, LUA_YIELD);  /* complete its execution */
     else {  /* Lua function */
       luaV_finishOp(L);  /* finish interrupted instruction */
-      luaV_execute(L);  /* execute down to higher C 'boundary' */
+      luaV_execute(L, ci);  /* execute down to higher C 'boundary' */
     }
   }
 }
@@ -583,12 +601,12 @@ static int recover (lua_State *L, int status) {
   CallInfo *ci = findpcall(L);
   if (ci == NULL) return 0;  /* no recovery point */
   /* "finish" luaD_pcall */
-  oldtop = restorestack(L, ci->extra);
-  luaF_close(L, oldtop);
-  seterrorobj(L, status, oldtop);
+  oldtop = restorestack(L, ci->u2.funcidx);
+  luaF_close(L, oldtop, status);  /* may change the stack */
+  oldtop = restorestack(L, ci->u2.funcidx);
+  luaD_seterrorobj(L, status, oldtop);
   L->ci = ci;
   L->allowhook = getoah(ci->callstatus);  /* restore original 'allowhook' */
-  L->nny = 0;  /* should be zero to be yieldable */
   luaD_shrinkstack(L);
   L->errfunc = ci->u.c.old_errfunc;
   return 1;  /* continue running the coroutine */
@@ -621,71 +639,68 @@ static void resume (lua_State *L, void *ud) {
   StkId firstArg = L->top - n;  /* first argument */
   CallInfo *ci = L->ci;
   if (L->status == LUA_OK) {  /* starting a coroutine? */
-    if (!luaD_precall(L, firstArg - 1, LUA_MULTRET))  /* Lua function? */
-      luaV_execute(L);  /* call it */
+    luaD_call(L, firstArg - 1, LUA_MULTRET);
   }
   else {  /* resuming from previous yield */
     lua_assert(L->status == LUA_YIELD);
     L->status = LUA_OK;  /* mark that it is running (again) */
-    ci->func = restorestack(L, ci->extra);
     if (isLua(ci))  /* yielded inside a hook? */
-      luaV_execute(L);  /* just continue running Lua code */
+      luaV_execute(L, ci);  /* just continue running Lua code */
     else {  /* 'common' yield */
       if (ci->u.c.k != NULL) {  /* does it have a continuation function? */
         lua_unlock(L);
         n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */
         lua_lock(L);
         api_checknelems(L, n);
-        firstArg = L->top - n;  /* yield results come from continuation */
       }
-      luaD_poscall(L, ci, firstArg, n);  /* finish 'luaD_precall' */
+      luaD_poscall(L, ci, n);  /* finish 'luaD_call' */
     }
     unroll(L, NULL);  /* run continuation */
   }
 }
 
-
-LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
+LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
+                                      int *nresults) {
   int status;
-  unsigned short oldnny = L->nny;  /* save "number of non-yieldable" calls */
   lua_lock(L);
   if (L->status == LUA_OK) {  /* may be starting a coroutine */
     if (L->ci != &L->base_ci)  /* not in base level? */
       return resume_error(L, "cannot resume non-suspended coroutine", nargs);
+    else if (L->top - (L->ci->func + 1) == nargs)  /* no function? */
+      return resume_error(L, "cannot resume dead coroutine", nargs);
   }
-  else if (L->status != LUA_YIELD)
+  else if (L->status != LUA_YIELD)  /* ended with errors? */
     return resume_error(L, "cannot resume dead coroutine", nargs);
-  L->nCcalls = (from) ? from->nCcalls + 1 : 1;
-  if (L->nCcalls >= LUAI_MAXCCALLS)
+  if (from == NULL)
+    L->nCcalls = CSTACKTHREAD;
+  else  /* correct 'nCcalls' for this thread */
+    L->nCcalls = getCcalls(from) + from->nci - L->nci - CSTACKCF;
+  if (L->nCcalls <= CSTACKERR)
     return resume_error(L, "C stack overflow", nargs);
   luai_userstateresume(L, nargs);
-  L->nny = 0;  /* allow yields */
   api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
   status = luaD_rawrunprotected(L, resume, &nargs);
-  if (status == -1)  /* error calling 'lua_resume'? */
-    status = LUA_ERRRUN;
-  else {  /* continue running after recoverable errors */
-    while (errorstatus(status) && recover(L, status)) {
-      /* unroll continuation */
-      status = luaD_rawrunprotected(L, unroll, &status);
-    }
-    if (errorstatus(status)) {  /* unrecoverable error? */
-      L->status = cast_byte(status);  /* mark thread as 'dead' */
-      seterrorobj(L, status, L->top);  /* push error message */
-      L->ci->top = L->top;
-    }
-    else lua_assert(status == L->status);  /* normal end or yield */
+   /* continue running after recoverable errors */
+  while (errorstatus(status) && recover(L, status)) {
+    /* unroll continuation */
+    status = luaD_rawrunprotected(L, unroll, &status);
+  }
+  if (likely(!errorstatus(status)))
+    lua_assert(status == L->status);  /* normal end or yield */
+  else {  /* unrecoverable error */
+    L->status = cast_byte(status);  /* mark thread as 'dead' */
+    luaD_seterrorobj(L, status, L->top);  /* push error message */
+    L->ci->top = L->top;
   }
-  L->nny = oldnny;  /* restore 'nny' */
-  L->nCcalls--;
-  lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
+  *nresults = (status == LUA_YIELD) ? L->ci->u2.nyield
+                                    : cast_int(L->top - (L->ci->func + 1));
   lua_unlock(L);
   return status;
 }
 
 
 LUA_API int lua_isyieldable (lua_State *L) {
-  return (L->nny == 0);
+  return yieldable(L);
 }
 
 
@@ -695,21 +710,22 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
   luai_userstateyield(L, nresults);
   lua_lock(L);
   api_checknelems(L, nresults);
-  if (L->nny > 0) {
+  if (unlikely(!yieldable(L))) {
     if (L != G(L)->mainthread)
       luaG_runerror(L, "attempt to yield across a C-call boundary");
     else
       luaG_runerror(L, "attempt to yield from outside a coroutine");
   }
   L->status = LUA_YIELD;
-  ci->extra = savestack(L, ci->func);  /* save current 'func' */
   if (isLua(ci)) {  /* inside a hook? */
+    lua_assert(!isLuacode(ci));
     api_check(L, k == NULL, "hooks cannot continue after yielding");
+    ci->u2.nyield = 0;  /* no results */
   }
   else {
     if ((ci->u.c.k = k) != NULL)  /* is there a continuation? */
       ci->u.c.ctx = ctx;  /* save context */
-    ci->func = L->top - nresults - 1;  /* protect stack below results */
+    ci->u2.nyield = nresults;  /* save number of results */
     luaD_throw(L, LUA_YIELD);
   }
   lua_assert(ci->callstatus & CIST_HOOKED);  /* must be inside a hook */
@@ -718,22 +734,26 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
 }
 
 
+/*
+** Call the C function 'func' in protected mode, restoring basic
+** thread information ('allowhook', etc.) and in particular
+** its stack level in case of errors.
+*/
 int luaD_pcall (lua_State *L, Pfunc func, void *u,
                 ptrdiff_t old_top, ptrdiff_t ef) {
   int status;
   CallInfo *old_ci = L->ci;
   lu_byte old_allowhooks = L->allowhook;
-  unsigned short old_nny = L->nny;
   ptrdiff_t old_errfunc = L->errfunc;
   L->errfunc = ef;
   status = luaD_rawrunprotected(L, func, u);
-  if (status != LUA_OK) {  /* an error occurred? */
+  if (unlikely(status != LUA_OK)) {  /* an error occurred? */
     StkId oldtop = restorestack(L, old_top);
-    luaF_close(L, oldtop);  /* close possible pending closures */
-    seterrorobj(L, status, oldtop);
     L->ci = old_ci;
     L->allowhook = old_allowhooks;
-    L->nny = old_nny;
+    status = luaF_close(L, oldtop, status);
+    oldtop = restorestack(L, old_top);  /* previous call may change stack */
+    luaD_seterrorobj(L, status, oldtop);
     luaD_shrinkstack(L);
   }
   L->errfunc = old_errfunc;
@@ -784,7 +804,7 @@ int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                         const char *mode) {
   struct SParser p;
   int status;
-  L->nny++;  /* cannot yield during parsing */
+  incnny(L);  /* cannot yield during parsing */
   p.z = z; p.name = name; p.mode = mode;
   p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0;
   p.dyd.gt.arr = NULL; p.dyd.gt.size = 0;
@@ -795,7 +815,7 @@ int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
   luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size);
   luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size);
   luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size);
-  L->nny--;
+  decnny(L);
   return status;
 }
 
diff --git a/libs/liblua/src/ldo.h b/libs/liblua/src/ldo.h
index 3b2983a386..7760f853b2 100644
--- a/libs/liblua/src/ldo.h
+++ b/libs/liblua/src/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 2.29.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ldo.h $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -22,7 +22,8 @@
 */
 #define luaD_checkstackaux(L,n,pre,pos)  \
 	if (L->stack_last - L->top <= (n)) \
-	  { pre; luaD_growstack(L, n); pos; } else { condmovestack(L,pre,pos); }
+	  { pre; luaD_growstack(L, n, 1); pos; } \
+        else { condmovestack(L,pre,pos); }
 
 /* In general, 'pre'/'pos' are empty (nothing to save) */
 #define luaD_checkstack(L,n)	luaD_checkstackaux(L,n,(void)0,(void)0)
@@ -30,24 +31,40 @@
 
 
 #define savestack(L,p)		((char *)(p) - (char *)L->stack)
-#define restorestack(L,n)	((TValue *)((char *)L->stack + (n)))
+#define restorestack(L,n)	((StkId)((char *)L->stack + (n)))
+
+
+/* macro to check stack size, preserving 'p' */
+#define checkstackp(L,n,p)  \
+  luaD_checkstackaux(L, n, \
+    ptrdiff_t t__ = savestack(L, p);  /* save 'p' */ \
+    luaC_checkGC(L),  /* stack grow uses memory */ \
+    p = restorestack(L, t__))  /* 'pos' part: restore 'p' */
+
+
+/* macro to check stack size and GC */
+#define checkstackGC(L,fsize)  \
+	luaD_checkstackaux(L, (fsize), (void)0, luaC_checkGC(L))
 
 
 /* type of protected functions, to be ran by 'runprotected' */
 typedef void (*Pfunc) (lua_State *L, void *ud);
 
+LUAI_FUNC void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop);
 LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                                   const char *mode);
-LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
-LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults);
+LUAI_FUNC void luaD_hook (lua_State *L, int event, int line,
+                                        int fTransfer, int nTransfer);
+LUAI_FUNC void luaD_hookcall (lua_State *L, CallInfo *ci);
+LUAI_FUNC void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int n);
 LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
 LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
+LUAI_FUNC void luaD_tryfuncTM (lua_State *L, StkId func);
 LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u,
                                         ptrdiff_t oldtop, ptrdiff_t ef);
-LUAI_FUNC int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult,
-                                          int nres);
-LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize);
-LUAI_FUNC void luaD_growstack (lua_State *L, int n);
+LUAI_FUNC void luaD_poscall (lua_State *L, CallInfo *ci, int nres);
+LUAI_FUNC int luaD_reallocstack (lua_State *L, int newsize, int raiseerror);
+LUAI_FUNC int luaD_growstack (lua_State *L, int n, int raiseerror);
 LUAI_FUNC void luaD_shrinkstack (lua_State *L);
 LUAI_FUNC void luaD_inctop (lua_State *L);
 
diff --git a/libs/liblua/src/ldump.c b/libs/liblua/src/ldump.c
index f025acac3c..f848b669cb 100644
--- a/libs/liblua/src/ldump.c
+++ b/libs/liblua/src/ldump.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldump.c,v 2.37.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ldump.c $
 ** save precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -29,15 +29,15 @@ typedef struct {
 
 
 /*
-** All high-level dumps go through DumpVector; you can change it to
+** All high-level dumps go through dumpVector; you can change it to
 ** change the endianness of the result
 */
-#define DumpVector(v,n,D)	DumpBlock(v,(n)*sizeof((v)[0]),D)
+#define dumpVector(D,v,n)	dumpBlock(D,v,(n)*sizeof((v)[0]))
 
-#define DumpLiteral(s,D)	DumpBlock(s, sizeof(s) - sizeof(char), D)
+#define dumpLiteral(D, s)	dumpBlock(D,s,sizeof(s) - sizeof(char))
 
 
-static void DumpBlock (const void *b, size_t size, DumpState *D) {
+static void dumpBlock (DumpState *D, const void *b, size_t size) {
   if (D->status == 0 && size > 0) {
     lua_unlock(D->L);
     D->status = (*D->writer)(D->L, b, size, D->data);
@@ -46,153 +46,164 @@ static void DumpBlock (const void *b, size_t size, DumpState *D) {
 }
 
 
-#define DumpVar(x,D)		DumpVector(&x,1,D)
+#define dumpVar(D,x)		dumpVector(D,&x,1)
 
 
-static void DumpByte (int y, DumpState *D) {
+static void dumpByte (DumpState *D, int y) {
   lu_byte x = (lu_byte)y;
-  DumpVar(x, D);
+  dumpVar(D, x);
 }
 
 
-static void DumpInt (int x, DumpState *D) {
-  DumpVar(x, D);
+/* dumpInt Buff Size */
+#define DIBS    ((sizeof(size_t) * 8 / 7) + 1)
+
+static void dumpSize (DumpState *D, size_t x) {
+  lu_byte buff[DIBS];
+  int n = 0;
+  do {
+    buff[DIBS - (++n)] = x & 0x7f;  /* fill buffer in reverse order */
+    x >>= 7;
+  } while (x != 0);
+  buff[DIBS - 1] |= 0x80;  /* mark last byte */
+  dumpVector(D, buff + DIBS - n, n);
+}
+
+
+static void dumpInt (DumpState *D, int x) {
+  dumpSize(D, x);
 }
 
 
-static void DumpNumber (lua_Number x, DumpState *D) {
-  DumpVar(x, D);
+static void dumpNumber (DumpState *D, lua_Number x) {
+  dumpVar(D, x);
 }
 
 
-static void DumpInteger (lua_Integer x, DumpState *D) {
-  DumpVar(x, D);
+static void dumpInteger (DumpState *D, lua_Integer x) {
+  dumpVar(D, x);
 }
 
 
-static void DumpString (const TString *s, DumpState *D) {
+static void dumpString (DumpState *D, const TString *s) {
   if (s == NULL)
-    DumpByte(0, D);
+    dumpSize(D, 0);
   else {
-    size_t size = tsslen(s) + 1;  /* include trailing '\0' */
+    size_t size = tsslen(s);
     const char *str = getstr(s);
-    if (size < 0xFF)
-      DumpByte(cast_int(size), D);
-    else {
-      DumpByte(0xFF, D);
-      DumpVar(size, D);
-    }
-    DumpVector(str, size - 1, D);  /* no need to save '\0' */
+    dumpSize(D, size + 1);
+    dumpVector(D, str, size);
   }
 }
 
 
-static void DumpCode (const Proto *f, DumpState *D) {
-  DumpInt(f->sizecode, D);
-  DumpVector(f->code, f->sizecode, D);
+static void dumpCode (DumpState *D, const Proto *f) {
+  dumpInt(D, f->sizecode);
+  dumpVector(D, f->code, f->sizecode);
 }
 
 
-static void DumpFunction(const Proto *f, TString *psource, DumpState *D);
+static void dumpFunction(DumpState *D, const Proto *f, TString *psource);
 
-static void DumpConstants (const Proto *f, DumpState *D) {
+static void dumpConstants (DumpState *D, const Proto *f) {
   int i;
   int n = f->sizek;
-  DumpInt(n, D);
+  dumpInt(D, n);
   for (i = 0; i < n; i++) {
     const TValue *o = &f->k[i];
-    DumpByte(ttype(o), D);
-    switch (ttype(o)) {
-    case LUA_TNIL:
-      break;
-    case LUA_TBOOLEAN:
-      DumpByte(bvalue(o), D);
-      break;
-    case LUA_TNUMFLT:
-      DumpNumber(fltvalue(o), D);
-      break;
-    case LUA_TNUMINT:
-      DumpInteger(ivalue(o), D);
-      break;
-    case LUA_TSHRSTR:
-    case LUA_TLNGSTR:
-      DumpString(tsvalue(o), D);
-      break;
-    default:
-      lua_assert(0);
+    int tt = ttypetag(o);
+    dumpByte(D, tt);
+    switch (tt) {
+      case LUA_VNUMFLT:
+        dumpNumber(D, fltvalue(o));
+        break;
+      case LUA_VNUMINT:
+        dumpInteger(D, ivalue(o));
+        break;
+      case LUA_VSHRSTR:
+      case LUA_VLNGSTR:
+        dumpString(D, tsvalue(o));
+        break;
+      default:
+        lua_assert(tt == LUA_VNIL || tt == LUA_VFALSE || tt == LUA_VTRUE);
     }
   }
 }
 
 
-static void DumpProtos (const Proto *f, DumpState *D) {
+static void dumpProtos (DumpState *D, const Proto *f) {
   int i;
   int n = f->sizep;
-  DumpInt(n, D);
+  dumpInt(D, n);
   for (i = 0; i < n; i++)
-    DumpFunction(f->p[i], f->source, D);
+    dumpFunction(D, f->p[i], f->source);
 }
 
 
-static void DumpUpvalues (const Proto *f, DumpState *D) {
+static void dumpUpvalues (DumpState *D, const Proto *f) {
   int i, n = f->sizeupvalues;
-  DumpInt(n, D);
+  dumpInt(D, n);
   for (i = 0; i < n; i++) {
-    DumpByte(f->upvalues[i].instack, D);
-    DumpByte(f->upvalues[i].idx, D);
+    dumpByte(D, f->upvalues[i].instack);
+    dumpByte(D, f->upvalues[i].idx);
+    dumpByte(D, f->upvalues[i].kind);
   }
 }
 
 
-static void DumpDebug (const Proto *f, DumpState *D) {
+static void dumpDebug (DumpState *D, const Proto *f) {
   int i, n;
   n = (D->strip) ? 0 : f->sizelineinfo;
-  DumpInt(n, D);
-  DumpVector(f->lineinfo, n, D);
+  dumpInt(D, n);
+  dumpVector(D, f->lineinfo, n);
+  n = (D->strip) ? 0 : f->sizeabslineinfo;
+  dumpInt(D, n);
+  for (i = 0; i < n; i++) {
+    dumpInt(D, f->abslineinfo[i].pc);
+    dumpInt(D, f->abslineinfo[i].line);
+  }
   n = (D->strip) ? 0 : f->sizelocvars;
-  DumpInt(n, D);
+  dumpInt(D, n);
   for (i = 0; i < n; i++) {
-    DumpString(f->locvars[i].varname, D);
-    DumpInt(f->locvars[i].startpc, D);
-    DumpInt(f->locvars[i].endpc, D);
+    dumpString(D, f->locvars[i].varname);
+    dumpInt(D, f->locvars[i].startpc);
+    dumpInt(D, f->locvars[i].endpc);
   }
   n = (D->strip) ? 0 : f->sizeupvalues;
-  DumpInt(n, D);
+  dumpInt(D, n);
   for (i = 0; i < n; i++)
-    DumpString(f->upvalues[i].name, D);
+    dumpString(D, f->upvalues[i].name);
 }
 
 
-static void DumpFunction (const Proto *f, TString *psource, DumpState *D) {
+static void dumpFunction (DumpState *D, const Proto *f, TString *psource) {
   if (D->strip || f->source == psource)
-    DumpString(NULL, D);  /* no debug info or same source as its parent */
+    dumpString(D, NULL);  /* no debug info or same source as its parent */
   else
-    DumpString(f->source, D);
-  DumpInt(f->linedefined, D);
-  DumpInt(f->lastlinedefined, D);
-  DumpByte(f->numparams, D);
-  DumpByte(f->is_vararg, D);
-  DumpByte(f->maxstacksize, D);
-  DumpCode(f, D);
-  DumpConstants(f, D);
-  DumpUpvalues(f, D);
-  DumpProtos(f, D);
-  DumpDebug(f, D);
+    dumpString(D, f->source);
+  dumpInt(D, f->linedefined);
+  dumpInt(D, f->lastlinedefined);
+  dumpByte(D, f->numparams);
+  dumpByte(D, f->is_vararg);
+  dumpByte(D, f->maxstacksize);
+  dumpCode(D, f);
+  dumpConstants(D, f);
+  dumpUpvalues(D, f);
+  dumpProtos(D, f);
+  dumpDebug(D, f);
 }
 
 
-static void DumpHeader (DumpState *D) {
-  DumpLiteral(LUA_SIGNATURE, D);
-  DumpByte(LUAC_VERSION, D);
-  DumpByte(LUAC_FORMAT, D);
-  DumpLiteral(LUAC_DATA, D);
-  DumpByte(sizeof(int), D);
-  DumpByte(sizeof(size_t), D);
-  DumpByte(sizeof(Instruction), D);
-  DumpByte(sizeof(lua_Integer), D);
-  DumpByte(sizeof(lua_Number), D);
-  DumpInteger(LUAC_INT, D);
-  DumpNumber(LUAC_NUM, D);
+static void dumpHeader (DumpState *D) {
+  dumpLiteral(D, LUA_SIGNATURE);
+  dumpByte(D, LUAC_VERSION);
+  dumpByte(D, LUAC_FORMAT);
+  dumpLiteral(D, LUAC_DATA);
+  dumpByte(D, sizeof(Instruction));
+  dumpByte(D, sizeof(lua_Integer));
+  dumpByte(D, sizeof(lua_Number));
+  dumpInteger(D, LUAC_INT);
+  dumpNumber(D, LUAC_NUM);
 }
 
 
@@ -207,9 +218,9 @@ int luaU_dump(lua_State *L, const Proto *f, lua_Writer w, void *data,
   D.data = data;
   D.strip = strip;
   D.status = 0;
-  DumpHeader(&D);
-  DumpByte(f->sizeupvalues, &D);
-  DumpFunction(f, NULL, &D);
+  dumpHeader(&D);
+  dumpByte(&D, f->sizeupvalues);
+  dumpFunction(&D, f, NULL);
   return D.status;
 }
 
diff --git a/libs/liblua/src/lfunc.c b/libs/liblua/src/lfunc.c
index ccafbb8ab3..10100e5aca 100644
--- a/libs/liblua/src/lfunc.c
+++ b/libs/liblua/src/lfunc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.c,v 2.45.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lfunc.c $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
@@ -14,6 +14,8 @@
 
 #include "lua.h"
 
+#include "ldebug.h"
+#include "ldo.h"
 #include "lfunc.h"
 #include "lgc.h"
 #include "lmem.h"
@@ -22,92 +24,237 @@
 
 
 
-CClosure *luaF_newCclosure (lua_State *L, int n) {
-  GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n));
+CClosure *luaF_newCclosure (lua_State *L, int nupvals) {
+  GCObject *o = luaC_newobj(L, LUA_VCCL, sizeCclosure(nupvals));
   CClosure *c = gco2ccl(o);
-  c->nupvalues = cast_byte(n);
+  c->nupvalues = cast_byte(nupvals);
   return c;
 }
 
 
-LClosure *luaF_newLclosure (lua_State *L, int n) {
-  GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n));
+LClosure *luaF_newLclosure (lua_State *L, int nupvals) {
+  GCObject *o = luaC_newobj(L, LUA_VLCL, sizeLclosure(nupvals));
   LClosure *c = gco2lcl(o);
   c->p = NULL;
-  c->nupvalues = cast_byte(n);
-  while (n--) c->upvals[n] = NULL;
+  c->nupvalues = cast_byte(nupvals);
+  while (nupvals--) c->upvals[nupvals] = NULL;
   return c;
 }
 
+
 /*
 ** fill a closure with new closed upvalues
 */
 void luaF_initupvals (lua_State *L, LClosure *cl) {
   int i;
   for (i = 0; i < cl->nupvalues; i++) {
-    UpVal *uv = luaM_new(L, UpVal);
-    uv->refcount = 1;
+    GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
+    UpVal *uv = gco2upv(o);
     uv->v = &uv->u.value;  /* make it closed */
     setnilvalue(uv->v);
     cl->upvals[i] = uv;
+    luaC_objbarrier(L, cl, o);
   }
 }
 
 
+/*
+** Create a new upvalue at the given level, and link it to the list of
+** open upvalues of 'L' after entry 'prev'.
+**/
+static UpVal *newupval (lua_State *L, int tbc, StkId level, UpVal **prev) {
+  GCObject *o = luaC_newobj(L, LUA_VUPVAL, sizeof(UpVal));
+  UpVal *uv = gco2upv(o);
+  UpVal *next = *prev;
+  uv->v = s2v(level);  /* current value lives in the stack */
+  uv->tbc = tbc;
+  uv->u.open.next = next;  /* link it to list of open upvalues */
+  uv->u.open.previous = prev;
+  if (next)
+    next->u.open.previous = &uv->u.open.next;
+  *prev = uv;
+  if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
+    L->twups = G(L)->twups;  /* link it to the list */
+    G(L)->twups = L;
+  }
+  return uv;
+}
+
+
+/*
+** Find and reuse, or create if it does not exist, an upvalue
+** at the given level.
+*/
 UpVal *luaF_findupval (lua_State *L, StkId level) {
   UpVal **pp = &L->openupval;
   UpVal *p;
-  UpVal *uv;
   lua_assert(isintwups(L) || L->openupval == NULL);
-  while (*pp != NULL && (p = *pp)->v >= level) {
-    lua_assert(upisopen(p));
-    if (p->v == level)  /* found a corresponding upvalue? */
+  while ((p = *pp) != NULL && uplevel(p) >= level) {  /* search for it */
+    lua_assert(!isdead(G(L), p));
+    if (uplevel(p) == level)  /* corresponding upvalue? */
       return p;  /* return it */
     pp = &p->u.open.next;
   }
-  /* not found: create a new upvalue */
-  uv = luaM_new(L, UpVal);
-  uv->refcount = 0;
-  uv->u.open.next = *pp;  /* link it to list of open upvalues */
-  uv->u.open.touched = 1;
-  *pp = uv;
-  uv->v = level;  /* current value lives in the stack */
-  if (!isintwups(L)) {  /* thread not in list of threads with upvalues? */
-    L->twups = G(L)->twups;  /* link it to the list */
-    G(L)->twups = L;
+  /* not found: create a new upvalue after 'pp' */
+  return newupval(L, 0, level, pp);
+}
+
+
+static void callclose (lua_State *L, void *ud) {
+  UNUSED(ud);
+  luaD_callnoyield(L, L->top - 3, 0);
+}
+
+
+/*
+** Prepare closing method plus its arguments for object 'obj' with
+** error message 'err'. (This function assumes EXTRA_STACK.)
+*/
+static int prepclosingmethod (lua_State *L, TValue *obj, TValue *err) {
+  StkId top = L->top;
+  const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
+  if (ttisnil(tm))  /* no metamethod? */
+    return 0;  /* nothing to call */
+  setobj2s(L, top, tm);  /* will call metamethod... */
+  setobj2s(L, top + 1, obj);  /* with 'self' as the 1st argument */
+  setobj2s(L, top + 2, err);  /* and error msg. as 2nd argument */
+  L->top = top + 3;  /* add function and arguments */
+  return 1;
+}
+
+
+/*
+** Raise an error with message 'msg', inserting the name of the
+** local variable at position 'level' in the stack.
+*/
+static void varerror (lua_State *L, StkId level, const char *msg) {
+  int idx = cast_int(level - L->ci->func);
+  const char *vname = luaG_findlocal(L, L->ci, idx, NULL);
+  if (vname == NULL) vname = "?";
+  luaG_runerror(L, msg, vname);
+}
+
+
+/*
+** Prepare and call a closing method. If status is OK, code is still
+** inside the original protected call, and so any error will be handled
+** there. Otherwise, a previous error already activated the original
+** protected call, and so the call to the closing method must be
+** protected here. (A status == CLOSEPROTECT behaves like a previous
+** error, to also run the closing method in protected mode).
+** If status is OK, the call to the closing method will be pushed
+** at the top of the stack. Otherwise, values are pushed after
+** the 'level' of the upvalue being closed, as everything after
+** that won't be used again.
+*/
+static int callclosemth (lua_State *L, StkId level, int status) {
+  TValue *uv = s2v(level);  /* value being closed */
+  if (likely(status == LUA_OK)) {
+    if (prepclosingmethod(L, uv, &G(L)->nilvalue))  /* something to call? */
+      callclose(L, NULL);  /* call closing method */
+    else if (!l_isfalse(uv))  /* non-closable non-false value? */
+      varerror(L, level, "attempt to close non-closable variable '%s'");
   }
-  return uv;
+  else {  /* must close the object in protected mode */
+    ptrdiff_t oldtop;
+    level++;  /* space for error message */
+    oldtop = savestack(L, level + 1);  /* top will be after that */
+    luaD_seterrorobj(L, status, level);  /* set error message */
+    if (prepclosingmethod(L, uv, s2v(level))) {  /* something to call? */
+      int newstatus = luaD_pcall(L, callclose, NULL, oldtop, 0);
+      if (newstatus != LUA_OK && status == CLOSEPROTECT)  /* first error? */
+        status = newstatus;  /* this will be the new error */
+      else {
+        if (newstatus != LUA_OK)  /* suppressed error? */
+          luaE_warnerror(L, "__close metamethod");
+        /* leave original error (or nil) on top */
+        L->top = restorestack(L, oldtop);
+      }
+    }
+    /* else no metamethod; ignore this case and keep original error */
+  }
+  return status;
+}
+
+
+/*
+** Try to create a to-be-closed upvalue
+** (can raise a memory-allocation error)
+*/
+static void trynewtbcupval (lua_State *L, void *ud) {
+  newupval(L, 1, cast(StkId, ud), &L->openupval);
+}
+
+
+/*
+** Create a to-be-closed upvalue. If there is a memory error
+** when creating the upvalue, the closing method must be called here,
+** as there is no upvalue to call it later.
+*/
+void luaF_newtbcupval (lua_State *L, StkId level) {
+  TValue *obj = s2v(level);
+  lua_assert(L->openupval == NULL || uplevel(L->openupval) < level);
+  if (!l_isfalse(obj)) {  /* false doesn't need to be closed */
+    int status;
+    const TValue *tm = luaT_gettmbyobj(L, obj, TM_CLOSE);
+    if (ttisnil(tm))  /* no metamethod? */
+      varerror(L, level, "variable '%s' got a non-closable value");
+    status = luaD_rawrunprotected(L, trynewtbcupval, level);
+    if (unlikely(status != LUA_OK)) {  /* memory error creating upvalue? */
+      lua_assert(status == LUA_ERRMEM);
+      luaD_seterrorobj(L, LUA_ERRMEM, level + 1);  /* save error message */
+      /* next call must succeed, as object is closable */
+      prepclosingmethod(L, s2v(level), s2v(level + 1));
+      callclose(L, NULL);  /* call closing method */
+      luaD_throw(L, LUA_ERRMEM);  /* throw memory error */
+    }
+  }
+}
+
+
+void luaF_unlinkupval (UpVal *uv) {
+  lua_assert(upisopen(uv));
+  *uv->u.open.previous = uv->u.open.next;
+  if (uv->u.open.next)
+    uv->u.open.next->u.open.previous = uv->u.open.previous;
 }
 
 
-void luaF_close (lua_State *L, StkId level) {
+int luaF_close (lua_State *L, StkId level, int status) {
   UpVal *uv;
-  while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
-    lua_assert(upisopen(uv));
-    L->openupval = uv->u.open.next;  /* remove from 'open' list */
-    if (uv->refcount == 0)  /* no references? */
-      luaM_free(L, uv);  /* free upvalue */
-    else {
-      setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */
-      uv->v = &uv->u.value;  /* now current value lives here */
-      luaC_upvalbarrier(L, uv);
+  while ((uv = L->openupval) != NULL && uplevel(uv) >= level) {
+    TValue *slot = &uv->u.value;  /* new position for value */
+    lua_assert(uplevel(uv) < L->top);
+    if (uv->tbc && status != NOCLOSINGMETH) {
+      /* must run closing method, which may change the stack */
+      ptrdiff_t levelrel = savestack(L, level);
+      status = callclosemth(L, uplevel(uv), status);
+      level = restorestack(L, levelrel);
     }
+    luaF_unlinkupval(uv);
+    setobj(L, slot, uv->v);  /* move value to upvalue slot */
+    uv->v = slot;  /* now current value lives here */
+    if (!iswhite(uv))
+      gray2black(uv);  /* closed upvalues cannot be gray */
+    luaC_barrier(L, uv, slot);
   }
+  return status;
 }
 
 
 Proto *luaF_newproto (lua_State *L) {
-  GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto));
+  GCObject *o = luaC_newobj(L, LUA_VPROTO, sizeof(Proto));
   Proto *f = gco2p(o);
   f->k = NULL;
   f->sizek = 0;
   f->p = NULL;
   f->sizep = 0;
   f->code = NULL;
-  f->cache = NULL;
   f->sizecode = 0;
   f->lineinfo = NULL;
   f->sizelineinfo = 0;
+  f->abslineinfo = NULL;
+  f->sizeabslineinfo = 0;
   f->upvalues = NULL;
   f->sizeupvalues = 0;
   f->numparams = 0;
@@ -127,6 +274,7 @@ void luaF_freeproto (lua_State *L, Proto *f) {
   luaM_freearray(L, f->p, f->sizep);
   luaM_freearray(L, f->k, f->sizek);
   luaM_freearray(L, f->lineinfo, f->sizelineinfo);
+  luaM_freearray(L, f->abslineinfo, f->sizeabslineinfo);
   luaM_freearray(L, f->locvars, f->sizelocvars);
   luaM_freearray(L, f->upvalues, f->sizeupvalues);
   luaM_free(L, f);
diff --git a/libs/liblua/src/lfunc.h b/libs/liblua/src/lfunc.h
index c916e9878a..8d6f965cfc 100644
--- a/libs/liblua/src/lfunc.h
+++ b/libs/liblua/src/lfunc.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.h,v 2.15.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lfunc.h $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
@@ -11,11 +11,11 @@
 #include "lobject.h"
 
 
-#define sizeCclosure(n)	(cast(int, sizeof(CClosure)) + \
-                         cast(int, sizeof(TValue)*((n)-1)))
+#define sizeCclosure(n)	(cast_int(offsetof(CClosure, upvalue)) + \
+                         cast_int(sizeof(TValue)) * (n))
 
-#define sizeLclosure(n)	(cast(int, sizeof(LClosure)) + \
-                         cast(int, sizeof(TValue *)*((n)-1)))
+#define sizeLclosure(n)	(cast_int(offsetof(LClosure, upvals)) + \
+                         cast_int(sizeof(TValue *)) * (n))
 
 
 /* test whether thread is in 'twups' list */
@@ -29,30 +29,38 @@
 #define MAXUPVAL	255
 
 
+#define upisopen(up)	((up)->v != &(up)->u.value)
+
+
+#define uplevel(up)	check_exp(upisopen(up), cast(StkId, (up)->v))
+
+
 /*
-** Upvalues for Lua closures
+** maximum number of misses before giving up the cache of closures
+** in prototypes
 */
-struct UpVal {
-  TValue *v;  /* points to stack or to its own value */
-  lu_mem refcount;  /* reference counter */
-  union {
-    struct {  /* (when open) */
-      UpVal *next;  /* linked list */
-      int touched;  /* mark to avoid cycles with dead threads */
-    } open;
-    TValue value;  /* the value (when closed) */
-  } u;
-};
+#define MAXMISS		10
 
-#define upisopen(up)	((up)->v != &(up)->u.value)
+
+/*
+** Special "status" for 'luaF_close'
+*/
+
+/* close upvalues without running their closing methods */
+#define NOCLOSINGMETH	(-1)
+
+/* close upvalues running all closing methods in protected mode */
+#define CLOSEPROTECT	(-2)
 
 
 LUAI_FUNC Proto *luaF_newproto (lua_State *L);
-LUAI_FUNC CClosure *luaF_newCclosure (lua_State *L, int nelems);
-LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nelems);
+LUAI_FUNC CClosure *luaF_newCclosure (lua_State *L, int nupvals);
+LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nupvals);
 LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl);
 LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
-LUAI_FUNC void luaF_close (lua_State *L, StkId level);
+LUAI_FUNC void luaF_newtbcupval (lua_State *L, StkId level);
+LUAI_FUNC int luaF_close (lua_State *L, StkId level, int status);
+LUAI_FUNC void luaF_unlinkupval (UpVal *uv);
 LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
 LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
                                          int pc);
diff --git a/libs/liblua/src/lgc.c b/libs/liblua/src/lgc.c
index db4df82922..f26c921a96 100644
--- a/libs/liblua/src/lgc.c
+++ b/libs/liblua/src/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.215.1.2 2017/08/31 16:15:27 roberto Exp $
+** $Id: lgc.c $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -9,9 +9,10 @@
 
 #include "lprefix.h"
 
-
+#include <stdio.h>
 #include <string.h>
 
+
 #include "lua.h"
 
 #include "ldebug.h"
@@ -27,29 +28,29 @@
 
 
 /*
-** internal state for collector while inside the atomic phase. The
-** collector should never be in this state while running regular code.
+** Maximum number of elements to sweep in each single step.
+** (Large enough to dissipate fixed overheads but small enough
+** to allow small steps for the collector.)
 */
-#define GCSinsideatomic		(GCSpause + 1)
+#define GCSWEEPMAX	100
 
 /*
-** cost of sweeping one element (the size of a small object divided
-** by some adjust for the sweep speed)
+** Maximum number of finalizers to call in each single step.
 */
-#define GCSWEEPCOST	((sizeof(TString) + 4) / 4)
+#define GCFINMAX	10
 
-/* maximum number of elements to sweep in each single step */
-#define GCSWEEPMAX	(cast_int((GCSTEPSIZE / GCSWEEPCOST) / 4))
 
-/* cost of calling one finalizer */
-#define GCFINALIZECOST	GCSWEEPCOST
+/*
+** Cost of calling one finalizer.
+*/
+#define GCFINALIZECOST	50
 
 
 /*
-** macro to adjust 'stepmul': 'stepmul' is actually used like
-** 'stepmul / STEPMULADJ' (value chosen by tests)
+** The equivalent, in bytes, of one unit of "work" (visiting a slot,
+** sweeping an object, etc.)
 */
-#define STEPMULADJ		200
+#define WORK2MEM	sizeof(TValue)
 
 
 /*
@@ -59,11 +60,11 @@
 #define PAUSEADJ		100
 
 
-/*
-** 'makewhite' erases all color bits then sets only the current white
-** bit
-*/
-#define maskcolors	(~(bitmask(BLACKBIT) | WHITEBITS))
+/* mask to erase all color bits (plus gen. related stuff) */
+#define maskcolors	(~(bitmask(BLACKBIT) | WHITEBITS | AGEBITS))
+
+
+/* macro to erase all color bits then sets only the current white bit */
 #define makewhite(g,x)	\
  (x->marked = cast_byte((x->marked & maskcolors) | luaC_white(g)))
 
@@ -73,16 +74,23 @@
 
 #define valiswhite(x)   (iscollectable(x) && iswhite(gcvalue(x)))
 
-#define checkdeadkey(n)	lua_assert(!ttisdeadkey(gkey(n)) || ttisnil(gval(n)))
+#define keyiswhite(n)   (keyiscollectable(n) && iswhite(gckey(n)))
 
 
 #define checkconsistency(obj)  \
   lua_longassert(!iscollectable(obj) || righttt(obj))
 
+/*
+** Protected access to objects in values
+*/
+#define gcvalueN(o)     (iscollectable(o) ? gcvalue(o) : NULL)
+
 
 #define markvalue(g,o) { checkconsistency(o); \
   if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); }
 
+#define markkey(g, n)	{ if keyiswhite(n) reallymarkobject(g,gckey(n)); }
+
 #define markobject(g,t)	{ if (iswhite(t)) reallymarkobject(g, obj2gco(t)); }
 
 /*
@@ -92,6 +100,8 @@
 #define markobjectN(g,t)	{ if (t) markobject(g,t); }
 
 static void reallymarkobject (global_State *g, GCObject *o);
+static lu_mem atomic (lua_State *L);
+static void entersweep (lua_State *L);
 
 
 /*
@@ -104,28 +114,52 @@ static void reallymarkobject (global_State *g, GCObject *o);
 /*
 ** one after last element in a hash array
 */
-#define gnodelast(h)	gnode(h, cast(size_t, sizenode(h)))
+#define gnodelast(h)	gnode(h, cast_sizet(sizenode(h)))
+
+
+static GCObject **getgclist (GCObject *o) {
+  switch (o->tt) {
+    case LUA_VTABLE: return &gco2t(o)->gclist;
+    case LUA_VLCL: return &gco2lcl(o)->gclist;
+    case LUA_VCCL: return &gco2ccl(o)->gclist;
+    case LUA_VTHREAD: return &gco2th(o)->gclist;
+    case LUA_VPROTO: return &gco2p(o)->gclist;
+    case LUA_VUSERDATA: {
+      Udata *u = gco2u(o);
+      lua_assert(u->nuvalue > 0);
+      return &u->gclist;
+    }
+    default: lua_assert(0); return 0;
+  }
+}
 
 
 /*
-** link collectable object 'o' into list pointed by 'p'
+** Link a collectable object 'o' with a known type into list pointed by 'p'.
 */
 #define linkgclist(o,p)	((o)->gclist = (p), (p) = obj2gco(o))
 
 
 /*
-** If key is not marked, mark its entry as dead. This allows key to be
-** collected, but keeps its entry in the table.  A dead node is needed
-** when Lua looks up for a key (it may be part of a chain) and when
-** traversing a weak table (key might be removed from the table during
-** traversal). Other places never manipulate dead keys, because its
-** associated nil value is enough to signal that the entry is logically
-** empty.
+** Link a generic collectable object 'o' into list pointed by 'p'.
 */
-static void removeentry (Node *n) {
-  lua_assert(ttisnil(gval(n)));
-  if (valiswhite(gkey(n)))
-    setdeadvalue(wgkey(n));  /* unused and unmarked key; remove it */
+#define linkobjgclist(o,p) (*getgclist(o) = (p), (p) = obj2gco(o))
+
+
+
+/*
+** Clear keys for empty entries in tables. If entry is empty
+** and its key is not marked, mark its entry as dead. This allows the
+** collection of the key, but keeps its entry in the table (its removal
+** could break a chain). The main feature of a dead key is that it must
+** be different from any other value, to do not disturb searches.
+** Other places never manipulate dead keys, because its associated empty
+** value is enough to signal that the entry is logically empty.
+*/
+static void clearkey (Node *n) {
+  lua_assert(isempty(gval(n)));
+  if (keyiswhite(n))
+    setdeadkey(n);  /* unused and unmarked key; remove it */
 }
 
 
@@ -136,27 +170,36 @@ static void removeentry (Node *n) {
 ** other objects: if really collected, cannot keep them; for objects
 ** being finalized, keep them in keys, but not in values
 */
-static int iscleared (global_State *g, const TValue *o) {
-  if (!iscollectable(o)) return 0;
-  else if (ttisstring(o)) {
-    markobject(g, tsvalue(o));  /* strings are 'values', so are never weak */
+static int iscleared (global_State *g, const GCObject *o) {
+  if (o == NULL) return 0;  /* non-collectable value */
+  else if (novariant(o->tt) == LUA_TSTRING) {
+    markobject(g, o);  /* strings are 'values', so are never weak */
     return 0;
   }
-  else return iswhite(gcvalue(o));
+  else return iswhite(o);
 }
 
 
 /*
 ** barrier that moves collector forward, that is, mark the white object
-** being pointed by a black object. (If in sweep phase, clear the black
-** object to white [sweep it] to avoid other barrier calls for this
-** same object.)
+** 'v' being pointed by the black object 'o'. (If in sweep phase, clear
+** the black object to white [sweep it] to avoid other barrier calls for
+** this same object.) In the generational mode, 'v' must also become
+** old, if 'o' is old; however, it cannot be changed directly to OLD,
+** because it may still point to non-old objects. So, it is marked as
+** OLD0. In the next cycle it will become OLD1, and in the next it
+** will finally become OLD (regular old).
 */
 void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
   global_State *g = G(L);
   lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
-  if (keepinvariant(g))  /* must keep invariant? */
+  if (keepinvariant(g)) {  /* must keep invariant? */
     reallymarkobject(g, v);  /* restore invariant */
+    if (isold(o)) {
+      lua_assert(!isold(v));  /* white object could not be old */
+      setage(v, G_OLD0);  /* restore generational invariant */
+    }
+  }
   else {  /* sweep phase */
     lua_assert(issweepphase(g));
     makewhite(g, o);  /* mark main obj. as white to avoid other barriers */
@@ -168,26 +211,14 @@ void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
 ** barrier that moves collector backward, that is, mark the black object
 ** pointing to a white object as gray again.
 */
-void luaC_barrierback_ (lua_State *L, Table *t) {
+void luaC_barrierback_ (lua_State *L, GCObject *o) {
   global_State *g = G(L);
-  lua_assert(isblack(t) && !isdead(g, t));
-  black2gray(t);  /* make table gray (again) */
-  linkgclist(t, g->grayagain);
-}
-
-
-/*
-** barrier for assignments to closed upvalues. Because upvalues are
-** shared among closures, it is impossible to know the color of all
-** closures pointing to it. So, we assume that the object being assigned
-** must be marked.
-*/
-void luaC_upvalbarrier_ (lua_State *L, UpVal *uv) {
-  global_State *g = G(L);
-  GCObject *o = gcvalue(uv->v);
-  lua_assert(!upisopen(uv));  /* ensured by macro luaC_upvalbarrier */
-  if (keepinvariant(g))
-    markobject(g, o);
+  lua_assert(isblack(o) && !isdead(g, o));
+  lua_assert(g->gckind != KGC_GEN || (isold(o) && getage(o) != G_TOUCHED1));
+  if (getage(o) != G_TOUCHED2)  /* not already in gray list? */
+    linkobjgclist(o, g->grayagain);  /* link it in 'grayagain' */
+  black2gray(o);  /* make object gray (again) */
+  setage(o, G_TOUCHED1);  /* touched in current cycle */
 }
 
 
@@ -195,6 +226,7 @@ void luaC_fix (lua_State *L, GCObject *o) {
   global_State *g = G(L);
   lua_assert(g->allgc == o);  /* object must be 1st in 'allgc' list! */
   white2gray(o);  /* they will be gray forever */
+  setage(o, G_OLD);  /* and old forever */
   g->allgc = o->next;  /* remove object from 'allgc' list */
   o->next = g->fixedgc;  /* link it to 'fixedgc' list */
   g->fixedgc = o;
@@ -227,55 +259,39 @@ GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) {
 
 
 /*
-** mark an object. Userdata, strings, and closed upvalues are visited
+** Mark an object. Userdata, strings, and closed upvalues are visited
 ** and turned black here. Other objects are marked gray and added
 ** to appropriate list to be visited (and turned black) later. (Open
-** upvalues are already linked in 'headuv' list.)
+** upvalues are already linked in 'headuv' list. They are kept gray
+** to avoid barriers, as their values will be revisited by the thread.)
 */
 static void reallymarkobject (global_State *g, GCObject *o) {
- reentry:
   white2gray(o);
   switch (o->tt) {
-    case LUA_TSHRSTR: {
+    case LUA_VSHRSTR:
+    case LUA_VLNGSTR: {
       gray2black(o);
-      g->GCmemtrav += sizelstring(gco2ts(o)->shrlen);
       break;
     }
-    case LUA_TLNGSTR: {
-      gray2black(o);
-      g->GCmemtrav += sizelstring(gco2ts(o)->u.lnglen);
+    case LUA_VUPVAL: {
+      UpVal *uv = gco2upv(o);
+      if (!upisopen(uv))  /* open upvalues are kept gray */
+        gray2black(o);
+      markvalue(g, uv->v);  /* mark its content */
       break;
     }
-    case LUA_TUSERDATA: {
-      TValue uvalue;
-      markobjectN(g, gco2u(o)->metatable);  /* mark its metatable */
-      gray2black(o);
-      g->GCmemtrav += sizeudata(gco2u(o));
-      getuservalue(g->mainthread, gco2u(o), &uvalue);
-      if (valiswhite(&uvalue)) {  /* markvalue(g, &uvalue); */
-        o = gcvalue(&uvalue);
-        goto reentry;
+    case LUA_VUSERDATA: {
+      Udata *u = gco2u(o);
+      if (u->nuvalue == 0) {  /* no user values? */
+        markobjectN(g, u->metatable);  /* mark its metatable */
+        gray2black(o);  /* nothing else to mark */
+        break;
       }
-      break;
-    }
-    case LUA_TLCL: {
-      linkgclist(gco2lcl(o), g->gray);
-      break;
-    }
-    case LUA_TCCL: {
-      linkgclist(gco2ccl(o), g->gray);
-      break;
-    }
-    case LUA_TTABLE: {
-      linkgclist(gco2t(o), g->gray);
-      break;
-    }
-    case LUA_TTHREAD: {
-      linkgclist(gco2th(o), g->gray);
-      break;
-    }
-    case LUA_TPROTO: {
-      linkgclist(gco2p(o), g->gray);
+      /* else... */
+    }  /* FALLTHROUGH */
+    case LUA_VLCL: case LUA_VCCL: case LUA_VTABLE:
+    case LUA_VTHREAD: case LUA_VPROTO: {
+      linkobjgclist(o, g->gray);
       break;
     }
     default: lua_assert(0); break;
@@ -296,10 +312,14 @@ static void markmt (global_State *g) {
 /*
 ** mark all objects in list of being-finalized
 */
-static void markbeingfnz (global_State *g) {
+static lu_mem markbeingfnz (global_State *g) {
   GCObject *o;
-  for (o = g->tobefnz; o != NULL; o = o->next)
+  lu_mem count = 0;
+  for (o = g->tobefnz; o != NULL; o = o->next) {
+    count++;
     markobject(g, o);
+  }
+  return count;
 }
 
 
@@ -309,10 +329,12 @@ static void markbeingfnz (global_State *g) {
 ** thread.) Remove from the list threads that no longer have upvalues and
 ** not-marked threads.
 */
-static void remarkupvals (global_State *g) {
+static int remarkupvals (global_State *g) {
   lua_State *thread;
   lua_State **p = &g->twups;
+  int work = 0;
   while ((thread = *p) != NULL) {
+    work++;
     lua_assert(!isblack(thread));  /* threads are never black */
     if (isgray(thread) && thread->openupval != NULL)
       p = &thread->twups;  /* keep marked thread with upvalues in the list */
@@ -321,13 +343,13 @@ static void remarkupvals (global_State *g) {
       *p = thread->twups;  /* remove thread from the list */
       thread->twups = thread;  /* mark that it is out of list */
       for (uv = thread->openupval; uv != NULL; uv = uv->u.open.next) {
-        if (uv->u.open.touched) {
-          markvalue(g, uv->v);  /* remark upvalue's value */
-          uv->u.open.touched = 0;
-        }
+        work++;
+        if (!iswhite(uv))  /* upvalue already visited? */
+          markvalue(g, uv->v);  /* mark its value */
       }
     }
   }
+  return work;
 }
 
 
@@ -362,22 +384,21 @@ static void traverseweakvalue (global_State *g, Table *h) {
   Node *n, *limit = gnodelast(h);
   /* if there is array part, assume it may have white values (it is not
      worth traversing it now just to check) */
-  int hasclears = (h->sizearray > 0);
+  int hasclears = (h->alimit > 0);
   for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
-    checkdeadkey(n);
-    if (ttisnil(gval(n)))  /* entry is empty? */
-      removeentry(n);  /* remove it */
+    if (isempty(gval(n)))  /* entry is empty? */
+      clearkey(n);  /* clear its key */
     else {
-      lua_assert(!ttisnil(gkey(n)));
-      markvalue(g, gkey(n));  /* mark key */
-      if (!hasclears && iscleared(g, gval(n)))  /* is there a white value? */
+      lua_assert(!keyisnil(n));
+      markkey(g, n);
+      if (!hasclears && iscleared(g, gcvalueN(gval(n))))  /* a white value? */
         hasclears = 1;  /* table will have to be cleared */
     }
   }
-  if (g->gcstate == GCSpropagate)
-    linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
-  else if (hasclears)
+  if (g->gcstate == GCSatomic && hasclears)
     linkgclist(h, g->weak);  /* has to be cleared later */
+  else
+    linkgclist(h, g->grayagain);  /* must retraverse it in atomic phase */
 }
 
 
@@ -389,27 +410,30 @@ static void traverseweakvalue (global_State *g, Table *h) {
 ** the atomic phase, if table has any white->white entry, it has to
 ** be revisited during ephemeron convergence (as that key may turn
 ** black). Otherwise, if it has any white key, table has to be cleared
-** (in the atomic phase).
+** (in the atomic phase). In generational mode, it (like all visited
+** tables) must be kept in some gray list for post-processing.
 */
-static int traverseephemeron (global_State *g, Table *h) {
+static int traverseephemeron (global_State *g, Table *h, int inv) {
   int marked = 0;  /* true if an object is marked in this traversal */
   int hasclears = 0;  /* true if table has white keys */
   int hasww = 0;  /* true if table has entry "white-key -> white-value" */
-  Node *n, *limit = gnodelast(h);
   unsigned int i;
+  unsigned int asize = luaH_realasize(h);
+  unsigned int nsize = sizenode(h);
   /* traverse array part */
-  for (i = 0; i < h->sizearray; i++) {
+  for (i = 0; i < asize; i++) {
     if (valiswhite(&h->array[i])) {
       marked = 1;
       reallymarkobject(g, gcvalue(&h->array[i]));
     }
   }
-  /* traverse hash part */
-  for (n = gnode(h, 0); n < limit; n++) {
-    checkdeadkey(n);
-    if (ttisnil(gval(n)))  /* entry is empty? */
-      removeentry(n);  /* remove it */
-    else if (iscleared(g, gkey(n))) {  /* key is not marked (yet)? */
+  /* traverse hash part; if 'inv', traverse descending
+     (see 'convergeephemerons') */
+  for (i = 0; i < nsize; i++) {
+    Node *n = inv ? gnode(h, nsize - 1 - i) : gnode(h, i);
+    if (isempty(gval(n)))  /* entry is empty? */
+      clearkey(n);  /* clear its key */
+    else if (iscleared(g, gckeyN(n))) {  /* key is not marked (yet)? */
       hasclears = 1;  /* table must be cleared */
       if (valiswhite(gval(n)))  /* value not marked yet? */
         hasww = 1;  /* white-white entry */
@@ -426,6 +450,10 @@ static int traverseephemeron (global_State *g, Table *h) {
     linkgclist(h, g->ephemeron);  /* have to propagate again */
   else if (hasclears)  /* table has white keys? */
     linkgclist(h, g->allweak);  /* may have to clean white keys */
+  else if (g->gckind == KGC_GEN)
+    linkgclist(h, g->grayagain);  /* keep it in some list */
+  else
+    gray2black(h);
   return marked;
 }
 
@@ -433,18 +461,22 @@ static int traverseephemeron (global_State *g, Table *h) {
 static void traversestrongtable (global_State *g, Table *h) {
   Node *n, *limit = gnodelast(h);
   unsigned int i;
-  for (i = 0; i < h->sizearray; i++)  /* traverse array part */
+  unsigned int asize = luaH_realasize(h);
+  for (i = 0; i < asize; i++)  /* traverse array part */
     markvalue(g, &h->array[i]);
   for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
-    checkdeadkey(n);
-    if (ttisnil(gval(n)))  /* entry is empty? */
-      removeentry(n);  /* remove it */
+    if (isempty(gval(n)))  /* entry is empty? */
+      clearkey(n);  /* clear its key */
     else {
-      lua_assert(!ttisnil(gkey(n)));
-      markvalue(g, gkey(n));  /* mark key */
-      markvalue(g, gval(n));  /* mark value */
+      lua_assert(!keyisnil(n));
+      markkey(g, n);
+      markvalue(g, gval(n));
     }
   }
+  if (g->gckind == KGC_GEN) {
+    linkgclist(h, g->grayagain);  /* keep it in some gray list */
+    black2gray(h);
+  }
 }
 
 
@@ -453,21 +485,33 @@ static lu_mem traversetable (global_State *g, Table *h) {
   const TValue *mode = gfasttm(g, h->metatable, TM_MODE);
   markobjectN(g, h->metatable);
   if (mode && ttisstring(mode) &&  /* is there a weak mode? */
-      ((weakkey = strchr(svalue(mode), 'k')),
-       (weakvalue = strchr(svalue(mode), 'v')),
+      (cast_void(weakkey = strchr(svalue(mode), 'k')),
+       cast_void(weakvalue = strchr(svalue(mode), 'v')),
        (weakkey || weakvalue))) {  /* is really weak? */
     black2gray(h);  /* keep table gray */
     if (!weakkey)  /* strong keys? */
       traverseweakvalue(g, h);
     else if (!weakvalue)  /* strong values? */
-      traverseephemeron(g, h);
+      traverseephemeron(g, h, 0);
     else  /* all weak */
       linkgclist(h, g->allweak);  /* nothing to traverse now */
   }
   else  /* not weak */
     traversestrongtable(g, h);
-  return sizeof(Table) + sizeof(TValue) * h->sizearray +
-                         sizeof(Node) * cast(size_t, allocsizenode(h));
+  return 1 + h->alimit + 2 * allocsizenode(h);
+}
+
+
+static int traverseudata (global_State *g, Udata *u) {
+  int i;
+  markobjectN(g, u->metatable);  /* mark its metatable */
+  for (i = 0; i < u->nuvalue; i++)
+    markvalue(g, &u->uv[i].uv);
+  if (g->gckind == KGC_GEN) {
+    linkgclist(u, g->grayagain);  /* keep it in some gray list */
+    black2gray(u);
+  }
+  return 1 + u->nuvalue;
 }
 
 
@@ -478,8 +522,6 @@ static lu_mem traversetable (global_State *g, Table *h) {
 */
 static int traverseproto (global_State *g, Proto *f) {
   int i;
-  if (f->cache && iswhite(f->cache))
-    f->cache = NULL;  /* allow cache to be collected */
   markobjectN(g, f->source);
   for (i = 0; i < f->sizek; i++)  /* mark literals */
     markvalue(g, &f->k[i]);
@@ -489,66 +531,61 @@ static int traverseproto (global_State *g, Proto *f) {
     markobjectN(g, f->p[i]);
   for (i = 0; i < f->sizelocvars; i++)  /* mark local-variable names */
     markobjectN(g, f->locvars[i].varname);
-  return sizeof(Proto) + sizeof(Instruction) * f->sizecode +
-                         sizeof(Proto *) * f->sizep +
-                         sizeof(TValue) * f->sizek +
-                         sizeof(int) * f->sizelineinfo +
-                         sizeof(LocVar) * f->sizelocvars +
-                         sizeof(Upvaldesc) * f->sizeupvalues;
+  return 1 + f->sizek + f->sizeupvalues + f->sizep + f->sizelocvars;
 }
 
 
-static lu_mem traverseCclosure (global_State *g, CClosure *cl) {
+static int traverseCclosure (global_State *g, CClosure *cl) {
   int i;
   for (i = 0; i < cl->nupvalues; i++)  /* mark its upvalues */
     markvalue(g, &cl->upvalue[i]);
-  return sizeCclosure(cl->nupvalues);
+  return 1 + cl->nupvalues;
 }
 
 /*
-** open upvalues point to values in a thread, so those values should
-** be marked when the thread is traversed except in the atomic phase
-** (because then the value cannot be changed by the thread and the
-** thread may not be traversed again)
+** Traverse a Lua closure, marking its prototype and its upvalues.
+** (Both can be NULL while closure is being created.)
 */
-static lu_mem traverseLclosure (global_State *g, LClosure *cl) {
+static int traverseLclosure (global_State *g, LClosure *cl) {
   int i;
   markobjectN(g, cl->p);  /* mark its prototype */
-  for (i = 0; i < cl->nupvalues; i++) {  /* mark its upvalues */
+  for (i = 0; i < cl->nupvalues; i++) {  /* visit its upvalues */
     UpVal *uv = cl->upvals[i];
-    if (uv != NULL) {
-      if (upisopen(uv) && g->gcstate != GCSinsideatomic)
-        uv->u.open.touched = 1;  /* can be marked in 'remarkupvals' */
-      else
-        markvalue(g, uv->v);
-    }
+    markobjectN(g, uv);  /* mark upvalue */
   }
-  return sizeLclosure(cl->nupvalues);
+  return 1 + cl->nupvalues;
 }
 
 
-static lu_mem traversethread (global_State *g, lua_State *th) {
+/*
+** Traverse a thread, marking the elements in the stack up to its top
+** and cleaning the rest of the stack in the final traversal.
+** That ensures that the entire stack have valid (non-dead) objects.
+*/
+static int traversethread (global_State *g, lua_State *th) {
+  UpVal *uv;
   StkId o = th->stack;
   if (o == NULL)
     return 1;  /* stack not completely built yet */
-  lua_assert(g->gcstate == GCSinsideatomic ||
+  lua_assert(g->gcstate == GCSatomic ||
              th->openupval == NULL || isintwups(th));
   for (; o < th->top; o++)  /* mark live elements in the stack */
-    markvalue(g, o);
-  if (g->gcstate == GCSinsideatomic) {  /* final traversal? */
+    markvalue(g, s2v(o));
+  for (uv = th->openupval; uv != NULL; uv = uv->u.open.next)
+    markobject(g, uv);  /* open upvalues cannot be collected */
+  if (g->gcstate == GCSatomic) {  /* final traversal? */
     StkId lim = th->stack + th->stacksize;  /* real end of stack */
     for (; o < lim; o++)  /* clear not-marked stack slice */
-      setnilvalue(o);
+      setnilvalue(s2v(o));
     /* 'remarkupvals' may have removed thread from 'twups' list */
     if (!isintwups(th) && th->openupval != NULL) {
       th->twups = g->twups;  /* link it back to the list */
       g->twups = th;
     }
   }
-  else if (g->gckind != KGC_EMERGENCY)
+  else if (!g->gcemergency)
     luaD_shrinkstack(th); /* do not change stack in emergency cycle */
-  return (sizeof(lua_State) + sizeof(TValue) * th->stacksize +
-          sizeof(CallInfo) * th->nci);
+  return 1 + th->stacksize;
 }
 
 
@@ -556,70 +593,59 @@ static lu_mem traversethread (global_State *g, lua_State *th) {
 ** traverse one gray object, turning it to black (except for threads,
 ** which are always gray).
 */
-static void propagatemark (global_State *g) {
-  lu_mem size;
+static lu_mem propagatemark (global_State *g) {
   GCObject *o = g->gray;
-  lua_assert(isgray(o));
   gray2black(o);
+  g->gray = *getgclist(o);  /* remove from 'gray' list */
   switch (o->tt) {
-    case LUA_TTABLE: {
-      Table *h = gco2t(o);
-      g->gray = h->gclist;  /* remove from 'gray' list */
-      size = traversetable(g, h);
-      break;
-    }
-    case LUA_TLCL: {
-      LClosure *cl = gco2lcl(o);
-      g->gray = cl->gclist;  /* remove from 'gray' list */
-      size = traverseLclosure(g, cl);
-      break;
-    }
-    case LUA_TCCL: {
-      CClosure *cl = gco2ccl(o);
-      g->gray = cl->gclist;  /* remove from 'gray' list */
-      size = traverseCclosure(g, cl);
-      break;
-    }
-    case LUA_TTHREAD: {
+    case LUA_VTABLE: return traversetable(g, gco2t(o));
+    case LUA_VUSERDATA: return traverseudata(g, gco2u(o));
+    case LUA_VLCL: return traverseLclosure(g, gco2lcl(o));
+    case LUA_VCCL: return traverseCclosure(g, gco2ccl(o));
+    case LUA_VPROTO: return traverseproto(g, gco2p(o));
+    case LUA_VTHREAD: {
       lua_State *th = gco2th(o);
-      g->gray = th->gclist;  /* remove from 'gray' list */
       linkgclist(th, g->grayagain);  /* insert into 'grayagain' list */
       black2gray(o);
-      size = traversethread(g, th);
-      break;
+      return traversethread(g, th);
     }
-    case LUA_TPROTO: {
-      Proto *p = gco2p(o);
-      g->gray = p->gclist;  /* remove from 'gray' list */
-      size = traverseproto(g, p);
-      break;
-    }
-    default: lua_assert(0); return;
+    default: lua_assert(0); return 0;
   }
-  g->GCmemtrav += size;
 }
 
 
-static void propagateall (global_State *g) {
-  while (g->gray) propagatemark(g);
+static lu_mem propagateall (global_State *g) {
+  lu_mem tot = 0;
+  while (g->gray)
+    tot += propagatemark(g);
+  return tot;
 }
 
 
+/*
+** Traverse all ephemeron tables propagating marks from keys to values.
+** Repeat until it converges, that is, nothing new is marked. 'dir'
+** inverts the direction of the traversals, trying to speed up
+** convergence on chains in the same table.
+**
+*/
 static void convergeephemerons (global_State *g) {
   int changed;
+  int dir = 0;
   do {
     GCObject *w;
     GCObject *next = g->ephemeron;  /* get ephemeron list */
     g->ephemeron = NULL;  /* tables may return to this list when traversed */
     changed = 0;
-    while ((w = next) != NULL) {
-      next = gco2t(w)->gclist;
-      if (traverseephemeron(g, gco2t(w))) {  /* traverse marked some value? */
+    while ((w = next) != NULL) {  /* for each ephemeron table */
+      next = gco2t(w)->gclist;  /* list is rebuilt during loop */
+      if (traverseephemeron(g, gco2t(w), dir)) {  /* marked some value? */
         propagateall(g);  /* propagate changes */
         changed = 1;  /* will have to revisit all ephemeron tables */
       }
     }
-  } while (changed);
+    dir = !dir;  /* invert direction next time */
+  } while (changed);  /* repeat until no more changes */
 }
 
 /* }====================================================== */
@@ -633,19 +659,18 @@ static void convergeephemerons (global_State *g) {
 
 
 /*
-** clear entries with unmarked keys from all weaktables in list 'l' up
-** to element 'f'
+** clear entries with unmarked keys from all weaktables in list 'l'
 */
-static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
-  for (; l != f; l = gco2t(l)->gclist) {
+static void clearbykeys (global_State *g, GCObject *l) {
+  for (; l; l = gco2t(l)->gclist) {
     Table *h = gco2t(l);
-    Node *n, *limit = gnodelast(h);
+    Node *limit = gnodelast(h);
+    Node *n;
     for (n = gnode(h, 0); n < limit; n++) {
-      if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
-        setnilvalue(gval(n));  /* remove value ... */
-      }
-      if (ttisnil(gval(n)))  /* is entry empty? */
-        removeentry(n);  /* remove entry from table */
+      if (iscleared(g, gckeyN(n)))  /* unmarked key? */
+        setempty(gval(n));  /* remove entry */
+      if (isempty(gval(n)))  /* is entry empty? */
+        clearkey(n);  /* clear its key */
     }
   }
 }
@@ -655,88 +680,85 @@ static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
 ** clear entries with unmarked values from all weaktables in list 'l' up
 ** to element 'f'
 */
-static void clearvalues (global_State *g, GCObject *l, GCObject *f) {
+static void clearbyvalues (global_State *g, GCObject *l, GCObject *f) {
   for (; l != f; l = gco2t(l)->gclist) {
     Table *h = gco2t(l);
     Node *n, *limit = gnodelast(h);
     unsigned int i;
-    for (i = 0; i < h->sizearray; i++) {
+    unsigned int asize = luaH_realasize(h);
+    for (i = 0; i < asize; i++) {
       TValue *o = &h->array[i];
-      if (iscleared(g, o))  /* value was collected? */
-        setnilvalue(o);  /* remove value */
+      if (iscleared(g, gcvalueN(o)))  /* value was collected? */
+        setempty(o);  /* remove entry */
     }
     for (n = gnode(h, 0); n < limit; n++) {
-      if (!ttisnil(gval(n)) && iscleared(g, gval(n))) {
-        setnilvalue(gval(n));  /* remove value ... */
-        removeentry(n);  /* and remove entry from table */
-      }
+      if (iscleared(g, gcvalueN(gval(n))))  /* unmarked value? */
+        setempty(gval(n));  /* remove entry */
+      if (isempty(gval(n)))  /* is entry empty? */
+        clearkey(n);  /* clear its key */
     }
   }
 }
 
 
-void luaC_upvdeccount (lua_State *L, UpVal *uv) {
-  lua_assert(uv->refcount > 0);
-  uv->refcount--;
-  if (uv->refcount == 0 && !upisopen(uv))
-    luaM_free(L, uv);
-}
-
-
-static void freeLclosure (lua_State *L, LClosure *cl) {
-  int i;
-  for (i = 0; i < cl->nupvalues; i++) {
-    UpVal *uv = cl->upvals[i];
-    if (uv)
-      luaC_upvdeccount(L, uv);
-  }
-  luaM_freemem(L, cl, sizeLclosure(cl->nupvalues));
+static void freeupval (lua_State *L, UpVal *uv) {
+  if (upisopen(uv))
+    luaF_unlinkupval(uv);
+  luaM_free(L, uv);
 }
 
 
 static void freeobj (lua_State *L, GCObject *o) {
   switch (o->tt) {
-    case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break;
-    case LUA_TLCL: {
-      freeLclosure(L, gco2lcl(o));
+    case LUA_VPROTO:
+      luaF_freeproto(L, gco2p(o));
       break;
-    }
-    case LUA_TCCL: {
+    case LUA_VUPVAL:
+      freeupval(L, gco2upv(o));
+      break;
+    case LUA_VLCL:
+      luaM_freemem(L, o, sizeLclosure(gco2lcl(o)->nupvalues));
+      break;
+    case LUA_VCCL:
       luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues));
       break;
+    case LUA_VTABLE:
+      luaH_free(L, gco2t(o));
+      break;
+    case LUA_VTHREAD:
+      luaE_freethread(L, gco2th(o));
+      break;
+    case LUA_VUSERDATA: {
+      Udata *u = gco2u(o);
+      luaM_freemem(L, o, sizeudata(u->nuvalue, u->len));
+      break;
     }
-    case LUA_TTABLE: luaH_free(L, gco2t(o)); break;
-    case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break;
-    case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
-    case LUA_TSHRSTR:
+    case LUA_VSHRSTR:
       luaS_remove(L, gco2ts(o));  /* remove it from hash table */
       luaM_freemem(L, o, sizelstring(gco2ts(o)->shrlen));
       break;
-    case LUA_TLNGSTR: {
+    case LUA_VLNGSTR:
       luaM_freemem(L, o, sizelstring(gco2ts(o)->u.lnglen));
       break;
-    }
     default: lua_assert(0);
   }
 }
 
 
-#define sweepwholelist(L,p)	sweeplist(L,p,MAX_LUMEM)
-static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count);
-
-
 /*
-** sweep at most 'count' elements from a list of GCObjects erasing dead
+** sweep at most 'countin' elements from a list of GCObjects erasing dead
 ** objects, where a dead object is one marked with the old (non current)
 ** white; change all non-dead objects back to white, preparing for next
 ** collection cycle. Return where to continue the traversal or NULL if
-** list is finished.
+** list is finished. ('*countout' gets the number of elements traversed.)
 */
-static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
+static GCObject **sweeplist (lua_State *L, GCObject **p, int countin,
+                             int *countout) {
   global_State *g = G(L);
   int ow = otherwhite(g);
+  int i;
   int white = luaC_white(g);  /* current white */
-  while (*p != NULL && count-- > 0) {
+  for (i = 0; *p != NULL && i < countin; i++) {
     GCObject *curr = *p;
     int marked = curr->marked;
     if (isdeadm(ow, marked)) {  /* is 'curr' dead? */
@@ -748,6 +770,8 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
       p = &curr->next;  /* go to next element */
     }
   }
+  if (countout)
+    *countout = i;  /* number of elements traversed */
   return (*p == NULL) ? NULL : p;
 }
 
@@ -758,7 +782,7 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
 static GCObject **sweeptolive (lua_State *L, GCObject **p) {
   GCObject **old = p;
   do {
-    p = sweeplist(L, p, 1);
+    p = sweeplist(L, p, 1, NULL);
   } while (p == old);
   return p;
 }
@@ -773,18 +797,23 @@ static GCObject **sweeptolive (lua_State *L, GCObject **p) {
 */
 
 /*
-** If possible, shrink string table
+** If possible, shrink string table.
 */
 static void checkSizes (lua_State *L, global_State *g) {
-  if (g->gckind != KGC_EMERGENCY) {
-    l_mem olddebt = g->GCdebt;
-    if (g->strt.nuse < g->strt.size / 4)  /* string table too big? */
-      luaS_resize(L, g->strt.size / 2);  /* shrink it a little */
-    g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
+  if (!g->gcemergency) {
+    if (g->strt.nuse < g->strt.size / 4) {  /* string table too big? */
+      l_mem olddebt = g->GCdebt;
+      luaS_resize(L, g->strt.size / 2);
+      g->GCestimate += g->GCdebt - olddebt;  /* correct estimate */
+    }
   }
 }
 
 
+/*
+** Get the next udata to be finalized from the 'tobefnz' list, and
+** link it back into the 'allgc' list.
+*/
 static GCObject *udata2finalize (global_State *g) {
   GCObject *o = g->tobefnz;  /* get first element */
   lua_assert(tofinalize(o));
@@ -804,51 +833,42 @@ static void dothecall (lua_State *L, void *ud) {
 }
 
 
-static void GCTM (lua_State *L, int propagateerrors) {
+static void GCTM (lua_State *L) {
   global_State *g = G(L);
   const TValue *tm;
   TValue v;
+  lua_assert(!g->gcemergency);
   setgcovalue(L, &v, udata2finalize(g));
   tm = luaT_gettmbyobj(L, &v, TM_GC);
-  if (tm != NULL && ttisfunction(tm)) {  /* is there a finalizer? */
+  if (!notm(tm)) {  /* is there a finalizer? */
     int status;
     lu_byte oldah = L->allowhook;
     int running  = g->gcrunning;
     L->allowhook = 0;  /* stop debug hooks during GC metamethod */
     g->gcrunning = 0;  /* avoid GC steps */
-    setobj2s(L, L->top, tm);  /* push finalizer... */
-    setobj2s(L, L->top + 1, &v);  /* ... and its argument */
-    L->top += 2;  /* and (next line) call the finalizer */
+    setobj2s(L, L->top++, tm);  /* push finalizer... */
+    setobj2s(L, L->top++, &v);  /* ... and its argument */
     L->ci->callstatus |= CIST_FIN;  /* will run a finalizer */
     status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
     L->ci->callstatus &= ~CIST_FIN;  /* not running a finalizer anymore */
     L->allowhook = oldah;  /* restore hooks */
     g->gcrunning = running;  /* restore state */
-    if (status != LUA_OK && propagateerrors) {  /* error while running __gc? */
-      if (status == LUA_ERRRUN) {  /* is there an error object? */
-        const char *msg = (ttisstring(L->top - 1))
-                            ? svalue(L->top - 1)
-                            : "no message";
-        luaO_pushfstring(L, "error in __gc metamethod (%s)", msg);
-        status = LUA_ERRGCMM;  /* error in __gc metamethod */
-      }
-      luaD_throw(L, status);  /* re-throw error */
+    if (unlikely(status != LUA_OK)) {  /* error while running __gc? */
+      luaE_warnerror(L, "__gc metamethod");
+      L->top--;  /* pops error object */
     }
   }
 }
 
 
 /*
-** call a few (up to 'g->gcfinnum') finalizers
+** Call a few finalizers
 */
-static int runafewfinalizers (lua_State *L) {
+static int runafewfinalizers (lua_State *L, int n) {
   global_State *g = G(L);
-  unsigned int i;
-  lua_assert(!g->tobefnz || g->gcfinnum > 0);
-  for (i = 0; g->tobefnz && i < g->gcfinnum; i++)
-    GCTM(L, 1);  /* call one finalizer */
-  g->gcfinnum = (!g->tobefnz) ? 0  /* nothing more to finalize? */
-                    : g->gcfinnum * 2;  /* else call a few more next time */
+  int i;
+  for (i = 0; i < n && g->tobefnz; i++)
+    GCTM(L);  /* call one finalizer */
   return i;
 }
 
@@ -859,7 +879,7 @@ static int runafewfinalizers (lua_State *L) {
 static void callallpendingfinalizers (lua_State *L) {
   global_State *g = G(L);
   while (g->tobefnz)
-    GCTM(L, 0);
+    GCTM(L);
 }
 
 
@@ -874,18 +894,23 @@ static GCObject **findlast (GCObject **p) {
 
 
 /*
-** move all unreachable objects (or 'all' objects) that need
-** finalization from list 'finobj' to list 'tobefnz' (to be finalized)
+** Move all unreachable objects (or 'all' objects) that need
+** finalization from list 'finobj' to list 'tobefnz' (to be finalized).
+** (Note that objects after 'finobjold' cannot be white, so they
+** don't need to be traversed. In incremental mode, 'finobjold' is NULL,
+** so the whole list is traversed.)
 */
 static void separatetobefnz (global_State *g, int all) {
   GCObject *curr;
   GCObject **p = &g->finobj;
   GCObject **lastnext = findlast(&g->tobefnz);
-  while ((curr = *p) != NULL) {  /* traverse all finalizable objects */
+  while ((curr = *p) != g->finobjold) {  /* traverse all finalizable objects */
     lua_assert(tofinalize(curr));
     if (!(iswhite(curr) || all))  /* not being collected? */
       p = &curr->next;  /* don't bother with it */
     else {
+      if (curr == g->finobjsur)  /* removing 'finobjsur'? */
+        g->finobjsur = curr->next;  /* correct it */
       *p = curr->next;  /* remove 'curr' from 'finobj' list */
       curr->next = *lastnext;  /* link at the end of 'tobefnz' list */
       *lastnext = curr;
@@ -911,6 +936,14 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
       if (g->sweepgc == &o->next)  /* should not remove 'sweepgc' object */
         g->sweepgc = sweeptolive(L, g->sweepgc);  /* change 'sweepgc' */
     }
+    else {  /* correct pointers into 'allgc' list, if needed */
+      if (o == g->survival)
+        g->survival = o->next;
+      if (o == g->old)
+        g->old = o->next;
+      if (o == g->reallyold)
+        g->reallyold = o->next;
+    }
     /* search for pointer pointing to 'o' */
     for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ }
     *p = o->next;  /* remove 'o' from 'allgc' list */
@@ -923,6 +956,390 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
 /* }====================================================== */
 
 
+/*
+** {======================================================
+** Generational Collector
+** =======================================================
+*/
+
+static void setpause (global_State *g);
+
+
+/* mask to erase all color bits, not changing gen-related stuff */
+#define maskgencolors	(~(bitmask(BLACKBIT) | WHITEBITS))
+
+
+/*
+** Sweep a list of objects, deleting dead ones and turning
+** the non dead to old (without changing their colors).
+*/
+static void sweep2old (lua_State *L, GCObject **p) {
+  GCObject *curr;
+  while ((curr = *p) != NULL) {
+    if (iswhite(curr)) {  /* is 'curr' dead? */
+      lua_assert(isdead(G(L), curr));
+      *p = curr->next;  /* remove 'curr' from list */
+      freeobj(L, curr);  /* erase 'curr' */
+    }
+    else {  /* all surviving objects become old */
+      setage(curr, G_OLD);
+      p = &curr->next;  /* go to next element */
+    }
+  }
+}
+
+
+/*
+** Sweep for generational mode. Delete dead objects. (Because the
+** collection is not incremental, there are no "new white" objects
+** during the sweep. So, any white object must be dead.) For
+** non-dead objects, advance their ages and clear the color of
+** new objects. (Old objects keep their colors.)
+*/
+static GCObject **sweepgen (lua_State *L, global_State *g, GCObject **p,
+                            GCObject *limit) {
+  static const lu_byte nextage[] = {
+    G_SURVIVAL,  /* from G_NEW */
+    G_OLD1,      /* from G_SURVIVAL */
+    G_OLD1,      /* from G_OLD0 */
+    G_OLD,       /* from G_OLD1 */
+    G_OLD,       /* from G_OLD (do not change) */
+    G_TOUCHED1,  /* from G_TOUCHED1 (do not change) */
+    G_TOUCHED2   /* from G_TOUCHED2 (do not change) */
+  };
+  int white = luaC_white(g);
+  GCObject *curr;
+  while ((curr = *p) != limit) {
+    if (iswhite(curr)) {  /* is 'curr' dead? */
+      lua_assert(!isold(curr) && isdead(g, curr));
+      *p = curr->next;  /* remove 'curr' from list */
+      freeobj(L, curr);  /* erase 'curr' */
+    }
+    else {  /* correct mark and age */
+      if (getage(curr) == G_NEW)
+        curr->marked = cast_byte((curr->marked & maskgencolors) | white);
+      setage(curr, nextage[getage(curr)]);
+      p = &curr->next;  /* go to next element */
+    }
+  }
+  return p;
+}
+
+
+/*
+** Traverse a list making all its elements white and clearing their
+** age.
+*/
+static void whitelist (global_State *g, GCObject *p) {
+  int white = luaC_white(g);
+  for (; p != NULL; p = p->next)
+    p->marked = cast_byte((p->marked & maskcolors) | white);
+}
+
+
+/*
+** Correct a list of gray objects.
+** Because this correction is done after sweeping, young objects might
+** be turned white and still be in the list. They are only removed.
+** For tables and userdata, advance 'touched1' to 'touched2'; 'touched2'
+** objects become regular old and are removed from the list.
+** For threads, just remove white ones from the list.
+*/
+static GCObject **correctgraylist (GCObject **p) {
+  GCObject *curr;
+  while ((curr = *p) != NULL) {
+    switch (curr->tt) {
+      case LUA_VTABLE: case LUA_VUSERDATA: {
+        GCObject **next = getgclist(curr);
+        if (getage(curr) == G_TOUCHED1) {  /* touched in this cycle? */
+          lua_assert(isgray(curr));
+          gray2black(curr);  /* make it black, for next barrier */
+          changeage(curr, G_TOUCHED1, G_TOUCHED2);
+          p = next;  /* go to next element */
+        }
+        else {  /* not touched in this cycle */
+          if (!iswhite(curr)) {  /* not white? */
+            lua_assert(isold(curr));
+            if (getage(curr) == G_TOUCHED2)  /* advance from G_TOUCHED2... */
+              changeage(curr, G_TOUCHED2, G_OLD);  /* ... to G_OLD */
+            gray2black(curr);  /* make it black */
+          }
+          /* else, object is white: just remove it from this list */
+          *p = *next;  /* remove 'curr' from gray list */
+        }
+        break;
+      }
+      case LUA_VTHREAD: {
+        lua_State *th = gco2th(curr);
+        lua_assert(!isblack(th));
+        if (iswhite(th))  /* new object? */
+          *p = th->gclist;  /* remove from gray list */
+        else  /* old threads remain gray */
+          p = &th->gclist;  /* go to next element */
+        break;
+      }
+      default: lua_assert(0);  /* nothing more could be gray here */
+    }
+  }
+  return p;
+}
+
+
+/*
+** Correct all gray lists, coalescing them into 'grayagain'.
+*/
+static void correctgraylists (global_State *g) {
+  GCObject **list = correctgraylist(&g->grayagain);
+  *list = g->weak; g->weak = NULL;
+  list = correctgraylist(list);
+  *list = g->allweak; g->allweak = NULL;
+  list = correctgraylist(list);
+  *list = g->ephemeron; g->ephemeron = NULL;
+  correctgraylist(list);
+}
+
+
+/*
+** Mark 'OLD1' objects when starting a new young collection.
+** Gray objects are already in some gray list, and so will be visited
+** in the atomic step.
+*/
+static void markold (global_State *g, GCObject *from, GCObject *to) {
+  GCObject *p;
+  for (p = from; p != to; p = p->next) {
+    if (getage(p) == G_OLD1) {
+      lua_assert(!iswhite(p));
+      if (isblack(p)) {
+        black2gray(p);  /* should be '2white', but gray works too */
+        reallymarkobject(g, p);
+      }
+    }
+  }
+}
+
+
+/*
+** Finish a young-generation collection.
+*/
+static void finishgencycle (lua_State *L, global_State *g) {
+  correctgraylists(g);
+  checkSizes(L, g);
+  g->gcstate = GCSpropagate;  /* skip restart */
+  if (!g->gcemergency)
+    callallpendingfinalizers(L);
+}
+
+
+/*
+** Does a young collection. First, mark 'OLD1' objects.  (Only survival
+** and "recent old" lists can contain 'OLD1' objects. New lists cannot
+** contain 'OLD1' objects, at most 'OLD0' objects that were already
+** visited when marked old.) Then does the atomic step. Then,
+** sweep all lists and advance pointers. Finally, finish the collection.
+*/
+static void youngcollection (lua_State *L, global_State *g) {
+  GCObject **psurvival;  /* to point to first non-dead survival object */
+  lua_assert(g->gcstate == GCSpropagate);
+  markold(g, g->survival, g->reallyold);
+  markold(g, g->finobj, g->finobjrold);
+  atomic(L);
+
+  /* sweep nursery and get a pointer to its last live element */
+  psurvival = sweepgen(L, g, &g->allgc, g->survival);
+  /* sweep 'survival' and 'old' */
+  sweepgen(L, g, psurvival, g->reallyold);
+  g->reallyold = g->old;
+  g->old = *psurvival;  /* 'survival' survivals are old now */
+  g->survival = g->allgc;  /* all news are survivals */
+
+  /* repeat for 'finobj' lists */
+  psurvival = sweepgen(L, g, &g->finobj, g->finobjsur);
+  /* sweep 'survival' and 'old' */
+  sweepgen(L, g, psurvival, g->finobjrold);
+  g->finobjrold = g->finobjold;
+  g->finobjold = *psurvival;  /* 'survival' survivals are old now */
+  g->finobjsur = g->finobj;  /* all news are survivals */
+
+  sweepgen(L, g, &g->tobefnz, NULL);
+
+  finishgencycle(L, g);
+}
+
+
+static void atomic2gen (lua_State *L, global_State *g) {
+  /* sweep all elements making them old */
+  sweep2old(L, &g->allgc);
+  /* everything alive now is old */
+  g->reallyold = g->old = g->survival = g->allgc;
+
+  /* repeat for 'finobj' lists */
+  sweep2old(L, &g->finobj);
+  g->finobjrold = g->finobjold = g->finobjsur = g->finobj;
+
+  sweep2old(L, &g->tobefnz);
+
+  g->gckind = KGC_GEN;
+  g->lastatomic = 0;
+  g->GCestimate = gettotalbytes(g);  /* base for memory control */
+  finishgencycle(L, g);
+}
+
+
+/*
+** Enter generational mode. Must go until the end of an atomic cycle
+** to ensure that all threads and weak tables are in the gray lists.
+** Then, turn all objects into old and finishes the collection.
+*/
+static lu_mem entergen (lua_State *L, global_State *g) {
+  lu_mem numobjs;
+  luaC_runtilstate(L, bitmask(GCSpause));  /* prepare to start a new cycle */
+  luaC_runtilstate(L, bitmask(GCSpropagate));  /* start new cycle */
+  numobjs = atomic(L);  /* propagates all and then do the atomic stuff */
+  atomic2gen(L, g);
+  return numobjs;
+}
+
+
+/*
+** Enter incremental mode. Turn all objects white, make all
+** intermediate lists point to NULL (to avoid invalid pointers),
+** and go to the pause state.
+*/
+static void enterinc (global_State *g) {
+  whitelist(g, g->allgc);
+  g->reallyold = g->old = g->survival = NULL;
+  whitelist(g, g->finobj);
+  whitelist(g, g->tobefnz);
+  g->finobjrold = g->finobjold = g->finobjsur = NULL;
+  g->gcstate = GCSpause;
+  g->gckind = KGC_INC;
+  g->lastatomic = 0;
+}
+
+
+/*
+** Change collector mode to 'newmode'.
+*/
+void luaC_changemode (lua_State *L, int newmode) {
+  global_State *g = G(L);
+  if (newmode != g->gckind) {
+    if (newmode == KGC_GEN)  /* entering generational mode? */
+      entergen(L, g);
+    else
+      enterinc(g);  /* entering incremental mode */
+  }
+  g->lastatomic = 0;
+}
+
+
+/*
+** Does a full collection in generational mode.
+*/
+static lu_mem fullgen (lua_State *L, global_State *g) {
+  enterinc(g);
+  return entergen(L, g);
+}
+
+
+/*
+** Set debt for the next minor collection, which will happen when
+** memory grows 'genminormul'%.
+*/
+static void setminordebt (global_State *g) {
+  luaE_setdebt(g, -(cast(l_mem, (gettotalbytes(g) / 100)) * g->genminormul));
+}
+
+
+/*
+** Does a major collection after last collection was a "bad collection".
+**
+** When the program is building a big structure, it allocates lots of
+** memory but generates very little garbage. In those scenarios,
+** the generational mode just wastes time doing small collections, and
+** major collections are frequently what we call a "bad collection", a
+** collection that frees too few objects. To avoid the cost of switching
+** between generational mode and the incremental mode needed for full
+** (major) collections, the collector tries to stay in incremental mode
+** after a bad collection, and to switch back to generational mode only
+** after a "good" collection (one that traverses less than 9/8 objects
+** of the previous one).
+** The collector must choose whether to stay in incremental mode or to
+** switch back to generational mode before sweeping. At this point, it
+** does not know the real memory in use, so it cannot use memory to
+** decide whether to return to generational mode. Instead, it uses the
+** number of objects traversed (returned by 'atomic') as a proxy. The
+** field 'g->lastatomic' keeps this count from the last collection.
+** ('g->lastatomic != 0' also means that the last collection was bad.)
+*/
+static void stepgenfull (lua_State *L, global_State *g) {
+  lu_mem newatomic;  /* count of traversed objects */
+  lu_mem lastatomic = g->lastatomic;  /* count from last collection */
+  if (g->gckind == KGC_GEN)  /* still in generational mode? */
+    enterinc(g);  /* enter incremental mode */
+  luaC_runtilstate(L, bitmask(GCSpropagate));  /* start new cycle */
+  newatomic = atomic(L);  /* mark everybody */
+  if (newatomic < lastatomic + (lastatomic >> 3)) {  /* good collection? */
+    atomic2gen(L, g);  /* return to generational mode */
+    setminordebt(g);
+  }
+  else {  /* another bad collection; stay in incremental mode */
+    g->GCestimate = gettotalbytes(g);  /* first estimate */;
+    entersweep(L);
+    luaC_runtilstate(L, bitmask(GCSpause));  /* finish collection */
+    setpause(g);
+    g->lastatomic = newatomic;
+  }
+}
+
+
+/*
+** Does a generational "step".
+** Usually, this means doing a minor collection and setting the debt to
+** make another collection when memory grows 'genminormul'% larger.
+**
+** However, there are exceptions.  If memory grows 'genmajormul'%
+** larger than it was at the end of the last major collection (kept
+** in 'g->GCestimate'), the function does a major collection. At the
+** end, it checks whether the major collection was able to free a
+** decent amount of memory (at least half the growth in memory since
+** previous major collection). If so, the collector keeps its state,
+** and the next collection will probably be minor again. Otherwise,
+** we have what we call a "bad collection". In that case, set the field
+** 'g->lastatomic' to signal that fact, so that the next collection will
+** go to 'stepgenfull'.
+**
+** 'GCdebt <= 0' means an explicit call to GC step with "size" zero;
+** in that case, do a minor collection.
+*/
+static void genstep (lua_State *L, global_State *g) {
+  if (g->lastatomic != 0)  /* last collection was a bad one? */
+    stepgenfull(L, g);  /* do a full step */
+  else {
+    lu_mem majorbase = g->GCestimate;  /* memory after last major collection */
+    lu_mem majorinc = (majorbase / 100) * getgcparam(g->genmajormul);
+    if (g->GCdebt > 0 && gettotalbytes(g) > majorbase + majorinc) {
+      lu_mem numobjs = fullgen(L, g);  /* do a major collection */
+      if (gettotalbytes(g) < majorbase + (majorinc / 2)) {
+        /* collected at least half of memory growth since last major
+           collection; keep doing minor collections */
+        setminordebt(g);
+      }
+      else {  /* bad collection */
+        g->lastatomic = numobjs;  /* signal that last collection was bad */
+        setpause(g);  /* do a long wait for next (major) collection */
+      }
+    }
+    else {  /* regular case; do a minor collection */
+      youngcollection(L, g);
+      setminordebt(g);
+      g->GCestimate = majorbase;  /* preserve base value */
+    }
+  }
+  lua_assert(isdecGCmodegen(g));
+}
+
+/* }====================================================== */
+
 
 /*
 ** {======================================================
@@ -932,26 +1349,28 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
 
 
 /*
-** Set a reasonable "time" to wait before starting a new GC cycle; cycle
-** will start when memory use hits threshold. (Division by 'estimate'
-** should be OK: it cannot be zero (because Lua cannot even start with
-** less than PAUSEADJ bytes).
+** Set the "time" to wait before starting a new GC cycle; cycle will
+** start when memory use hits the threshold of ('estimate' * pause /
+** PAUSEADJ). (Division by 'estimate' should be OK: it cannot be zero,
+** because Lua cannot even start with less than PAUSEADJ bytes).
 */
 static void setpause (global_State *g) {
   l_mem threshold, debt;
+  int pause = getgcparam(g->gcpause);
   l_mem estimate = g->GCestimate / PAUSEADJ;  /* adjust 'estimate' */
   lua_assert(estimate > 0);
-  threshold = (g->gcpause < MAX_LMEM / estimate)  /* overflow? */
-            ? estimate * g->gcpause  /* no overflow */
+  threshold = (pause < MAX_LMEM / estimate)  /* overflow? */
+            ? estimate * pause  /* no overflow */
             : MAX_LMEM;  /* overflow; truncate to maximum */
   debt = gettotalbytes(g) - threshold;
+  if (debt > 0) debt = 0;
   luaE_setdebt(g, debt);
 }
 
 
 /*
 ** Enter first sweep phase.
-** The call to 'sweeplist' tries to make pointer point to an object
+** The call to 'sweeptolive' makes the pointer point to an object
 ** inside the list (instead of to the header), so that the real sweep do
 ** not need to skip objects created between "now" and the start of the
 ** real sweep.
@@ -960,85 +1379,97 @@ static void entersweep (lua_State *L) {
   global_State *g = G(L);
   g->gcstate = GCSswpallgc;
   lua_assert(g->sweepgc == NULL);
-  g->sweepgc = sweeplist(L, &g->allgc, 1);
+  g->sweepgc = sweeptolive(L, &g->allgc);
 }
 
 
+/*
+** Delete all objects in list 'p' until (but not including) object
+** 'limit'.
+*/
+static void deletelist (lua_State *L, GCObject *p, GCObject *limit) {
+  while (p != limit) {
+    GCObject *next = p->next;
+    freeobj(L, p);
+    p = next;
+  }
+}
+
+
+/*
+** Call all finalizers of the objects in the given Lua state, and
+** then free all objects, except for the main thread.
+*/
 void luaC_freeallobjects (lua_State *L) {
   global_State *g = G(L);
+  luaC_changemode(L, KGC_INC);
   separatetobefnz(g, 1);  /* separate all objects with finalizers */
   lua_assert(g->finobj == NULL);
   callallpendingfinalizers(L);
-  lua_assert(g->tobefnz == NULL);
-  g->currentwhite = WHITEBITS; /* this "white" makes all objects look dead */
-  g->gckind = KGC_NORMAL;
-  sweepwholelist(L, &g->finobj);
-  sweepwholelist(L, &g->allgc);
-  sweepwholelist(L, &g->fixedgc);  /* collect fixed objects */
+  deletelist(L, g->allgc, obj2gco(g->mainthread));
+  deletelist(L, g->finobj, NULL);
+  deletelist(L, g->fixedgc, NULL);  /* collect fixed objects */
   lua_assert(g->strt.nuse == 0);
 }
 
 
-static l_mem atomic (lua_State *L) {
+static lu_mem atomic (lua_State *L) {
   global_State *g = G(L);
-  l_mem work;
+  lu_mem work = 0;
   GCObject *origweak, *origall;
   GCObject *grayagain = g->grayagain;  /* save original list */
+  g->grayagain = NULL;
   lua_assert(g->ephemeron == NULL && g->weak == NULL);
   lua_assert(!iswhite(g->mainthread));
-  g->gcstate = GCSinsideatomic;
-  g->GCmemtrav = 0;  /* start counting work */
+  g->gcstate = GCSatomic;
   markobject(g, L);  /* mark running thread */
   /* registry and global metatables may be changed by API */
   markvalue(g, &g->l_registry);
   markmt(g);  /* mark global metatables */
+  work += propagateall(g);  /* empties 'gray' list */
   /* remark occasional upvalues of (maybe) dead threads */
-  remarkupvals(g);
-  propagateall(g);  /* propagate changes */
-  work = g->GCmemtrav;  /* stop counting (do not recount 'grayagain') */
+  work += remarkupvals(g);
+  work += propagateall(g);  /* propagate changes */
   g->gray = grayagain;
-  propagateall(g);  /* traverse 'grayagain' list */
-  g->GCmemtrav = 0;  /* restart counting */
+  work += propagateall(g);  /* traverse 'grayagain' list */
   convergeephemerons(g);
   /* at this point, all strongly accessible objects are marked. */
   /* Clear values from weak tables, before checking finalizers */
-  clearvalues(g, g->weak, NULL);
-  clearvalues(g, g->allweak, NULL);
+  clearbyvalues(g, g->weak, NULL);
+  clearbyvalues(g, g->allweak, NULL);
   origweak = g->weak; origall = g->allweak;
-  work += g->GCmemtrav;  /* stop counting (objects being finalized) */
   separatetobefnz(g, 0);  /* separate objects to be finalized */
-  g->gcfinnum = 1;  /* there may be objects to be finalized */
-  markbeingfnz(g);  /* mark objects that will be finalized */
-  propagateall(g);  /* remark, to propagate 'resurrection' */
-  g->GCmemtrav = 0;  /* restart counting */
+  work += markbeingfnz(g);  /* mark objects that will be finalized */
+  work += propagateall(g);  /* remark, to propagate 'resurrection' */
   convergeephemerons(g);
   /* at this point, all resurrected objects are marked. */
   /* remove dead objects from weak tables */
-  clearkeys(g, g->ephemeron, NULL);  /* clear keys from all ephemeron tables */
-  clearkeys(g, g->allweak, NULL);  /* clear keys from all 'allweak' tables */
+  clearbykeys(g, g->ephemeron);  /* clear keys from all ephemeron tables */
+  clearbykeys(g, g->allweak);  /* clear keys from all 'allweak' tables */
   /* clear values from resurrected weak tables */
-  clearvalues(g, g->weak, origweak);
-  clearvalues(g, g->allweak, origall);
+  clearbyvalues(g, g->weak, origweak);
+  clearbyvalues(g, g->allweak, origall);
   luaS_clearcache(g);
   g->currentwhite = cast_byte(otherwhite(g));  /* flip current white */
-  work += g->GCmemtrav;  /* complete counting */
-  return work;  /* estimate of memory marked by 'atomic' */
+  lua_assert(g->gray == NULL);
+  return work;  /* estimate of slots marked by 'atomic' */
 }
 
 
-static lu_mem sweepstep (lua_State *L, global_State *g,
-                         int nextstate, GCObject **nextlist) {
+static int sweepstep (lua_State *L, global_State *g,
+                      int nextstate, GCObject **nextlist) {
   if (g->sweepgc) {
     l_mem olddebt = g->GCdebt;
-    g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
+    int count;
+    g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX, &count);
     g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
-    if (g->sweepgc)  /* is there still something to sweep? */
-      return (GCSWEEPMAX * GCSWEEPCOST);
+    return count;
+  }
+  else {  /* enter next state */
+    g->gcstate = nextstate;
+    g->sweepgc = nextlist;
+    return 0;  /* no work done */
   }
-  /* else enter next state */
-  g->gcstate = nextstate;
-  g->sweepgc = nextlist;
-  return 0;
 }
 
 
@@ -1046,23 +1477,20 @@ static lu_mem singlestep (lua_State *L) {
   global_State *g = G(L);
   switch (g->gcstate) {
     case GCSpause: {
-      g->GCmemtrav = g->strt.size * sizeof(GCObject*);
       restartcollection(g);
       g->gcstate = GCSpropagate;
-      return g->GCmemtrav;
+      return 1;
     }
     case GCSpropagate: {
-      g->GCmemtrav = 0;
-      lua_assert(g->gray);
-      propagatemark(g);
-       if (g->gray == NULL)  /* no more gray objects? */
-        g->gcstate = GCSatomic;  /* finish propagate phase */
-      return g->GCmemtrav;  /* memory traversed in this step */
+      if (g->gray == NULL) {  /* no more gray objects? */
+        g->gcstate = GCSenteratomic;  /* finish propagate phase */
+        return 0;
+      }
+      else
+        return propagatemark(g);  /* traverse one gray object */
     }
-    case GCSatomic: {
-      lu_mem work;
-      propagateall(g);  /* make sure gray list is empty */
-      work = atomic(L);  /* work is what was traversed by 'atomic' */
+    case GCSenteratomic: {
+      lu_mem work = atomic(L);  /* work is what was traversed by 'atomic' */
       entersweep(L);
       g->GCestimate = gettotalbytes(g);  /* first estimate */;
       return work;
@@ -1077,15 +1505,14 @@ static lu_mem singlestep (lua_State *L) {
       return sweepstep(L, g, GCSswpend, NULL);
     }
     case GCSswpend: {  /* finish sweeps */
-      makewhite(g, g->mainthread);  /* sweep main thread */
       checkSizes(L, g);
       g->gcstate = GCScallfin;
       return 0;
     }
     case GCScallfin: {  /* call remaining finalizers */
-      if (g->tobefnz && g->gckind != KGC_EMERGENCY) {
-        int n = runafewfinalizers(L);
-        return (n * GCFINALIZECOST);
+      if (g->tobefnz && !g->gcemergency) {
+        int n = runafewfinalizers(L, GCFINMAX);
+        return n * GCFINALIZECOST;
       }
       else {  /* emergency mode or no more finalizers */
         g->gcstate = GCSpause;  /* finish collection */
@@ -1109,71 +1536,81 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
 
 
 /*
-** get GC debt and convert it from Kb to 'work units' (avoid zero debt
-** and overflows)
+** Performs a basic incremental step. The debt and step size are
+** converted from bytes to "units of work"; then the function loops
+** running single steps until adding that many units of work or
+** finishing a cycle (pause state). Finally, it sets the debt that
+** controls when next step will be performed.
 */
-static l_mem getdebt (global_State *g) {
-  l_mem debt = g->GCdebt;
-  int stepmul = g->gcstepmul;
-  if (debt <= 0) return 0;  /* minimal debt */
+static void incstep (lua_State *L, global_State *g) {
+  int stepmul = (getgcparam(g->gcstepmul) | 1);  /* avoid division by 0 */
+  l_mem debt = (g->GCdebt / WORK2MEM) * stepmul;
+  l_mem stepsize = (g->gcstepsize <= log2maxs(l_mem))
+                 ? ((cast(l_mem, 1) << g->gcstepsize) / WORK2MEM) * stepmul
+                 : MAX_LMEM;  /* overflow; keep maximum value */
+  do {  /* repeat until pause or enough "credit" (negative debt) */
+    lu_mem work = singlestep(L);  /* perform one single step */
+    debt -= work;
+  } while (debt > -stepsize && g->gcstate != GCSpause);
+  if (g->gcstate == GCSpause)
+    setpause(g);  /* pause until next cycle */
   else {
-    debt = (debt / STEPMULADJ) + 1;
-    debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
-    return debt;
+    debt = (debt / stepmul) * WORK2MEM;  /* convert 'work units' to bytes */
+    luaE_setdebt(g, debt);
   }
 }
 
 /*
-** performs a basic GC step when collector is running
+** performs a basic GC step if collector is running
 */
 void luaC_step (lua_State *L) {
   global_State *g = G(L);
-  l_mem debt = getdebt(g);  /* GC deficit (be paid now) */
-  if (!g->gcrunning) {  /* not running? */
-    luaE_setdebt(g, -GCSTEPSIZE * 10);  /* avoid being called too often */
-    return;
-  }
-  do {  /* repeat until pause or enough "credit" (negative debt) */
-    lu_mem work = singlestep(L);  /* perform one single step */
-    debt -= work;
-  } while (debt > -GCSTEPSIZE && g->gcstate != GCSpause);
-  if (g->gcstate == GCSpause)
-    setpause(g);  /* pause until next cycle */
-  else {
-    debt = (debt / g->gcstepmul) * STEPMULADJ;  /* convert 'work units' to Kb */
-    luaE_setdebt(g, debt);
-    runafewfinalizers(L);
+  lua_assert(!g->gcemergency);
+  if (g->gcrunning) {  /* running? */
+    if(isdecGCmodegen(g))
+      genstep(L, g);
+    else
+      incstep(L, g);
   }
 }
 
 
 /*
-** Performs a full GC cycle; if 'isemergency', set a flag to avoid
-** some operations which could change the interpreter state in some
-** unexpected ways (running finalizers and shrinking some structures).
+** Perform a full collection in incremental mode.
 ** Before running the collection, check 'keepinvariant'; if it is true,
 ** there may be some objects marked as black, so the collector has
 ** to sweep all objects to turn them back to white (as white has not
 ** changed, nothing will be collected).
 */
-void luaC_fullgc (lua_State *L, int isemergency) {
-  global_State *g = G(L);
-  lua_assert(g->gckind == KGC_NORMAL);
-  if (isemergency) g->gckind = KGC_EMERGENCY;  /* set flag */
-  if (keepinvariant(g)) {  /* black objects? */
+static void fullinc (lua_State *L, global_State *g) {
+  if (keepinvariant(g))  /* black objects? */
     entersweep(L); /* sweep everything to turn them back to white */
-  }
   /* finish any pending sweep phase to start a new cycle */
   luaC_runtilstate(L, bitmask(GCSpause));
-  luaC_runtilstate(L, ~bitmask(GCSpause));  /* start new collection */
   luaC_runtilstate(L, bitmask(GCScallfin));  /* run up to finalizers */
   /* estimate must be correct after a full GC cycle */
   lua_assert(g->GCestimate == gettotalbytes(g));
   luaC_runtilstate(L, bitmask(GCSpause));  /* finish collection */
-  g->gckind = KGC_NORMAL;
   setpause(g);
 }
 
+
+/*
+** Performs a full GC cycle; if 'isemergency', set a flag to avoid
+** some operations which could change the interpreter state in some
+** unexpected ways (running finalizers and shrinking some structures).
+*/
+void luaC_fullgc (lua_State *L, int isemergency) {
+  global_State *g = G(L);
+  lua_assert(!g->gcemergency);
+  g->gcemergency = isemergency;  /* set flag */
+  if (g->gckind == KGC_INC)
+    fullinc(L, g);
+  else
+    fullgen(L, g);
+  g->gcemergency = 0;
+}
+
 /* }====================================================== */
 
 
diff --git a/libs/liblua/src/lgc.h b/libs/liblua/src/lgc.h
index 425cd7cef3..b972472f8d 100644
--- a/libs/liblua/src/lgc.h
+++ b/libs/liblua/src/lgc.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.h,v 2.91.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lgc.h $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -25,25 +25,18 @@
 */
 
 
-
-/* how much to allocate before next GC step */
-#if !defined(GCSTEPSIZE)
-/* ~100 small strings */
-#define GCSTEPSIZE	(cast_int(100 * sizeof(TString)))
-#endif
-
-
 /*
 ** Possible states of the Garbage Collector
 */
 #define GCSpropagate	0
-#define GCSatomic	1
-#define GCSswpallgc	2
-#define GCSswpfinobj	3
-#define GCSswptobefnz	4
-#define GCSswpend	5
-#define GCScallfin	6
-#define GCSpause	7
+#define GCSenteratomic	1
+#define GCSatomic	2
+#define GCSswpallgc	3
+#define GCSswpfinobj	4
+#define GCSswptobefnz	5
+#define GCSswpend	6
+#define GCScallfin	7
+#define GCSpause	8
 
 
 #define issweepphase(g)  \
@@ -64,7 +57,7 @@
 /*
 ** some useful bit tricks
 */
-#define resetbits(x,m)		((x) &= cast(lu_byte, ~(m)))
+#define resetbits(x,m)		((x) &= cast_byte(~(m)))
 #define setbits(x,m)		((x) |= (m))
 #define testbits(x,m)		((x) & (m))
 #define bitmask(b)		(1<<(b))
@@ -74,12 +67,17 @@
 #define testbit(x,b)		testbits(x, bitmask(b))
 
 
-/* Layout for bit use in 'marked' field: */
-#define WHITE0BIT	0  /* object is white (type 0) */
-#define WHITE1BIT	1  /* object is white (type 1) */
-#define BLACKBIT	2  /* object is black */
-#define FINALIZEDBIT	3  /* object has been marked for finalization */
-/* bit 7 is currently used by tests (luaL_checkmemory) */
+/*
+** Layout for bit use in 'marked' field. First three bits are
+** used for object "age" in generational mode. Last bit is free
+** to be used by respective objects.
+*/
+#define WHITE0BIT	3  /* object is white (type 0) */
+#define WHITE1BIT	4  /* object is white (type 1) */
+#define BLACKBIT	5  /* object is black */
+#define FINALIZEDBIT	6  /* object has been marked for finalization */
+
+
 
 #define WHITEBITS	bit2mask(WHITE0BIT, WHITE1BIT)
 
@@ -92,15 +90,61 @@
 #define tofinalize(x)	testbit((x)->marked, FINALIZEDBIT)
 
 #define otherwhite(g)	((g)->currentwhite ^ WHITEBITS)
-#define isdeadm(ow,m)	(!(((m) ^ WHITEBITS) & (ow)))
+#define isdeadm(ow,m)	((m) & (ow))
 #define isdead(g,v)	isdeadm(otherwhite(g), (v)->marked)
 
 #define changewhite(x)	((x)->marked ^= WHITEBITS)
 #define gray2black(x)	l_setbit((x)->marked, BLACKBIT)
 
-#define luaC_white(g)	cast(lu_byte, (g)->currentwhite & WHITEBITS)
+#define luaC_white(g)	cast_byte((g)->currentwhite & WHITEBITS)
+
+
+/* object age in generational mode */
+#define G_NEW		0	/* created in current cycle */
+#define G_SURVIVAL	1	/* created in previous cycle */
+#define G_OLD0		2	/* marked old by frw. barrier in this cycle */
+#define G_OLD1		3	/* first full cycle as old */
+#define G_OLD		4	/* really old object (not to be visited) */
+#define G_TOUCHED1	5	/* old object touched this cycle */
+#define G_TOUCHED2	6	/* old object touched in previous cycle */
+
+#define AGEBITS		7  /* all age bits (111) */
+
+#define getage(o)	((o)->marked & AGEBITS)
+#define setage(o,a)  ((o)->marked = cast_byte(((o)->marked & (~AGEBITS)) | a))
+#define isold(o)	(getage(o) > G_SURVIVAL)
+
+#define changeage(o,f,t)  \
+	check_exp(getage(o) == (f), (o)->marked ^= ((f)^(t)))
 
 
+/* Default Values for GC parameters */
+#define LUAI_GENMAJORMUL         100
+#define LUAI_GENMINORMUL         20
+
+/* wait memory to double before starting new cycle */
+#define LUAI_GCPAUSE    200
+
+/*
+** some gc parameters are stored divided by 4 to allow a maximum value
+** up to 1023 in a 'lu_byte'.
+*/
+#define getgcparam(p)	((p) * 4)
+#define setgcparam(p,v)	((p) = (v) / 4)
+
+#define LUAI_GCMUL      100
+
+/* how much to allocate before next GC step (log2) */
+#define LUAI_GCSTEPSIZE 13      /* 8 KB */
+
+
+/*
+** Check whether the declared GC mode is generational. While in
+** generational mode, the collector can go temporarily to incremental
+** mode to improve performance. This is signaled by 'g->lastatomic != 0'.
+*/
+#define isdecGCmodegen(g)	(g->gckind == KGC_GEN || g->lastatomic != 0)
+
 /*
 ** Does one step of collection when debt becomes positive. 'pre'/'pos'
 ** allows some adjustments to be done only when needed. macro
@@ -127,10 +171,6 @@
 	(isblack(p) && iswhite(o)) ? \
 	luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))
 
-#define luaC_upvalbarrier(L,uv) ( \
-	(iscollectable((uv)->v) && !upisopen(uv)) ? \
-         luaC_upvalbarrier_(L,uv) : cast_void(0))
-
 LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o);
 LUAI_FUNC void luaC_freeallobjects (lua_State *L);
 LUAI_FUNC void luaC_step (lua_State *L);
@@ -138,10 +178,9 @@ LUAI_FUNC void luaC_runtilstate (lua_State *L, int statesmask);
 LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency);
 LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz);
 LUAI_FUNC void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v);
-LUAI_FUNC void luaC_barrierback_ (lua_State *L, Table *o);
-LUAI_FUNC void luaC_upvalbarrier_ (lua_State *L, UpVal *uv);
+LUAI_FUNC void luaC_barrierback_ (lua_State *L, GCObject *o);
 LUAI_FUNC void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt);
-LUAI_FUNC void luaC_upvdeccount (lua_State *L, UpVal *uv);
+LUAI_FUNC void luaC_changemode (lua_State *L, int newmode);
 
 
 #endif
diff --git a/libs/liblua/src/linit.c b/libs/liblua/src/linit.c
index 480da52c7e..69808f84f4 100644
--- a/libs/liblua/src/linit.c
+++ b/libs/liblua/src/linit.c
@@ -1,5 +1,5 @@
 /*
-** $Id: linit.c,v 1.39.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: linit.c $
 ** Initialization of libraries for lua.c and other clients
 ** See Copyright Notice in lua.h
 */
@@ -40,7 +40,7 @@
 ** program
 */
 static const luaL_Reg loadedlibs[] = {
-  {"_G", luaopen_base},
+  {LUA_GNAME, luaopen_base},
   {LUA_LOADLIBNAME, luaopen_package},
   {LUA_COLIBNAME, luaopen_coroutine},
   {LUA_TABLIBNAME, luaopen_table},
@@ -50,9 +50,6 @@ static const luaL_Reg loadedlibs[] = {
   {LUA_MATHLIBNAME, luaopen_math},
   {LUA_UTF8LIBNAME, luaopen_utf8},
   {LUA_DBLIBNAME, luaopen_debug},
-#if defined(LUA_COMPAT_BITLIB)
-  {LUA_BITLIBNAME, luaopen_bit32},
-#endif
   {NULL, NULL}
 };
 
diff --git a/libs/liblua/src/liolib.c b/libs/liblua/src/liolib.c
index 8a9e75cd08..7ac3444393 100644
--- a/libs/liblua/src/liolib.c
+++ b/libs/liblua/src/liolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: liolib.c,v 2.151.1.1 2017/04/19 17:29:57 roberto Exp $
+** $Id: liolib.c $
 ** Standard I/O (and system) library
 ** See Copyright Notice in lua.h
 */
@@ -39,7 +39,7 @@
 /* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */
 static int l_checkmode (const char *mode) {
   return (*mode != '\0' && strchr("rwa", *(mode++)) != NULL &&
-         (*mode != '+' || (++mode, 1)) &&  /* skip if char is '+' */
+         (*mode != '+' || ((void)(++mode), 1)) &&  /* skip if char is '+' */
          (strspn(mode, L_MODEEXT) == strlen(mode)));  /* check extensions */
 }
 
@@ -68,7 +68,7 @@ static int l_checkmode (const char *mode) {
 
 /* ISO C definitions */
 #define l_popen(L,c,m)  \
-	  ((void)((void)c, m), \
+	  ((void)c, (void)m, \
 	  luaL_error(L, "'popen' not supported"), \
 	  (FILE*)0)
 #define l_pclose(L,file)		((void)L, (void)file, -1)
@@ -133,6 +133,7 @@ static int l_checkmode (const char *mode) {
 /* }====================================================== */
 
 
+
 #define IO_PREFIX	"_IO_"
 #define IOPREF_LEN	(sizeof(IO_PREFIX)/sizeof(char) - 1)
 #define IO_INPUT	(IO_PREFIX "input")
@@ -152,7 +153,7 @@ static int io_type (lua_State *L) {
   luaL_checkany(L, 1);
   p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);
   if (p == NULL)
-    lua_pushnil(L);  /* not a file */
+    luaL_pushfail(L);  /* not a file */
   else if (isclosed(p))
     lua_pushliteral(L, "closed file");
   else
@@ -186,7 +187,7 @@ static FILE *tofile (lua_State *L) {
 ** handle is in a consistent state.
 */
 static LStream *newprefile (lua_State *L) {
-  LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));
+  LStream *p = (LStream *)lua_newuserdatauv(L, sizeof(LStream), 0);
   p->closef = NULL;  /* mark file handle as 'closed' */
   luaL_setmetatable(L, LUA_FILEHANDLE);
   return p;
@@ -214,7 +215,7 @@ static int f_close (lua_State *L) {
 
 static int io_close (lua_State *L) {
   if (lua_isnone(L, 1))  /* no argument? */
-    lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT);  /* use standard output */
+    lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT);  /* use default output */
   return f_close(L);
 }
 
@@ -269,6 +270,7 @@ static int io_open (lua_State *L) {
 */
 static int io_pclose (lua_State *L) {
   LStream *p = tolstream(L);
+  errno = 0;
   return luaL_execresult(L, l_pclose(L, p->f));
 }
 
@@ -295,7 +297,7 @@ static FILE *getiofile (lua_State *L, const char *findex) {
   lua_getfield(L, LUA_REGISTRYINDEX, findex);
   p = (LStream *)lua_touserdata(L, -1);
   if (isclosed(p))
-    luaL_error(L, "standard %s file is closed", findex + IOPREF_LEN);
+    luaL_error(L, "default %s file is closed", findex + IOPREF_LEN);
   return p->f;
 }
 
@@ -336,12 +338,22 @@ static int io_readline (lua_State *L);
 */
 #define MAXARGLINE	250
 
+/*
+** Auxiliary function to create the iteration function for 'lines'.
+** The iteration function is a closure over 'io_readline', with
+** the following upvalues:
+** 1) The file being read (first value in the stack)
+** 2) the number of arguments to read
+** 3) a boolean, true iff file has to be closed when finished ('toclose')
+** *) a variable number of format arguments (rest of the stack)
+*/
 static void aux_lines (lua_State *L, int toclose) {
   int n = lua_gettop(L) - 1;  /* number of arguments to read */
   luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments");
+  lua_pushvalue(L, 1);  /* file */
   lua_pushinteger(L, n);  /* number of arguments to read */
   lua_pushboolean(L, toclose);  /* close/not close file when finished */
-  lua_rotate(L, 2, 2);  /* move 'n' and 'toclose' to their positions */
+  lua_rotate(L, 2, 3);  /* move the three values to their positions */
   lua_pushcclosure(L, io_readline, 3 + n);
 }
 
@@ -353,6 +365,11 @@ static int f_lines (lua_State *L) {
 }
 
 
+/*
+** Return an iteration function for 'io.lines'. If file has to be
+** closed, also returns the file itself as a second result (to be
+** closed as the state at the exit of a generic for).
+*/
 static int io_lines (lua_State *L) {
   int toclose;
   if (lua_isnone(L, 1)) lua_pushnil(L);  /* at least one argument */
@@ -368,8 +385,15 @@ static int io_lines (lua_State *L) {
     lua_replace(L, 1);  /* put file at index 1 */
     toclose = 1;  /* close it after iteration */
   }
-  aux_lines(L, toclose);
-  return 1;
+  aux_lines(L, toclose);  /* push iteration function */
+  if (toclose) {
+    lua_pushnil(L);  /* state */
+    lua_pushnil(L);  /* control */
+    lua_pushvalue(L, 1);  /* file is the to-be-closed variable (4th result) */
+    return 4;
+  }
+  else
+    return 1;
 }
 
 
@@ -435,7 +459,7 @@ static int readdigits (RN *rn, int hex) {
 /*
 ** Read a number: first reads a valid prefix of a numeral into a buffer.
 ** Then it calls 'lua_stringtonumber' to check whether the format is
-** correct and to convert it to a Lua number
+** correct and to convert it to a Lua number.
 */
 static int read_number (lua_State *L, FILE *f) {
   RN rn;
@@ -447,7 +471,7 @@ static int read_number (lua_State *L, FILE *f) {
   decp[1] = '.';  /* always accept a dot */
   l_lockfile(rn.f);
   do { rn.c = l_getc(rn.f); } while (isspace(rn.c));  /* skip spaces */
-  test2(&rn, "-+");  /* optional signal */
+  test2(&rn, "-+");  /* optional sign */
   if (test2(&rn, "00")) {
     if (test2(&rn, "xX")) hex = 1;  /* numeral is hexadecimal */
     else count = 1;  /* count initial '0' as a valid digit */
@@ -456,7 +480,7 @@ static int read_number (lua_State *L, FILE *f) {
   if (test2(&rn, decp))  /* decimal point? */
     count += readdigits(&rn, hex);  /* fractional part */
   if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) {  /* exponent mark? */
-    test2(&rn, "-+");  /* exponent signal */
+    test2(&rn, "-+");  /* exponent sign */
     readdigits(&rn, 0);  /* exponent digits */
   }
   ungetc(rn.c, rn.f);  /* unread look-ahead char */
@@ -481,17 +505,17 @@ static int test_eof (lua_State *L, FILE *f) {
 
 static int read_line (lua_State *L, FILE *f, int chop) {
   luaL_Buffer b;
-  int c = '\0';
+  int c;
   luaL_buffinit(L, &b);
-  while (c != EOF && c != '\n') {  /* repeat until end of line */
-    char *buff = luaL_prepbuffer(&b);  /* preallocate buffer */
+  do {  /* may need to read several chunks to get whole line */
+    char *buff = luaL_prepbuffer(&b);  /* preallocate buffer space */
     int i = 0;
     l_lockfile(f);  /* no memory errors can happen inside the lock */
     while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
-      buff[i++] = c;
+      buff[i++] = c;  /* read up to end of line or buffer limit */
     l_unlockfile(f);
     luaL_addsize(&b, i);
-  }
+  } while (c != EOF && c != '\n');  /* repeat until end of line */
   if (!chop && c == '\n')  /* want a newline and have one? */
     luaL_addchar(&b, c);  /* add ending newline to result */
   luaL_pushresult(&b);  /* close buffer */
@@ -528,14 +552,14 @@ static int read_chars (lua_State *L, FILE *f, size_t n) {
 
 static int g_read (lua_State *L, FILE *f, int first) {
   int nargs = lua_gettop(L) - 1;
-  int success;
-  int n;
+  int n, success;
   clearerr(f);
   if (nargs == 0) {  /* no arguments? */
     success = read_line(L, f, 1);
-    n = first+1;  /* to return 1 result */
+    n = first + 1;  /* to return 1 result */
   }
-  else {  /* ensure stack space for all results and for auxlib's buffer */
+  else {
+    /* ensure stack space for all results and for auxlib's buffer */
     luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
     success = 1;
     for (n = first; nargs-- && success; n++) {
@@ -570,7 +594,7 @@ static int g_read (lua_State *L, FILE *f, int first) {
     return luaL_fileresult(L, 0, NULL);
   if (!success) {
     lua_pop(L, 1);  /* remove last result */
-    lua_pushnil(L);  /* push nil instead */
+    luaL_pushfail(L);  /* push nil instead */
   }
   return n - first;
 }
@@ -586,6 +610,9 @@ static int f_read (lua_State *L) {
 }
 
 
+/*
+** Iteration function for 'lines'.
+*/
 static int io_readline (lua_State *L) {
   LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
   int i;
@@ -600,14 +627,14 @@ static int io_readline (lua_State *L) {
   lua_assert(n > 0);  /* should return at least a nil */
   if (lua_toboolean(L, -n))  /* read at least one value? */
     return n;  /* return them */
-  else {  /* first result is nil: EOF or error */
+  else {  /* first result is false: EOF or error */
     if (n > 1) {  /* is there error information? */
       /* 2nd result is error message */
       return luaL_error(L, "%s", lua_tostring(L, -n + 1));
     }
     if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */
-      lua_settop(L, 0);
-      lua_pushvalue(L, lua_upvalueindex(1));
+      lua_settop(L, 0);  /* clear stack */
+      lua_pushvalue(L, lua_upvalueindex(1));  /* push file at index 1 */
       aux_close(L);  /* close it */
     }
     return 0;
@@ -716,26 +743,37 @@ static const luaL_Reg iolib[] = {
 /*
 ** methods for file handles
 */
-static const luaL_Reg flib[] = {
-  {"close", f_close},
-  {"flush", f_flush},
-  {"lines", f_lines},
+static const luaL_Reg meth[] = {
   {"read", f_read},
+  {"write", f_write},
+  {"lines", f_lines},
+  {"flush", f_flush},
   {"seek", f_seek},
+  {"close", f_close},
   {"setvbuf", f_setvbuf},
-  {"write", f_write},
+  {NULL, NULL}
+};
+
+
+/*
+** metamethods for file handles
+*/
+static const luaL_Reg metameth[] = {
+  {"__index", NULL},  /* place holder */
   {"__gc", f_gc},
+  {"__close", f_gc},
   {"__tostring", f_tostring},
   {NULL, NULL}
 };
 
 
 static void createmeta (lua_State *L) {
-  luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
-  lua_pushvalue(L, -1);  /* push metatable */
-  lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
-  luaL_setfuncs(L, flib, 0);  /* add file methods to new metatable */
-  lua_pop(L, 1);  /* pop new metatable */
+  luaL_newmetatable(L, LUA_FILEHANDLE);  /* metatable for file handles */
+  luaL_setfuncs(L, metameth, 0);  /* add metamethods to new metatable */
+  luaL_newlibtable(L, meth);  /* create method table */
+  luaL_setfuncs(L, meth, 0);  /* add file methods to method table */
+  lua_setfield(L, -2, "__index");  /* metatable.__index = method table */
+  lua_pop(L, 1);  /* pop metatable */
 }
 
 
@@ -745,7 +783,7 @@ static void createmeta (lua_State *L) {
 static int io_noclose (lua_State *L) {
   LStream *p = tolstream(L);
   p->closef = &io_noclose;  /* keep file opened */
-  lua_pushnil(L);
+  luaL_pushfail(L);
   lua_pushliteral(L, "cannot close standard file");
   return 2;
 }
diff --git a/libs/liblua/src/ljumptab.h b/libs/liblua/src/ljumptab.h
new file mode 100644
index 0000000000..8306f250cc
--- /dev/null
+++ b/libs/liblua/src/ljumptab.h
@@ -0,0 +1,112 @@
+/*
+** $Id: ljumptab.h $
+** Jump Table for the Lua interpreter
+** See Copyright Notice in lua.h
+*/
+
+
+#undef vmdispatch
+#undef vmcase
+#undef vmbreak
+
+#define vmdispatch(x)     goto *disptab[x];
+
+#define vmcase(l)     L_##l:
+
+#define vmbreak		vmfetch(); vmdispatch(GET_OPCODE(i));
+
+
+static const void *const disptab[NUM_OPCODES] = {
+
+#if 0
+** you can update the following list with this command:
+**
+**  sed -n '/^OP_/\!d; s/OP_/\&\&L_OP_/ ; s/,.*/,/ ; s/\/.*// ; p'  lopcodes.h
+**
+#endif
+
+&&L_OP_MOVE,
+&&L_OP_LOADI,
+&&L_OP_LOADF,
+&&L_OP_LOADK,
+&&L_OP_LOADKX,
+&&L_OP_LOADFALSE,
+&&L_OP_LFALSESKIP,
+&&L_OP_LOADTRUE,
+&&L_OP_LOADNIL,
+&&L_OP_GETUPVAL,
+&&L_OP_SETUPVAL,
+&&L_OP_GETTABUP,
+&&L_OP_GETTABLE,
+&&L_OP_GETI,
+&&L_OP_GETFIELD,
+&&L_OP_SETTABUP,
+&&L_OP_SETTABLE,
+&&L_OP_SETI,
+&&L_OP_SETFIELD,
+&&L_OP_NEWTABLE,
+&&L_OP_SELF,
+&&L_OP_ADDI,
+&&L_OP_ADDK,
+&&L_OP_SUBK,
+&&L_OP_MULK,
+&&L_OP_MODK,
+&&L_OP_POWK,
+&&L_OP_DIVK,
+&&L_OP_IDIVK,
+&&L_OP_BANDK,
+&&L_OP_BORK,
+&&L_OP_BXORK,
+&&L_OP_SHRI,
+&&L_OP_SHLI,
+&&L_OP_ADD,
+&&L_OP_SUB,
+&&L_OP_MUL,
+&&L_OP_MOD,
+&&L_OP_POW,
+&&L_OP_DIV,
+&&L_OP_IDIV,
+&&L_OP_BAND,
+&&L_OP_BOR,
+&&L_OP_BXOR,
+&&L_OP_SHL,
+&&L_OP_SHR,
+&&L_OP_MMBIN,
+&&L_OP_MMBINI,
+&&L_OP_MMBINK,
+&&L_OP_UNM,
+&&L_OP_BNOT,
+&&L_OP_NOT,
+&&L_OP_LEN,
+&&L_OP_CONCAT,
+&&L_OP_CLOSE,
+&&L_OP_TBC,
+&&L_OP_JMP,
+&&L_OP_EQ,
+&&L_OP_LT,
+&&L_OP_LE,
+&&L_OP_EQK,
+&&L_OP_EQI,
+&&L_OP_LTI,
+&&L_OP_LEI,
+&&L_OP_GTI,
+&&L_OP_GEI,
+&&L_OP_TEST,
+&&L_OP_TESTSET,
+&&L_OP_CALL,
+&&L_OP_TAILCALL,
+&&L_OP_RETURN,
+&&L_OP_RETURN0,
+&&L_OP_RETURN1,
+&&L_OP_FORLOOP,
+&&L_OP_FORPREP,
+&&L_OP_TFORPREP,
+&&L_OP_TFORCALL,
+&&L_OP_TFORLOOP,
+&&L_OP_SETLIST,
+&&L_OP_CLOSURE,
+&&L_OP_VARARG,
+&&L_OP_VARARGPREP,
+&&L_OP_EXTRAARG
+
+};
diff --git a/libs/liblua/src/llex.c b/libs/liblua/src/llex.c
index 66fd411ba9..90a7951f70 100644
--- a/libs/liblua/src/llex.c
+++ b/libs/liblua/src/llex.c
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.96.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: llex.c $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -29,7 +29,7 @@
 
 
 
-#define next(ls) (ls->current = zgetc(ls->z))
+#define next(ls)	(ls->current = zgetc(ls->z))
 
 
 
@@ -63,7 +63,7 @@ static void save (LexState *ls, int c) {
     newsize = luaZ_sizebuffer(b) * 2;
     luaZ_resizebuffer(ls->L, b, newsize);
   }
-  b->buffer[luaZ_bufflen(b)++] = cast(char, c);
+  b->buffer[luaZ_bufflen(b)++] = cast_char(c);
 }
 
 
@@ -82,7 +82,10 @@ void luaX_init (lua_State *L) {
 const char *luaX_token2str (LexState *ls, int token) {
   if (token < FIRST_RESERVED) {  /* single-byte symbols? */
     lua_assert(token == cast_uchar(token));
-    return luaO_pushfstring(ls->L, "'%c'", token);
+    if (lisprint(token))
+      return luaO_pushfstring(ls->L, "'%c'", token);
+    else  /* control character */
+      return luaO_pushfstring(ls->L, "'<\\%d>'", token);
   }
   else {
     const char *s = luaX_tokens[token - FIRST_RESERVED];
@@ -129,15 +132,15 @@ TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
   TValue *o;  /* entry for 'str' */
   TString *ts = luaS_newlstr(L, str, l);  /* create new string */
   setsvalue2s(L, L->top++, ts);  /* temporarily anchor it in stack */
-  o = luaH_set(L, ls->h, L->top - 1);
-  if (ttisnil(o)) {  /* not in use yet? */
+  o = luaH_set(L, ls->h, s2v(L->top - 1));
+  if (isempty(o)) {  /* not in use yet? */
     /* boolean value does not need GC barrier;
-       table has no metatable, so it does not need to invalidate cache */
-    setbvalue(o, 1);  /* t[string] = true */
+       table is not a metatable, so it does not need to invalidate cache */
+    setbtvalue(o);  /* t[string] = true */
     luaC_checkGC(L);
   }
   else {  /* string already present */
-    ts = tsvalue(keyfromval(o));  /* re-use value previously stored */
+    ts = keystrval(nodefromval(o));  /* re-use value previously stored */
   }
   L->top--;  /* remove string from stack */
   return ts;
@@ -208,8 +211,16 @@ static int check_next2 (LexState *ls, const char *set) {
 
 /* LUA_NUMBER */
 /*
-** this function is quite liberal in what it accepts, as 'luaO_str2num'
-** will reject ill-formed numerals.
+** This function is quite liberal in what it accepts, as 'luaO_str2num'
+** will reject ill-formed numerals. Roughly, it accepts the following
+** pattern:
+**
+**   %d(%x|%.|([Ee][+-]?))* | 0[Xx](%x|%.|([Pp][+-]?))*
+**
+** The only tricky part is to accept [+-] only after a valid exponent
+** mark, to avoid reading '3-4' or '0xe+1' as a single number.
+**
+** The caller might have already read an initial dot.
 */
 static int read_numeral (LexState *ls, SemInfo *seminfo) {
   TValue obj;
@@ -220,14 +231,14 @@ static int read_numeral (LexState *ls, SemInfo *seminfo) {
   if (first == '0' && check_next2(ls, "xX"))  /* hexadecimal? */
     expo = "Pp";
   for (;;) {
-    if (check_next2(ls, expo))  /* exponent part? */
+    if (check_next2(ls, expo))  /* exponent mark? */
       check_next2(ls, "-+");  /* optional exponent sign */
-    if (lisxdigit(ls->current))
-      save_and_next(ls);
-    else if (ls->current == '.')
+    else if (lisxdigit(ls->current) || ls->current == '.')  /* '%x|%.' */
       save_and_next(ls);
     else break;
   }
+  if (lislalpha(ls->current))  /* is numeral touching a letter? */
+    save_and_next(ls);  /* force an error */
   save(ls, '\0');
   if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0)  /* format error? */
     lexerror(ls, "malformed number", TK_FLT);
@@ -244,12 +255,12 @@ static int read_numeral (LexState *ls, SemInfo *seminfo) {
 
 
 /*
-** skip a sequence '[=*[' or ']=*]'; if sequence is well formed, return
-** its number of '='s; otherwise, return a negative number (-1 iff there
-** are no '='s after initial bracket)
+** reads a sequence '[=*[' or ']=*]', leaving the last bracket.
+** If sequence is well formed, return its number of '='s + 2; otherwise,
+** return 1 if there is no '='s or 0 otherwise (an unfinished '[==...').
 */
-static int skip_sep (LexState *ls) {
-  int count = 0;
+static size_t skip_sep (LexState *ls) {
+  size_t count = 0;
   int s = ls->current;
   lua_assert(s == '[' || s == ']');
   save_and_next(ls);
@@ -257,11 +268,13 @@ static int skip_sep (LexState *ls) {
     save_and_next(ls);
     count++;
   }
-  return (ls->current == s) ? count : (-count) - 1;
+  return (ls->current == s) ? count + 2
+         : (count == 0) ? 1
+         : 0;
 }
 
 
-static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
+static void read_long_string (LexState *ls, SemInfo *seminfo, size_t sep) {
   int line = ls->linenumber;  /* initial line (for error message) */
   save_and_next(ls);  /* skip 2nd '[' */
   if (currIsNewline(ls))  /* string starts with a newline? */
@@ -295,8 +308,8 @@ static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
     }
   } endloop:
   if (seminfo)
-    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep),
-                                     luaZ_bufflen(ls->buff) - 2*(2 + sep));
+    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + sep,
+                                     luaZ_bufflen(ls->buff) - 2 * sep);
 }
 
 
@@ -330,10 +343,10 @@ static unsigned long readutf8esc (LexState *ls) {
   save_and_next(ls);  /* skip 'u' */
   esccheck(ls, ls->current == '{', "missing '{'");
   r = gethexa(ls);  /* must have at least one digit */
-  while ((save_and_next(ls), lisxdigit(ls->current))) {
+  while (cast_void(save_and_next(ls)), lisxdigit(ls->current)) {
     i++;
+    esccheck(ls, r <= (0x7FFFFFFFu >> 4), "UTF-8 value too large");
     r = (r << 4) + luaO_hexavalue(ls->current);
-    esccheck(ls, r <= 0x10FFFF, "UTF-8 value too large");
   }
   esccheck(ls, ls->current == '}', "missing '}'");
   next(ls);  /* skip '}' */
@@ -444,9 +457,9 @@ static int llex (LexState *ls, SemInfo *seminfo) {
         /* else is a comment */
         next(ls);
         if (ls->current == '[') {  /* long comment? */
-          int sep = skip_sep(ls);
+          size_t sep = skip_sep(ls);
           luaZ_resetbuffer(ls->buff);  /* 'skip_sep' may dirty the buffer */
-          if (sep >= 0) {
+          if (sep >= 2) {
             read_long_string(ls, NULL, sep);  /* skip long comment */
             luaZ_resetbuffer(ls->buff);  /* previous call may dirty the buff. */
             break;
@@ -458,12 +471,12 @@ static int llex (LexState *ls, SemInfo *seminfo) {
         break;
       }
       case '[': {  /* long string or simply '[' */
-        int sep = skip_sep(ls);
-        if (sep >= 0) {
+        size_t sep = skip_sep(ls);
+        if (sep >= 2) {
           read_long_string(ls, seminfo, sep);
           return TK_STRING;
         }
-        else if (sep != -1)  /* '[=...' missing second bracket */
+        else if (sep == 0)  /* '[=...' missing second bracket? */
           lexerror(ls, "invalid long string delimiter", TK_STRING);
         return '[';
       }
diff --git a/libs/liblua/src/llex.h b/libs/liblua/src/llex.h
index 2ed0af66a4..d1a4cba7c2 100644
--- a/libs/liblua/src/llex.h
+++ b/libs/liblua/src/llex.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.h,v 1.79.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: llex.h $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -37,7 +37,7 @@ enum RESERVED {
 };
 
 /* number of reserved words */
-#define NUM_RESERVED	(cast(int, TK_WHILE-FIRST_RESERVED+1))
+#define NUM_RESERVED	(cast_int(TK_WHILE-FIRST_RESERVED + 1))
 
 
 typedef union {
diff --git a/libs/liblua/src/llimits.h b/libs/liblua/src/llimits.h
index d1036f6bc8..b86d345256 100644
--- a/libs/liblua/src/llimits.h
+++ b/libs/liblua/src/llimits.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llimits.h,v 1.141.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: llimits.h $
 ** Limits, basic types, and some other 'installation-dependent' definitions
 ** See Copyright Notice in lua.h
 */
@@ -14,6 +14,7 @@
 
 #include "lua.h"
 
+
 /*
 ** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count
 ** the total memory used by Lua (in bytes). Usually, 'size_t' and
@@ -22,7 +23,7 @@
 #if defined(LUAI_MEM)		/* { external definitions? */
 typedef LUAI_UMEM lu_mem;
 typedef LUAI_MEM l_mem;
-#elif LUAI_BITSINT >= 32	/* }{ */
+#elif LUAI_IS32INT	/* }{ */
 typedef size_t lu_mem;
 typedef ptrdiff_t l_mem;
 #else  /* 16-bit ints */	/* }{ */
@@ -33,12 +34,13 @@ typedef long l_mem;
 
 /* chars used as small naturals (so that 'char' is reserved for characters) */
 typedef unsigned char lu_byte;
+typedef signed char ls_byte;
 
 
 /* maximum value for size_t */
 #define MAX_SIZET	((size_t)(~(size_t)0))
 
-/* maximum size visible for Lua (must be representable in a lua_Integer */
+/* maximum size visible for Lua (must be representable in a lua_Integer) */
 #define MAX_SIZE	(sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \
                           : (size_t)(LUA_MAXINTEGER))
 
@@ -51,6 +53,23 @@ typedef unsigned char lu_byte;
 #define MAX_INT		INT_MAX  /* maximum value of an int */
 
 
+/*
+** floor of the log2 of the maximum signed value for integral type 't'.
+** (That is, maximum 'n' such that '2^n' fits in the given signed type.)
+*/
+#define log2maxs(t)	(sizeof(t) * 8 - 2)
+
+
+/*
+** test whether an unsigned value is a power of 2 (or zero)
+*/
+#define ispow2(x)	(((x) & ((x) - 1)) == 0)
+
+
+/* number of chars of a literal string without the ending \0 */
+#define LL(x)   (sizeof(x)/sizeof(char) - 1)
+
+
 /*
 ** conversion of pointer to unsigned integer:
 ** this is for hashing only; there is no problem if the integer
@@ -60,21 +79,6 @@ typedef unsigned char lu_byte;
 
 
 
-/* type to ensure maximum alignment */
-#if defined(LUAI_USER_ALIGNMENT_T)
-typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
-#else
-typedef union {
-  lua_Number n;
-  double u;
-  void *s;
-  lua_Integer i;
-  long l;
-} L_Umaxalign;
-#endif
-
-
-
 /* types of 'usual argument conversions' for lua_Number and lua_Integer */
 typedef LUAI_UACNUMBER l_uacNumber;
 typedef LUAI_UACINT l_uacInt;
@@ -95,7 +99,7 @@ typedef LUAI_UACINT l_uacInt;
 ** assertion for checking API calls
 */
 #if !defined(luai_apicheck)
-#define luai_apicheck(l,e)	lua_assert(e)
+#define luai_apicheck(l,e)	((void)l, lua_assert(e))
 #endif
 
 #define api_check(l,e,msg)	luai_apicheck(l,(e) && msg)
@@ -111,10 +115,15 @@ typedef LUAI_UACINT l_uacInt;
 #define cast(t, exp)	((t)(exp))
 
 #define cast_void(i)	cast(void, (i))
-#define cast_byte(i)	cast(lu_byte, (i))
+#define cast_voidp(i)	cast(void *, (i))
 #define cast_num(i)	cast(lua_Number, (i))
 #define cast_int(i)	cast(int, (i))
+#define cast_uint(i)	cast(unsigned int, (i))
+#define cast_byte(i)	cast(lu_byte, (i))
 #define cast_uchar(i)	cast(unsigned char, (i))
+#define cast_char(i)	cast(char, (i))
+#define cast_charp(i)	cast(char *, (i))
+#define cast_sizet(i)	cast(size_t, (i))
 
 
 /* cast a signed lua_Integer to lua_Unsigned */
@@ -133,38 +142,49 @@ typedef LUAI_UACINT l_uacInt;
 
 
 /*
-** non-return type
+** macros to improve jump prediction (used mainly for error handling)
 */
+#if !defined(likely)
+
 #if defined(__GNUC__)
-#define l_noret		void __attribute__((noreturn))
-#elif defined(_MSC_VER) && _MSC_VER >= 1200
-#define l_noret		void __declspec(noreturn)
+#define likely(x)	(__builtin_expect(((x) != 0), 1))
+#define unlikely(x)	(__builtin_expect(((x) != 0), 0))
 #else
-#define l_noret		void
+#define likely(x)	(x)
+#define unlikely(x)	(x)
 #endif
 
+#endif
 
 
 /*
-** maximum depth for nested C calls and syntactical nested non-terminals
-** in a program. (Value must fit in an unsigned short int.)
+** non-return type
 */
-#if !defined(LUAI_MAXCCALLS)
-#define LUAI_MAXCCALLS		200
+#if !defined(l_noret)
+
+#if defined(__GNUC__)
+#define l_noret		void __attribute__((noreturn))
+#elif defined(_MSC_VER) && _MSC_VER >= 1200
+#define l_noret		void __declspec(noreturn)
+#else
+#define l_noret		void
 #endif
 
+#endif
 
 
 /*
 ** type for virtual-machine instructions;
 ** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h)
 */
-#if LUAI_BITSINT >= 32
-typedef unsigned int Instruction;
+#if LUAI_IS32INT
+typedef unsigned int l_uint32;
 #else
-typedef unsigned long Instruction;
+typedef unsigned long l_uint32;
 #endif
 
+typedef l_uint32 Instruction;
+
 
 
 /*
@@ -225,8 +245,7 @@ typedef unsigned long Instruction;
 
 
 /*
-** these macros allow user-specific actions on threads when you defined
-** LUAI_EXTRASPACE and need to do something extra when a thread is
+** these macros allow user-specific actions when a thread is
 ** created/deleted/resumed/yielded.
 */
 #if !defined(luai_userstateopen)
@@ -270,15 +289,20 @@ typedef unsigned long Instruction;
 #endif
 
 /*
-** modulo: defined as 'a - floor(a/b)*b'; this definition gives NaN when
-** 'b' is huge, but the result should be 'a'. 'fmod' gives the result of
-** 'a - trunc(a/b)*b', and therefore must be corrected when 'trunc(a/b)
-** ~= floor(a/b)'. That happens when the division has a non-integer
-** negative result, which is equivalent to the test below.
+** modulo: defined as 'a - floor(a/b)*b'; the direct computation
+** using this definition has several problems with rounding errors,
+** so it is better to use 'fmod'. 'fmod' gives the result of
+** 'a - trunc(a/b)*b', and therefore must be corrected when
+** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a
+** non-integer negative result: non-integer result is equivalent to
+** a non-zero remainder 'm'; negative result is equivalent to 'a' and
+** 'b' with different signs, or 'm' and 'b' with different signs
+** (as the result 'm' of 'fmod' has the same sign of 'a').
 */
 #if !defined(luai_nummod)
 #define luai_nummod(L,a,b,m)  \
-  { (m) = l_mathop(fmod)(a,b); if ((m)*(b) < 0) (m) += (b); }
+  { (void)L; (m) = l_mathop(fmod)(a,b); \
+    if (((m) > 0) ? (b) < 0 : ((m) < 0 && (b) > 0)) (m) += (b); }
 #endif
 
 /* exponentiation */
@@ -295,6 +319,8 @@ typedef unsigned long Instruction;
 #define luai_numeq(a,b)         ((a)==(b))
 #define luai_numlt(a,b)         ((a)<(b))
 #define luai_numle(a,b)         ((a)<=(b))
+#define luai_numgt(a,b)         ((a)>(b))
+#define luai_numge(a,b)         ((a)>=(b))
 #define luai_numisnan(a)        (!luai_numeq((a), (a)))
 #endif
 
@@ -310,7 +336,7 @@ typedef unsigned long Instruction;
 #else
 /* realloc stack keeping its size */
 #define condmovestack(L,pre,pos)  \
-	{ int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_); pos; }
+  { int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_, 0); pos; }
 #endif
 
 #if !defined(HARDMEMTESTS)
diff --git a/libs/liblua/src/lmathlib.c b/libs/liblua/src/lmathlib.c
index 7ef7e593fd..86def470c4 100644
--- a/libs/liblua/src/lmathlib.c
+++ b/libs/liblua/src/lmathlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmathlib.c,v 1.119.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lmathlib.c $
 ** Standard mathematical library
 ** See Copyright Notice in lua.h
 */
@@ -10,8 +10,11 @@
 #include "lprefix.h"
 
 
-#include <stdlib.h>
+#include <float.h>
+#include <limits.h>
 #include <math.h>
+#include <stdlib.h>
+#include <time.h>
 
 #include "lua.h"
 
@@ -23,19 +26,6 @@
 #define PI	(l_mathop(3.141592653589793238462643383279502884))
 
 
-#if !defined(l_rand)		/* { */
-#if defined(LUA_USE_POSIX)
-#define l_rand()	random()
-#define l_srand(x)	srandom(x)
-#define L_RANDMAX	2147483647	/* (2^31 - 1), following POSIX */
-#else
-#define l_rand()	rand()
-#define l_srand(x)	srand(x)
-#define L_RANDMAX	RAND_MAX
-#endif
-#endif				/* } */
-
-
 static int math_abs (lua_State *L) {
   if (lua_isinteger(L, 1)) {
     lua_Integer n = lua_tointeger(L, 1);
@@ -87,7 +77,7 @@ static int math_toint (lua_State *L) {
     lua_pushinteger(L, n);
   else {
     luaL_checkany(L, 1);
-    lua_pushnil(L);  /* value is not convertible to integer */
+    luaL_pushfail(L);  /* value is not convertible to integer */
   }
   return 1;
 }
@@ -239,22 +229,347 @@ static int math_max (lua_State *L) {
   return 1;
 }
 
+
+static int math_type (lua_State *L) {
+  if (lua_type(L, 1) == LUA_TNUMBER)
+    lua_pushstring(L, (lua_isinteger(L, 1)) ? "integer" : "float");
+  else {
+    luaL_checkany(L, 1);
+    luaL_pushfail(L);
+  }
+  return 1;
+}
+
+
+
+/*
+** {==================================================================
+** Pseudo-Random Number Generator based on 'xoshiro256**'.
+** ===================================================================
+*/
+
+/* number of binary digits in the mantissa of a float */
+#define FIGS	l_floatatt(MANT_DIG)
+
+#if FIGS > 64
+/* there are only 64 random bits; use them all */
+#undef FIGS
+#define FIGS	64
+#endif
+
+
+/*
+** LUA_RAND32 forces the use of 32-bit integers in the implementation
+** of the PRN generator (mainly for testing).
+*/
+#if !defined(LUA_RAND32) && !defined(Rand64)
+
+/* try to find an integer type with at least 64 bits */
+
+#if (ULONG_MAX >> 31 >> 31) >= 3
+
+/* 'long' has at least 64 bits */
+#define Rand64		unsigned long
+
+#elif !defined(LUA_USE_C89) && defined(LLONG_MAX)
+
+/* there is a 'long long' type (which must have at least 64 bits) */
+#define Rand64		unsigned long long
+
+#elif (LUA_MAXUNSIGNED >> 31 >> 31) >= 3
+
+/* 'lua_Integer' has at least 64 bits */
+#define Rand64		lua_Unsigned
+
+#endif
+
+#endif
+
+
+#if defined(Rand64)  /* { */
+
+/*
+** Standard implementation, using 64-bit integers.
+** If 'Rand64' has more than 64 bits, the extra bits do not interfere
+** with the 64 initial bits, except in a right shift. Moreover, the
+** final result has to discard the extra bits.
+*/
+
+/* avoid using extra bits when needed */
+#define trim64(x)	((x) & 0xffffffffffffffffu)
+
+
+/* rotate left 'x' by 'n' bits */
+static Rand64 rotl (Rand64 x, int n) {
+  return (x << n) | (trim64(x) >> (64 - n));
+}
+
+static Rand64 nextrand (Rand64 *state) {
+  Rand64 state0 = state[0];
+  Rand64 state1 = state[1];
+  Rand64 state2 = state[2] ^ state0;
+  Rand64 state3 = state[3] ^ state1;
+  Rand64 res = rotl(state1 * 5, 7) * 9;
+  state[0] = state0 ^ state3;
+  state[1] = state1 ^ state2;
+  state[2] = state2 ^ (state1 << 17);
+  state[3] = rotl(state3, 45);
+  return res;
+}
+
+
+/* must take care to not shift stuff by more than 63 slots */
+
+
+/*
+** Convert bits from a random integer into a float in the
+** interval [0,1), getting the higher FIG bits from the
+** random unsigned integer and converting that to a float.
+*/
+
+/* must throw out the extra (64 - FIGS) bits */
+#define shift64_FIG	(64 - FIGS)
+
+/* to scale to [0, 1), multiply by scaleFIG = 2^(-FIGS) */
+#define scaleFIG	(l_mathop(0.5) / ((Rand64)1 << (FIGS - 1)))
+
+static lua_Number I2d (Rand64 x) {
+  return (lua_Number)(trim64(x) >> shift64_FIG) * scaleFIG;
+}
+
+/* convert a 'Rand64' to a 'lua_Unsigned' */
+#define I2UInt(x)	((lua_Unsigned)trim64(x))
+
+/* convert a 'lua_Unsigned' to a 'Rand64' */
+#define Int2I(x)	((Rand64)(x))
+
+
+#else	/* no 'Rand64'   }{ */
+
+/* get an integer with at least 32 bits */
+#if LUAI_IS32INT
+typedef unsigned int lu_int32;
+#else
+typedef unsigned long lu_int32;
+#endif
+
+
 /*
-** This function uses 'double' (instead of 'lua_Number') to ensure that
-** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0'
-** will keep full precision (ensuring that 'r' is always less than 1.0.)
+** Use two 32-bit integers to represent a 64-bit quantity.
 */
+typedef struct Rand64 {
+  lu_int32 h;  /* higher half */
+  lu_int32 l;  /* lower half */
+} Rand64;
+
+
+/*
+** If 'lu_int32' has more than 32 bits, the extra bits do not interfere
+** with the 32 initial bits, except in a right shift and comparisons.
+** Moreover, the final result has to discard the extra bits.
+*/
+
+/* avoid using extra bits when needed */
+#define trim32(x)	((x) & 0xffffffffu)
+
+
+/*
+** basic operations on 'Rand64' values
+*/
+
+/* build a new Rand64 value */
+static Rand64 packI (lu_int32 h, lu_int32 l) {
+  Rand64 result;
+  result.h = h;
+  result.l = l;
+  return result;
+}
+
+/* return i << n */
+static Rand64 Ishl (Rand64 i, int n) {
+  lua_assert(n > 0 && n < 32);
+  return packI((i.h << n) | (trim32(i.l) >> (32 - n)), i.l << n);
+}
+
+/* i1 ^= i2 */
+static void Ixor (Rand64 *i1, Rand64 i2) {
+  i1->h ^= i2.h;
+  i1->l ^= i2.l;
+}
+
+/* return i1 + i2 */
+static Rand64 Iadd (Rand64 i1, Rand64 i2) {
+  Rand64 result = packI(i1.h + i2.h, i1.l + i2.l);
+  if (trim32(result.l) < trim32(i1.l))  /* carry? */
+    result.h++;
+  return result;
+}
+
+/* return i * 5 */
+static Rand64 times5 (Rand64 i) {
+  return Iadd(Ishl(i, 2), i);  /* i * 5 == (i << 2) + i */
+}
+
+/* return i * 9 */
+static Rand64 times9 (Rand64 i) {
+  return Iadd(Ishl(i, 3), i);  /* i * 9 == (i << 3) + i */
+}
+
+/* return 'i' rotated left 'n' bits */
+static Rand64 rotl (Rand64 i, int n) {
+  lua_assert(n > 0 && n < 32);
+  return packI((i.h << n) | (trim32(i.l) >> (32 - n)),
+               (trim32(i.h) >> (32 - n)) | (i.l << n));
+}
+
+/* for offsets larger than 32, rotate right by 64 - offset */
+static Rand64 rotl1 (Rand64 i, int n) {
+  lua_assert(n > 32 && n < 64);
+  n = 64 - n;
+  return packI((trim32(i.h) >> n) | (i.l << (32 - n)),
+               (i.h << (32 - n)) | (trim32(i.l) >> n));
+}
+
+/*
+** implementation of 'xoshiro256**' algorithm on 'Rand64' values
+*/
+static Rand64 nextrand (Rand64 *state) {
+  Rand64 res = times9(rotl(times5(state[1]), 7));
+  Rand64 t = Ishl(state[1], 17);
+  Ixor(&state[2], state[0]);
+  Ixor(&state[3], state[1]);
+  Ixor(&state[1], state[2]);
+  Ixor(&state[0], state[3]);
+  Ixor(&state[2], t);
+  state[3] = rotl1(state[3], 45);
+  return res;
+}
+
+
+/*
+** Converts a 'Rand64' into a float.
+*/
+
+/* an unsigned 1 with proper type */
+#define UONE		((lu_int32)1)
+
+
+#if FIGS <= 32
+
+/* 2^(-FIGS) */
+#define scaleFIG       (l_mathop(0.5) / (UONE << (FIGS - 1)))
+
+/*
+** get up to 32 bits from higher half, shifting right to
+** throw out the extra bits.
+*/
+static lua_Number I2d (Rand64 x) {
+  lua_Number h = (lua_Number)(trim32(x.h) >> (32 - FIGS));
+  return h * scaleFIG;
+}
+
+#else	/* 32 < FIGS <= 64 */
+
+/* must take care to not shift stuff by more than 31 slots */
+
+/* 2^(-FIGS) = 1.0 / 2^30 / 2^3 / 2^(FIGS-33) */
+#define scaleFIG  \
+	((lua_Number)1.0 / (UONE << 30) / 8.0 / (UONE << (FIGS - 33)))
+
+/*
+** use FIGS - 32 bits from lower half, throwing out the other
+** (32 - (FIGS - 32)) = (64 - FIGS) bits
+*/
+#define shiftLOW	(64 - FIGS)
+
+/*
+** higher 32 bits go after those (FIGS - 32) bits: shiftHI = 2^(FIGS - 32)
+*/
+#define shiftHI		((lua_Number)(UONE << (FIGS - 33)) * 2.0)
+
+
+static lua_Number I2d (Rand64 x) {
+  lua_Number h = (lua_Number)trim32(x.h) * shiftHI;
+  lua_Number l = (lua_Number)(trim32(x.l) >> shiftLOW);
+  return (h + l) * scaleFIG;
+}
+
+#endif
+
+
+/* convert a 'Rand64' to a 'lua_Unsigned' */
+static lua_Unsigned I2UInt (Rand64 x) {
+  return ((lua_Unsigned)trim32(x.h) << 31 << 1) | (lua_Unsigned)trim32(x.l);
+}
+
+/* convert a 'lua_Unsigned' to a 'Rand64' */
+static Rand64 Int2I (lua_Unsigned n) {
+  return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n);
+}
+
+#endif  /* } */
+
+
+/*
+** A state uses four 'Rand64' values.
+*/
+typedef struct {
+  Rand64 s[4];
+} RanState;
+
+
+/*
+** Project the random integer 'ran' into the interval [0, n].
+** Because 'ran' has 2^B possible values, the projection can only be
+** uniform when the size of the interval is a power of 2 (exact
+** division). Otherwise, to get a uniform projection into [0, n], we
+** first compute 'lim', the smallest Mersenne number not smaller than
+** 'n'. We then project 'ran' into the interval [0, lim].  If the result
+** is inside [0, n], we are done. Otherwise, we try with another 'ran',
+** until we have a result inside the interval.
+*/
+static lua_Unsigned project (lua_Unsigned ran, lua_Unsigned n,
+                             RanState *state) {
+  if ((n & (n + 1)) == 0)  /* is 'n + 1' a power of 2? */
+    return ran & n;  /* no bias */
+  else {
+    lua_Unsigned lim = n;
+    /* compute the smallest (2^b - 1) not smaller than 'n' */
+    lim |= (lim >> 1);
+    lim |= (lim >> 2);
+    lim |= (lim >> 4);
+    lim |= (lim >> 8);
+    lim |= (lim >> 16);
+#if (LUA_MAXUNSIGNED >> 31) >= 3
+    lim |= (lim >> 32);  /* integer type has more than 32 bits */
+#endif
+    lua_assert((lim & (lim + 1)) == 0  /* 'lim + 1' is a power of 2, */
+      && lim >= n  /* not smaller than 'n', */
+      && (lim >> 1) < n);  /* and it is the smallest one */
+    while ((ran &= lim) > n)  /* project 'ran' into [0..lim] */
+      ran = I2UInt(nextrand(state->s));  /* not inside [0..n]? try again */
+    return ran;
+  }
+}
+
+
 static int math_random (lua_State *L) {
   lua_Integer low, up;
-  double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0));
+  lua_Unsigned p;
+  RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
+  Rand64 rv = nextrand(state->s);  /* next pseudo-random value */
   switch (lua_gettop(L)) {  /* check number of arguments */
     case 0: {  /* no arguments */
-      lua_pushnumber(L, (lua_Number)r);  /* Number between 0 and 1 */
+      lua_pushnumber(L, I2d(rv));  /* float between 0 and 1 */
       return 1;
     }
     case 1: {  /* only upper limit */
       low = 1;
       up = luaL_checkinteger(L, 1);
+      if (up == 0) {  /* single 0 as argument? */
+        lua_pushinteger(L, I2UInt(rv));  /* full random integer */
+        return 1;
+      }
       break;
     }
     case 2: {  /* lower and upper limits */
@@ -266,35 +581,72 @@ static int math_random (lua_State *L) {
   }
   /* random integer in the interval [low, up] */
   luaL_argcheck(L, low <= up, 1, "interval is empty");
-  luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
-                   "interval too large");
-  r *= (double)(up - low) + 1.0;
-  lua_pushinteger(L, (lua_Integer)r + low);
+  /* project random integer into the interval [0, up - low] */
+  p = project(I2UInt(rv), (lua_Unsigned)up - (lua_Unsigned)low, state);
+  lua_pushinteger(L, p + (lua_Unsigned)low);
   return 1;
 }
 
 
-static int math_randomseed (lua_State *L) {
-  l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));
-  (void)l_rand(); /* discard first value to avoid undesirable correlations */
-  return 0;
+static void setseed (lua_State *L, Rand64 *state,
+                     lua_Unsigned n1, lua_Unsigned n2) {
+  int i;
+  state[0] = Int2I(n1);
+  state[1] = Int2I(0xff);  /* avoid a zero state */
+  state[2] = Int2I(n2);
+  state[3] = Int2I(0);
+  for (i = 0; i < 16; i++)
+    nextrand(state);  /* discard initial values to "spread" seed */
+  lua_pushinteger(L, n1);
+  lua_pushinteger(L, n2);
 }
 
 
-static int math_type (lua_State *L) {
-  if (lua_type(L, 1) == LUA_TNUMBER) {
-      if (lua_isinteger(L, 1))
-        lua_pushliteral(L, "integer");
-      else
-        lua_pushliteral(L, "float");
+/*
+** Set a "random" seed. To get some randomness, use the current time
+** and the address of 'L' (in case the machine does address space layout
+** randomization).
+*/
+static void randseed (lua_State *L, RanState *state) {
+  lua_Unsigned seed1 = (lua_Unsigned)time(NULL);
+  lua_Unsigned seed2 = (lua_Unsigned)(size_t)L;
+  setseed(L, state->s, seed1, seed2);
+}
+
+
+static int math_randomseed (lua_State *L) {
+  RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
+  if (lua_isnone(L, 1)) {
+    randseed(L, state);
   }
   else {
-    luaL_checkany(L, 1);
-    lua_pushnil(L);
+    lua_Integer n1 = luaL_checkinteger(L, 1);
+    lua_Integer n2 = luaL_optinteger(L, 2, 0);
+    setseed(L, state->s, n1, n2);
   }
-  return 1;
+  return 2;  /* return seeds */
+}
+
+
+static const luaL_Reg randfuncs[] = {
+  {"random", math_random},
+  {"randomseed", math_randomseed},
+  {NULL, NULL}
+};
+
+
+/*
+** Register the random functions and initialize their state.
+*/
+static void setrandfunc (lua_State *L) {
+  RanState *state = (RanState *)lua_newuserdatauv(L, sizeof(RanState), 0);
+  randseed(L, state);  /* initialize with a "random" seed */
+  lua_pop(L, 2);  /* remove pushed seeds */
+  luaL_setfuncs(L, randfuncs, 1);
 }
 
+/* }================================================================== */
+
 
 /*
 ** {==================================================================
@@ -367,8 +719,6 @@ static const luaL_Reg mathlib[] = {
   {"min",   math_min},
   {"modf",   math_modf},
   {"rad",   math_rad},
-  {"random",     math_random},
-  {"randomseed", math_randomseed},
   {"sin",   math_sin},
   {"sqrt",  math_sqrt},
   {"tan",   math_tan},
@@ -384,6 +734,8 @@ static const luaL_Reg mathlib[] = {
   {"log10", math_log10},
 #endif
   /* placeholders */
+  {"random", NULL},
+  {"randomseed", NULL},
   {"pi", NULL},
   {"huge", NULL},
   {"maxinteger", NULL},
@@ -405,6 +757,7 @@ LUAMOD_API int luaopen_math (lua_State *L) {
   lua_setfield(L, -2, "maxinteger");
   lua_pushinteger(L, LUA_MININTEGER);
   lua_setfield(L, -2, "mininteger");
+  setrandfunc(L);
   return 1;
 }
 
diff --git a/libs/liblua/src/lmem.c b/libs/liblua/src/lmem.c
index 0241cc3bac..65bfa5249f 100644
--- a/libs/liblua/src/lmem.c
+++ b/libs/liblua/src/lmem.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.c,v 1.91.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lmem.c $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -22,79 +22,181 @@
 #include "lstate.h"
 
 
+#if defined(HARDMEMTESTS)
+/*
+** First allocation will fail whenever not building initial state
+** and not shrinking a block. (This fail will trigger 'tryagain' and
+** a full GC cycle at every allocation.)
+*/
+static void *firsttry (global_State *g, void *block, size_t os, size_t ns) {
+  if (ttisnil(&g->nilvalue) && ns > os)
+    return NULL;  /* fail */
+  else  /* normal allocation */
+    return (*g->frealloc)(g->ud, block, os, ns);
+}
+#else
+#define firsttry(g,block,os,ns)    ((*g->frealloc)(g->ud, block, os, ns))
+#endif
+
+
+
+
 
 /*
 ** About the realloc function:
-** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
+** void *frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
 ** ('osize' is the old size, 'nsize' is the new size)
 **
-** * frealloc(ud, NULL, x, s) creates a new block of size 's' (no
-** matter 'x').
+** - frealloc(ud, p, x, 0) frees the block 'p' and returns NULL.
+** Particularly, frealloc(ud, NULL, 0, 0) does nothing,
+** which is equivalent to free(NULL) in ISO C.
 **
-** * frealloc(ud, p, x, 0) frees the block 'p'
-** (in this specific case, frealloc must return NULL);
-** particularly, frealloc(ud, NULL, 0, 0) does nothing
-** (which is equivalent to free(NULL) in ISO C)
+** - frealloc(ud, NULL, x, s) creates a new block of size 's'
+** (no matter 'x'). Returns NULL if it cannot create the new block.
 **
-** frealloc returns NULL if it cannot create or reallocate the area
-** (any reallocation to an equal or smaller size cannot fail!)
+** - otherwise, frealloc(ud, b, x, y) reallocates the block 'b' from
+** size 'x' to size 'y'. Returns NULL if it cannot reallocate the
+** block to the new size.
 */
 
 
 
+
+/*
+** {==================================================================
+** Functions to allocate/deallocate arrays for the Parser
+** ===================================================================
+*/
+
+/*
+** Minimum size for arrays during parsing, to avoid overhead of
+** reallocating to size 1, then 2, and then 4. All these arrays
+** will be reallocated to exact sizes or erased when parsing ends.
+*/
 #define MINSIZEARRAY	4
 
 
-void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
-                     int limit, const char *what) {
+void *luaM_growaux_ (lua_State *L, void *block, int nelems, int *psize,
+                     int size_elems, int limit, const char *what) {
   void *newblock;
-  int newsize;
-  if (*size >= limit/2) {  /* cannot double it? */
-    if (*size >= limit)  /* cannot grow even a little? */
+  int size = *psize;
+  if (nelems + 1 <= size)  /* does one extra element still fit? */
+    return block;  /* nothing to be done */
+  if (size >= limit / 2) {  /* cannot double it? */
+    if (unlikely(size >= limit))  /* cannot grow even a little? */
       luaG_runerror(L, "too many %s (limit is %d)", what, limit);
-    newsize = limit;  /* still have at least one free place */
+    size = limit;  /* still have at least one free place */
   }
   else {
-    newsize = (*size)*2;
-    if (newsize < MINSIZEARRAY)
-      newsize = MINSIZEARRAY;  /* minimum size */
+    size *= 2;
+    if (size < MINSIZEARRAY)
+      size = MINSIZEARRAY;  /* minimum size */
   }
-  newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
-  *size = newsize;  /* update only when everything else is OK */
+  lua_assert(nelems + 1 <= size && size <= limit);
+  /* 'limit' ensures that multiplication will not overflow */
+  newblock = luaM_saferealloc_(L, block, cast_sizet(*psize) * size_elems,
+                                         cast_sizet(size) * size_elems);
+  *psize = size;  /* update only when everything else is OK */
+  return newblock;
+}
+
+
+/*
+** In prototypes, the size of the array is also its number of
+** elements (to save memory). So, if it cannot shrink an array
+** to its number of elements, the only option is to raise an
+** error.
+*/
+void *luaM_shrinkvector_ (lua_State *L, void *block, int *size,
+                          int final_n, int size_elem) {
+  void *newblock;
+  size_t oldsize = cast_sizet((*size) * size_elem);
+  size_t newsize = cast_sizet(final_n * size_elem);
+  lua_assert(newsize <= oldsize);
+  newblock = luaM_saferealloc_(L, block, oldsize, newsize);
+  *size = final_n;
   return newblock;
 }
 
+/* }================================================================== */
+
 
 l_noret luaM_toobig (lua_State *L) {
   luaG_runerror(L, "memory allocation error: block too big");
 }
 
 
+/*
+** Free memory
+*/
+void luaM_free_ (lua_State *L, void *block, size_t osize) {
+  global_State *g = G(L);
+  lua_assert((osize == 0) == (block == NULL));
+  (*g->frealloc)(g->ud, block, osize, 0);
+  g->GCdebt -= osize;
+}
+
+
+/*
+** In case of allocation fail, this function will call the GC to try
+** to free some memory and then try the allocation again.
+** (It should not be called when shrinking a block, because then the
+** interpreter may be in the middle of a collection step.)
+*/
+static void *tryagain (lua_State *L, void *block,
+                       size_t osize, size_t nsize) {
+  global_State *g = G(L);
+  if (ttisnil(&g->nilvalue)) {  /* is state fully build? */
+    luaC_fullgc(L, 1);  /* try to free some memory... */
+    return (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
+  }
+  else return NULL;  /* cannot free any memory without a full state */
+}
+
 
 /*
-** generic allocation routine.
+** Generic allocation routine.
+** If allocation fails while shrinking a block, do not try again; the
+** GC shrinks some blocks and it is not reentrant.
 */
 void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
   void *newblock;
   global_State *g = G(L);
-  size_t realosize = (block) ? osize : 0;
-  lua_assert((realosize == 0) == (block == NULL));
-#if defined(HARDMEMTESTS)
-  if (nsize > realosize && g->gcrunning)
-    luaC_fullgc(L, 1);  /* force a GC whenever possible */
-#endif
-  newblock = (*g->frealloc)(g->ud, block, osize, nsize);
-  if (newblock == NULL && nsize > 0) {
-    lua_assert(nsize > realosize);  /* cannot fail when shrinking a block */
-    if (g->version) {  /* is state fully built? */
-      luaC_fullgc(L, 1);  /* try to free some memory... */
-      newblock = (*g->frealloc)(g->ud, block, osize, nsize);  /* try again */
-    }
-    if (newblock == NULL)
-      luaD_throw(L, LUA_ERRMEM);
+  lua_assert((osize == 0) == (block == NULL));
+  newblock = firsttry(g, block, osize, nsize);
+  if (unlikely(newblock == NULL && nsize > 0)) {
+    if (nsize > osize)  /* not shrinking a block? */
+      newblock = tryagain(L, block, osize, nsize);
+    if (newblock == NULL)  /* still no memory? */
+      return NULL;  /* do not update 'GCdebt' */
   }
   lua_assert((nsize == 0) == (newblock == NULL));
-  g->GCdebt = (g->GCdebt + nsize) - realosize;
+  g->GCdebt = (g->GCdebt + nsize) - osize;
+  return newblock;
+}
+
+
+void *luaM_saferealloc_ (lua_State *L, void *block, size_t osize,
+                                                    size_t nsize) {
+  void *newblock = luaM_realloc_(L, block, osize, nsize);
+  if (unlikely(newblock == NULL && nsize > 0))  /* allocation failed? */
+    luaM_error(L);
   return newblock;
 }
 
+
+void *luaM_malloc_ (lua_State *L, size_t size, int tag) {
+  if (size == 0)
+    return NULL;  /* that's all */
+  else {
+    global_State *g = G(L);
+    void *newblock = firsttry(g, NULL, tag, size);
+    if (unlikely(newblock == NULL)) {
+      newblock = tryagain(L, NULL, tag, size);
+      if (newblock == NULL)
+        luaM_error(L);
+    }
+    g->GCdebt += size;
+    return newblock;
+  }
+}
diff --git a/libs/liblua/src/lmem.h b/libs/liblua/src/lmem.h
index 357b1e43e7..8c75a44beb 100644
--- a/libs/liblua/src/lmem.h
+++ b/libs/liblua/src/lmem.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.43.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lmem.h $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -14,12 +14,13 @@
 #include "lua.h"
 
 
+#define luaM_error(L)	luaD_throw(L, LUA_ERRMEM)
+
+
 /*
-** This macro reallocs a vector 'b' from 'on' to 'n' elements, where
-** each element has size 'e'. In case of arithmetic overflow of the
-** product 'n'*'e', it raises an error (calling 'luaM_toobig'). Because
-** 'e' is always constant, it avoids the runtime division MAX_SIZET/(e).
-**
+** This macro tests whether it is safe to multiply 'n' by the size of
+** type 't' without overflows. Because 'e' is always constant, it avoids
+** the runtime division MAX_SIZET/(e).
 ** (The macro is somewhat complex to avoid warnings:  The 'sizeof'
 ** comparison avoids a runtime comparison when overflow cannot occur.
 ** The compiler should be able to optimize the real test by itself, but
@@ -27,43 +28,66 @@
 ** false due to limited range of data type"; the +1 tricks the compiler,
 ** avoiding this warning but also this optimization.)
 */
-#define luaM_reallocv(L,b,on,n,e) \
-  (((sizeof(n) >= sizeof(size_t) && cast(size_t, (n)) + 1 > MAX_SIZET/(e)) \
-      ? luaM_toobig(L) : cast_void(0)) , \
-   luaM_realloc_(L, (b), (on)*(e), (n)*(e)))
+#define luaM_testsize(n,e)  \
+	(sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e))
+
+#define luaM_checksize(L,n,e)  \
+	(luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0))
+
+
+/*
+** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that
+** the result is not larger than 'n' and cannot overflow a 'size_t'
+** when multiplied by the size of type 't'. (Assumes that 'n' is an
+** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.)
+*/
+#define luaM_limitN(n,t)  \
+  ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) :  \
+     cast_uint((MAX_SIZET/sizeof(t))))
+
 
 /*
 ** Arrays of chars do not need any test
 */
 #define luaM_reallocvchar(L,b,on,n)  \
-    cast(char *, luaM_realloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
+  cast_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
 
-#define luaM_freemem(L, b, s)	luaM_realloc_(L, (b), (s), 0)
-#define luaM_free(L, b)		luaM_realloc_(L, (b), sizeof(*(b)), 0)
-#define luaM_freearray(L, b, n)   luaM_realloc_(L, (b), (n)*sizeof(*(b)), 0)
+#define luaM_freemem(L, b, s)	luaM_free_(L, (b), (s))
+#define luaM_free(L, b)		luaM_free_(L, (b), sizeof(*(b)))
+#define luaM_freearray(L, b, n)   luaM_free_(L, (b), (n)*sizeof(*(b)))
 
-#define luaM_malloc(L,s)	luaM_realloc_(L, NULL, 0, (s))
-#define luaM_new(L,t)		cast(t *, luaM_malloc(L, sizeof(t)))
-#define luaM_newvector(L,n,t) \
-		cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t)))
+#define luaM_new(L,t)		cast(t*, luaM_malloc_(L, sizeof(t), 0))
+#define luaM_newvector(L,n,t)	cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0))
+#define luaM_newvectorchecked(L,n,t) \
+  (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t))
 
-#define luaM_newobject(L,tag,s)	luaM_realloc_(L, NULL, tag, (s))
+#define luaM_newobject(L,tag,s)	luaM_malloc_(L, (s), tag)
 
 #define luaM_growvector(L,v,nelems,size,t,limit,e) \
-          if ((nelems)+1 > (size)) \
-            ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e)))
+	((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t), \
+                         luaM_limitN(limit,t),e)))
 
 #define luaM_reallocvector(L, v,oldn,n,t) \
-   ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
+   (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \
+                                  cast_sizet(n) * sizeof(t))))
+
+#define luaM_shrinkvector(L,v,size,fs,t) \
+   ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, sizeof(t))))
 
 LUAI_FUNC l_noret luaM_toobig (lua_State *L);
 
 /* not to be called directly */
 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
                                                           size_t size);
-LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size,
-                               size_t size_elem, int limit,
+LUAI_FUNC void *luaM_saferealloc_ (lua_State *L, void *block, size_t oldsize,
+                                                              size_t size);
+LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize);
+LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems,
+                               int *size, int size_elem, int limit,
                                const char *what);
+LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem,
+                                    int final_n, int size_elem);
+LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag);
 
 #endif
 
diff --git a/libs/liblua/src/loadlib.c b/libs/liblua/src/loadlib.c
index 45f44d3225..c0ec9a131b 100644
--- a/libs/liblua/src/loadlib.c
+++ b/libs/liblua/src/loadlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: loadlib.c,v 1.130.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: loadlib.c $
 ** Dynamic library loader for Lua
 ** See Copyright Notice in lua.h
 **
@@ -56,10 +56,10 @@
 
 
 /*
-** unique key for table in the registry that keeps handles
+** key for table in the registry that keeps handles
 ** for all loaded C libraries
 */
-static const int CLIBS = 0;
+static const char *const CLIBS = "_CLIBS";
 
 #define LIB_FAIL	"open"
 
@@ -67,6 +67,13 @@ static const int CLIBS = 0;
 #define setprogdir(L)           ((void)0)
 
 
+/*
+** Special type equivalent to '(void*)' for functions in gcc
+** (to suppress warnings when converting function pointers)
+*/
+typedef void (*voidf)(void);
+
+
 /*
 ** system-dependent functions
 */
@@ -206,7 +213,7 @@ static void *lsys_load (lua_State *L, const char *path, int seeglb) {
 
 
 static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
-  lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
+  lua_CFunction f = (lua_CFunction)(voidf)GetProcAddress((HMODULE)lib, sym);
   if (f == NULL) pusherror(L);
   return f;
 }
@@ -269,8 +276,6 @@ static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
 #endif
 
 
-#define AUXMARK         "\1"	/* auxiliary mark */
-
 
 /*
 ** return registry.LUA_NOENV as a boolean
@@ -290,22 +295,33 @@ static int noenv (lua_State *L) {
 static void setpath (lua_State *L, const char *fieldname,
                                    const char *envname,
                                    const char *dft) {
+  const char *dftmark;
   const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX);
-  const char *path = getenv(nver);  /* use versioned name */
-  if (path == NULL)  /* no environment variable? */
+  const char *path = getenv(nver);  /* try versioned name */
+  if (path == NULL)  /* no versioned environment variable? */
     path = getenv(envname);  /* try unversioned name */
   if (path == NULL || noenv(L))  /* no environment variable? */
     lua_pushstring(L, dft);  /* use default */
-  else {
-    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
-    path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
-                              LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
-    luaL_gsub(L, path, AUXMARK, dft);
-    lua_remove(L, -2); /* remove result from 1st 'gsub' */
+  else if ((dftmark = strstr(path, LUA_PATH_SEP LUA_PATH_SEP)) == NULL)
+    lua_pushstring(L, path);  /* nothing to change */
+  else {  /* path contains a ";;": insert default path in its place */
+    size_t len = strlen(path);
+    luaL_Buffer b;
+    luaL_buffinit(L, &b);
+    if (path < dftmark) {  /* is there a prefix before ';;'? */
+      luaL_addlstring(&b, path, dftmark - path);  /* add it */
+      luaL_addchar(&b, *LUA_PATH_SEP);
+    }
+    luaL_addstring(&b, dft);  /* add default */
+    if (dftmark < path + len - 2) {  /* is there a suffix after ';;'? */
+      luaL_addchar(&b, *LUA_PATH_SEP);
+      luaL_addlstring(&b, dftmark + 2, (path + len - 2) - dftmark);
+    }
+    luaL_pushresult(&b);
   }
   setprogdir(L);
   lua_setfield(L, -3, fieldname);  /* package[fieldname] = path value */
-  lua_pop(L, 1);  /* pop versioned variable name */
+  lua_pop(L, 1);  /* pop versioned variable name ('nver') */
 }
 
 /* }================================================================== */
@@ -316,7 +332,7 @@ static void setpath (lua_State *L, const char *fieldname,
 */
 static void *checkclib (lua_State *L, const char *path) {
   void *plib;
-  lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
+  lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
   lua_getfield(L, -1, path);
   plib = lua_touserdata(L, -1);  /* plib = CLIBS[path] */
   lua_pop(L, 2);  /* pop CLIBS table and 'plib' */
@@ -329,7 +345,7 @@ static void *checkclib (lua_State *L, const char *path) {
 ** registry.CLIBS[#CLIBS + 1] = plib  -- also keep a list of all libraries
 */
 static void addtoclib (lua_State *L, const char *path, void *plib) {
-  lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS);
+  lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
   lua_pushlightuserdata(L, plib);
   lua_pushvalue(L, -1);
   lua_setfield(L, -3, path);  /* CLIBS[path] = plib */
@@ -397,10 +413,10 @@ static int ll_loadlib (lua_State *L) {
   if (stat == 0)  /* no errors? */
     return 1;  /* return the loaded function */
   else {  /* error; error message is on stack top */
-    lua_pushnil(L);
+    luaL_pushfail(L);
     lua_insert(L, -2);
     lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
-    return 3;  /* return nil, error message, and where */
+    return 3;  /* return fail, error message, and where */
   }
 }
 
@@ -421,14 +437,42 @@ static int readable (const char *filename) {
 }
 
 
-static const char *pushnexttemplate (lua_State *L, const char *path) {
-  const char *l;
-  while (*path == *LUA_PATH_SEP) path++;  /* skip separators */
-  if (*path == '\0') return NULL;  /* no more templates */
-  l = strchr(path, *LUA_PATH_SEP);  /* find next separator */
-  if (l == NULL) l = path + strlen(path);
-  lua_pushlstring(L, path, l - path);  /* template */
-  return l;
+/*
+** Get the next name in '*path' = 'name1;name2;name3;...', changing
+** the ending ';' to '\0' to create a zero-terminated string. Return
+** NULL when list ends.
+*/
+static const char *getnextfilename (char **path, char *end) {
+  char *sep;
+  char *name = *path;
+  if (name == end)
+    return NULL;  /* no more names */
+  else if (*name == '\0') {  /* from previous iteration? */
+    *name = *LUA_PATH_SEP;  /* restore separator */
+    name++;  /* skip it */
+  }
+  sep = strchr(name, *LUA_PATH_SEP);  /* find next separator */
+  if (sep == NULL)  /* separator not found? */
+    sep = end;  /* name goes until the end */
+  *sep = '\0';  /* finish file name */
+  *path = sep;  /* will start next search from here */
+  return name;
+}
+
+
+/*
+** Given a path such as ";blabla.so;blublu.so", pushes the string
+**
+** no file 'blabla.so'
+**	no file 'blublu.so'
+*/
+static void pusherrornotfound (lua_State *L, const char *path) {
+  luaL_Buffer b;
+  luaL_buffinit(L, &b);
+  luaL_addstring(&b, "no file '");
+  luaL_addgsub(&b, path, LUA_PATH_SEP, "'\n\tno file '");
+  luaL_addstring(&b, "'");
+  luaL_pushresult(&b);
 }
 
 
@@ -436,21 +480,25 @@ static const char *searchpath (lua_State *L, const char *name,
                                              const char *path,
                                              const char *sep,
                                              const char *dirsep) {
-  luaL_Buffer msg;  /* to build error message */
-  luaL_buffinit(L, &msg);
-  if (*sep != '\0')  /* non-empty separator? */
+  luaL_Buffer buff;
+  char *pathname;  /* path with name inserted */
+  char *endpathname;  /* its end */
+  const char *filename;
+  /* separator is non-empty and appears in 'name'? */
+  if (*sep != '\0' && strchr(name, *sep) != NULL)
     name = luaL_gsub(L, name, sep, dirsep);  /* replace it by 'dirsep' */
-  while ((path = pushnexttemplate(L, path)) != NULL) {
-    const char *filename = luaL_gsub(L, lua_tostring(L, -1),
-                                     LUA_PATH_MARK, name);
-    lua_remove(L, -2);  /* remove path template */
+  luaL_buffinit(L, &buff);
+  /* add path to the buffer, replacing marks ('?') with the file name */
+  luaL_addgsub(&buff, path, LUA_PATH_MARK, name);
+  luaL_addchar(&buff, '\0');
+  pathname = luaL_buffaddr(&buff);  /* writable list of file names */
+  endpathname = pathname + luaL_bufflen(&buff) - 1;
+  while ((filename = getnextfilename(&pathname, endpathname)) != NULL) {
     if (readable(filename))  /* does file exist and is readable? */
-      return filename;  /* return that file name */
-    lua_pushfstring(L, "\n\tno file '%s'", filename);
-    lua_remove(L, -2);  /* remove file name */
-    luaL_addvalue(&msg);  /* concatenate error msg. entry */
+      return lua_pushstring(L, filename);  /* save and return name */
   }
-  luaL_pushresult(&msg);  /* create error message */
+  luaL_pushresult(&buff);  /* push path to create error message */
+  pusherrornotfound(L, lua_tostring(L, -1));  /* create error message */
   return NULL;  /* not found */
 }
 
@@ -462,9 +510,9 @@ static int ll_searchpath (lua_State *L) {
                                 luaL_optstring(L, 4, LUA_DIRSEP));
   if (f != NULL) return 1;
   else {  /* error message is on top of the stack */
-    lua_pushnil(L);
+    luaL_pushfail(L);
     lua_insert(L, -2);
-    return 2;  /* return nil + error message */
+    return 2;  /* return fail + error message */
   }
 }
 
@@ -548,7 +596,7 @@ static int searcher_Croot (lua_State *L) {
     if (stat != ERRFUNC)
       return checkload(L, 0, filename);  /* real error */
     else {  /* open function not found */
-      lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename);
+      lua_pushfstring(L, "no module '%s' in file '%s'", name, filename);
       return 1;
     }
   }
@@ -560,23 +608,30 @@ static int searcher_Croot (lua_State *L) {
 static int searcher_preload (lua_State *L) {
   const char *name = luaL_checkstring(L, 1);
   lua_getfield(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
-  if (lua_getfield(L, -1, name) == LUA_TNIL)  /* not found? */
-    lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
-  return 1;
+  if (lua_getfield(L, -1, name) == LUA_TNIL) {  /* not found? */
+    lua_pushfstring(L, "no field package.preload['%s']", name);
+    return 1;
+  }
+  else {
+    lua_pushliteral(L, ":preload:");
+    return 2;
+  }
 }
 
 
 static void findloader (lua_State *L, const char *name) {
   int i;
   luaL_Buffer msg;  /* to build error message */
-  luaL_buffinit(L, &msg);
   /* push 'package.searchers' to index 3 in the stack */
   if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
     luaL_error(L, "'package.searchers' must be a table");
+  luaL_buffinit(L, &msg);
   /*  iterate over available searchers to find a loader */
   for (i = 1; ; i++) {
+    luaL_addstring(&msg, "\n\t");  /* error-message prefix */
     if (lua_rawgeti(L, 3, i) == LUA_TNIL) {  /* no more searchers? */
       lua_pop(L, 1);  /* remove nil */
+      luaL_buffsub(&msg, 2);  /* remove prefix */
       luaL_pushresult(&msg);  /* create error message */
       luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
     }
@@ -588,8 +643,10 @@ static void findloader (lua_State *L, const char *name) {
       lua_pop(L, 1);  /* remove extra return */
       luaL_addvalue(&msg);  /* concatenate error message */
     }
-    else
+    else {  /* no error message */
       lua_pop(L, 2);  /* remove both returns */
+      luaL_buffsub(&msg, 2);  /* remove prefix */
+    }
   }
 }
 
@@ -604,113 +661,33 @@ static int ll_require (lua_State *L) {
   /* else must load package */
   lua_pop(L, 1);  /* remove 'getfield' result */
   findloader(L, name);
-  lua_pushstring(L, name);  /* pass name as argument to module loader */
-  lua_insert(L, -2);  /* name is 1st argument (before search data) */
+  lua_rotate(L, -2, 1);  /* function <-> loader data */
+  lua_pushvalue(L, 1);  /* name is 1st argument to module loader */
+  lua_pushvalue(L, -3);  /* loader data is 2nd argument */
+  /* stack: ...; loader data; loader function; mod. name; loader data */
   lua_call(L, 2, 1);  /* run loader to load module */
+  /* stack: ...; loader data; result from loader */
   if (!lua_isnil(L, -1))  /* non-nil return? */
     lua_setfield(L, 2, name);  /* LOADED[name] = returned value */
+  else
+    lua_pop(L, 1);  /* pop nil */
   if (lua_getfield(L, 2, name) == LUA_TNIL) {   /* module set no value? */
     lua_pushboolean(L, 1);  /* use true as result */
-    lua_pushvalue(L, -1);  /* extra copy to be returned */
+    lua_copy(L, -1, -2);  /* replace loader result */
     lua_setfield(L, 2, name);  /* LOADED[name] = true */
   }
-  return 1;
+  lua_rotate(L, -2, 1);  /* loader data <-> module result  */
+  return 2;  /* return module result and loader data */
 }
 
 /* }====================================================== */
 
 
 
-/*
-** {======================================================
-** 'module' function
-** =======================================================
-*/
-#if defined(LUA_COMPAT_MODULE)
-
-/*
-** changes the environment variable of calling function
-*/
-static void set_env (lua_State *L) {
-  lua_Debug ar;
-  if (lua_getstack(L, 1, &ar) == 0 ||
-      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
-      lua_iscfunction(L, -1))
-    luaL_error(L, "'module' not called from a Lua function");
-  lua_pushvalue(L, -2);  /* copy new environment table to top */
-  lua_setupvalue(L, -2, 1);
-  lua_pop(L, 1);  /* remove function */
-}
-
-
-static void dooptions (lua_State *L, int n) {
-  int i;
-  for (i = 2; i <= n; i++) {
-    if (lua_isfunction(L, i)) {  /* avoid 'calling' extra info. */
-      lua_pushvalue(L, i);  /* get option (a function) */
-      lua_pushvalue(L, -2);  /* module */
-      lua_call(L, 1, 0);
-    }
-  }
-}
-
-
-static void modinit (lua_State *L, const char *modname) {
-  const char *dot;
-  lua_pushvalue(L, -1);
-  lua_setfield(L, -2, "_M");  /* module._M = module */
-  lua_pushstring(L, modname);
-  lua_setfield(L, -2, "_NAME");
-  dot = strrchr(modname, '.');  /* look for last dot in module name */
-  if (dot == NULL) dot = modname;
-  else dot++;
-  /* set _PACKAGE as package name (full module name minus last part) */
-  lua_pushlstring(L, modname, dot - modname);
-  lua_setfield(L, -2, "_PACKAGE");
-}
-
-
-static int ll_module (lua_State *L) {
-  const char *modname = luaL_checkstring(L, 1);
-  int lastarg = lua_gettop(L);  /* last parameter */
-  luaL_pushmodule(L, modname, 1);  /* get/create module table */
-  /* check whether table already has a _NAME field */
-  if (lua_getfield(L, -1, "_NAME") != LUA_TNIL)
-    lua_pop(L, 1);  /* table is an initialized module */
-  else {  /* no; initialize it */
-    lua_pop(L, 1);
-    modinit(L, modname);
-  }
-  lua_pushvalue(L, -1);
-  set_env(L);
-  dooptions(L, lastarg);
-  return 1;
-}
-
-
-static int ll_seeall (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TTABLE);
-  if (!lua_getmetatable(L, 1)) {
-    lua_createtable(L, 0, 1); /* create new metatable */
-    lua_pushvalue(L, -1);
-    lua_setmetatable(L, 1);
-  }
-  lua_pushglobaltable(L);
-  lua_setfield(L, -2, "__index");  /* mt.__index = _G */
-  return 0;
-}
-
-#endif
-/* }====================================================== */
-
-
 
 static const luaL_Reg pk_funcs[] = {
   {"loadlib", ll_loadlib},
   {"searchpath", ll_searchpath},
-#if defined(LUA_COMPAT_MODULE)
-  {"seeall", ll_seeall},
-#endif
   /* placeholders */
   {"preload", NULL},
   {"cpath", NULL},
@@ -722,9 +699,6 @@ static const luaL_Reg pk_funcs[] = {
 
 
 static const luaL_Reg ll_funcs[] = {
-#if defined(LUA_COMPAT_MODULE)
-  {"module", ll_module},
-#endif
   {"require", ll_require},
   {NULL, NULL}
 };
@@ -742,10 +716,6 @@ static void createsearcherstable (lua_State *L) {
     lua_pushcclosure(L, searchers[i], 1);
     lua_rawseti(L, -2, i+1);
   }
-#if defined(LUA_COMPAT_LOADERS)
-  lua_pushvalue(L, -1);  /* make a copy of 'searchers' table */
-  lua_setfield(L, -3, "loaders");  /* put it in field 'loaders' */
-#endif
   lua_setfield(L, -2, "searchers");  /* put it in field 'searchers' */
 }
 
@@ -755,12 +725,11 @@ static void createsearcherstable (lua_State *L) {
 ** setting a finalizer to close all libraries when closing state.
 */
 static void createclibstable (lua_State *L) {
-  lua_newtable(L);  /* create CLIBS table */
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);  /* create CLIBS table */
   lua_createtable(L, 0, 1);  /* create metatable for CLIBS */
   lua_pushcfunction(L, gctm);
   lua_setfield(L, -2, "__gc");  /* set finalizer for CLIBS table */
   lua_setmetatable(L, -2);
-  lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS);  /* set CLIBS table in registry */
 }
 
 
diff --git a/libs/liblua/src/lobject.c b/libs/liblua/src/lobject.c
index 2218c8cdd7..b4efae4f33 100644
--- a/libs/liblua/src/lobject.c
+++ b/libs/liblua/src/lobject.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.c,v 2.113.1.1 2017/04/19 17:29:57 roberto Exp $
+** $Id: lobject.c $
 ** Some generic functions over Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -29,36 +29,6 @@
 #include "lvm.h"
 
 
-
-LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
-
-
-/*
-** converts an integer to a "floating point byte", represented as
-** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
-** eeeee != 0 and (xxx) otherwise.
-*/
-int luaO_int2fb (unsigned int x) {
-  int e = 0;  /* exponent */
-  if (x < 8) return x;
-  while (x >= (8 << 4)) {  /* coarse steps */
-    x = (x + 0xf) >> 4;  /* x = ceil(x / 16) */
-    e += 4;
-  }
-  while (x >= (8 << 1)) {  /* fine steps */
-    x = (x + 1) >> 1;  /* x = ceil(x / 2) */
-    e++;
-  }
-  return ((e+1) << 3) | (cast_int(x) - 8);
-}
-
-
-/* converts back */
-int luaO_fb2int (int x) {
-  return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
-}
-
-
 /*
 ** Computes ceil(log2(x))
 */
@@ -87,7 +57,7 @@ static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
     case LUA_OPSUB:return intop(-, v1, v2);
     case LUA_OPMUL:return intop(*, v1, v2);
     case LUA_OPMOD: return luaV_mod(L, v1, v2);
-    case LUA_OPIDIV: return luaV_div(L, v1, v2);
+    case LUA_OPIDIV: return luaV_idiv(L, v1, v2);
     case LUA_OPBAND: return intop(&, v1, v2);
     case LUA_OPBOR: return intop(|, v1, v2);
     case LUA_OPBXOR: return intop(^, v1, v2);
@@ -110,53 +80,55 @@ static lua_Number numarith (lua_State *L, int op, lua_Number v1,
     case LUA_OPPOW: return luai_numpow(L, v1, v2);
     case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
     case LUA_OPUNM: return luai_numunm(L, v1);
-    case LUA_OPMOD: {
-      lua_Number m;
-      luai_nummod(L, v1, v2, m);
-      return m;
-    }
+    case LUA_OPMOD: return luaV_modf(L, v1, v2);
     default: lua_assert(0); return 0;
   }
 }
 
 
-void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
-                 TValue *res) {
+int luaO_rawarith (lua_State *L, int op, const TValue *p1, const TValue *p2,
+                   TValue *res) {
   switch (op) {
     case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
     case LUA_OPSHL: case LUA_OPSHR:
     case LUA_OPBNOT: {  /* operate only on integers */
       lua_Integer i1; lua_Integer i2;
-      if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
+      if (tointegerns(p1, &i1) && tointegerns(p2, &i2)) {
         setivalue(res, intarith(L, op, i1, i2));
-        return;
+        return 1;
       }
-      else break;  /* go to the end */
+      else return 0;  /* fail */
     }
     case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */
       lua_Number n1; lua_Number n2;
-      if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
+      if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
         setfltvalue(res, numarith(L, op, n1, n2));
-        return;
+        return 1;
       }
-      else break;  /* go to the end */
+      else return 0;  /* fail */
     }
     default: {  /* other operations */
       lua_Number n1; lua_Number n2;
       if (ttisinteger(p1) && ttisinteger(p2)) {
         setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
-        return;
+        return 1;
       }
-      else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
+      else if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
         setfltvalue(res, numarith(L, op, n1, n2));
-        return;
+        return 1;
       }
-      else break;  /* go to the end */
+      else return 0;  /* fail */
     }
   }
-  /* could not perform raw operation; try metamethod */
-  lua_assert(L != NULL);  /* should not fail when folding (compile time) */
-  luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
+}
+
+
+void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
+                 StkId res) {
+  if (!luaO_rawarith(L, op, p1, p2, s2v(res))) {
+    /* could not perform raw operation; try metamethod */
+    luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
+  }
 }
 
 
@@ -187,7 +159,7 @@ static int isneg (const char **s) {
 #define MAXSIGDIG	30
 
 /*
-** convert an hexadecimal numeric string to a number, following
+** convert a hexadecimal numeric string to a number, following
 ** C99 specification for 'strtod'
 */
 static lua_Number lua_strx2number (const char *s, char **endptr) {
@@ -198,9 +170,9 @@ static lua_Number lua_strx2number (const char *s, char **endptr) {
   int e = 0;  /* exponent correction */
   int neg;  /* 1 if number is negative */
   int hasdot = 0;  /* true after seen a dot */
-  *endptr = cast(char *, s);  /* nothing is valid yet */
+  *endptr = cast_charp(s);  /* nothing is valid yet */
   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
-  neg = isneg(&s);  /* check signal */
+  neg = isneg(&s);  /* check sign */
   if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
     return 0.0;  /* invalid format (no '0x') */
   for (s += 2; ; s++) {  /* skip '0x' and read numeral */
@@ -220,20 +192,20 @@ static lua_Number lua_strx2number (const char *s, char **endptr) {
   }
   if (nosigdig + sigdig == 0)  /* no digits? */
     return 0.0;  /* invalid format */
-  *endptr = cast(char *, s);  /* valid up to here */
+  *endptr = cast_charp(s);  /* valid up to here */
   e *= 4;  /* each digit multiplies/divides value by 2^4 */
   if (*s == 'p' || *s == 'P') {  /* exponent part? */
     int exp1 = 0;  /* exponent value */
-    int neg1;  /* exponent signal */
+    int neg1;  /* exponent sign */
     s++;  /* skip 'p' */
-    neg1 = isneg(&s);  /* signal */
+    neg1 = isneg(&s);  /* sign */
     if (!lisdigit(cast_uchar(*s)))
       return 0.0;  /* invalid; must have at least one digit */
     while (lisdigit(cast_uchar(*s)))  /* read exponent */
       exp1 = exp1 * 10 + *(s++) - '0';
     if (neg1) exp1 = -exp1;
     e += exp1;
-    *endptr = cast(char *, s);  /* valid up to here */
+    *endptr = cast_charp(s);  /* valid up to here */
   }
   if (neg) r = -r;
   return l_mathop(ldexp)(r, e);
@@ -262,11 +234,11 @@ static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
 ** Convert string 's' to a Lua number (put in 'result'). Return NULL
 ** on fail or the address of the ending '\0' on success.
 ** 'pmode' points to (and 'mode' contains) special things in the string:
-** - 'x'/'X' means an hexadecimal numeral
+** - 'x'/'X' means a hexadecimal numeral
 ** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
 ** - '.' just optimizes the search for the common case (nothing special)
 ** This function accepts both the current locale or a dot as the radix
-** mark. If the convertion fails, it may mean number has a dot but
+** mark. If the conversion fails, it may mean number has a dot but
 ** locale accepts something else. In that case, the code copies 's'
 ** to a buffer (because 's' is read-only), changes the dot to the
 ** current locale radix mark, and tries to convert again.
@@ -345,17 +317,17 @@ size_t luaO_str2num (const char *s, TValue *o) {
 
 int luaO_utf8esc (char *buff, unsigned long x) {
   int n = 1;  /* number of bytes put in buffer (backwards) */
-  lua_assert(x <= 0x10FFFF);
+  lua_assert(x <= 0x7FFFFFFFu);
   if (x < 0x80)  /* ascii? */
-    buff[UTF8BUFFSZ - 1] = cast(char, x);
+    buff[UTF8BUFFSZ - 1] = cast_char(x);
   else {  /* need continuation bytes */
     unsigned int mfb = 0x3f;  /* maximum that fits in first byte */
     do {  /* add continuation bytes */
-      buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
+      buff[UTF8BUFFSZ - (n++)] = cast_char(0x80 | (x & 0x3f));
       x >>= 6;  /* remove added bits */
       mfb >>= 1;  /* now there is one less bit available in first byte */
     } while (x > mfb);  /* still needs continuation byte? */
-    buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x);  /* add first byte */
+    buff[UTF8BUFFSZ - n] = cast_char((~mfb << 1) | x);  /* add first byte */
   }
   return n;
 }
@@ -366,88 +338,178 @@ int luaO_utf8esc (char *buff, unsigned long x) {
 
 
 /*
-** Convert a number object to a string
+** Convert a number object to a string, adding it to a buffer
 */
-void luaO_tostring (lua_State *L, StkId obj) {
-  char buff[MAXNUMBER2STR];
-  size_t len;
+static int tostringbuff (TValue *obj, char *buff) {
+  int len;
   lua_assert(ttisnumber(obj));
   if (ttisinteger(obj))
-    len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
+    len = lua_integer2str(buff, MAXNUMBER2STR, ivalue(obj));
   else {
-    len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
-#if !defined(LUA_COMPAT_FLOATSTRING)
+    len = lua_number2str(buff, MAXNUMBER2STR, fltvalue(obj));
     if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
       buff[len++] = lua_getlocaledecpoint();
       buff[len++] = '0';  /* adds '.0' to result */
     }
-#endif
   }
-  setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
+  return len;
 }
 
 
-static void pushstr (lua_State *L, const char *str, size_t l) {
+/*
+** Convert a number object to a Lua string, replacing the value at 'obj'
+*/
+void luaO_tostring (lua_State *L, TValue *obj) {
+  char buff[MAXNUMBER2STR];
+  int len = tostringbuff(obj, buff);
+  setsvalue(L, obj, luaS_newlstr(L, buff, len));
+}
+
+
+
+
+/*
+** {==================================================================
+** 'luaO_pushvfstring'
+** ===================================================================
+*/
+
+/* size for buffer space used by 'luaO_pushvfstring' */
+#define BUFVFS		400
+
+/* buffer used by 'luaO_pushvfstring' */
+typedef struct BuffFS {
+  lua_State *L;
+  int pushed;  /* number of string pieces already on the stack */
+  int blen;  /* length of partial string in 'space' */
+  char space[BUFVFS];  /* holds last part of the result */
+} BuffFS;
+
+
+/*
+** Push given string to the stack, as part of the buffer. If the stack
+** is almost full, join all partial strings in the stack into one.
+*/
+static void pushstr (BuffFS *buff, const char *str, size_t l) {
+  lua_State *L = buff->L;
   setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
-  luaD_inctop(L);
+  L->top++;  /* may use one extra slot */
+  buff->pushed++;
+  if (buff->pushed > 1 && L->top + 1 >= L->stack_last) {
+    luaV_concat(L, buff->pushed);  /* join all partial results into one */
+    buff->pushed = 1;
+  }
 }
 
 
 /*
-** this function handles only '%d', '%c', '%f', '%p', and '%s'
+** empty the buffer space into the stack
+*/
+static void clearbuff (BuffFS *buff) {
+  pushstr(buff, buff->space, buff->blen);  /* push buffer contents */
+  buff->blen = 0;  /* space now is empty */
+}
+
+
+/*
+** Get a space of size 'sz' in the buffer. If buffer has not enough
+** space, empty it. 'sz' must fit in an empty buffer.
+*/
+static char *getbuff (BuffFS *buff, int sz) {
+  lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS);
+  if (sz > BUFVFS - buff->blen)  /* not enough space? */
+    clearbuff(buff);
+  return buff->space + buff->blen;
+}
+
+
+#define addsize(b,sz)	((b)->blen += (sz))
+
+
+/*
+** Add 'str' to the buffer. If string is larger than the buffer space,
+** push the string directly to the stack.
+*/
+static void addstr2buff (BuffFS *buff, const char *str, size_t slen) {
+  if (slen <= BUFVFS) {  /* does string fit into buffer? */
+    char *bf = getbuff(buff, cast_int(slen));
+    memcpy(bf, str, slen);  /* add string to buffer */
+    addsize(buff, cast_int(slen));
+  }
+  else {  /* string larger than buffer */
+    clearbuff(buff);  /* string comes after buffer's content */
+    pushstr(buff, str, slen);  /* push string */
+  }
+}
+
+
+/*
+** Add a number to the buffer.
+*/
+static void addnum2buff (BuffFS *buff, TValue *num) {
+  char *numbuff = getbuff(buff, MAXNUMBER2STR);
+  int len = tostringbuff(num, numbuff);  /* format number into 'numbuff' */
+  addsize(buff, len);
+}
+
+
+/*
+** this function handles only '%d', '%c', '%f', '%p', '%s', and '%%'
    conventional formats, plus Lua-specific '%I' and '%U'
 */
 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
-  int n = 0;
-  for (;;) {
-    const char *e = strchr(fmt, '%');
-    if (e == NULL) break;
-    pushstr(L, fmt, e - fmt);
-    switch (*(e+1)) {
+  BuffFS buff;  /* holds last part of the result */
+  const char *e;  /* points to next '%' */
+  buff.pushed = buff.blen = 0;
+  buff.L = L;
+  while ((e = strchr(fmt, '%')) != NULL) {
+    addstr2buff(&buff, fmt, e - fmt);  /* add 'fmt' up to '%' */
+    switch (*(e + 1)) {  /* conversion specifier */
       case 's': {  /* zero-terminated string */
         const char *s = va_arg(argp, char *);
         if (s == NULL) s = "(null)";
-        pushstr(L, s, strlen(s));
+        addstr2buff(&buff, s, strlen(s));
         break;
       }
       case 'c': {  /* an 'int' as a character */
-        char buff = cast(char, va_arg(argp, int));
-        if (lisprint(cast_uchar(buff)))
-          pushstr(L, &buff, 1);
-        else  /* non-printable character; print its code */
-          luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
+        char c = cast_uchar(va_arg(argp, int));
+        addstr2buff(&buff, &c, sizeof(char));
         break;
       }
       case 'd': {  /* an 'int' */
-        setivalue(L->top, va_arg(argp, int));
-        goto top2str;
+        TValue num;
+        setivalue(&num, va_arg(argp, int));
+        addnum2buff(&buff, &num);
+        break;
       }
       case 'I': {  /* a 'lua_Integer' */
-        setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
-        goto top2str;
+        TValue num;
+        setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt)));
+        addnum2buff(&buff, &num);
+        break;
       }
       case 'f': {  /* a 'lua_Number' */
-        setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
-      top2str:  /* convert the top element to a string */
-        luaD_inctop(L);
-        luaO_tostring(L, L->top - 1);
+        TValue num;
+        setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber)));
+        addnum2buff(&buff, &num);
         break;
       }
       case 'p': {  /* a pointer */
-        char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
+        const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */
+        char *bf = getbuff(&buff, sz);
         void *p = va_arg(argp, void *);
-        int l = lua_pointer2str(buff, sizeof(buff), p);
-        pushstr(L, buff, l);
+        int len = lua_pointer2str(bf, sz, p);
+        addsize(&buff, len);
         break;
       }
-      case 'U': {  /* an 'int' as a UTF-8 sequence */
-        char buff[UTF8BUFFSZ];
-        int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
-        pushstr(L, buff + UTF8BUFFSZ - l, l);
+      case 'U': {  /* a 'long' as a UTF-8 sequence */
+        char bf[UTF8BUFFSZ];
+        int len = luaO_utf8esc(bf, va_arg(argp, long));
+        addstr2buff(&buff, bf + UTF8BUFFSZ - len, len);
         break;
       }
       case '%': {
-        pushstr(L, "%", 1);
+        addstr2buff(&buff, "%", 1);
         break;
       }
       default: {
@@ -455,13 +517,13 @@ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
                          *(e + 1));
       }
     }
-    n += 2;
-    fmt = e+2;
+    fmt = e + 2;  /* skip '%' and the specifier */
   }
-  luaD_checkstack(L, 1);
-  pushstr(L, fmt, strlen(fmt));
-  if (n > 0) luaV_concat(L, n + 1);
-  return svalue(L->top - 1);
+  addstr2buff(&buff, fmt, strlen(fmt));  /* rest of 'fmt' */
+  clearbuff(&buff);  /* empty buffer into the stack */
+  if (buff.pushed > 1)
+    luaV_concat(L, buff.pushed);  /* join all partial results */
+  return svalue(s2v(L->top - 1));
 }
 
 
@@ -474,9 +536,8 @@ const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
   return msg;
 }
 
+/* }================================================================== */
 
-/* number of chars of a literal string without the ending \0 */
-#define LL(x)	(sizeof(x)/sizeof(char) - 1)
 
 #define RETS	"..."
 #define PRE	"[string \""
@@ -484,36 +545,36 @@ const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
 
 #define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )
 
-void luaO_chunkid (char *out, const char *source, size_t bufflen) {
-  size_t l = strlen(source);
+void luaO_chunkid (char *out, const char *source, size_t srclen) {
+  size_t bufflen = LUA_IDSIZE;  /* free space in buffer */
   if (*source == '=') {  /* 'literal' source */
-    if (l <= bufflen)  /* small enough? */
-      memcpy(out, source + 1, l * sizeof(char));
+    if (srclen <= bufflen)  /* small enough? */
+      memcpy(out, source + 1, srclen * sizeof(char));
     else {  /* truncate it */
       addstr(out, source + 1, bufflen - 1);
       *out = '\0';
     }
   }
   else if (*source == '@') {  /* file name */
-    if (l <= bufflen)  /* small enough? */
-      memcpy(out, source + 1, l * sizeof(char));
+    if (srclen <= bufflen)  /* small enough? */
+      memcpy(out, source + 1, srclen * sizeof(char));
     else {  /* add '...' before rest of name */
       addstr(out, RETS, LL(RETS));
       bufflen -= LL(RETS);
-      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
+      memcpy(out, source + 1 + srclen - bufflen, bufflen * sizeof(char));
     }
   }
   else {  /* string; format as [string "source"] */
     const char *nl = strchr(source, '\n');  /* find first new line (if any) */
     addstr(out, PRE, LL(PRE));  /* add prefix */
     bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
-    if (l < bufflen && nl == NULL) {  /* small one-line source? */
-      addstr(out, source, l);  /* keep it */
+    if (srclen < bufflen && nl == NULL) {  /* small one-line source? */
+      addstr(out, source, srclen);  /* keep it */
     }
     else {
-      if (nl != NULL) l = nl - source;  /* stop at first newline */
-      if (l > bufflen) l = bufflen;
-      addstr(out, source, l);
+      if (nl != NULL) srclen = nl - source;  /* stop at first newline */
+      if (srclen > bufflen) srclen = bufflen;
+      addstr(out, source, srclen);
       addstr(out, RETS, LL(RETS));
     }
     memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
diff --git a/libs/liblua/src/lobject.h b/libs/liblua/src/lobject.h
index 2408861402..04a81d3de4 100644
--- a/libs/liblua/src/lobject.h
+++ b/libs/liblua/src/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 2.117.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lobject.h $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -17,288 +17,346 @@
 
 
 /*
-** Extra tags for non-values
+** Extra types for collectable non-values
 */
-#define LUA_TPROTO	LUA_NUMTAGS		/* function prototypes */
-#define LUA_TDEADKEY	(LUA_NUMTAGS+1)		/* removed keys in tables */
+#define LUA_TUPVAL	LUA_NUMTYPES  /* upvalues */
+#define LUA_TPROTO	(LUA_NUMTYPES+1)  /* function prototypes */
+
 
 /*
-** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
+** number of all possible types (including LUA_TNONE)
 */
-#define LUA_TOTALTAGS	(LUA_TPROTO + 2)
+#define LUA_TOTALTYPES		(LUA_TPROTO + 2)
 
 
 /*
 ** tags for Tagged Values have the following use of bits:
-** bits 0-3: actual tag (a LUA_T* value)
+** bits 0-3: actual tag (a LUA_T* constant)
 ** bits 4-5: variant bits
 ** bit 6: whether value is collectable
 */
 
+/* add variant bits to a type */
+#define makevariant(t,v)	((t) | ((v) << 4))
+
+
 
 /*
-** LUA_TFUNCTION variants:
-** 0 - Lua function
-** 1 - light C function
-** 2 - regular C function (closure)
+** Union of all Lua values
 */
+typedef union Value {
+  struct GCObject *gc;    /* collectable objects */
+  void *p;         /* light userdata */
+  lua_CFunction f; /* light C functions */
+  lua_Integer i;   /* integer numbers */
+  lua_Number n;    /* float numbers */
+} Value;
 
-/* Variant tags for functions */
-#define LUA_TLCL	(LUA_TFUNCTION | (0 << 4))  /* Lua closure */
-#define LUA_TLCF	(LUA_TFUNCTION | (1 << 4))  /* light C function */
-#define LUA_TCCL	(LUA_TFUNCTION | (2 << 4))  /* C closure */
 
+/*
+** Tagged Values. This is the basic representation of values in Lua:
+** an actual value plus a tag with its type.
+*/
 
-/* Variant tags for strings */
-#define LUA_TSHRSTR	(LUA_TSTRING | (0 << 4))  /* short strings */
-#define LUA_TLNGSTR	(LUA_TSTRING | (1 << 4))  /* long strings */
+#define TValuefields	Value value_; lu_byte tt_
 
+typedef struct TValue {
+  TValuefields;
+} TValue;
 
-/* Variant tags for numbers */
-#define LUA_TNUMFLT	(LUA_TNUMBER | (0 << 4))  /* float numbers */
-#define LUA_TNUMINT	(LUA_TNUMBER | (1 << 4))  /* integer numbers */
+
+#define val_(o)		((o)->value_)
+#define valraw(o)	(&val_(o))
 
 
-/* Bit mark for collectable types */
-#define BIT_ISCOLLECTABLE	(1 << 6)
+/* raw type tag of a TValue */
+#define rawtt(o)	((o)->tt_)
 
-/* mark a tag as collectable */
-#define ctb(t)			((t) | BIT_ISCOLLECTABLE)
+/* tag with no variants (bits 0-3) */
+#define novariant(t)	((t) & 0x0F)
+
+/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
+#define withvariant(t)	((t) & 0x3F)
+#define ttypetag(o)	withvariant(rawtt(o))
+
+/* type of a TValue */
+#define ttype(o)	(novariant(rawtt(o)))
 
 
+/* Macros to test type */
+#define checktag(o,t)		(rawtt(o) == (t))
+#define checktype(o,t)		(ttype(o) == (t))
+
+
+/* Macros for internal tests */
+
+/* collectable object has the same tag as the original value */
+#define righttt(obj)		(ttypetag(obj) == gcvalue(obj)->tt)
+
 /*
-** Common type for all collectable objects
+** Any value being manipulated by the program either is non
+** collectable, or the collectable object has the right tag
+** and it is not dead.
 */
-typedef struct GCObject GCObject;
+#define checkliveness(L,obj) \
+	((void)L, lua_longassert(!iscollectable(obj) || \
+		(righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj))))))
 
 
+/* Macros to set values */
+
+/* set a value's tag */
+#define settt_(o,t)	((o)->tt_=(t))
+
+
+/* main macro to copy values (from 'obj1' to 'obj2') */
+#define setobj(L,obj1,obj2) \
+	{ TValue *io1=(obj1); const TValue *io2=(obj2); \
+          io1->value_ = io2->value_; settt_(io1, io2->tt_); \
+	  checkliveness(L,io1); lua_assert(!isnonstrictnil(io1)); }
+
 /*
-** Common Header for all collectable objects (in macro form, to be
-** included in other objects)
+** Different types of assignments, according to source and destination.
+** (They are mostly equal now, but may be different in the future.)
 */
-#define CommonHeader	GCObject *next; lu_byte tt; lu_byte marked
+
+/* from stack to stack */
+#define setobjs2s(L,o1,o2)	setobj(L,s2v(o1),s2v(o2))
+/* to stack (not from same stack) */
+#define setobj2s(L,o1,o2)	setobj(L,s2v(o1),o2)
+/* from table to same table */
+#define setobjt2t	setobj
+/* to new object */
+#define setobj2n	setobj
+/* to table */
+#define setobj2t	setobj
 
 
 /*
-** Common type has only the common header
+** Entries in the Lua stack
 */
-struct GCObject {
-  CommonHeader;
-};
+typedef union StackValue {
+  TValue val;
+} StackValue;
 
 
+/* index to stack elements */
+typedef StackValue *StkId;
+
+/* convert a 'StackValue' to a 'TValue' */
+#define s2v(o)	(&(o)->val)
 
 
-/*
-** Tagged Values. This is the basic representation of values in Lua,
-** an actual value plus a tag with its type.
-*/
 
 /*
-** Union of all Lua values
+** {==================================================================
+** Nil
+** ===================================================================
 */
-typedef union Value {
-  GCObject *gc;    /* collectable objects */
-  void *p;         /* light userdata */
-  int b;           /* booleans */
-  lua_CFunction f; /* light C functions */
-  lua_Integer i;   /* integer numbers */
-  lua_Number n;    /* float numbers */
-} Value;
 
+/* Standard nil */
+#define LUA_VNIL	makevariant(LUA_TNIL, 0)
 
-#define TValuefields	Value value_; int tt_
+/* Empty slot (which might be different from a slot containing nil) */
+#define LUA_VEMPTY	makevariant(LUA_TNIL, 1)
 
+/* Value returned for a key not found in a table (absent key) */
+#define LUA_VABSTKEY	makevariant(LUA_TNIL, 2)
 
-typedef struct lua_TValue {
-  TValuefields;
-} TValue;
 
+/* macro to test for (any kind of) nil */
+#define ttisnil(v)		checktype((v), LUA_TNIL)
 
 
-/* macro defining a nil value */
-#define NILCONSTANT	{NULL}, LUA_TNIL
+/* macro to test for a standard nil */
+#define ttisstrictnil(o)	checktag((o), LUA_VNIL)
 
 
-#define val_(o)		((o)->value_)
+#define setnilvalue(obj) settt_(obj, LUA_VNIL)
 
 
-/* raw type tag of a TValue */
-#define rttype(o)	((o)->tt_)
+#define isabstkey(v)		checktag((v), LUA_VABSTKEY)
 
-/* tag with no variants (bits 0-3) */
-#define novariant(x)	((x) & 0x0F)
 
-/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
-#define ttype(o)	(rttype(o) & 0x3F)
+/*
+** macro to detect non-standard nils (used only in assertions)
+*/
+#define isnonstrictnil(v)	(ttisnil(v) && !ttisstrictnil(v))
 
-/* type tag of a TValue with no variants (bits 0-3) */
-#define ttnov(o)	(novariant(rttype(o)))
 
+/*
+** By default, entries with any kind of nil are considered empty.
+** (In any definition, values associated with absent keys must also
+** be accepted as empty.)
+*/
+#define isempty(v)		ttisnil(v)
 
-/* Macros to test type */
-#define checktag(o,t)		(rttype(o) == (t))
-#define checktype(o,t)		(ttnov(o) == (t))
-#define ttisnumber(o)		checktype((o), LUA_TNUMBER)
-#define ttisfloat(o)		checktag((o), LUA_TNUMFLT)
-#define ttisinteger(o)		checktag((o), LUA_TNUMINT)
-#define ttisnil(o)		checktag((o), LUA_TNIL)
-#define ttisboolean(o)		checktag((o), LUA_TBOOLEAN)
-#define ttislightuserdata(o)	checktag((o), LUA_TLIGHTUSERDATA)
-#define ttisstring(o)		checktype((o), LUA_TSTRING)
-#define ttisshrstring(o)	checktag((o), ctb(LUA_TSHRSTR))
-#define ttislngstring(o)	checktag((o), ctb(LUA_TLNGSTR))
-#define ttistable(o)		checktag((o), ctb(LUA_TTABLE))
-#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
-#define ttisclosure(o)		((rttype(o) & 0x1F) == LUA_TFUNCTION)
-#define ttisCclosure(o)		checktag((o), ctb(LUA_TCCL))
-#define ttisLclosure(o)		checktag((o), ctb(LUA_TLCL))
-#define ttislcf(o)		checktag((o), LUA_TLCF)
-#define ttisfulluserdata(o)	checktag((o), ctb(LUA_TUSERDATA))
-#define ttisthread(o)		checktag((o), ctb(LUA_TTHREAD))
-#define ttisdeadkey(o)		checktag((o), LUA_TDEADKEY)
 
+/* macro defining a value corresponding to an absent key */
+#define ABSTKEYCONSTANT		{NULL}, LUA_VABSTKEY
 
-/* Macros to access values */
-#define ivalue(o)	check_exp(ttisinteger(o), val_(o).i)
-#define fltvalue(o)	check_exp(ttisfloat(o), val_(o).n)
-#define nvalue(o)	check_exp(ttisnumber(o), \
-	(ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
-#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)
-#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
-#define tsvalue(o)	check_exp(ttisstring(o), gco2ts(val_(o).gc))
-#define uvalue(o)	check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))
-#define clvalue(o)	check_exp(ttisclosure(o), gco2cl(val_(o).gc))
-#define clLvalue(o)	check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
-#define clCvalue(o)	check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))
-#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
-#define hvalue(o)	check_exp(ttistable(o), gco2t(val_(o).gc))
-#define bvalue(o)	check_exp(ttisboolean(o), val_(o).b)
-#define thvalue(o)	check_exp(ttisthread(o), gco2th(val_(o).gc))
-/* a dead value may get the 'gc' field, but cannot access its contents */
-#define deadvalue(o)	check_exp(ttisdeadkey(o), cast(void *, val_(o).gc))
 
-#define l_isfalse(o)	(ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
+/* mark an entry as empty */
+#define setempty(v)		settt_(v, LUA_VEMPTY)
 
 
-#define iscollectable(o)	(rttype(o) & BIT_ISCOLLECTABLE)
 
+/* }================================================================== */
 
-/* Macros for internal tests */
-#define righttt(obj)		(ttype(obj) == gcvalue(obj)->tt)
 
-#define checkliveness(L,obj) \
-	lua_longassert(!iscollectable(obj) || \
-		(righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj)))))
+/*
+** {==================================================================
+** Booleans
+** ===================================================================
+*/
 
 
-/* Macros to set values */
-#define settt_(o,t)	((o)->tt_=(t))
+#define LUA_VFALSE	makevariant(LUA_TBOOLEAN, 0)
+#define LUA_VTRUE	makevariant(LUA_TBOOLEAN, 1)
 
-#define setfltvalue(obj,x) \
-  { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_TNUMFLT); }
+#define ttisboolean(o)		checktype((o), LUA_TBOOLEAN)
+#define ttisfalse(o)		checktag((o), LUA_VFALSE)
+#define ttistrue(o)		checktag((o), LUA_VTRUE)
 
-#define chgfltvalue(obj,x) \
-  { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); }
 
-#define setivalue(obj,x) \
-  { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_TNUMINT); }
+#define l_isfalse(o)	(ttisfalse(o) || ttisnil(o))
 
-#define chgivalue(obj,x) \
-  { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); }
 
-#define setnilvalue(obj) settt_(obj, LUA_TNIL)
+#define setbfvalue(obj)		settt_(obj, LUA_VFALSE)
+#define setbtvalue(obj)		settt_(obj, LUA_VTRUE)
 
-#define setfvalue(obj,x) \
-  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); }
+/* }================================================================== */
 
-#define setpvalue(obj,x) \
-  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); }
 
-#define setbvalue(obj,x) \
-  { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
+/*
+** {==================================================================
+** Threads
+** ===================================================================
+*/
 
-#define setgcovalue(L,obj,x) \
-  { TValue *io = (obj); GCObject *i_g=(x); \
-    val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); }
+#define LUA_VTHREAD		makevariant(LUA_TTHREAD, 0)
 
-#define setsvalue(L,obj,x) \
-  { TValue *io = (obj); TString *x_ = (x); \
-    val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
-    checkliveness(L,io); }
+#define ttisthread(o)		checktag((o), ctb(LUA_VTHREAD))
 
-#define setuvalue(L,obj,x) \
-  { TValue *io = (obj); Udata *x_ = (x); \
-    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TUSERDATA)); \
-    checkliveness(L,io); }
+#define thvalue(o)	check_exp(ttisthread(o), gco2th(val_(o).gc))
 
 #define setthvalue(L,obj,x) \
   { TValue *io = (obj); lua_State *x_ = (x); \
-    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTHREAD)); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTHREAD)); \
     checkliveness(L,io); }
 
-#define setclLvalue(L,obj,x) \
-  { TValue *io = (obj); LClosure *x_ = (x); \
-    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TLCL)); \
-    checkliveness(L,io); }
+#define setthvalue2s(L,o,t)	setthvalue(L,s2v(o),t)
 
-#define setclCvalue(L,obj,x) \
-  { TValue *io = (obj); CClosure *x_ = (x); \
-    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TCCL)); \
-    checkliveness(L,io); }
+/* }================================================================== */
 
-#define sethvalue(L,obj,x) \
-  { TValue *io = (obj); Table *x_ = (x); \
-    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTABLE)); \
-    checkliveness(L,io); }
 
-#define setdeadvalue(obj)	settt_(obj, LUA_TDEADKEY)
+/*
+** {==================================================================
+** Collectable Objects
+** ===================================================================
+*/
 
+/*
+** Common Header for all collectable objects (in macro form, to be
+** included in other objects)
+*/
+#define CommonHeader	struct GCObject *next; lu_byte tt; lu_byte marked
 
 
-#define setobj(L,obj1,obj2) \
-	{ TValue *io1=(obj1); *io1 = *(obj2); \
-	  (void)L; checkliveness(L,io1); }
+/* Common type for all collectable objects */
+typedef struct GCObject {
+  CommonHeader;
+} GCObject;
+
+
+/* Bit mark for collectable types */
+#define BIT_ISCOLLECTABLE	(1 << 6)
+
+#define iscollectable(o)	(rawtt(o) & BIT_ISCOLLECTABLE)
+
+/* mark a tag as collectable */
+#define ctb(t)			((t) | BIT_ISCOLLECTABLE)
+
+#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)
+
+#define gcvalueraw(v)	((v).gc)
+
+#define setgcovalue(L,obj,x) \
+  { TValue *io = (obj); GCObject *i_g=(x); \
+    val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); }
+
+/* }================================================================== */
 
 
 /*
-** different types of assignments, according to destination
+** {==================================================================
+** Numbers
+** ===================================================================
 */
 
-/* from stack to (same) stack */
-#define setobjs2s	setobj
-/* to stack (not from same stack) */
-#define setobj2s	setobj
-#define setsvalue2s	setsvalue
-#define sethvalue2s	sethvalue
-#define setptvalue2s	setptvalue
-/* from table to same table */
-#define setobjt2t	setobj
-/* to new object */
-#define setobj2n	setobj
-#define setsvalue2n	setsvalue
+/* Variant tags for numbers */
+#define LUA_VNUMINT	makevariant(LUA_TNUMBER, 0)  /* integer numbers */
+#define LUA_VNUMFLT	makevariant(LUA_TNUMBER, 1)  /* float numbers */
+
+#define ttisnumber(o)		checktype((o), LUA_TNUMBER)
+#define ttisfloat(o)		checktag((o), LUA_VNUMFLT)
+#define ttisinteger(o)		checktag((o), LUA_VNUMINT)
+
+#define nvalue(o)	check_exp(ttisnumber(o), \
+	(ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o)))
+#define fltvalue(o)	check_exp(ttisfloat(o), val_(o).n)
+#define ivalue(o)	check_exp(ttisinteger(o), val_(o).i)
+
+#define fltvalueraw(v)	((v).n)
+#define ivalueraw(v)	((v).i)
+
+#define setfltvalue(obj,x) \
+  { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_VNUMFLT); }
 
-/* to table (define it as an expression to be used in macros) */
-#define setobj2t(L,o1,o2)  ((void)L, *(o1)=*(o2), checkliveness(L,(o1)))
+#define chgfltvalue(obj,x) \
+  { TValue *io=(obj); lua_assert(ttisfloat(io)); val_(io).n=(x); }
 
+#define setivalue(obj,x) \
+  { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_VNUMINT); }
+
+#define chgivalue(obj,x) \
+  { TValue *io=(obj); lua_assert(ttisinteger(io)); val_(io).i=(x); }
 
+/* }================================================================== */
 
 
 /*
-** {======================================================
-** types and prototypes
-** =======================================================
+** {==================================================================
+** Strings
+** ===================================================================
 */
 
+/* Variant tags for strings */
+#define LUA_VSHRSTR	makevariant(LUA_TSTRING, 0)  /* short strings */
+#define LUA_VLNGSTR	makevariant(LUA_TSTRING, 1)  /* long strings */
 
-typedef TValue *StkId;  /* index to stack elements */
+#define ttisstring(o)		checktype((o), LUA_TSTRING)
+#define ttisshrstring(o)	checktag((o), ctb(LUA_VSHRSTR))
+#define ttislngstring(o)	checktag((o), ctb(LUA_VLNGSTR))
 
+#define tsvalueraw(v)	(gco2ts((v).gc))
 
+#define tsvalue(o)	check_exp(ttisstring(o), gco2ts(val_(o).gc))
+
+#define setsvalue(L,obj,x) \
+  { TValue *io = (obj); TString *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
+    checkliveness(L,io); }
+
+/* set a string to the stack */
+#define setsvalue2s(L,o,s)	setsvalue(L,s2v(o),s)
+
+/* set a string to a new object */
+#define setsvalue2n	setsvalue
 
 
 /*
-** Header for string value; string bytes follow the end of this structure
-** (aligned according to 'UTString'; see next).
+** Header for a string value.
 */
 typedef struct TString {
   CommonHeader;
@@ -309,75 +367,121 @@ typedef struct TString {
     size_t lnglen;  /* length for long strings */
     struct TString *hnext;  /* linked list for hash table */
   } u;
+  char contents[1];
 } TString;
 
 
-/*
-** Ensures that address after this type is always fully aligned.
-*/
-typedef union UTString {
-  L_Umaxalign dummy;  /* ensures maximum alignment for strings */
-  TString tsv;
-} UTString;
-
 
 /*
 ** Get the actual string (array of bytes) from a 'TString'.
-** (Access to 'extra' ensures that value is really a 'TString'.)
 */
-#define getstr(ts)  \
-  check_exp(sizeof((ts)->extra), cast(char *, (ts)) + sizeof(UTString))
+#define getstr(ts)  ((ts)->contents)
 
 
 /* get the actual string (array of bytes) from a Lua value */
 #define svalue(o)       getstr(tsvalue(o))
 
 /* get string length from 'TString *s' */
-#define tsslen(s)	((s)->tt == LUA_TSHRSTR ? (s)->shrlen : (s)->u.lnglen)
+#define tsslen(s)	((s)->tt == LUA_VSHRSTR ? (s)->shrlen : (s)->u.lnglen)
 
 /* get string length from 'TValue *o' */
 #define vslen(o)	tsslen(tsvalue(o))
 
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Userdata
+** ===================================================================
+*/
+
 
 /*
-** Header for userdata; memory area follows the end of this structure
-** (aligned according to 'UUdata'; see next).
+** Light userdata should be a variant of userdata, but for compatibility
+** reasons they are also different types.
+*/
+#define LUA_VLIGHTUSERDATA	makevariant(LUA_TLIGHTUSERDATA, 0)
+
+#define LUA_VUSERDATA		makevariant(LUA_TUSERDATA, 0)
+
+#define ttislightuserdata(o)	checktag((o), LUA_VLIGHTUSERDATA)
+#define ttisfulluserdata(o)	checktag((o), ctb(LUA_VUSERDATA))
+
+#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
+#define uvalue(o)	check_exp(ttisfulluserdata(o), gco2u(val_(o).gc))
+
+#define pvalueraw(v)	((v).p)
+
+#define setpvalue(obj,x) \
+  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_VLIGHTUSERDATA); }
+
+#define setuvalue(L,obj,x) \
+  { TValue *io = (obj); Udata *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VUSERDATA)); \
+    checkliveness(L,io); }
+
+
+/* Ensures that addresses after this type are always fully aligned. */
+typedef union UValue {
+  TValue uv;
+  LUAI_MAXALIGN;  /* ensures maximum alignment for udata bytes */
+} UValue;
+
+
+/*
+** Header for userdata with user values;
+** memory area follows the end of this structure.
 */
 typedef struct Udata {
   CommonHeader;
-  lu_byte ttuv_;  /* user value's tag */
-  struct Table *metatable;
+  unsigned short nuvalue;  /* number of user values */
   size_t len;  /* number of bytes */
-  union Value user_;  /* user value */
+  struct Table *metatable;
+  GCObject *gclist;
+  UValue uv[1];  /* user values */
 } Udata;
 
 
 /*
-** Ensures that address after this type is always fully aligned.
+** Header for userdata with no user values. These userdata do not need
+** to be gray during GC, and therefore do not need a 'gclist' field.
+** To simplify, the code always use 'Udata' for both kinds of userdata,
+** making sure it never accesses 'gclist' on userdata with no user values.
+** This structure here is used only to compute the correct size for
+** this representation. (The 'bindata' field in its end ensures correct
+** alignment for binary data following this header.)
 */
-typedef union UUdata {
-  L_Umaxalign dummy;  /* ensures maximum alignment for 'local' udata */
-  Udata uv;
-} UUdata;
+typedef struct Udata0 {
+  CommonHeader;
+  unsigned short nuvalue;  /* number of user values */
+  size_t len;  /* number of bytes */
+  struct Table *metatable;
+  union {LUAI_MAXALIGN;} bindata;
+} Udata0;
 
 
-/*
-**  Get the address of memory block inside 'Udata'.
-** (Access to 'ttuv_' ensures that value is really a 'Udata'.)
-*/
-#define getudatamem(u)  \
-  check_exp(sizeof((u)->ttuv_), (cast(char*, (u)) + sizeof(UUdata)))
+/* compute the offset of the memory area of a userdata */
+#define udatamemoffset(nuv) \
+	((nuv) == 0 ? offsetof(Udata0, bindata)  \
+                    : offsetof(Udata, uv) + (sizeof(UValue) * (nuv)))
+
+/* get the address of the memory block inside 'Udata' */
+#define getudatamem(u)	(cast_charp(u) + udatamemoffset((u)->nuvalue))
 
-#define setuservalue(L,u,o) \
-	{ const TValue *io=(o); Udata *iu = (u); \
-	  iu->user_ = io->value_; iu->ttuv_ = rttype(io); \
-	  checkliveness(L,io); }
+/* compute the size of a userdata */
+#define sizeudata(nuv,nb)	(udatamemoffset(nuv) + (nb))
 
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Prototypes
+** ===================================================================
+*/
 
-#define getuservalue(L,u,o) \
-	{ TValue *io=(o); const Udata *iu = (u); \
-	  io->value_ = iu->user_; settt_(io, iu->ttuv_); \
-	  checkliveness(L,io); }
+#define LUA_VPROTO	makevariant(LUA_TPROTO, 0)
 
 
 /*
@@ -387,6 +491,7 @@ typedef struct Upvaldesc {
   TString *name;  /* upvalue name (for debug information) */
   lu_byte instack;  /* whether it is in stack (register) */
   lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
+  lu_byte kind;  /* kind of corresponding variable */
 } Upvaldesc;
 
 
@@ -401,12 +506,27 @@ typedef struct LocVar {
 } LocVar;
 
 
+/*
+** Associates the absolute line source for a given instruction ('pc').
+** The array 'lineinfo' gives, for each instruction, the difference in
+** lines from the previous instruction. When that difference does not
+** fit into a byte, Lua saves the absolute line for that instruction.
+** (Lua also saves the absolute line periodically, to speed up the
+** computation of a line number: we can use binary search in the
+** absolute-line array, but we must traverse the 'lineinfo' array
+** linearly to compute a line.)
+*/
+typedef struct AbsLineInfo {
+  int pc;
+  int line;
+} AbsLineInfo;
+
 /*
 ** Function Prototypes
 */
 typedef struct Proto {
   CommonHeader;
-  lu_byte numparams;  /* number of fixed parameters */
+  lu_byte numparams;  /* number of fixed (named) parameters */
   lu_byte is_vararg;
   lu_byte maxstacksize;  /* number of registers needed by this function */
   int sizeupvalues;  /* size of 'upvalues' */
@@ -415,30 +535,85 @@ typedef struct Proto {
   int sizelineinfo;
   int sizep;  /* size of 'p' */
   int sizelocvars;
+  int sizeabslineinfo;  /* size of 'abslineinfo' */
   int linedefined;  /* debug information  */
   int lastlinedefined;  /* debug information  */
   TValue *k;  /* constants used by the function */
   Instruction *code;  /* opcodes */
   struct Proto **p;  /* functions defined inside the function */
-  int *lineinfo;  /* map from opcodes to source lines (debug information) */
-  LocVar *locvars;  /* information about local variables (debug information) */
   Upvaldesc *upvalues;  /* upvalue information */
-  struct LClosure *cache;  /* last-created closure with this prototype */
+  ls_byte *lineinfo;  /* information about source lines (debug information) */
+  AbsLineInfo *abslineinfo;  /* idem */
+  LocVar *locvars;  /* information about local variables (debug information) */
   TString  *source;  /* used for debug information */
   GCObject *gclist;
 } Proto;
 
+/* }================================================================== */
 
 
 /*
-** Lua Upvalues
+** {==================================================================
+** Closures
+** ===================================================================
 */
-typedef struct UpVal UpVal;
+
+#define LUA_VUPVAL	makevariant(LUA_TUPVAL, 0)
+
+
+/* Variant tags for functions */
+#define LUA_VLCL	makevariant(LUA_TFUNCTION, 0)  /* Lua closure */
+#define LUA_VLCF	makevariant(LUA_TFUNCTION, 1)  /* light C function */
+#define LUA_VCCL	makevariant(LUA_TFUNCTION, 2)  /* C closure */
+
+#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
+#define ttisclosure(o)		((rawtt(o) & 0x1F) == LUA_VLCL)
+#define ttisLclosure(o)		checktag((o), ctb(LUA_VLCL))
+#define ttislcf(o)		checktag((o), LUA_VLCF)
+#define ttisCclosure(o)		checktag((o), ctb(LUA_VCCL))
+
+#define isLfunction(o)	ttisLclosure(o)
+
+#define clvalue(o)	check_exp(ttisclosure(o), gco2cl(val_(o).gc))
+#define clLvalue(o)	check_exp(ttisLclosure(o), gco2lcl(val_(o).gc))
+#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
+#define clCvalue(o)	check_exp(ttisCclosure(o), gco2ccl(val_(o).gc))
+
+#define fvalueraw(v)	((v).f)
+
+#define setclLvalue(L,obj,x) \
+  { TValue *io = (obj); LClosure *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VLCL)); \
+    checkliveness(L,io); }
+
+#define setclLvalue2s(L,o,cl)	setclLvalue(L,s2v(o),cl)
+
+#define setfvalue(obj,x) \
+  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_VLCF); }
+
+#define setclCvalue(L,obj,x) \
+  { TValue *io = (obj); CClosure *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VCCL)); \
+    checkliveness(L,io); }
 
 
 /*
-** Closures
+** Upvalues for Lua closures
 */
+typedef struct UpVal {
+  CommonHeader;
+  lu_byte tbc;  /* true if it represents a to-be-closed variable */
+  TValue *v;  /* points to stack or to its own value */
+  union {
+    struct {  /* (when open) */
+      struct UpVal *next;  /* linked list */
+      struct UpVal **previous;
+    } open;
+    TValue value;  /* the value (when closed) */
+  } u;
+} UpVal;
+
+
 
 #define ClosureHeader \
 	CommonHeader; lu_byte nupvalues; GCObject *gclist
@@ -463,42 +638,81 @@ typedef union Closure {
 } Closure;
 
 
-#define isLfunction(o)	ttisLclosure(o)
-
 #define getproto(o)	(clLvalue(o)->p)
 
+/* }================================================================== */
+
 
 /*
+** {==================================================================
 ** Tables
+** ===================================================================
 */
 
-typedef union TKey {
-  struct {
-    TValuefields;
-    int next;  /* for chaining (offset for next node) */
-  } nk;
-  TValue tvk;
-} TKey;
+#define LUA_VTABLE	makevariant(LUA_TTABLE, 0)
+
+#define ttistable(o)		checktag((o), ctb(LUA_VTABLE))
+
+#define hvalue(o)	check_exp(ttistable(o), gco2t(val_(o).gc))
 
+#define sethvalue(L,obj,x) \
+  { TValue *io = (obj); Table *x_ = (x); \
+    val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_VTABLE)); \
+    checkliveness(L,io); }
 
-/* copy a value into a key without messing up field 'next' */
-#define setnodekey(L,key,obj) \
-	{ TKey *k_=(key); const TValue *io_=(obj); \
-	  k_->nk.value_ = io_->value_; k_->nk.tt_ = io_->tt_; \
-	  (void)L; checkliveness(L,io_); }
+#define sethvalue2s(L,o,h)	sethvalue(L,s2v(o),h)
 
 
-typedef struct Node {
-  TValue i_val;
-  TKey i_key;
+/*
+** Nodes for Hash tables: A pack of two TValue's (key-value pairs)
+** plus a 'next' field to link colliding entries. The distribution
+** of the key's fields ('key_tt' and 'key_val') not forming a proper
+** 'TValue' allows for a smaller size for 'Node' both in 4-byte
+** and 8-byte alignments.
+*/
+typedef union Node {
+  struct NodeKey {
+    TValuefields;  /* fields for value */
+    lu_byte key_tt;  /* key type */
+    int next;  /* for chaining */
+    Value key_val;  /* key value */
+  } u;
+  TValue i_val;  /* direct access to node's value as a proper 'TValue' */
 } Node;
 
 
+/* copy a value into a key */
+#define setnodekey(L,node,obj) \
+	{ Node *n_=(node); const TValue *io_=(obj); \
+	  n_->u.key_val = io_->value_; n_->u.key_tt = io_->tt_; \
+	  checkliveness(L,io_); }
+
+
+/* copy a value from a key */
+#define getnodekey(L,obj,node) \
+	{ TValue *io_=(obj); const Node *n_=(node); \
+	  io_->value_ = n_->u.key_val; io_->tt_ = n_->u.key_tt; \
+	  checkliveness(L,io_); }
+
+
+/*
+** About 'alimit': if 'isrealasize(t)' is true, then 'alimit' is the
+** real size of 'array'. Otherwise, the real size of 'array' is the
+** smallest power of two not smaller than 'alimit' (or zero iff 'alimit'
+** is zero); 'alimit' is then used as a hint for #t.
+*/
+
+#define BITRAS		(1 << 7)
+#define isrealasize(t)		(!((t)->marked & BITRAS))
+#define setrealasize(t)		((t)->marked &= cast_byte(~BITRAS))
+#define setnorealasize(t)	((t)->marked |= BITRAS)
+
+
 typedef struct Table {
   CommonHeader;
   lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
   lu_byte lsizenode;  /* log2 of size of 'node' array */
-  unsigned int sizearray;  /* size of 'array' array */
+  unsigned int alimit;  /* "limit" of 'array' array */
   TValue *array;  /* array part */
   Node *node;
   Node *lastfree;  /* any free position is before this position */
@@ -507,42 +721,66 @@ typedef struct Table {
 } Table;
 
 
+/*
+** Macros to manipulate keys inserted in nodes
+*/
+#define keytt(node)		((node)->u.key_tt)
+#define keyval(node)		((node)->u.key_val)
+
+#define keyisnil(node)		(keytt(node) == LUA_TNIL)
+#define keyisinteger(node)	(keytt(node) == LUA_VNUMINT)
+#define keyival(node)		(keyval(node).i)
+#define keyisshrstr(node)	(keytt(node) == ctb(LUA_VSHRSTR))
+#define keystrval(node)		(gco2ts(keyval(node).gc))
+
+#define setnilkey(node)		(keytt(node) = LUA_TNIL)
+
+#define keyiscollectable(n)	(keytt(n) & BIT_ISCOLLECTABLE)
+
+#define gckey(n)	(keyval(n).gc)
+#define gckeyN(n)	(keyiscollectable(n) ? gckey(n) : NULL)
+
 
 /*
-** 'module' operation for hashing (size is always a power of 2)
+** Use a "nil table" to mark dead keys in a table. Those keys serve
+** to keep space for removed entries, which may still be part of
+** chains. Note that the 'keytt' does not have the BIT_ISCOLLECTABLE
+** set, so these values are considered not collectable and are different
+** from any valid value.
 */
-#define lmod(s,size) \
-	(check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
+#define setdeadkey(n)	(keytt(n) = LUA_TTABLE, gckey(n) = NULL)
 
+/* }================================================================== */
 
-#define twoto(x)	(1<<(x))
-#define sizenode(t)	(twoto((t)->lsizenode))
 
 
 /*
-** (address of) a fixed nil value
+** 'module' operation for hashing (size is always a power of 2)
 */
-#define luaO_nilobject		(&luaO_nilobject_)
+#define lmod(s,size) \
+	(check_exp((size&(size-1))==0, (cast_int((s) & ((size)-1)))))
+
 
+#define twoto(x)	(1<<(x))
+#define sizenode(t)	(twoto((t)->lsizenode))
 
-LUAI_DDEC const TValue luaO_nilobject_;
 
 /* size of buffer for 'luaO_utf8esc' function */
 #define UTF8BUFFSZ	8
 
-LUAI_FUNC int luaO_int2fb (unsigned int x);
-LUAI_FUNC int luaO_fb2int (int x);
 LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x);
 LUAI_FUNC int luaO_ceillog2 (unsigned int x);
+LUAI_FUNC int luaO_rawarith (lua_State *L, int op, const TValue *p1,
+                             const TValue *p2, TValue *res);
 LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1,
-                           const TValue *p2, TValue *res);
+                           const TValue *p2, StkId res);
 LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o);
 LUAI_FUNC int luaO_hexavalue (int c);
-LUAI_FUNC void luaO_tostring (lua_State *L, StkId obj);
+LUAI_FUNC void luaO_tostring (lua_State *L, TValue *obj);
 LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
                                                        va_list argp);
 LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
-LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
+LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t srclen);
 
 
 #endif
diff --git a/libs/liblua/src/lopcodes.c b/libs/liblua/src/lopcodes.c
index 5ca3eb261a..c67aa227c5 100644
--- a/libs/liblua/src/lopcodes.c
+++ b/libs/liblua/src/lopcodes.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.c,v 1.55.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lopcodes.c $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -10,115 +10,95 @@
 #include "lprefix.h"
 
 
-#include <stddef.h>
-
 #include "lopcodes.h"
 
 
 /* ORDER OP */
 
-LUAI_DDEF const char *const luaP_opnames[NUM_OPCODES+1] = {
-  "MOVE",
-  "LOADK",
-  "LOADKX",
-  "LOADBOOL",
-  "LOADNIL",
-  "GETUPVAL",
-  "GETTABUP",
-  "GETTABLE",
-  "SETTABUP",
-  "SETUPVAL",
-  "SETTABLE",
-  "NEWTABLE",
-  "SELF",
-  "ADD",
-  "SUB",
-  "MUL",
-  "MOD",
-  "POW",
-  "DIV",
-  "IDIV",
-  "BAND",
-  "BOR",
-  "BXOR",
-  "SHL",
-  "SHR",
-  "UNM",
-  "BNOT",
-  "NOT",
-  "LEN",
-  "CONCAT",
-  "JMP",
-  "EQ",
-  "LT",
-  "LE",
-  "TEST",
-  "TESTSET",
-  "CALL",
-  "TAILCALL",
-  "RETURN",
-  "FORLOOP",
-  "FORPREP",
-  "TFORCALL",
-  "TFORLOOP",
-  "SETLIST",
-  "CLOSURE",
-  "VARARG",
-  "EXTRAARG",
-  NULL
-};
-
-
-#define opmode(t,a,b,c,m) (((t)<<7) | ((a)<<6) | ((b)<<4) | ((c)<<2) | (m))
-
 LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = {
-/*       T  A    B       C     mode		   opcode	*/
-  opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_MOVE */
- ,opmode(0, 1, OpArgK, OpArgN, iABx)		/* OP_LOADK */
- ,opmode(0, 1, OpArgN, OpArgN, iABx)		/* OP_LOADKX */
- ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_LOADBOOL */
- ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_LOADNIL */
- ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_GETUPVAL */
- ,opmode(0, 1, OpArgU, OpArgK, iABC)		/* OP_GETTABUP */
- ,opmode(0, 1, OpArgR, OpArgK, iABC)		/* OP_GETTABLE */
- ,opmode(0, 0, OpArgK, OpArgK, iABC)		/* OP_SETTABUP */
- ,opmode(0, 0, OpArgU, OpArgN, iABC)		/* OP_SETUPVAL */
- ,opmode(0, 0, OpArgK, OpArgK, iABC)		/* OP_SETTABLE */
- ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_NEWTABLE */
- ,opmode(0, 1, OpArgR, OpArgK, iABC)		/* OP_SELF */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_ADD */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SUB */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_MUL */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_MOD */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_POW */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_DIV */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_IDIV */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_BAND */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_BOR */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_BXOR */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SHL */
- ,opmode(0, 1, OpArgK, OpArgK, iABC)		/* OP_SHR */
- ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_UNM */
- ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_BNOT */
- ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_NOT */
- ,opmode(0, 1, OpArgR, OpArgN, iABC)		/* OP_LEN */
- ,opmode(0, 1, OpArgR, OpArgR, iABC)		/* OP_CONCAT */
- ,opmode(0, 0, OpArgR, OpArgN, iAsBx)		/* OP_JMP */
- ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_EQ */
- ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_LT */
- ,opmode(1, 0, OpArgK, OpArgK, iABC)		/* OP_LE */
- ,opmode(1, 0, OpArgN, OpArgU, iABC)		/* OP_TEST */
- ,opmode(1, 1, OpArgR, OpArgU, iABC)		/* OP_TESTSET */
- ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_CALL */
- ,opmode(0, 1, OpArgU, OpArgU, iABC)		/* OP_TAILCALL */
- ,opmode(0, 0, OpArgU, OpArgN, iABC)		/* OP_RETURN */
- ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_FORLOOP */
- ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_FORPREP */
- ,opmode(0, 0, OpArgN, OpArgU, iABC)		/* OP_TFORCALL */
- ,opmode(0, 1, OpArgR, OpArgN, iAsBx)		/* OP_TFORLOOP */
- ,opmode(0, 0, OpArgU, OpArgU, iABC)		/* OP_SETLIST */
- ,opmode(0, 1, OpArgU, OpArgN, iABx)		/* OP_CLOSURE */
- ,opmode(0, 1, OpArgU, OpArgN, iABC)		/* OP_VARARG */
- ,opmode(0, 0, OpArgU, OpArgU, iAx)		/* OP_EXTRAARG */
+/*       MM OT IT T  A  mode		   opcode  */
+  opmode(0, 0, 0, 0, 1, iABC)		/* OP_MOVE */
+ ,opmode(0, 0, 0, 0, 1, iAsBx)		/* OP_LOADI */
+ ,opmode(0, 0, 0, 0, 1, iAsBx)		/* OP_LOADF */
+ ,opmode(0, 0, 0, 0, 1, iABx)		/* OP_LOADK */
+ ,opmode(0, 0, 0, 0, 1, iABx)		/* OP_LOADKX */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_LOADFALSE */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_LFALSESKIP */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_LOADTRUE */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_LOADNIL */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_GETUPVAL */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_SETUPVAL */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_GETTABUP */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_GETTABLE */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_GETI */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_GETFIELD */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_SETTABUP */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_SETTABLE */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_SETI */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_SETFIELD */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_NEWTABLE */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SELF */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_ADDI */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_ADDK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SUBK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_MULK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_MODK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_POWK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_DIVK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_IDIVK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BANDK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BORK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BXORK */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SHRI */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SHLI */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_ADD */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SUB */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_MUL */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_MOD */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_POW */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_DIV */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_IDIV */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BAND */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BOR */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BXOR */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SHL */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_SHR */
+ ,opmode(1, 0, 0, 0, 0, iABC)		/* OP_MMBIN */
+ ,opmode(1, 0, 0, 0, 0, iABC)		/* OP_MMBINI*/
+ ,opmode(1, 0, 0, 0, 0, iABC)		/* OP_MMBINK*/
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_UNM */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_BNOT */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_NOT */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_LEN */
+ ,opmode(0, 0, 0, 0, 1, iABC)		/* OP_CONCAT */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_CLOSE */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_TBC */
+ ,opmode(0, 0, 0, 0, 0, isJ)		/* OP_JMP */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_EQ */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_LT */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_LE */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_EQK */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_EQI */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_LTI */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_LEI */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_GTI */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_GEI */
+ ,opmode(0, 0, 0, 1, 0, iABC)		/* OP_TEST */
+ ,opmode(0, 0, 0, 1, 1, iABC)		/* OP_TESTSET */
+ ,opmode(0, 1, 1, 0, 1, iABC)		/* OP_CALL */
+ ,opmode(0, 1, 1, 0, 1, iABC)		/* OP_TAILCALL */
+ ,opmode(0, 0, 1, 0, 0, iABC)		/* OP_RETURN */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_RETURN0 */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_RETURN1 */
+ ,opmode(0, 0, 0, 0, 1, iABx)		/* OP_FORLOOP */
+ ,opmode(0, 0, 0, 0, 1, iABx)		/* OP_FORPREP */
+ ,opmode(0, 0, 0, 0, 0, iABx)		/* OP_TFORPREP */
+ ,opmode(0, 0, 0, 0, 0, iABC)		/* OP_TFORCALL */
+ ,opmode(0, 0, 0, 0, 1, iABx)		/* OP_TFORLOOP */
+ ,opmode(0, 0, 1, 0, 0, iABC)		/* OP_SETLIST */
+ ,opmode(0, 0, 0, 0, 1, iABx)		/* OP_CLOSURE */
+ ,opmode(0, 1, 0, 0, 1, iABC)		/* OP_VARARG */
+ ,opmode(0, 0, 1, 0, 1, iABC)		/* OP_VARARGPREP */
+ ,opmode(0, 0, 0, 0, 0, iAx)		/* OP_EXTRAARG */
 };
 
diff --git a/libs/liblua/src/lopcodes.h b/libs/liblua/src/lopcodes.h
index 6feaa1cd07..122e5d21f2 100644
--- a/libs/liblua/src/lopcodes.h
+++ b/libs/liblua/src/lopcodes.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.h,v 1.149.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lopcodes.h $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -11,69 +11,94 @@
 
 
 /*===========================================================================
-  We assume that instructions are unsigned numbers.
-  All instructions have an opcode in the first 6 bits.
-  Instructions can have the following fields:
-	'A' : 8 bits
-	'B' : 9 bits
-	'C' : 9 bits
-	'Ax' : 26 bits ('A', 'B', and 'C' together)
-	'Bx' : 18 bits ('B' and 'C' together)
-	'sBx' : signed Bx
-
-  A signed argument is represented in excess K; that is, the number
-  value is the unsigned value minus K. K is exactly the maximum value
-  for that argument (so that -max is represented by 0, and +max is
-  represented by 2*max), which is half the maximum for the corresponding
-  unsigned argument.
+  We assume that instructions are unsigned 32-bit integers.
+  All instructions have an opcode in the first 7 bits.
+  Instructions can have the following formats:
+
+        3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
+        1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+iABC          C(8)     |      B(8)     |k|     A(8)      |   Op(7)     |
+iABx                Bx(17)               |     A(8)      |   Op(7)     |
+iAsBx              sBx (signed)(17)      |     A(8)      |   Op(7)     |
+iAx                           Ax(25)                     |   Op(7)     |
+isJ                           sJ(25)                     |   Op(7)     |
+
+  A signed argument is represented in excess K: the represented value is
+  the written unsigned value minus K, where K is half the maximum for the
+  corresponding unsigned argument.
 ===========================================================================*/
 
 
-enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
+enum OpMode {iABC, iABx, iAsBx, iAx, isJ};  /* basic instruction formats */
 
 
 /*
 ** size and position of opcode arguments.
 */
-#define SIZE_C		9
-#define SIZE_B		9
-#define SIZE_Bx		(SIZE_C + SIZE_B)
+#define SIZE_C		8
+#define SIZE_B		8
+#define SIZE_Bx		(SIZE_C + SIZE_B + 1)
 #define SIZE_A		8
-#define SIZE_Ax		(SIZE_C + SIZE_B + SIZE_A)
+#define SIZE_Ax		(SIZE_Bx + SIZE_A)
+#define SIZE_sJ		(SIZE_Bx + SIZE_A)
 
-#define SIZE_OP		6
+#define SIZE_OP		7
 
 #define POS_OP		0
+
 #define POS_A		(POS_OP + SIZE_OP)
-#define POS_C		(POS_A + SIZE_A)
-#define POS_B		(POS_C + SIZE_C)
-#define POS_Bx		POS_C
+#define POS_k		(POS_A + SIZE_A)
+#define POS_B		(POS_k + 1)
+#define POS_C		(POS_B + SIZE_B)
+
+#define POS_Bx		POS_k
+
 #define POS_Ax		POS_A
 
+#define POS_sJ		POS_A
+
 
 /*
 ** limits for opcode arguments.
-** we use (signed) int to manipulate most arguments,
-** so they must fit in LUAI_BITSINT-1 bits (-1 for sign)
+** we use (signed) 'int' to manipulate most arguments,
+** so they must fit in ints.
 */
-#if SIZE_Bx < LUAI_BITSINT-1
-#define MAXARG_Bx        ((1<<SIZE_Bx)-1)
-#define MAXARG_sBx        (MAXARG_Bx>>1)         /* 'sBx' is signed */
+
+/* Check whether type 'int' has at least 'b' bits ('b' < 32) */
+#define L_INTHASBITS(b)		((UINT_MAX >> ((b) - 1)) >= 1)
+
+
+#if L_INTHASBITS(SIZE_Bx)
+#define MAXARG_Bx	((1<<SIZE_Bx)-1)
 #else
-#define MAXARG_Bx        MAX_INT
-#define MAXARG_sBx        MAX_INT
+#define MAXARG_Bx	MAX_INT
 #endif
 
-#if SIZE_Ax < LUAI_BITSINT-1
+#define OFFSET_sBx	(MAXARG_Bx>>1)         /* 'sBx' is signed */
+
+
+#if L_INTHASBITS(SIZE_Ax)
 #define MAXARG_Ax	((1<<SIZE_Ax)-1)
 #else
 #define MAXARG_Ax	MAX_INT
 #endif
 
+#if L_INTHASBITS(SIZE_sJ)
+#define MAXARG_sJ	((1 << SIZE_sJ) - 1)
+#else
+#define MAXARG_sJ	MAX_INT
+#endif
 
-#define MAXARG_A        ((1<<SIZE_A)-1)
-#define MAXARG_B        ((1<<SIZE_B)-1)
-#define MAXARG_C        ((1<<SIZE_C)-1)
+#define OFFSET_sJ	(MAXARG_sJ >> 1)
+
+
+#define MAXARG_A	((1<<SIZE_A)-1)
+#define MAXARG_B	((1<<SIZE_B)-1)
+#define MAXARG_C	((1<<SIZE_C)-1)
+#define OFFSET_sC	(MAXARG_C >> 1)
+
+#define int2sC(i)	((i) + OFFSET_sC)
+#define sC2int(i)	((i) - OFFSET_sC)
 
 
 /* creates a mask with 'n' 1 bits at position 'p' */
@@ -90,33 +115,49 @@ enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
 #define SET_OPCODE(i,o)	((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \
 		((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP))))
 
-#define getarg(i,pos,size)	(cast(int, ((i)>>pos) & MASK1(size,0)))
+#define checkopm(i,m)	(getOpMode(GET_OPCODE(i)) == m)
+
+
+#define getarg(i,pos,size)	(cast_int(((i)>>(pos)) & MASK1(size,0)))
 #define setarg(i,v,pos,size)	((i) = (((i)&MASK0(size,pos)) | \
                 ((cast(Instruction, v)<<pos)&MASK1(size,pos))))
 
 #define GETARG_A(i)	getarg(i, POS_A, SIZE_A)
 #define SETARG_A(i,v)	setarg(i, v, POS_A, SIZE_A)
 
-#define GETARG_B(i)	getarg(i, POS_B, SIZE_B)
+#define GETARG_B(i)	check_exp(checkopm(i, iABC), getarg(i, POS_B, SIZE_B))
+#define GETARG_sB(i)	sC2int(GETARG_B(i))
 #define SETARG_B(i,v)	setarg(i, v, POS_B, SIZE_B)
 
-#define GETARG_C(i)	getarg(i, POS_C, SIZE_C)
+#define GETARG_C(i)	check_exp(checkopm(i, iABC), getarg(i, POS_C, SIZE_C))
+#define GETARG_sC(i)	sC2int(GETARG_C(i))
 #define SETARG_C(i,v)	setarg(i, v, POS_C, SIZE_C)
 
-#define GETARG_Bx(i)	getarg(i, POS_Bx, SIZE_Bx)
+#define TESTARG_k(i)	check_exp(checkopm(i, iABC), (cast_int(((i) & (1u << POS_k)))))
+#define GETARG_k(i)	check_exp(checkopm(i, iABC), getarg(i, POS_k, 1))
+#define SETARG_k(i,v)	setarg(i, v, POS_k, 1)
+
+#define GETARG_Bx(i)	check_exp(checkopm(i, iABx), getarg(i, POS_Bx, SIZE_Bx))
 #define SETARG_Bx(i,v)	setarg(i, v, POS_Bx, SIZE_Bx)
 
-#define GETARG_Ax(i)	getarg(i, POS_Ax, SIZE_Ax)
+#define GETARG_Ax(i)	check_exp(checkopm(i, iAx), getarg(i, POS_Ax, SIZE_Ax))
 #define SETARG_Ax(i,v)	setarg(i, v, POS_Ax, SIZE_Ax)
 
-#define GETARG_sBx(i)	(GETARG_Bx(i)-MAXARG_sBx)
-#define SETARG_sBx(i,b)	SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx))
+#define GETARG_sBx(i)  \
+	check_exp(checkopm(i, iAsBx), getarg(i, POS_Bx, SIZE_Bx) - OFFSET_sBx)
+#define SETARG_sBx(i,b)	SETARG_Bx((i),cast_uint((b)+OFFSET_sBx))
+
+#define GETARG_sJ(i)  \
+	check_exp(checkopm(i, isJ), getarg(i, POS_sJ, SIZE_sJ) - OFFSET_sJ)
+#define SETARG_sJ(i,j) \
+	setarg(i, cast_uint((j)+OFFSET_sJ), POS_sJ, SIZE_sJ)
 
 
-#define CREATE_ABC(o,a,b,c)	((cast(Instruction, o)<<POS_OP) \
+#define CREATE_ABCk(o,a,b,c,k)	((cast(Instruction, o)<<POS_OP) \
 			| (cast(Instruction, a)<<POS_A) \
 			| (cast(Instruction, b)<<POS_B) \
-			| (cast(Instruction, c)<<POS_C))
+			| (cast(Instruction, c)<<POS_C) \
+			| (cast(Instruction, k)<<POS_k))
 
 #define CREATE_ABx(o,a,bc)	((cast(Instruction, o)<<POS_OP) \
 			| (cast(Instruction, a)<<POS_A) \
@@ -125,27 +166,15 @@ enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
 #define CREATE_Ax(o,a)		((cast(Instruction, o)<<POS_OP) \
 			| (cast(Instruction, a)<<POS_Ax))
 
+#define CREATE_sJ(o,j,k)	((cast(Instruction, o) << POS_OP) \
+			| (cast(Instruction, j) << POS_sJ) \
+			| (cast(Instruction, k) << POS_k))
 
-/*
-** Macros to operate RK indices
-*/
-
-/* this bit 1 means constant (0 means register) */
-#define BITRK		(1 << (SIZE_B - 1))
-
-/* test whether value is a constant */
-#define ISK(x)		((x) & BITRK)
-
-/* gets the index of the constant */
-#define INDEXK(r)	((int)(r) & ~BITRK)
 
 #if !defined(MAXINDEXRK)  /* (for debugging only) */
-#define MAXINDEXRK	(BITRK - 1)
+#define MAXINDEXRK	MAXARG_B
 #endif
 
-/* code a constant index as a RK value */
-#define RKASK(x)	((x) | BITRK)
-
 
 /*
 ** invalid register that fits in 8 bits
@@ -154,9 +183,9 @@ enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
 
 
 /*
-** R(x) - register
-** Kst(x) - constant (in constant table)
-** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x)
+** R[x] - register
+** K[x] - constant (in constant table)
+** RK(x) == if k(i) then K[x] else R[x]
 */
 
 
@@ -166,132 +195,198 @@ enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
 
 typedef enum {
 /*----------------------------------------------------------------------
-name		args	description
+  name		args	description
 ------------------------------------------------------------------------*/
-OP_MOVE,/*	A B	R(A) := R(B)					*/
-OP_LOADK,/*	A Bx	R(A) := Kst(Bx)					*/
-OP_LOADKX,/*	A 	R(A) := Kst(extra arg)				*/
-OP_LOADBOOL,/*	A B C	R(A) := (Bool)B; if (C) pc++			*/
-OP_LOADNIL,/*	A B	R(A), R(A+1), ..., R(A+B) := nil		*/
-OP_GETUPVAL,/*	A B	R(A) := UpValue[B]				*/
-
-OP_GETTABUP,/*	A B C	R(A) := UpValue[B][RK(C)]			*/
-OP_GETTABLE,/*	A B C	R(A) := R(B)[RK(C)]				*/
-
-OP_SETTABUP,/*	A B C	UpValue[A][RK(B)] := RK(C)			*/
-OP_SETUPVAL,/*	A B	UpValue[B] := R(A)				*/
-OP_SETTABLE,/*	A B C	R(A)[RK(B)] := RK(C)				*/
-
-OP_NEWTABLE,/*	A B C	R(A) := {} (size = B,C)				*/
-
-OP_SELF,/*	A B C	R(A+1) := R(B); R(A) := R(B)[RK(C)]		*/
-
-OP_ADD,/*	A B C	R(A) := RK(B) + RK(C)				*/
-OP_SUB,/*	A B C	R(A) := RK(B) - RK(C)				*/
-OP_MUL,/*	A B C	R(A) := RK(B) * RK(C)				*/
-OP_MOD,/*	A B C	R(A) := RK(B) % RK(C)				*/
-OP_POW,/*	A B C	R(A) := RK(B) ^ RK(C)				*/
-OP_DIV,/*	A B C	R(A) := RK(B) / RK(C)				*/
-OP_IDIV,/*	A B C	R(A) := RK(B) // RK(C)				*/
-OP_BAND,/*	A B C	R(A) := RK(B) & RK(C)				*/
-OP_BOR,/*	A B C	R(A) := RK(B) | RK(C)				*/
-OP_BXOR,/*	A B C	R(A) := RK(B) ~ RK(C)				*/
-OP_SHL,/*	A B C	R(A) := RK(B) << RK(C)				*/
-OP_SHR,/*	A B C	R(A) := RK(B) >> RK(C)				*/
-OP_UNM,/*	A B	R(A) := -R(B)					*/
-OP_BNOT,/*	A B	R(A) := ~R(B)					*/
-OP_NOT,/*	A B	R(A) := not R(B)				*/
-OP_LEN,/*	A B	R(A) := length of R(B)				*/
-
-OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
-
-OP_JMP,/*	A sBx	pc+=sBx; if (A) close all upvalues >= R(A - 1)	*/
-OP_EQ,/*	A B C	if ((RK(B) == RK(C)) ~= A) then pc++		*/
-OP_LT,/*	A B C	if ((RK(B) <  RK(C)) ~= A) then pc++		*/
-OP_LE,/*	A B C	if ((RK(B) <= RK(C)) ~= A) then pc++		*/
-
-OP_TEST,/*	A C	if not (R(A) <=> C) then pc++			*/
-OP_TESTSET,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/
+OP_MOVE,/*	A B	R[A] := R[B]					*/
+OP_LOADI,/*	A sBx	R[A] := sBx					*/
+OP_LOADF,/*	A sBx	R[A] := (lua_Number)sBx				*/
+OP_LOADK,/*	A Bx	R[A] := K[Bx]					*/
+OP_LOADKX,/*	A	R[A] := K[extra arg]				*/
+OP_LOADFALSE,/*	A	R[A] := false					*/
+OP_LFALSESKIP,/*A	R[A] := false; pc++				*/
+OP_LOADTRUE,/*	A	R[A] := true					*/
+OP_LOADNIL,/*	A B	R[A], R[A+1], ..., R[A+B] := nil		*/
+OP_GETUPVAL,/*	A B	R[A] := UpValue[B]				*/
+OP_SETUPVAL,/*	A B	UpValue[B] := R[A]				*/
+
+OP_GETTABUP,/*	A B C	R[A] := UpValue[B][K[C]:string]			*/
+OP_GETTABLE,/*	A B C	R[A] := R[B][R[C]]				*/
+OP_GETI,/*	A B C	R[A] := R[B][C]					*/
+OP_GETFIELD,/*	A B C	R[A] := R[B][K[C]:string]			*/
+
+OP_SETTABUP,/*	A B C	UpValue[A][K[B]:string] := RK(C)		*/
+OP_SETTABLE,/*	A B C	R[A][R[B]] := RK(C)				*/
+OP_SETI,/*	A B C	R[A][B] := RK(C)				*/
+OP_SETFIELD,/*	A B C	R[A][K[B]:string] := RK(C)			*/
+
+OP_NEWTABLE,/*	A B C k	R[A] := {}					*/
+
+OP_SELF,/*	A B C	R[A+1] := R[B]; R[A] := R[B][RK(C):string]	*/
+
+OP_ADDI,/*	A B sC	R[A] := R[B] + sC				*/
+
+OP_ADDK,/*	A B C	R[A] := R[B] + K[C]				*/
+OP_SUBK,/*	A B C	R[A] := R[B] - K[C]				*/
+OP_MULK,/*	A B C	R[A] := R[B] * K[C]				*/
+OP_MODK,/*	A B C	R[A] := R[B] % K[C]				*/
+OP_POWK,/*	A B C	R[A] := R[B] ^ K[C]				*/
+OP_DIVK,/*	A B C	R[A] := R[B] / K[C]				*/
+OP_IDIVK,/*	A B C	R[A] := R[B] // K[C]				*/
+
+OP_BANDK,/*	A B C	R[A] := R[B] & K[C]:integer			*/
+OP_BORK,/*	A B C	R[A] := R[B] | K[C]:integer			*/
+OP_BXORK,/*	A B C	R[A] := R[B] ~ K[C]:integer			*/
+
+OP_SHRI,/*	A B sC	R[A] := R[B] >> sC				*/
+OP_SHLI,/*	A B sC	R[A] := sC << R[B]				*/
+
+OP_ADD,/*	A B C	R[A] := R[B] + R[C]				*/
+OP_SUB,/*	A B C	R[A] := R[B] - R[C]				*/
+OP_MUL,/*	A B C	R[A] := R[B] * R[C]				*/
+OP_MOD,/*	A B C	R[A] := R[B] % R[C]				*/
+OP_POW,/*	A B C	R[A] := R[B] ^ R[C]				*/
+OP_DIV,/*	A B C	R[A] := R[B] / R[C]				*/
+OP_IDIV,/*	A B C	R[A] := R[B] // R[C]				*/
+
+OP_BAND,/*	A B C	R[A] := R[B] & R[C]				*/
+OP_BOR,/*	A B C	R[A] := R[B] | R[C]				*/
+OP_BXOR,/*	A B C	R[A] := R[B] ~ R[C]				*/
+OP_SHL,/*	A B C	R[A] := R[B] << R[C]				*/
+OP_SHR,/*	A B C	R[A] := R[B] >> R[C]				*/
+
+OP_MMBIN,/*	A B C	call C metamethod over R[A] and R[B]		*/
+OP_MMBINI,/*	A sB C k	call C metamethod over R[A] and sB	*/
+OP_MMBINK,/*	A B C k		call C metamethod over R[A] and K[B]	*/
+
+OP_UNM,/*	A B	R[A] := -R[B]					*/
+OP_BNOT,/*	A B	R[A] := ~R[B]					*/
+OP_NOT,/*	A B	R[A] := not R[B]				*/
+OP_LEN,/*	A B	R[A] := length of R[B]				*/
+
+OP_CONCAT,/*	A B	R[A] := R[A].. ... ..R[A + B - 1]		*/
+
+OP_CLOSE,/*	A	close all upvalues >= R[A]			*/
+OP_TBC,/*	A	mark variable A "to be closed"			*/
+OP_JMP,/*	sJ	pc += sJ					*/
+OP_EQ,/*	A B k	if ((R[A] == R[B]) ~= k) then pc++		*/
+OP_LT,/*	A B k	if ((R[A] <  R[B]) ~= k) then pc++		*/
+OP_LE,/*	A B k	if ((R[A] <= R[B]) ~= k) then pc++		*/
+
+OP_EQK,/*	A B k	if ((R[A] == K[B]) ~= k) then pc++		*/
+OP_EQI,/*	A sB k	if ((R[A] == sB) ~= k) then pc++		*/
+OP_LTI,/*	A sB k	if ((R[A] < sB) ~= k) then pc++			*/
+OP_LEI,/*	A sB k	if ((R[A] <= sB) ~= k) then pc++		*/
+OP_GTI,/*	A sB k	if ((R[A] > sB) ~= k) then pc++			*/
+OP_GEI,/*	A sB k	if ((R[A] >= sB) ~= k) then pc++		*/
+
+OP_TEST,/*	A k	if (not R[A] == k) then pc++			*/
+OP_TESTSET,/*	A B k	if (not R[B] == k) then pc++ else R[A] := R[B]	*/
+
+OP_CALL,/*	A B C	R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */
+OP_TAILCALL,/*	A B C k	return R[A](R[A+1], ... ,R[A+B-1])		*/
+
+OP_RETURN,/*	A B C k	return R[A], ... ,R[A+B-2]	(see note)	*/
+OP_RETURN0,/*		return						*/
+OP_RETURN1,/*	A	return R[A]					*/
+
+OP_FORLOOP,/*	A Bx	update counters; if loop continues then pc-=Bx; */
+OP_FORPREP,/*	A Bx	<check values and prepare counters>;
+                        if not to run then pc+=Bx+1;			*/
+
+OP_TFORPREP,/*	A Bx	create upvalue for R[A + 3]; pc+=Bx		*/
+OP_TFORCALL,/*	A C	R[A+4], ... ,R[A+3+C] := R[A](R[A+1], R[A+2]);	*/
+OP_TFORLOOP,/*	A Bx	if R[A+2] ~= nil then { R[A]=R[A+2]; pc -= Bx }	*/
+
+OP_SETLIST,/*	A B C k	R[A][(C-1)*FPF+i] := R[A+i], 1 <= i <= B	*/
+
+OP_CLOSURE,/*	A Bx	R[A] := closure(KPROTO[Bx])			*/
+
+OP_VARARG,/*	A C	R[A], R[A+1], ..., R[A+C-2] = vararg		*/
 
-OP_CALL,/*	A B C	R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
-OP_TAILCALL,/*	A B C	return R(A)(R(A+1), ... ,R(A+B-1))		*/
-OP_RETURN,/*	A B	return R(A), ... ,R(A+B-2)	(see note)	*/
-
-OP_FORLOOP,/*	A sBx	R(A)+=R(A+2);
-			if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
-OP_FORPREP,/*	A sBx	R(A)-=R(A+2); pc+=sBx				*/
-
-OP_TFORCALL,/*	A C	R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));	*/
-OP_TFORLOOP,/*	A sBx	if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
-
-OP_SETLIST,/*	A B C	R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B	*/
-
-OP_CLOSURE,/*	A Bx	R(A) := closure(KPROTO[Bx])			*/
-
-OP_VARARG,/*	A B	R(A), R(A+1), ..., R(A+B-2) = vararg		*/
+OP_VARARGPREP,/*A	(adjust vararg parameters)			*/
 
 OP_EXTRAARG/*	Ax	extra (larger) argument for previous opcode	*/
 } OpCode;
 
 
-#define NUM_OPCODES	(cast(int, OP_EXTRAARG) + 1)
+#define NUM_OPCODES	((int)(OP_EXTRAARG) + 1)
 
 
 
 /*===========================================================================
   Notes:
-  (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then 'top' is
-  set to last_result+1, so next open instruction (OP_CALL, OP_RETURN,
-  OP_SETLIST) may use 'top'.
+  (*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
+  'top' is set to last_result+1, so next open instruction (OP_CALL,
+  OP_RETURN*, OP_SETLIST) may use 'top'.
 
-  (*) In OP_VARARG, if (B == 0) then use actual number of varargs and
+  (*) In OP_VARARG, if (C == 0) then use actual number of varargs and
   set top (like in OP_CALL with C == 0).
 
   (*) In OP_RETURN, if (B == 0) then return up to 'top'.
 
-  (*) In OP_SETLIST, if (B == 0) then B = 'top'; if (C == 0) then next
-  'instruction' is EXTRAARG(real C).
+  (*) In OP_LOADKX and OP_NEWTABLE, the next instruction is always
+  OP_EXTRAARG.
 
-  (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG.
+  (*) In OP_SETLIST, if (B == 0) then real B = 'top'; if k, then
+  real C = EXTRAARG _ C (the bits of EXTRAARG concatenated with the
+  bits of C).
 
-  (*) For comparisons, A specifies what condition the test should accept
+  (*) In OP_NEWTABLE, B is log2 of the hash size (which is always a
+  power of 2) plus 1, or zero for size zero. If not k, the array size
+  is C. Otherwise, the array size is EXTRAARG _ C.
+
+  (*) For comparisons, k specifies what condition the test should accept
   (true or false).
 
+  (*) In OP_MMBINI/OP_MMBINK, k means the arguments were flipped
+   (the constant is the first operand).
+
   (*) All 'skips' (pc++) assume that next instruction is a jump.
 
+  (*) In instructions OP_RETURN/OP_TAILCALL, 'k' specifies that the
+  function builds upvalues, which may need to be closed. C > 0 means
+  the function is vararg, so that its 'func' must be corrected before
+  returning; in this case, (C - 1) is its number of fixed parameters.
+
+  (*) In comparisons with an immediate operand, C signals whether the
+  original operand was a float. (It must be corrected in case of
+  metamethods.)
+
 ===========================================================================*/
 
 
 /*
 ** masks for instruction properties. The format is:
-** bits 0-1: op mode
-** bits 2-3: C arg mode
-** bits 4-5: B arg mode
-** bit 6: instruction set register A
-** bit 7: operator is a test (next instruction must be a jump)
+** bits 0-2: op mode
+** bit 3: instruction set register A
+** bit 4: operator is a test (next instruction must be a jump)
+** bit 5: instruction uses 'L->top' set by previous instruction (when B == 0)
+** bit 6: instruction sets 'L->top' for next instruction (when C == 0)
+** bit 7: instruction is an MM instruction (call a metamethod)
 */
 
-enum OpArgMask {
-  OpArgN,  /* argument is not used */
-  OpArgU,  /* argument is used */
-  OpArgR,  /* argument is a register or a jump offset */
-  OpArgK   /* argument is a constant or register/constant */
-};
+LUAI_DDEC(const lu_byte luaP_opmodes[NUM_OPCODES];)
 
-LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES];
+#define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 7))
+#define testAMode(m)	(luaP_opmodes[m] & (1 << 3))
+#define testTMode(m)	(luaP_opmodes[m] & (1 << 4))
+#define testITMode(m)	(luaP_opmodes[m] & (1 << 5))
+#define testOTMode(m)	(luaP_opmodes[m] & (1 << 6))
+#define testMMMode(m)	(luaP_opmodes[m] & (1 << 7))
 
-#define getOpMode(m)	(cast(enum OpMode, luaP_opmodes[m] & 3))
-#define getBMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3))
-#define getCMode(m)	(cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3))
-#define testAMode(m)	(luaP_opmodes[m] & (1 << 6))
-#define testTMode(m)	(luaP_opmodes[m] & (1 << 7))
+/* "out top" (set top for next instruction) */
+#define isOT(i)  \
+	((testOTMode(GET_OPCODE(i)) && GETARG_C(i) == 0) || \
+          GET_OPCODE(i) == OP_TAILCALL)
 
+/* "in top" (uses top from previous instruction) */
+#define isIT(i)		(testITMode(GET_OPCODE(i)) && GETARG_B(i) == 0)
 
-LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1];  /* opcode names */
+#define opmode(mm,ot,it,t,a,m)  \
+    (((mm) << 7) | ((ot) << 6) | ((it) << 5) | ((t) << 4) | ((a) << 3) | (m))
 
 
 /* number of list items to accumulate before a SETLIST instruction */
 #define LFIELDS_PER_FLUSH	50
 
-
 #endif
diff --git a/libs/liblua/src/lopnames.h b/libs/liblua/src/lopnames.h
new file mode 100644
index 0000000000..965cec9bf2
--- /dev/null
+++ b/libs/liblua/src/lopnames.h
@@ -0,0 +1,103 @@
+/*
+** $Id: lopnames.h $
+** Opcode names
+** See Copyright Notice in lua.h
+*/
+
+#if !defined(lopnames_h)
+#define lopnames_h
+
+#include <stddef.h>
+
+
+/* ORDER OP */
+
+static const char *const opnames[] = {
+  "MOVE",
+  "LOADI",
+  "LOADF",
+  "LOADK",
+  "LOADKX",
+  "LOADFALSE",
+  "LFALSESKIP",
+  "LOADTRUE",
+  "LOADNIL",
+  "GETUPVAL",
+  "SETUPVAL",
+  "GETTABUP",
+  "GETTABLE",
+  "GETI",
+  "GETFIELD",
+  "SETTABUP",
+  "SETTABLE",
+  "SETI",
+  "SETFIELD",
+  "NEWTABLE",
+  "SELF",
+  "ADDI",
+  "ADDK",
+  "SUBK",
+  "MULK",
+  "MODK",
+  "POWK",
+  "DIVK",
+  "IDIVK",
+  "BANDK",
+  "BORK",
+  "BXORK",
+  "SHRI",
+  "SHLI",
+  "ADD",
+  "SUB",
+  "MUL",
+  "MOD",
+  "POW",
+  "DIV",
+  "IDIV",
+  "BAND",
+  "BOR",
+  "BXOR",
+  "SHL",
+  "SHR",
+  "MMBIN",
+  "MMBINI",
+  "MMBINK",
+  "UNM",
+  "BNOT",
+  "NOT",
+  "LEN",
+  "CONCAT",
+  "CLOSE",
+  "TBC",
+  "JMP",
+  "EQ",
+  "LT",
+  "LE",
+  "EQK",
+  "EQI",
+  "LTI",
+  "LEI",
+  "GTI",
+  "GEI",
+  "TEST",
+  "TESTSET",
+  "CALL",
+  "TAILCALL",
+  "RETURN",
+  "RETURN0",
+  "RETURN1",
+  "FORLOOP",
+  "FORPREP",
+  "TFORPREP",
+  "TFORCALL",
+  "TFORLOOP",
+  "SETLIST",
+  "CLOSURE",
+  "VARARG",
+  "VARARGPREP",
+  "EXTRAARG",
+  NULL
+};
+
+#endif
+
diff --git a/libs/liblua/src/loslib.c b/libs/liblua/src/loslib.c
index de590c6b71..e65e188bd7 100644
--- a/libs/liblua/src/loslib.c
+++ b/libs/liblua/src/loslib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: loslib.c,v 1.65.1.1 2017/04/19 17:29:57 roberto Exp $
+** $Id: loslib.c $
 ** Standard Operating System library
 ** See Copyright Notice in lua.h
 */
@@ -59,18 +59,20 @@
 ** ===================================================================
 */
 
-#if !defined(l_time_t)		/* { */
 /*
 ** type to represent time_t in Lua
 */
+#if !defined(LUA_NUMTIME)	/* { */
+
 #define l_timet			lua_Integer
 #define l_pushtime(L,t)		lua_pushinteger(L,(lua_Integer)(t))
+#define l_gettime(L,arg)	luaL_checkinteger(L, arg)
 
-static time_t l_checktime (lua_State *L, int arg) {
-  lua_Integer t = luaL_checkinteger(L, arg);
-  luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
-  return (time_t)t;
-}
+#else				/* }{ */
+
+#define l_timet			lua_Number
+#define l_pushtime(L,t)		lua_pushnumber(L,(lua_Number)(t))
+#define l_gettime(L,arg)	luaL_checknumber(L, arg)
 
 #endif				/* } */
 
@@ -90,7 +92,7 @@ static time_t l_checktime (lua_State *L, int arg) {
 
 /* ISO C definitions */
 #define l_gmtime(t,r)		((void)(r)->tm_sec, gmtime(t))
-#define l_localtime(t,r)  	((void)(r)->tm_sec, localtime(t))
+#define l_localtime(t,r)	((void)(r)->tm_sec, localtime(t))
 
 #endif				/* } */
 
@@ -137,10 +139,11 @@ static time_t l_checktime (lua_State *L, int arg) {
 
 
 
-
 static int os_execute (lua_State *L) {
   const char *cmd = luaL_optstring(L, 1, NULL);
-  int stat = system(cmd);
+  int stat;
+  errno = 0;
+  stat = system(cmd);
   if (cmd != NULL)
     return luaL_execresult(L, stat);
   else {
@@ -194,11 +197,25 @@ static int os_clock (lua_State *L) {
 ** =======================================================
 */
 
-static void setfield (lua_State *L, const char *key, int value) {
-  lua_pushinteger(L, value);
+/*
+** About the overflow check: an overflow cannot occur when time
+** is represented by a lua_Integer, because either lua_Integer is
+** large enough to represent all int fields or it is not large enough
+** to represent a time that cause a field to overflow.  However, if
+** times are represented as doubles and lua_Integer is int, then the
+** time 0x1.e1853b0d184f6p+55 would cause an overflow when adding 1900
+** to compute the year.
+*/
+static void setfield (lua_State *L, const char *key, int value, int delta) {
+  #if (defined(LUA_NUMTIME) && LUA_MAXINTEGER <= INT_MAX)
+    if (value > LUA_MAXINTEGER - delta)
+      luaL_error(L, "field '%s' is out-of-bound", key);
+  #endif
+  lua_pushinteger(L, (lua_Integer)value + delta);
   lua_setfield(L, -2, key);
 }
 
+
 static void setboolfield (lua_State *L, const char *key, int value) {
   if (value < 0)  /* undefined? */
     return;  /* does not set field */
@@ -211,14 +228,14 @@ static void setboolfield (lua_State *L, const char *key, int value) {
 ** Set all fields from structure 'tm' in the table on top of the stack
 */
 static void setallfields (lua_State *L, struct tm *stm) {
-  setfield(L, "sec", stm->tm_sec);
-  setfield(L, "min", stm->tm_min);
-  setfield(L, "hour", stm->tm_hour);
-  setfield(L, "day", stm->tm_mday);
-  setfield(L, "month", stm->tm_mon + 1);
-  setfield(L, "year", stm->tm_year + 1900);
-  setfield(L, "wday", stm->tm_wday + 1);
-  setfield(L, "yday", stm->tm_yday + 1);
+  setfield(L, "year", stm->tm_year, 1900);
+  setfield(L, "month", stm->tm_mon, 1);
+  setfield(L, "day", stm->tm_mday, 0);
+  setfield(L, "hour", stm->tm_hour, 0);
+  setfield(L, "min", stm->tm_min, 0);
+  setfield(L, "sec", stm->tm_sec, 0);
+  setfield(L, "yday", stm->tm_yday, 1);
+  setfield(L, "wday", stm->tm_wday, 1);
   setboolfield(L, "isdst", stm->tm_isdst);
 }
 
@@ -231,11 +248,6 @@ static int getboolfield (lua_State *L, const char *key) {
 }
 
 
-/* maximum value for date fields (to avoid arithmetic overflows with 'int') */
-#if !defined(L_MAXDATEFIELD)
-#define L_MAXDATEFIELD	(INT_MAX / 2)
-#endif
-
 static int getfield (lua_State *L, const char *key, int d, int delta) {
   int isnum;
   int t = lua_getfield(L, -1, key);  /* get field and its type */
@@ -248,7 +260,9 @@ static int getfield (lua_State *L, const char *key, int d, int delta) {
     res = d;
   }
   else {
-    if (!(-L_MAXDATEFIELD <= res && res <= L_MAXDATEFIELD))
+    /* unsigned avoids overflow when lua_Integer has 32 bits */
+    if (!(res >= 0 ? (lua_Unsigned)res <= (lua_Unsigned)INT_MAX + delta
+                   : (lua_Integer)INT_MIN + delta <= res))
       return luaL_error(L, "field '%s' is out-of-bound", key);
     res -= delta;
   }
@@ -276,6 +290,13 @@ static const char *checkoption (lua_State *L, const char *conv,
 }
 
 
+static time_t l_checktime (lua_State *L, int arg) {
+  l_timet t = l_gettime(L, arg);
+  luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
+  return (time_t)t;
+}
+
+
 /* maximum size for an individual 'strftime' item */
 #define SIZETIMEFMT	250
 
@@ -294,7 +315,7 @@ static int os_date (lua_State *L) {
     stm = l_localtime(&t, &tmr);
   if (stm == NULL)  /* invalid date? */
     return luaL_error(L,
-                 "time result cannot be represented in this installation");
+                 "date result cannot be represented in this installation");
   if (strcmp(s, "*t") == 0) {
     lua_createtable(L, 0, 9);  /* 9 = number of fields */
     setallfields(L, stm);
@@ -330,12 +351,12 @@ static int os_time (lua_State *L) {
     struct tm ts;
     luaL_checktype(L, 1, LUA_TTABLE);
     lua_settop(L, 1);  /* make sure table is at the top */
-    ts.tm_sec = getfield(L, "sec", 0, 0);
-    ts.tm_min = getfield(L, "min", 0, 0);
-    ts.tm_hour = getfield(L, "hour", 12, 0);
-    ts.tm_mday = getfield(L, "day", -1, 0);
-    ts.tm_mon = getfield(L, "month", -1, 1);
     ts.tm_year = getfield(L, "year", -1, 1900);
+    ts.tm_mon = getfield(L, "month", -1, 1);
+    ts.tm_mday = getfield(L, "day", -1, 0);
+    ts.tm_hour = getfield(L, "hour", 12, 0);
+    ts.tm_min = getfield(L, "min", 0, 0);
+    ts.tm_sec = getfield(L, "sec", 0, 0);
     ts.tm_isdst = getboolfield(L, "isdst");
     t = mktime(&ts);
     setallfields(L, &ts);  /* update fields with normalized values */
diff --git a/libs/liblua/src/lparser.c b/libs/liblua/src/lparser.c
index cc54de43c6..bc7d9a4f2d 100644
--- a/libs/liblua/src/lparser.c
+++ b/libs/liblua/src/lparser.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.c,v 2.155.1.2 2017/04/29 18:11:40 roberto Exp $
+** $Id: lparser.c $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -10,6 +10,7 @@
 #include "lprefix.h"
 
 
+#include <limits.h>
 #include <string.h>
 
 #include "lua.h"
@@ -52,6 +53,7 @@ typedef struct BlockCnt {
   lu_byte nactvar;  /* # active locals outside the block */
   lu_byte upval;  /* true if some variable in the block is an upvalue */
   lu_byte isloop;  /* true if 'block' is a loop */
+  lu_byte insidetbc;  /* true if inside the scope of a to-be-closed var. */
 } BlockCnt;
 
 
@@ -63,13 +65,6 @@ static void statement (LexState *ls);
 static void expr (LexState *ls, expdesc *v);
 
 
-/* semantic error */
-static l_noret semerror (LexState *ls, const char *msg) {
-  ls->t.token = 0;  /* remove "near <token>" from final message */
-  luaX_syntaxerror(ls, msg);
-}
-
-
 static l_noret error_expected (LexState *ls, int token) {
   luaX_syntaxerror(ls,
       luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token)));
@@ -94,6 +89,9 @@ static void checklimit (FuncState *fs, int v, int l, const char *what) {
 }
 
 
+/*
+** Test whether next token is 'c'; if so, skip it.
+*/
 static int testnext (LexState *ls, int c) {
   if (ls->t.token == c) {
     luaX_next(ls);
@@ -103,12 +101,18 @@ static int testnext (LexState *ls, int c) {
 }
 
 
+/*
+** Check that next token is 'c'.
+*/
 static void check (LexState *ls, int c) {
   if (ls->t.token != c)
     error_expected(ls, c);
 }
 
 
+/*
+** Check that next token is 'c' and skip it.
+*/
 static void checknext (LexState *ls, int c) {
   check(ls, c);
   luaX_next(ls);
@@ -118,11 +122,15 @@ static void checknext (LexState *ls, int c) {
 #define check_condition(ls,c,msg)	{ if (!(c)) luaX_syntaxerror(ls, msg); }
 
 
-
+/*
+** Check that next token is 'what' and skip it. In case of error,
+** raise an error that the expected 'what' should match a 'who'
+** in line 'where' (if that is not the current line).
+*/
 static void check_match (LexState *ls, int what, int who, int where) {
-  if (!testnext(ls, what)) {
-    if (where == ls->linenumber)
-      error_expected(ls, what);
+  if (unlikely(!testnext(ls, what))) {
+    if (where == ls->linenumber)  /* all in the same line? */
+      error_expected(ls, what);  /* do not need a complex message */
     else {
       luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
              "%s expected (to close %s at line %d)",
@@ -148,73 +156,189 @@ static void init_exp (expdesc *e, expkind k, int i) {
 }
 
 
-static void codestring (LexState *ls, expdesc *e, TString *s) {
-  init_exp(e, VK, luaK_stringK(ls->fs, s));
+static void codestring (expdesc *e, TString *s) {
+  e->f = e->t = NO_JUMP;
+  e->k = VKSTR;
+  e->u.strval = s;
 }
 
 
-static void checkname (LexState *ls, expdesc *e) {
-  codestring(ls, e, str_checkname(ls));
+static void codename (LexState *ls, expdesc *e) {
+  codestring(e, str_checkname(ls));
 }
 
 
-static int registerlocalvar (LexState *ls, TString *varname) {
-  FuncState *fs = ls->fs;
+/*
+** Register a new local variable in the active 'Proto' (for debug
+** information).
+*/
+static int registerlocalvar (LexState *ls, FuncState *fs, TString *varname) {
   Proto *f = fs->f;
   int oldsize = f->sizelocvars;
-  luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
+  luaM_growvector(ls->L, f->locvars, fs->ndebugvars, f->sizelocvars,
                   LocVar, SHRT_MAX, "local variables");
   while (oldsize < f->sizelocvars)
     f->locvars[oldsize++].varname = NULL;
-  f->locvars[fs->nlocvars].varname = varname;
+  f->locvars[fs->ndebugvars].varname = varname;
+  f->locvars[fs->ndebugvars].startpc = fs->pc;
   luaC_objbarrier(ls->L, f, varname);
-  return fs->nlocvars++;
+  return fs->ndebugvars++;
 }
 
 
-static void new_localvar (LexState *ls, TString *name) {
+/*
+** Create a new local variable with the given 'name'. Return its index
+** in the function.
+*/
+static int new_localvar (LexState *ls, TString *name) {
+  lua_State *L = ls->L;
   FuncState *fs = ls->fs;
   Dyndata *dyd = ls->dyd;
-  int reg = registerlocalvar(ls, name);
+  Vardesc *var;
   checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal,
-                  MAXVARS, "local variables");
-  luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1,
-                  dyd->actvar.size, Vardesc, MAX_INT, "local variables");
-  dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg);
+                 MAXVARS, "local variables");
+  luaM_growvector(L, dyd->actvar.arr, dyd->actvar.n + 1,
+                  dyd->actvar.size, Vardesc, USHRT_MAX, "local variables");
+  var = &dyd->actvar.arr[dyd->actvar.n++];
+  var->vd.kind = VDKREG;  /* default */
+  var->vd.name = name;
+  return dyd->actvar.n - 1 - fs->firstlocal;
 }
 
+#define new_localvarliteral(ls,v) \
+    new_localvar(ls,  \
+      luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char)) - 1));
+
 
-static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) {
-  new_localvar(ls, luaX_newstring(ls, name, sz));
+
+/*
+** Return the "variable description" (Vardesc) of a given variable.
+** (Unless noted otherwise, all variables are referred to by their
+** compiler indices.)
+*/
+static Vardesc *getlocalvardesc (FuncState *fs, int vidx) {
+  return &fs->ls->dyd->actvar.arr[fs->firstlocal + vidx];
 }
 
-#define new_localvarliteral(ls,v) \
-	new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1)
+
+/*
+** Convert 'nvar', a compiler index level, to it corresponding
+** stack index level. For that, search for the highest variable
+** below that level that is in the stack and uses its stack
+** index ('sidx').
+*/
+static int stacklevel (FuncState *fs, int nvar) {
+  while (nvar-- > 0) {
+    Vardesc *vd = getlocalvardesc(fs, nvar);  /* get variable */
+    if (vd->vd.kind != RDKCTC)  /* is in the stack? */
+      return vd->vd.sidx + 1;
+  }
+  return 0;  /* no variables in the stack */
+}
+
+
+/*
+** Return the number of variables in the stack for function 'fs'
+*/
+int luaY_nvarstack (FuncState *fs) {
+  return stacklevel(fs, fs->nactvar);
+}
 
 
-static LocVar *getlocvar (FuncState *fs, int i) {
-  int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx;
-  lua_assert(idx < fs->nlocvars);
-  return &fs->f->locvars[idx];
+/*
+** Get the debug-information entry for current variable 'vidx'.
+*/
+static LocVar *localdebuginfo (FuncState *fs, int vidx) {
+  Vardesc *vd = getlocalvardesc(fs,  vidx);
+  if (vd->vd.kind == RDKCTC)
+    return NULL;  /* no debug info. for constants */
+  else {
+    int idx = vd->vd.pidx;
+    lua_assert(idx < fs->ndebugvars);
+    return &fs->f->locvars[idx];
+  }
 }
 
 
+/*
+** Create an expression representing variable 'vidx'
+*/
+static void init_var (FuncState *fs, expdesc *e, int vidx) {
+  e->f = e->t = NO_JUMP;
+  e->k = VLOCAL;
+  e->u.var.vidx = vidx;
+  e->u.var.sidx = getlocalvardesc(fs, vidx)->vd.sidx;
+}
+
+
+/*
+** Raises an error if variable described by 'e' is read only
+*/
+static void check_readonly (LexState *ls, expdesc *e) {
+  FuncState *fs = ls->fs;
+  TString *varname = NULL;  /* to be set if variable is const */
+  switch (e->k) {
+    case VCONST: {
+      varname = ls->dyd->actvar.arr[e->u.info].vd.name;
+      break;
+    }
+    case VLOCAL: {
+      Vardesc *vardesc = getlocalvardesc(fs, e->u.var.vidx);
+      if (vardesc->vd.kind != VDKREG)  /* not a regular variable? */
+        varname = vardesc->vd.name;
+      break;
+    }
+    case VUPVAL: {
+      Upvaldesc *up = &fs->f->upvalues[e->u.info];
+      if (up->kind != VDKREG)
+        varname = up->name;
+      break;
+    }
+    default:
+      return;  /* other cases cannot be read-only */
+  }
+  if (varname) {
+    const char *msg = luaO_pushfstring(ls->L,
+       "attempt to assign to const variable '%s'", getstr(varname));
+    luaK_semerror(ls, msg);  /* error */
+  }
+}
+
+
+/*
+** Start the scope for the last 'nvars' created variables.
+*/
 static void adjustlocalvars (LexState *ls, int nvars) {
   FuncState *fs = ls->fs;
-  fs->nactvar = cast_byte(fs->nactvar + nvars);
-  for (; nvars; nvars--) {
-    getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc;
+  int stklevel = luaY_nvarstack(fs);
+  int i;
+  for (i = 0; i < nvars; i++) {
+    int vidx = fs->nactvar++;
+    Vardesc *var = getlocalvardesc(fs, vidx);
+    var->vd.sidx = stklevel++;
+    var->vd.pidx = registerlocalvar(ls, fs, var->vd.name);
   }
 }
 
 
+/*
+** Close the scope for all variables up to level 'tolevel'.
+** (debug info.)
+*/
 static void removevars (FuncState *fs, int tolevel) {
   fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel);
-  while (fs->nactvar > tolevel)
-    getlocvar(fs, --fs->nactvar)->endpc = fs->pc;
+  while (fs->nactvar > tolevel) {
+    LocVar *var = localdebuginfo(fs, --fs->nactvar);
+    if (var)  /* does it have debug information? */
+      var->endpc = fs->pc;
+  }
 }
 
 
+/*
+** Search the upvalues of the function 'fs' for one
+** with the given 'name'.
+*/
 static int searchupvalue (FuncState *fs, TString *name) {
   int i;
   Upvaldesc *up = fs->f->upvalues;
@@ -225,7 +349,7 @@ static int searchupvalue (FuncState *fs, TString *name) {
 }
 
 
-static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
+static Upvaldesc *allocupvalue (FuncState *fs) {
   Proto *f = fs->f;
   int oldsize = f->sizeupvalues;
   checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues");
@@ -233,58 +357,87 @@ static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
                   Upvaldesc, MAXUPVAL, "upvalues");
   while (oldsize < f->sizeupvalues)
     f->upvalues[oldsize++].name = NULL;
-  f->upvalues[fs->nups].instack = (v->k == VLOCAL);
-  f->upvalues[fs->nups].idx = cast_byte(v->u.info);
-  f->upvalues[fs->nups].name = name;
-  luaC_objbarrier(fs->ls->L, f, name);
-  return fs->nups++;
+  return &f->upvalues[fs->nups++];
 }
 
 
-static int searchvar (FuncState *fs, TString *n) {
+static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
+  Upvaldesc *up = allocupvalue(fs);
+  FuncState *prev = fs->prev;
+  if (v->k == VLOCAL) {
+    up->instack = 1;
+    up->idx = v->u.var.sidx;
+    up->kind = getlocalvardesc(prev, v->u.var.vidx)->vd.kind;
+    lua_assert(eqstr(name, getlocalvardesc(prev, v->u.var.vidx)->vd.name));
+  }
+  else {
+    up->instack = 0;
+    up->idx = cast_byte(v->u.info);
+    up->kind = prev->f->upvalues[v->u.info].kind;
+    lua_assert(eqstr(name, prev->f->upvalues[v->u.info].name));
+  }
+  up->name = name;
+  luaC_objbarrier(fs->ls->L, fs->f, name);
+  return fs->nups - 1;
+}
+
+
+/*
+** Look for an active local variable with the name 'n' in the
+** function 'fs'. If found, initialize 'var' with it and return
+** its expression kind; otherwise return -1.
+*/
+static int searchvar (FuncState *fs, TString *n, expdesc *var) {
   int i;
   for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) {
-    if (eqstr(n, getlocvar(fs, i)->varname))
-      return i;
+    Vardesc *vd = getlocalvardesc(fs, i);
+    if (eqstr(n, vd->vd.name)) {  /* found? */
+      if (vd->vd.kind == RDKCTC)  /* compile-time constant? */
+        init_exp(var, VCONST, fs->firstlocal + i);
+      else  /* real variable */
+        init_var(fs, var, i);
+      return var->k;
+    }
   }
   return -1;  /* not found */
 }
 
 
 /*
-  Mark block where variable at given level was defined
-  (to emit close instructions later).
+** Mark block where variable at given level was defined
+** (to emit close instructions later).
 */
 static void markupval (FuncState *fs, int level) {
   BlockCnt *bl = fs->bl;
   while (bl->nactvar > level)
     bl = bl->previous;
   bl->upval = 1;
+  fs->needclose = 1;
 }
 
 
 /*
-  Find variable with given name 'n'. If it is an upvalue, add this
-  upvalue into all intermediate functions.
+** Find a variable with the given name 'n'. If it is an upvalue, add
+** this upvalue into all intermediate functions. If it is a global, set
+** 'var' as 'void' as a flag.
 */
 static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
   if (fs == NULL)  /* no more levels? */
     init_exp(var, VVOID, 0);  /* default is global */
   else {
-    int v = searchvar(fs, n);  /* look up locals at current level */
+    int v = searchvar(fs, n, var);  /* look up locals at current level */
     if (v >= 0) {  /* found? */
-      init_exp(var, VLOCAL, v);  /* variable is local */
-      if (!base)
-        markupval(fs, v);  /* local will be used as an upval */
+      if (v == VLOCAL && !base)
+        markupval(fs, var->u.var.vidx);  /* local will be used as an upval */
     }
     else {  /* not found as local at current level; try upvalues */
       int idx = searchupvalue(fs, n);  /* try existing upvalues */
       if (idx < 0) {  /* not found? */
         singlevaraux(fs->prev, n, var, 0);  /* try upper levels */
-        if (var->k == VVOID)  /* not found? */
-          return;  /* it is a global */
-        /* else was LOCAL or UPVAL */
-        idx  = newupvalue(fs, n, var);  /* will be a new upvalue */
+        if (var->k == VLOCAL || var->k == VUPVAL)  /* local or upvalue? */
+          idx  = newupvalue(fs, n, var);  /* will be a new upvalue */
+        else  /* it is a global or a constant */
+          return;  /* don't need to do anything at this level */
       }
       init_exp(var, VUPVAL, idx);  /* new or old upvalue */
     }
@@ -292,6 +445,10 @@ static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
 }
 
 
+/*
+** Find a variable with the given name 'n', handling global variables
+** too.
+*/
 static void singlevar (LexState *ls, expdesc *var) {
   TString *varname = str_checkname(ls);
   FuncState *fs = ls->fs;
@@ -300,88 +457,96 @@ static void singlevar (LexState *ls, expdesc *var) {
     expdesc key;
     singlevaraux(fs, ls->envn, var, 1);  /* get environment variable */
     lua_assert(var->k != VVOID);  /* this one must exist */
-    codestring(ls, &key, varname);  /* key is variable name */
+    codestring(&key, varname);  /* key is variable name */
     luaK_indexed(fs, var, &key);  /* env[varname] */
   }
 }
 
 
+/*
+** Adjust the number of results from an expression list 'e' with 'nexps'
+** expressions to 'nvars' values.
+*/
 static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
   FuncState *fs = ls->fs;
-  int extra = nvars - nexps;
-  if (hasmultret(e->k)) {
-    extra++;  /* includes call itself */
-    if (extra < 0) extra = 0;
+  int needed = nvars - nexps;  /* extra values needed */
+  if (hasmultret(e->k)) {  /* last expression has multiple returns? */
+    int extra = needed + 1;  /* discount last expression itself */
+    if (extra < 0)
+      extra = 0;
     luaK_setreturns(fs, e, extra);  /* last exp. provides the difference */
-    if (extra > 1) luaK_reserveregs(fs, extra-1);
   }
   else {
-    if (e->k != VVOID) luaK_exp2nextreg(fs, e);  /* close last expression */
-    if (extra > 0) {
-      int reg = fs->freereg;
-      luaK_reserveregs(fs, extra);
-      luaK_nil(fs, reg, extra);
-    }
+    if (e->k != VVOID)  /* at least one expression? */
+      luaK_exp2nextreg(fs, e);  /* close last expression */
+    if (needed > 0)  /* missing values? */
+      luaK_nil(fs, fs->freereg, needed);  /* complete with nils */
   }
-  if (nexps > nvars)
-    ls->fs->freereg -= nexps - nvars;  /* remove extra values */
+  if (needed > 0)
+    luaK_reserveregs(fs, needed);  /* registers for extra values */
+  else  /* adding 'needed' is actually a subtraction */
+    fs->freereg += needed;  /* remove extra values */
 }
 
 
-static void enterlevel (LexState *ls) {
-  lua_State *L = ls->L;
-  ++L->nCcalls;
-  checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels");
-}
+/*
+** Macros to limit the maximum recursion depth while parsing
+*/
+#define enterlevel(ls)	luaE_enterCcall((ls)->L)
+
+#define leavelevel(ls)	luaE_exitCcall((ls)->L)
 
 
-#define leavelevel(ls)	((ls)->L->nCcalls--)
+/*
+** Generates an error that a goto jumps into the scope of some
+** local variable.
+*/
+static l_noret jumpscopeerror (LexState *ls, Labeldesc *gt) {
+  const char *varname = getstr(getlocalvardesc(ls->fs, gt->nactvar)->vd.name);
+  const char *msg = "<goto %s> at line %d jumps into the scope of local '%s'";
+  msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line, varname);
+  luaK_semerror(ls, msg);  /* raise the error */
+}
 
 
-static void closegoto (LexState *ls, int g, Labeldesc *label) {
+/*
+** Solves the goto at index 'g' to given 'label' and removes it
+** from the list of pending goto's.
+** If it jumps into the scope of some variable, raises an error.
+*/
+static void solvegoto (LexState *ls, int g, Labeldesc *label) {
   int i;
-  FuncState *fs = ls->fs;
-  Labellist *gl = &ls->dyd->gt;
-  Labeldesc *gt = &gl->arr[g];
+  Labellist *gl = &ls->dyd->gt;  /* list of goto's */
+  Labeldesc *gt = &gl->arr[g];  /* goto to be resolved */
   lua_assert(eqstr(gt->name, label->name));
-  if (gt->nactvar < label->nactvar) {
-    TString *vname = getlocvar(fs, gt->nactvar)->varname;
-    const char *msg = luaO_pushfstring(ls->L,
-      "<goto %s> at line %d jumps into the scope of local '%s'",
-      getstr(gt->name), gt->line, getstr(vname));
-    semerror(ls, msg);
-  }
-  luaK_patchlist(fs, gt->pc, label->pc);
-  /* remove goto from pending list */
-  for (i = g; i < gl->n - 1; i++)
+  if (unlikely(gt->nactvar < label->nactvar))  /* enter some scope? */
+    jumpscopeerror(ls, gt);
+  luaK_patchlist(ls->fs, gt->pc, label->pc);
+  for (i = g; i < gl->n - 1; i++)  /* remove goto from pending list */
     gl->arr[i] = gl->arr[i + 1];
   gl->n--;
 }
 
 
 /*
-** try to close a goto with existing labels; this solves backward jumps
+** Search for an active label with the given name.
 */
-static int findlabel (LexState *ls, int g) {
+static Labeldesc *findlabel (LexState *ls, TString *name) {
   int i;
-  BlockCnt *bl = ls->fs->bl;
   Dyndata *dyd = ls->dyd;
-  Labeldesc *gt = &dyd->gt.arr[g];
-  /* check labels in current block for a match */
-  for (i = bl->firstlabel; i < dyd->label.n; i++) {
+  /* check labels in current function for a match */
+  for (i = ls->fs->firstlabel; i < dyd->label.n; i++) {
     Labeldesc *lb = &dyd->label.arr[i];
-    if (eqstr(lb->name, gt->name)) {  /* correct label? */
-      if (gt->nactvar > lb->nactvar &&
-          (bl->upval || dyd->label.n > bl->firstlabel))
-        luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
-      closegoto(ls, g, lb);  /* close it */
-      return 1;
-    }
+    if (eqstr(lb->name, name))  /* correct label? */
+      return lb;
   }
-  return 0;  /* label not found; cannot close goto */
+  return NULL;  /* label not found */
 }
 
 
+/*
+** Adds a new label/goto in the corresponding list.
+*/
 static int newlabelentry (LexState *ls, Labellist *l, TString *name,
                           int line, int pc) {
   int n = l->n;
@@ -390,48 +555,76 @@ static int newlabelentry (LexState *ls, Labellist *l, TString *name,
   l->arr[n].name = name;
   l->arr[n].line = line;
   l->arr[n].nactvar = ls->fs->nactvar;
+  l->arr[n].close = 0;
   l->arr[n].pc = pc;
   l->n = n + 1;
   return n;
 }
 
 
+static int newgotoentry (LexState *ls, TString *name, int line, int pc) {
+  return newlabelentry(ls, &ls->dyd->gt, name, line, pc);
+}
+
+
 /*
-** check whether new label 'lb' matches any pending gotos in current
-** block; solves forward jumps
+** Solves forward jumps. Check whether new label 'lb' matches any
+** pending gotos in current block and solves them. Return true
+** if any of the goto's need to close upvalues.
 */
-static void findgotos (LexState *ls, Labeldesc *lb) {
+static int solvegotos (LexState *ls, Labeldesc *lb) {
   Labellist *gl = &ls->dyd->gt;
   int i = ls->fs->bl->firstgoto;
+  int needsclose = 0;
   while (i < gl->n) {
-    if (eqstr(gl->arr[i].name, lb->name))
-      closegoto(ls, i, lb);
+    if (eqstr(gl->arr[i].name, lb->name)) {
+      needsclose |= gl->arr[i].close;
+      solvegoto(ls, i, lb);  /* will remove 'i' from the list */
+    }
     else
       i++;
   }
+  return needsclose;
 }
 
 
 /*
-** export pending gotos to outer level, to check them against
-** outer labels; if the block being exited has upvalues, and
-** the goto exits the scope of any variable (which can be the
-** upvalue), close those variables being exited.
+** Create a new label with the given 'name' at the given 'line'.
+** 'last' tells whether label is the last non-op statement in its
+** block. Solves all pending goto's to this new label and adds
+** a close instruction if necessary.
+** Returns true iff it added a close instruction.
+*/
+static int createlabel (LexState *ls, TString *name, int line,
+                        int last) {
+  FuncState *fs = ls->fs;
+  Labellist *ll = &ls->dyd->label;
+  int l = newlabelentry(ls, ll, name, line, luaK_getlabel(fs));
+  if (last) {  /* label is last no-op statement in the block? */
+    /* assume that locals are already out of scope */
+    ll->arr[l].nactvar = fs->bl->nactvar;
+  }
+  if (solvegotos(ls, &ll->arr[l])) {  /* need close? */
+    luaK_codeABC(fs, OP_CLOSE, luaY_nvarstack(fs), 0, 0);
+    return 1;
+  }
+  return 0;
+}
+
+
+/*
+** Adjust pending gotos to outer level of a block.
 */
 static void movegotosout (FuncState *fs, BlockCnt *bl) {
-  int i = bl->firstgoto;
+  int i;
   Labellist *gl = &fs->ls->dyd->gt;
-  /* correct pending gotos to current block and try to close it
-     with visible labels */
-  while (i < gl->n) {
+  /* correct pending gotos to current block */
+  for (i = bl->firstgoto; i < gl->n; i++) {  /* for each pending goto */
     Labeldesc *gt = &gl->arr[i];
-    if (gt->nactvar > bl->nactvar) {
-      if (bl->upval)
-        luaK_patchclose(fs, gt->pc, bl->nactvar);
-      gt->nactvar = bl->nactvar;
-    }
-    if (!findlabel(fs->ls, i))
-      i++;  /* move to next one */
+    /* leaving a variable scope? */
+    if (stacklevel(fs, gt->nactvar) > stacklevel(fs, bl->nactvar))
+      gt->close |= bl->upval;  /* jump may need a close */
+    gt->nactvar = bl->nactvar;  /* update goto level */
   }
 }
 
@@ -442,54 +635,50 @@ static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) {
   bl->firstlabel = fs->ls->dyd->label.n;
   bl->firstgoto = fs->ls->dyd->gt.n;
   bl->upval = 0;
+  bl->insidetbc = (fs->bl != NULL && fs->bl->insidetbc);
   bl->previous = fs->bl;
   fs->bl = bl;
-  lua_assert(fs->freereg == fs->nactvar);
+  lua_assert(fs->freereg == luaY_nvarstack(fs));
 }
 
 
 /*
-** create a label named 'break' to resolve break statements
-*/
-static void breaklabel (LexState *ls) {
-  TString *n = luaS_new(ls->L, "break");
-  int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc);
-  findgotos(ls, &ls->dyd->label.arr[l]);
-}
-
-/*
-** generates an error for an undefined 'goto'; choose appropriate
-** message when label name is a reserved word (which can only be 'break')
+** generates an error for an undefined 'goto'.
 */
 static l_noret undefgoto (LexState *ls, Labeldesc *gt) {
-  const char *msg = isreserved(gt->name)
-                    ? "<%s> at line %d not inside a loop"
-                    : "no visible label '%s' for <goto> at line %d";
-  msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
-  semerror(ls, msg);
+  const char *msg;
+  if (eqstr(gt->name, luaS_newliteral(ls->L, "break"))) {
+    msg = "break outside loop at line %d";
+    msg = luaO_pushfstring(ls->L, msg, gt->line);
+  }
+  else {
+    msg = "no visible label '%s' for <goto> at line %d";
+    msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
+  }
+  luaK_semerror(ls, msg);
 }
 
 
 static void leaveblock (FuncState *fs) {
   BlockCnt *bl = fs->bl;
   LexState *ls = fs->ls;
-  if (bl->previous && bl->upval) {
-    /* create a 'jump to here' to close upvalues */
-    int j = luaK_jump(fs);
-    luaK_patchclose(fs, j, bl->nactvar);
-    luaK_patchtohere(fs, j);
-  }
-  if (bl->isloop)
-    breaklabel(ls);  /* close pending breaks */
+  int hasclose = 0;
+  int stklevel = stacklevel(fs, bl->nactvar);  /* level outside the block */
+  if (bl->isloop)  /* fix pending breaks? */
+    hasclose = createlabel(ls, luaS_newliteral(ls->L, "break"), 0, 0);
+  if (!hasclose && bl->previous && bl->upval)
+    luaK_codeABC(fs, OP_CLOSE, stklevel, 0, 0);
   fs->bl = bl->previous;
   removevars(fs, bl->nactvar);
   lua_assert(bl->nactvar == fs->nactvar);
-  fs->freereg = fs->nactvar;  /* free registers */
+  fs->freereg = stklevel;  /* free registers */
   ls->dyd->label.n = bl->firstlabel;  /* remove local labels */
   if (bl->previous)  /* inner block? */
     movegotosout(fs, bl);  /* update pending gotos to outer block */
-  else if (bl->firstgoto < ls->dyd->gt.n)  /* pending gotos in outer block? */
-    undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]);  /* error */
+  else {
+    if (bl->firstgoto < ls->dyd->gt.n)  /* pending gotos in outer block? */
+      undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]);  /* error */
+  }
 }
 
 
@@ -515,35 +704,40 @@ static Proto *addprototype (LexState *ls) {
 
 /*
 ** codes instruction to create new closure in parent function.
-** The OP_CLOSURE instruction must use the last available register,
+** The OP_CLOSURE instruction uses the last available register,
 ** so that, if it invokes the GC, the GC knows which registers
 ** are in use at that time.
+
 */
 static void codeclosure (LexState *ls, expdesc *v) {
   FuncState *fs = ls->fs->prev;
-  init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
+  init_exp(v, VRELOC, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
   luaK_exp2nextreg(fs, v);  /* fix it at the last register */
 }
 
 
 static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
-  Proto *f;
+  Proto *f = fs->f;
   fs->prev = ls->fs;  /* linked list of funcstates */
   fs->ls = ls;
   ls->fs = fs;
   fs->pc = 0;
+  fs->previousline = f->linedefined;
+  fs->iwthabs = 0;
   fs->lasttarget = 0;
-  fs->jpc = NO_JUMP;
   fs->freereg = 0;
   fs->nk = 0;
+  fs->nabslineinfo = 0;
   fs->np = 0;
   fs->nups = 0;
-  fs->nlocvars = 0;
+  fs->ndebugvars = 0;
   fs->nactvar = 0;
+  fs->needclose = 0;
   fs->firstlocal = ls->dyd->actvar.n;
+  fs->firstlabel = ls->dyd->label.n;
   fs->bl = NULL;
-  f = fs->f;
   f->source = ls->source;
+  luaC_objbarrier(ls->L, f, f->source);
   f->maxstacksize = 2;  /* registers 0/1 are always valid */
   enterblock(fs, bl, 0);
 }
@@ -553,21 +747,18 @@ static void close_func (LexState *ls) {
   lua_State *L = ls->L;
   FuncState *fs = ls->fs;
   Proto *f = fs->f;
-  luaK_ret(fs, 0, 0);  /* final return */
+  luaK_ret(fs, luaY_nvarstack(fs), 0);  /* final return */
   leaveblock(fs);
-  luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
-  f->sizecode = fs->pc;
-  luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
-  f->sizelineinfo = fs->pc;
-  luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue);
-  f->sizek = fs->nk;
-  luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
-  f->sizep = fs->np;
-  luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
-  f->sizelocvars = fs->nlocvars;
-  luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc);
-  f->sizeupvalues = fs->nups;
   lua_assert(fs->bl == NULL);
+  luaK_finish(fs);
+  luaM_shrinkvector(L, f->code, f->sizecode, fs->pc, Instruction);
+  luaM_shrinkvector(L, f->lineinfo, f->sizelineinfo, fs->pc, ls_byte);
+  luaM_shrinkvector(L, f->abslineinfo, f->sizeabslineinfo,
+                       fs->nabslineinfo, AbsLineInfo);
+  luaM_shrinkvector(L, f->k, f->sizek, fs->nk, TValue);
+  luaM_shrinkvector(L, f->p, f->sizep, fs->np, Proto *);
+  luaM_shrinkvector(L, f->locvars, f->sizelocvars, fs->ndebugvars, LocVar);
+  luaM_shrinkvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc);
   ls->fs = fs->prev;
   luaC_checkGC(L);
 }
@@ -613,7 +804,7 @@ static void fieldsel (LexState *ls, expdesc *v) {
   expdesc key;
   luaK_exp2anyregup(fs, v);
   luaX_next(ls);  /* skip the dot or colon */
-  checkname(ls, &key);
+  codename(ls, &key);
   luaK_indexed(fs, v, &key);
 }
 
@@ -634,48 +825,49 @@ static void yindex (LexState *ls, expdesc *v) {
 */
 
 
-struct ConsControl {
+typedef struct ConsControl {
   expdesc v;  /* last list item read */
   expdesc *t;  /* table descriptor */
   int nh;  /* total number of 'record' elements */
-  int na;  /* total number of array elements */
+  int na;  /* number of array elements already stored */
   int tostore;  /* number of array elements pending to be stored */
-};
+} ConsControl;
 
 
-static void recfield (LexState *ls, struct ConsControl *cc) {
-  /* recfield -> (NAME | '['exp1']') = exp1 */
+static void recfield (LexState *ls, ConsControl *cc) {
+  /* recfield -> (NAME | '['exp']') = exp */
   FuncState *fs = ls->fs;
   int reg = ls->fs->freereg;
-  expdesc key, val;
-  int rkkey;
+  expdesc tab, key, val;
   if (ls->t.token == TK_NAME) {
     checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
-    checkname(ls, &key);
+    codename(ls, &key);
   }
   else  /* ls->t.token == '[' */
     yindex(ls, &key);
   cc->nh++;
   checknext(ls, '=');
-  rkkey = luaK_exp2RK(fs, &key);
+  tab = *cc->t;
+  luaK_indexed(fs, &tab, &key);
   expr(ls, &val);
-  luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val));
+  luaK_storevar(fs, &tab, &val);
   fs->freereg = reg;  /* free registers */
 }
 
 
-static void closelistfield (FuncState *fs, struct ConsControl *cc) {
+static void closelistfield (FuncState *fs, ConsControl *cc) {
   if (cc->v.k == VVOID) return;  /* there is no list item */
   luaK_exp2nextreg(fs, &cc->v);
   cc->v.k = VVOID;
   if (cc->tostore == LFIELDS_PER_FLUSH) {
     luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);  /* flush */
+    cc->na += cc->tostore;
     cc->tostore = 0;  /* no more items pending */
   }
 }
 
 
-static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
+static void lastlistfield (FuncState *fs, ConsControl *cc) {
   if (cc->tostore == 0) return;
   if (hasmultret(cc->v.k)) {
     luaK_setmultret(fs, &cc->v);
@@ -687,19 +879,18 @@ static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
       luaK_exp2nextreg(fs, &cc->v);
     luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);
   }
+  cc->na += cc->tostore;
 }
 
 
-static void listfield (LexState *ls, struct ConsControl *cc) {
+static void listfield (LexState *ls, ConsControl *cc) {
   /* listfield -> exp */
   expr(ls, &cc->v);
-  checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
-  cc->na++;
   cc->tostore++;
 }
 
 
-static void field (LexState *ls, struct ConsControl *cc) {
+static void field (LexState *ls, ConsControl *cc) {
   /* field -> listfield | recfield */
   switch(ls->t.token) {
     case TK_NAME: {  /* may be 'listfield' or 'recfield' */
@@ -727,12 +918,13 @@ static void constructor (LexState *ls, expdesc *t) {
   FuncState *fs = ls->fs;
   int line = ls->linenumber;
   int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
-  struct ConsControl cc;
+  ConsControl cc;
+  luaK_code(fs, 0);  /* space for extra arg. */
   cc.na = cc.nh = cc.tostore = 0;
   cc.t = t;
-  init_exp(t, VRELOCABLE, pc);
+  init_exp(t, VNONRELOC, fs->freereg);  /* table will be at stack top */
+  luaK_reserveregs(fs, 1);
   init_exp(&cc.v, VVOID, 0);  /* no value (yet) */
-  luaK_exp2nextreg(ls->fs, t);  /* fix it at stack top */
   checknext(ls, '{');
   do {
     lua_assert(cc.v.k == VVOID || cc.tostore > 0);
@@ -742,20 +934,24 @@ static void constructor (LexState *ls, expdesc *t) {
   } while (testnext(ls, ',') || testnext(ls, ';'));
   check_match(ls, '}', '{', line);
   lastlistfield(fs, &cc);
-  SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
-  SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh));  /* set initial table size */
+  luaK_settablesize(fs, pc, t->u.info, cc.na, cc.nh);
 }
 
 /* }====================================================================== */
 
 
+static void setvararg (FuncState *fs, int nparams) {
+  fs->f->is_vararg = 1;
+  luaK_codeABC(fs, OP_VARARGPREP, nparams, 0, 0);
+}
+
 
 static void parlist (LexState *ls) {
   /* parlist -> [ param { ',' param } ] */
   FuncState *fs = ls->fs;
   Proto *f = fs->f;
   int nparams = 0;
-  f->is_vararg = 0;
+  int isvararg = 0;
   if (ls->t.token != ')') {  /* is 'parlist' not empty? */
     do {
       switch (ls->t.token) {
@@ -766,16 +962,18 @@ static void parlist (LexState *ls) {
         }
         case TK_DOTS: {  /* param -> '...' */
           luaX_next(ls);
-          f->is_vararg = 1;  /* declared vararg */
+          isvararg = 1;
           break;
         }
         default: luaX_syntaxerror(ls, "<name> or '...' expected");
       }
-    } while (!f->is_vararg && testnext(ls, ','));
+    } while (!isvararg && testnext(ls, ','));
   }
   adjustlocalvars(ls, nparams);
   f->numparams = cast_byte(fs->nactvar);
-  luaK_reserveregs(fs, fs->nactvar);  /* reserve register for parameters */
+  if (isvararg)
+    setvararg(fs, f->numparams);  /* declared vararg */
+  luaK_reserveregs(fs, fs->nactvar);  /* reserve registers for parameters */
 }
 
 
@@ -825,7 +1023,8 @@ static void funcargs (LexState *ls, expdesc *f, int line) {
         args.k = VVOID;
       else {
         explist(ls, &args);
-        luaK_setmultret(fs, &args);
+        if (hasmultret(args.k))
+          luaK_setmultret(fs, &args);
       }
       check_match(ls, ')', '(', line);
       break;
@@ -835,7 +1034,7 @@ static void funcargs (LexState *ls, expdesc *f, int line) {
       break;
     }
     case TK_STRING: {  /* funcargs -> STRING */
-      codestring(ls, &args, ls->t.seminfo.ts);
+      codestring(&args, ls->t.seminfo.ts);
       luaX_next(ls);  /* must use 'seminfo' before 'next' */
       break;
     }
@@ -902,7 +1101,7 @@ static void suffixedexp (LexState *ls, expdesc *v) {
         fieldsel(ls, v);
         break;
       }
-      case '[': {  /* '[' exp1 ']' */
+      case '[': {  /* '[' exp ']' */
         expdesc key;
         luaK_exp2anyregup(fs, v);
         yindex(ls, &key);
@@ -912,7 +1111,7 @@ static void suffixedexp (LexState *ls, expdesc *v) {
       case ':': {  /* ':' NAME funcargs */
         expdesc key;
         luaX_next(ls);
-        checkname(ls, &key);
+        codename(ls, &key);
         luaK_self(fs, v, &key);
         funcargs(ls, v, line);
         break;
@@ -943,7 +1142,7 @@ static void simpleexp (LexState *ls, expdesc *v) {
       break;
     }
     case TK_STRING: {
-      codestring(ls, v, ls->t.seminfo.ts);
+      codestring(v, ls->t.seminfo.ts);
       break;
     }
     case TK_NIL: {
@@ -962,7 +1161,7 @@ static void simpleexp (LexState *ls, expdesc *v) {
       FuncState *fs = ls->fs;
       check_condition(ls, fs->f->is_vararg,
                       "cannot use '...' outside a vararg function");
-      init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
+      init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 0, 1));
       break;
     }
     case '{': {  /* constructor */
@@ -1022,6 +1221,9 @@ static BinOpr getbinopr (int op) {
 }
 
 
+/*
+** Priority table for binary operators.
+*/
 static const struct {
   lu_byte left;  /* left priority for each binary operator */
   lu_byte right; /* right priority */
@@ -1050,9 +1252,9 @@ static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
   UnOpr uop;
   enterlevel(ls);
   uop = getunopr(ls->t.token);
-  if (uop != OPR_NOUNOPR) {
+  if (uop != OPR_NOUNOPR) {  /* prefix (unary) operator? */
     int line = ls->linenumber;
-    luaX_next(ls);
+    luaX_next(ls);  /* skip operator */
     subexpr(ls, v, UNARY_PRIORITY);
     luaK_prefix(ls->fs, uop, v, line);
   }
@@ -1063,7 +1265,7 @@ static BinOpr subexpr (LexState *ls, expdesc *v, int limit) {
     expdesc v2;
     BinOpr nextop;
     int line = ls->linenumber;
-    luaX_next(ls);
+    luaX_next(ls);  /* skip operator */
     luaK_infix(ls->fs, op, v);
     /* read sub-expression with higher priority */
     nextop = subexpr(ls, &v2, priority[op].right);
@@ -1121,43 +1323,60 @@ static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
   int extra = fs->freereg;  /* eventual position to save local variable */
   int conflict = 0;
   for (; lh; lh = lh->prev) {  /* check all previous assignments */
-    if (lh->v.k == VINDEXED) {  /* assigning to a table? */
-      /* table is the upvalue/local being assigned now? */
-      if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) {
-        conflict = 1;
-        lh->v.u.ind.vt = VLOCAL;
-        lh->v.u.ind.t = extra;  /* previous assignment will use safe copy */
+    if (vkisindexed(lh->v.k)) {  /* assignment to table field? */
+      if (lh->v.k == VINDEXUP) {  /* is table an upvalue? */
+        if (v->k == VUPVAL && lh->v.u.ind.t == v->u.info) {
+          conflict = 1;  /* table is the upvalue being assigned now */
+          lh->v.k = VINDEXSTR;
+          lh->v.u.ind.t = extra;  /* assignment will use safe copy */
+        }
       }
-      /* index is the local being assigned? (index cannot be upvalue) */
-      if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) {
-        conflict = 1;
-        lh->v.u.ind.idx = extra;  /* previous assignment will use safe copy */
+      else {  /* table is a register */
+        if (v->k == VLOCAL && lh->v.u.ind.t == v->u.var.sidx) {
+          conflict = 1;  /* table is the local being assigned now */
+          lh->v.u.ind.t = extra;  /* assignment will use safe copy */
+        }
+        /* is index the local being assigned? */
+        if (lh->v.k == VINDEXED && v->k == VLOCAL &&
+            lh->v.u.ind.idx == v->u.var.sidx) {
+          conflict = 1;
+          lh->v.u.ind.idx = extra;  /* previous assignment will use safe copy */
+        }
       }
     }
   }
   if (conflict) {
     /* copy upvalue/local value to a temporary (in position 'extra') */
-    OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
-    luaK_codeABC(fs, op, extra, v->u.info, 0);
+    if (v->k == VLOCAL)
+      luaK_codeABC(fs, OP_MOVE, extra, v->u.var.sidx, 0);
+    else
+      luaK_codeABC(fs, OP_GETUPVAL, extra, v->u.info, 0);
     luaK_reserveregs(fs, 1);
   }
 }
 
-
-static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
+/*
+** Parse and compile a multiple assignment. The first "variable"
+** (a 'suffixedexp') was already read by the caller.
+**
+** assignment -> suffixedexp restassign
+** restassign -> ',' suffixedexp restassign | '=' explist
+*/
+static void restassign (LexState *ls, struct LHS_assign *lh, int nvars) {
   expdesc e;
   check_condition(ls, vkisvar(lh->v.k), "syntax error");
-  if (testnext(ls, ',')) {  /* assignment -> ',' suffixedexp assignment */
+  check_readonly(ls, &lh->v);
+  if (testnext(ls, ',')) {  /* restassign -> ',' suffixedexp restassign */
     struct LHS_assign nv;
     nv.prev = lh;
     suffixedexp(ls, &nv.v);
-    if (nv.v.k != VINDEXED)
+    if (!vkisindexed(nv.v.k))
       check_conflict(ls, lh, &nv.v);
-    checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS,
-                    "C levels");
-    assignment(ls, &nv, nvars+1);
+    enterlevel(ls);  /* control recursion depth */
+    restassign(ls, &nv, nvars+1);
+    leavelevel(ls);
   }
-  else {  /* assignment -> '=' explist */
+  else {  /* restassign -> '=' explist */
     int nexps;
     checknext(ls, '=');
     nexps = explist(ls, &e);
@@ -1184,57 +1403,55 @@ static int cond (LexState *ls) {
 }
 
 
-static void gotostat (LexState *ls, int pc) {
+static void gotostat (LexState *ls) {
+  FuncState *fs = ls->fs;
   int line = ls->linenumber;
-  TString *label;
-  int g;
-  if (testnext(ls, TK_GOTO))
-    label = str_checkname(ls);
-  else {
-    luaX_next(ls);  /* skip break */
-    label = luaS_new(ls->L, "break");
+  TString *name = str_checkname(ls);  /* label's name */
+  Labeldesc *lb = findlabel(ls, name);
+  if (lb == NULL)  /* no label? */
+    /* forward jump; will be resolved when the label is declared */
+    newgotoentry(ls, name, line, luaK_jump(fs));
+  else {  /* found a label */
+    /* backward jump; will be resolved here */
+    int lblevel = stacklevel(fs, lb->nactvar);  /* label level */
+    if (luaY_nvarstack(fs) > lblevel)  /* leaving the scope of a variable? */
+      luaK_codeABC(fs, OP_CLOSE, lblevel, 0, 0);
+    /* create jump and link it to the label */
+    luaK_patchlist(fs, luaK_jump(fs), lb->pc);
   }
-  g = newlabelentry(ls, &ls->dyd->gt, label, line, pc);
-  findlabel(ls, g);  /* close it if label already defined */
 }
 
 
-/* check for repeated labels on the same block */
-static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) {
-  int i;
-  for (i = fs->bl->firstlabel; i < ll->n; i++) {
-    if (eqstr(label, ll->arr[i].name)) {
-      const char *msg = luaO_pushfstring(fs->ls->L,
-                          "label '%s' already defined on line %d",
-                          getstr(label), ll->arr[i].line);
-      semerror(fs->ls, msg);
-    }
-  }
+/*
+** Break statement. Semantically equivalent to "goto break".
+*/
+static void breakstat (LexState *ls) {
+  int line = ls->linenumber;
+  luaX_next(ls);  /* skip break */
+  newgotoentry(ls, luaS_newliteral(ls->L, "break"), line, luaK_jump(ls->fs));
 }
 
 
-/* skip no-op statements */
-static void skipnoopstat (LexState *ls) {
-  while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
-    statement(ls);
+/*
+** Check whether there is already a label with the given 'name'.
+*/
+static void checkrepeated (LexState *ls, TString *name) {
+  Labeldesc *lb = findlabel(ls, name);
+  if (unlikely(lb != NULL)) {  /* already defined? */
+    const char *msg = "label '%s' already defined on line %d";
+    msg = luaO_pushfstring(ls->L, msg, getstr(name), lb->line);
+    luaK_semerror(ls, msg);  /* error */
+  }
 }
 
 
-static void labelstat (LexState *ls, TString *label, int line) {
+static void labelstat (LexState *ls, TString *name, int line) {
   /* label -> '::' NAME '::' */
-  FuncState *fs = ls->fs;
-  Labellist *ll = &ls->dyd->label;
-  int l;  /* index of new label being created */
-  checkrepeated(fs, ll, label);  /* check for repeated labels */
   checknext(ls, TK_DBCOLON);  /* skip double colon */
-  /* create new entry for this label */
-  l = newlabelentry(ls, ll, label, line, luaK_getlabel(fs));
-  skipnoopstat(ls);  /* skip other no-op statements */
-  if (block_follow(ls, 0)) {  /* label is last no-op statement in the block? */
-    /* assume that locals are already out of scope */
-    ll->arr[l].nactvar = fs->bl->nactvar;
-  }
-  findgotos(ls, &ll->arr[l]);
+  while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
+    statement(ls);  /* skip other no-op statements */
+  checkrepeated(ls, name);  /* check for repeated labels */
+  createlabel(ls, name, line, block_follow(ls, 0));
 }
 
 
@@ -1269,58 +1486,83 @@ static void repeatstat (LexState *ls, int line) {
   statlist(ls);
   check_match(ls, TK_UNTIL, TK_REPEAT, line);
   condexit = cond(ls);  /* read condition (inside scope block) */
-  if (bl2.upval)  /* upvalues? */
-    luaK_patchclose(fs, condexit, bl2.nactvar);
   leaveblock(fs);  /* finish scope */
+  if (bl2.upval) {  /* upvalues? */
+    int exit = luaK_jump(fs);  /* normal exit must jump over fix */
+    luaK_patchtohere(fs, condexit);  /* repetition must close upvalues */
+    luaK_codeABC(fs, OP_CLOSE, stacklevel(fs, bl2.nactvar), 0, 0);
+    condexit = luaK_jump(fs);  /* repeat after closing upvalues */
+    luaK_patchtohere(fs, exit);  /* normal exit comes to here */
+  }
   luaK_patchlist(fs, condexit, repeat_init);  /* close the loop */
   leaveblock(fs);  /* finish loop */
 }
 
 
-static int exp1 (LexState *ls) {
+/*
+** Read an expression and generate code to put its results in next
+** stack slot.
+**
+*/
+static void exp1 (LexState *ls) {
   expdesc e;
-  int reg;
   expr(ls, &e);
   luaK_exp2nextreg(ls->fs, &e);
   lua_assert(e.k == VNONRELOC);
-  reg = e.u.info;
-  return reg;
 }
 
 
-static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
+/*
+** Fix for instruction at position 'pc' to jump to 'dest'.
+** (Jump addresses are relative in Lua). 'back' true means
+** a back jump.
+*/
+static void fixforjump (FuncState *fs, int pc, int dest, int back) {
+  Instruction *jmp = &fs->f->code[pc];
+  int offset = dest - (pc + 1);
+  if (back)
+    offset = -offset;
+  if (unlikely(offset > MAXARG_Bx))
+    luaX_syntaxerror(fs->ls, "control structure too long");
+  SETARG_Bx(*jmp, offset);
+}
+
+
+/*
+** Generate code for a 'for' loop.
+*/
+static void forbody (LexState *ls, int base, int line, int nvars, int isgen) {
   /* forbody -> DO block */
+  static const OpCode forprep[2] = {OP_FORPREP, OP_TFORPREP};
+  static const OpCode forloop[2] = {OP_FORLOOP, OP_TFORLOOP};
   BlockCnt bl;
   FuncState *fs = ls->fs;
   int prep, endfor;
-  adjustlocalvars(ls, 3);  /* control variables */
   checknext(ls, TK_DO);
-  prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
+  prep = luaK_codeABx(fs, forprep[isgen], base, 0);
   enterblock(fs, &bl, 0);  /* scope for declared variables */
   adjustlocalvars(ls, nvars);
   luaK_reserveregs(fs, nvars);
   block(ls);
   leaveblock(fs);  /* end of scope for declared variables */
-  luaK_patchtohere(fs, prep);
-  if (isnum)  /* numeric for? */
-    endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
-  else {  /* generic for */
+  fixforjump(fs, prep, luaK_getlabel(fs), 0);
+  if (isgen) {  /* generic for? */
     luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
     luaK_fixline(fs, line);
-    endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP);
   }
-  luaK_patchlist(fs, endfor, prep + 1);
+  endfor = luaK_codeABx(fs, forloop[isgen], base, 0);
+  fixforjump(fs, endfor, prep + 1, 1);
   luaK_fixline(fs, line);
 }
 
 
 static void fornum (LexState *ls, TString *varname, int line) {
-  /* fornum -> NAME = exp1,exp1[,exp1] forbody */
+  /* fornum -> NAME = exp,exp[,exp] forbody */
   FuncState *fs = ls->fs;
   int base = fs->freereg;
-  new_localvarliteral(ls, "(for index)");
-  new_localvarliteral(ls, "(for limit)");
-  new_localvarliteral(ls, "(for step)");
+  new_localvarliteral(ls, "(for state)");
+  new_localvarliteral(ls, "(for state)");
+  new_localvarliteral(ls, "(for state)");
   new_localvar(ls, varname);
   checknext(ls, '=');
   exp1(ls);  /* initial value */
@@ -1329,10 +1571,11 @@ static void fornum (LexState *ls, TString *varname, int line) {
   if (testnext(ls, ','))
     exp1(ls);  /* optional step */
   else {  /* default step = 1 */
-    luaK_codek(fs, fs->freereg, luaK_intK(fs, 1));
+    luaK_int(fs, fs->freereg, 1);
     luaK_reserveregs(fs, 1);
   }
-  forbody(ls, base, line, 1, 1);
+  adjustlocalvars(ls, 3);  /* control variables */
+  forbody(ls, base, line, 1, 0);
 }
 
 
@@ -1340,13 +1583,14 @@ static void forlist (LexState *ls, TString *indexname) {
   /* forlist -> NAME {,NAME} IN explist forbody */
   FuncState *fs = ls->fs;
   expdesc e;
-  int nvars = 4;  /* gen, state, control, plus at least one declared var */
+  int nvars = 5;  /* gen, state, control, toclose, 'indexname' */
   int line;
   int base = fs->freereg;
   /* create control variables */
-  new_localvarliteral(ls, "(for generator)");
   new_localvarliteral(ls, "(for state)");
-  new_localvarliteral(ls, "(for control)");
+  new_localvarliteral(ls, "(for state)");
+  new_localvarliteral(ls, "(for state)");
+  new_localvarliteral(ls, "(for state)");
   /* create declared variables */
   new_localvar(ls, indexname);
   while (testnext(ls, ',')) {
@@ -1355,9 +1599,11 @@ static void forlist (LexState *ls, TString *indexname) {
   }
   checknext(ls, TK_IN);
   line = ls->linenumber;
-  adjust_assign(ls, 3, explist(ls, &e), &e);
+  adjust_assign(ls, 4, explist(ls, &e), &e);
+  adjustlocalvars(ls, 4);  /* control variables */
+  markupval(fs, fs->nactvar);  /* last control var. must be closed */
   luaK_checkstack(fs, 3);  /* extra space to call generator */
-  forbody(ls, base, line, nvars - 3, 0);
+  forbody(ls, base, line, nvars - 4, 1);
 }
 
 
@@ -1379,28 +1625,68 @@ static void forstat (LexState *ls, int line) {
 }
 
 
+/*
+** Check whether next instruction is a single jump (a 'break', a 'goto'
+** to a forward label, or a 'goto' to a backward label with no variable
+** to close). If so, set the name of the 'label' it is jumping to
+** ("break" for a 'break') or to where it is jumping to ('target') and
+** return true. If not a single jump, leave input unchanged, to be
+** handled as a regular statement.
+*/
+static int issinglejump (LexState *ls, TString **label, int *target) {
+  if (testnext(ls, TK_BREAK)) {  /* a break? */
+    *label = luaS_newliteral(ls->L, "break");
+    return 1;
+  }
+  else if (ls->t.token != TK_GOTO || luaX_lookahead(ls) != TK_NAME)
+    return 0;  /* not a valid goto */
+  else {
+    TString *lname = ls->lookahead.seminfo.ts;  /* label's id */
+    Labeldesc *lb = findlabel(ls, lname);
+    if (lb) {  /* a backward jump? */
+      /* does it need to close variables? */
+      if (luaY_nvarstack(ls->fs) > stacklevel(ls->fs, lb->nactvar))
+        return 0;  /* not a single jump; cannot optimize */
+      *target = lb->pc;
+    }
+    else  /* jump forward */
+      *label = lname;
+    luaX_next(ls);  /* skip goto */
+    luaX_next(ls);  /* skip name */
+    return 1;
+  }
+}
+
+
 static void test_then_block (LexState *ls, int *escapelist) {
   /* test_then_block -> [IF | ELSEIF] cond THEN block */
   BlockCnt bl;
+  int line;
   FuncState *fs = ls->fs;
+  TString *jlb = NULL;
+  int target = NO_JUMP;
   expdesc v;
   int jf;  /* instruction to skip 'then' code (if condition is false) */
   luaX_next(ls);  /* skip IF or ELSEIF */
   expr(ls, &v);  /* read condition */
   checknext(ls, TK_THEN);
-  if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) {
+  line = ls->linenumber;
+  if (issinglejump(ls, &jlb, &target)) {  /* 'if x then goto' ? */
     luaK_goiffalse(ls->fs, &v);  /* will jump to label if condition is true */
     enterblock(fs, &bl, 0);  /* must enter block before 'goto' */
-    gotostat(ls, v.t);  /* handle goto/break */
-    while (testnext(ls, ';')) {}  /* skip colons */
-    if (block_follow(ls, 0)) {  /* 'goto' is the entire block? */
+    if (jlb != NULL)  /* forward jump? */
+      newgotoentry(ls, jlb, line, v.t);  /* will be resolved later */
+    else  /* backward jump */
+      luaK_patchlist(fs, v.t, target);  /* jump directly to 'target' */
+    while (testnext(ls, ';')) {}  /* skip semicolons */
+    if (block_follow(ls, 0)) {  /* jump is the entire block? */
       leaveblock(fs);
       return;  /* and that is it */
     }
     else  /* must skip over 'then' part if condition is false */
       jf = luaK_jump(fs);
   }
-  else {  /* regular case (not goto/break) */
+  else {  /* regular case (not a jump) */
     luaK_goiftrue(ls->fs, &v);  /* skip over block if condition is false */
     enterblock(fs, &bl, 0);
     jf = v.f;
@@ -1431,21 +1717,60 @@ static void ifstat (LexState *ls, int line) {
 static void localfunc (LexState *ls) {
   expdesc b;
   FuncState *fs = ls->fs;
+  int fvar = fs->nactvar;  /* function's variable index */
   new_localvar(ls, str_checkname(ls));  /* new local variable */
   adjustlocalvars(ls, 1);  /* enter its scope */
   body(ls, &b, 0, ls->linenumber);  /* function created in next register */
   /* debug information will only see the variable after this point! */
-  getlocvar(fs, b.u.info)->startpc = fs->pc;
+  localdebuginfo(fs, fvar)->startpc = fs->pc;
+}
+
+
+static int getlocalattribute (LexState *ls) {
+  /* ATTRIB -> ['<' Name '>'] */
+  if (testnext(ls, '<')) {
+    const char *attr = getstr(str_checkname(ls));
+    checknext(ls, '>');
+    if (strcmp(attr, "const") == 0)
+      return RDKCONST;  /* read-only variable */
+    else if (strcmp(attr, "close") == 0)
+      return RDKTOCLOSE;  /* to-be-closed variable */
+    else
+      luaK_semerror(ls,
+        luaO_pushfstring(ls->L, "unknown attribute '%s'", attr));
+  }
+  return VDKREG;  /* regular variable */
+}
+
+
+static void checktoclose (LexState *ls, int level) {
+  if (level != -1) {  /* is there a to-be-closed variable? */
+    FuncState *fs = ls->fs;
+    markupval(fs, level + 1);
+    fs->bl->insidetbc = 1;  /* in the scope of a to-be-closed variable */
+    luaK_codeABC(fs, OP_TBC, stacklevel(fs, level), 0, 0);
+  }
 }
 
 
 static void localstat (LexState *ls) {
-  /* stat -> LOCAL NAME {',' NAME} ['=' explist] */
+  /* stat -> LOCAL ATTRIB NAME {',' ATTRIB NAME} ['=' explist] */
+  FuncState *fs = ls->fs;
+  int toclose = -1;  /* index of to-be-closed variable (if any) */
+  Vardesc *var;  /* last variable */
+  int vidx, kind;  /* index and kind of last variable */
   int nvars = 0;
   int nexps;
   expdesc e;
   do {
-    new_localvar(ls, str_checkname(ls));
+    vidx = new_localvar(ls, str_checkname(ls));
+    kind = getlocalattribute(ls);
+    getlocalvardesc(fs, vidx)->vd.kind = kind;
+    if (kind == RDKTOCLOSE) {  /* to-be-closed? */
+      if (toclose != -1)  /* one already present? */
+        luaK_semerror(ls, "multiple to-be-closed variables in local list");
+      toclose = fs->nactvar + nvars;
+    }
     nvars++;
   } while (testnext(ls, ','));
   if (testnext(ls, '='))
@@ -1454,8 +1779,19 @@ static void localstat (LexState *ls) {
     e.k = VVOID;
     nexps = 0;
   }
-  adjust_assign(ls, nvars, nexps, &e);
-  adjustlocalvars(ls, nvars);
+  var = getlocalvardesc(fs, vidx);  /* get last variable */
+  if (nvars == nexps &&  /* no adjustments? */
+      var->vd.kind == RDKCONST &&  /* last variable is const? */
+      luaK_exp2const(fs, &e, &var->k)) {  /* compile-time constant? */
+    var->vd.kind = RDKCTC;  /* variable is a compile-time constant */
+    adjustlocalvars(ls, nvars - 1);  /* exclude last variable */
+    fs->nactvar++;  /* but count it */
+  }
+  else {
+    adjust_assign(ls, nvars, nexps, &e);
+    adjustlocalvars(ls, nvars);
+  }
+  checktoclose(ls, toclose);
 }
 
 
@@ -1492,11 +1828,13 @@ static void exprstat (LexState *ls) {
   suffixedexp(ls, &v.v);
   if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */
     v.prev = NULL;
-    assignment(ls, &v, 1);
+    restassign(ls, &v, 1);
   }
   else {  /* stat -> func */
+    Instruction *inst;
     check_condition(ls, v.v.k == VCALL, "syntax error");
-    SETARG_C(getinstruction(fs, &v.v), 1);  /* call statement uses no results */
+    inst = &getinstruction(fs, &v.v);
+    SETARG_C(*inst, 1);  /* call statement uses no results */
   }
 }
 
@@ -1505,26 +1843,25 @@ static void retstat (LexState *ls) {
   /* stat -> RETURN [explist] [';'] */
   FuncState *fs = ls->fs;
   expdesc e;
-  int first, nret;  /* registers with returned values */
+  int nret;  /* number of values being returned */
+  int first = luaY_nvarstack(fs);  /* first slot to be returned */
   if (block_follow(ls, 1) || ls->t.token == ';')
-    first = nret = 0;  /* return no values */
+    nret = 0;  /* return no values */
   else {
     nret = explist(ls, &e);  /* optional return values */
     if (hasmultret(e.k)) {
       luaK_setmultret(fs, &e);
-      if (e.k == VCALL && nret == 1) {  /* tail call? */
+      if (e.k == VCALL && nret == 1 && !fs->bl->insidetbc) {  /* tail call? */
         SET_OPCODE(getinstruction(fs,&e), OP_TAILCALL);
-        lua_assert(GETARG_A(getinstruction(fs,&e)) == fs->nactvar);
+        lua_assert(GETARG_A(getinstruction(fs,&e)) == luaY_nvarstack(fs));
       }
-      first = fs->nactvar;
       nret = LUA_MULTRET;  /* return all values */
     }
     else {
       if (nret == 1)  /* only one single value? */
-        first = luaK_exp2anyreg(fs, &e);
-      else {
-        luaK_exp2nextreg(fs, &e);  /* values must go to the stack */
-        first = fs->nactvar;  /* return all active values */
+        first = luaK_exp2anyreg(fs, &e);  /* can use original slot */
+      else {  /* values must go to the top of the stack */
+        luaK_exp2nextreg(fs, &e);
         lua_assert(nret == fs->freereg - first);
       }
     }
@@ -1586,9 +1923,13 @@ static void statement (LexState *ls) {
       retstat(ls);
       break;
     }
-    case TK_BREAK:   /* stat -> breakstat */
+    case TK_BREAK: {  /* stat -> breakstat */
+      breakstat(ls);
+      break;
+    }
     case TK_GOTO: {  /* stat -> 'goto' NAME */
-      gotostat(ls, luaK_jump(ls->fs));
+      luaX_next(ls);  /* skip 'goto' */
+      gotostat(ls);
       break;
     }
     default: {  /* stat -> func | assignment */
@@ -1597,8 +1938,8 @@ static void statement (LexState *ls) {
     }
   }
   lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
-             ls->fs->freereg >= ls->fs->nactvar);
-  ls->fs->freereg = ls->fs->nactvar;  /* free registers */
+             ls->fs->freereg >= luaY_nvarstack(ls->fs));
+  ls->fs->freereg = luaY_nvarstack(ls->fs);  /* free registers */
   leavelevel(ls);
 }
 
@@ -1611,11 +1952,15 @@ static void statement (LexState *ls) {
 */
 static void mainfunc (LexState *ls, FuncState *fs) {
   BlockCnt bl;
-  expdesc v;
+  Upvaldesc *env;
   open_func(ls, fs, &bl);
-  fs->f->is_vararg = 1;  /* main function is always declared vararg */
-  init_exp(&v, VLOCAL, 0);  /* create and... */
-  newupvalue(fs, ls->envn, &v);  /* ...set environment upvalue */
+  setvararg(fs, 0);  /* main function is always declared vararg */
+  env = allocupvalue(fs);  /* ...set environment upvalue */
+  env->instack = 1;
+  env->idx = 0;
+  env->kind = VDKREG;
+  env->name = ls->envn;
+  luaC_objbarrier(ls->L, fs->f, env->name);
   luaX_next(ls);  /* read first token */
   statlist(ls);  /* parse main body */
   check(ls, TK_EOS);
@@ -1628,14 +1973,15 @@ LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
   LexState lexstate;
   FuncState funcstate;
   LClosure *cl = luaF_newLclosure(L, 1);  /* create main closure */
-  setclLvalue(L, L->top, cl);  /* anchor it (to avoid being collected) */
+  setclLvalue2s(L, L->top, cl);  /* anchor it (to avoid being collected) */
   luaD_inctop(L);
   lexstate.h = luaH_new(L);  /* create table for scanner */
-  sethvalue(L, L->top, lexstate.h);  /* anchor it */
+  sethvalue2s(L, L->top, lexstate.h);  /* anchor it */
   luaD_inctop(L);
   funcstate.f = cl->p = luaF_newproto(L);
+  luaC_objbarrier(L, cl, cl->p);
   funcstate.f->source = luaS_new(L, name);  /* create and anchor TString */
-  lua_assert(iswhite(funcstate.f));  /* do not need barrier here */
+  luaC_objbarrier(L, funcstate.f, funcstate.f->source);
   lexstate.buff = buff;
   lexstate.dyd = dyd;
   dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
diff --git a/libs/liblua/src/lparser.h b/libs/liblua/src/lparser.h
index f45b23cba5..618cb0106f 100644
--- a/libs/liblua/src/lparser.h
+++ b/libs/liblua/src/lparser.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.h,v 1.76.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lparser.h $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -30,56 +30,88 @@ typedef enum {
   VFALSE,  /* constant false */
   VK,  /* constant in 'k'; info = index of constant in 'k' */
   VKFLT,  /* floating constant; nval = numerical float value */
-  VKINT,  /* integer constant; nval = numerical integer value */
+  VKINT,  /* integer constant; ival = numerical integer value */
+  VKSTR,  /* string constant; strval = TString address;
+             (string is fixed by the lexer) */
   VNONRELOC,  /* expression has its value in a fixed register;
                  info = result register */
-  VLOCAL,  /* local variable; info = local register */
+  VLOCAL,  /* local variable; var.sidx = stack index (local register);
+              var.vidx = relative index in 'actvar.arr'  */
   VUPVAL,  /* upvalue variable; info = index of upvalue in 'upvalues' */
+  VCONST,  /* compile-time constant; info = absolute index in 'actvar.arr'  */
   VINDEXED,  /* indexed variable;
-                ind.vt = whether 't' is register or upvalue;
-                ind.t = table register or upvalue;
-                ind.idx = key's R/K index */
+                ind.t = table register;
+                ind.idx = key's R index */
+  VINDEXUP,  /* indexed upvalue;
+                ind.t = table upvalue;
+                ind.idx = key's K index */
+  VINDEXI, /* indexed variable with constant integer;
+                ind.t = table register;
+                ind.idx = key's value */
+  VINDEXSTR, /* indexed variable with literal string;
+                ind.t = table register;
+                ind.idx = key's K index */
   VJMP,  /* expression is a test/comparison;
             info = pc of corresponding jump instruction */
-  VRELOCABLE,  /* expression can put result in any register;
-                  info = instruction pc */
+  VRELOC,  /* expression can put result in any register;
+              info = instruction pc */
   VCALL,  /* expression is a function call; info = instruction pc */
   VVARARG  /* vararg expression; info = instruction pc */
 } expkind;
 
 
-#define vkisvar(k)	(VLOCAL <= (k) && (k) <= VINDEXED)
-#define vkisinreg(k)	((k) == VNONRELOC || (k) == VLOCAL)
+#define vkisvar(k)	(VLOCAL <= (k) && (k) <= VINDEXSTR)
+#define vkisindexed(k)	(VINDEXED <= (k) && (k) <= VINDEXSTR)
+
 
 typedef struct expdesc {
   expkind k;
   union {
     lua_Integer ival;    /* for VKINT */
     lua_Number nval;  /* for VKFLT */
+    TString *strval;  /* for VKSTR */
     int info;  /* for generic use */
-    struct {  /* for indexed variables (VINDEXED) */
-      short idx;  /* index (R/K) */
+    struct {  /* for indexed variables */
+      short idx;  /* index (R or "long" K) */
       lu_byte t;  /* table (register or upvalue) */
-      lu_byte vt;  /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
     } ind;
+    struct {  /* for local variables */
+      lu_byte sidx;  /* index in the stack */
+      unsigned short vidx;  /* compiler index (in 'actvar.arr')  */
+    } var;
   } u;
   int t;  /* patch list of 'exit when true' */
   int f;  /* patch list of 'exit when false' */
 } expdesc;
 
 
-/* description of active local variable */
-typedef struct Vardesc {
-  short idx;  /* variable index in stack */
+/* kinds of variables */
+#define VDKREG		0   /* regular */
+#define RDKCONST	1   /* constant */
+#define RDKTOCLOSE	2   /* to-be-closed */
+#define RDKCTC		3   /* compile-time constant */
+
+/* description of an active local variable */
+typedef union Vardesc {
+  struct {
+    TValuefields;  /* constant value (if it is a compile-time constant) */
+    lu_byte kind;
+    lu_byte sidx;  /* index of the variable in the stack */
+    short pidx;  /* index of the variable in the Proto's 'locvars' array */
+    TString *name;  /* variable name */
+  } vd;
+  TValue k;  /* constant value (if any) */
 } Vardesc;
 
 
+
 /* description of pending goto statements and label statements */
 typedef struct Labeldesc {
   TString *name;  /* label identifier */
   int pc;  /* position in code */
   int line;  /* line where it appeared */
-  lu_byte nactvar;  /* local level where it appears in current block */
+  lu_byte nactvar;  /* number of active variables in that position */
+  lu_byte close;  /* goto that escapes upvalues */
 } Labeldesc;
 
 
@@ -93,7 +125,7 @@ typedef struct Labellist {
 
 /* dynamic structures used by the parser */
 typedef struct Dyndata {
-  struct {  /* list of active local variables */
+  struct {  /* list of all active local variables */
     Vardesc *arr;
     int n;
     int size;
@@ -115,17 +147,22 @@ typedef struct FuncState {
   struct BlockCnt *bl;  /* chain of current blocks */
   int pc;  /* next position to code (equivalent to 'ncode') */
   int lasttarget;   /* 'label' of last 'jump label' */
-  int jpc;  /* list of pending jumps to 'pc' */
+  int previousline;  /* last line that was saved in 'lineinfo' */
   int nk;  /* number of elements in 'k' */
   int np;  /* number of elements in 'p' */
+  int nabslineinfo;  /* number of elements in 'abslineinfo' */
   int firstlocal;  /* index of first local var (in Dyndata array) */
-  short nlocvars;  /* number of elements in 'f->locvars' */
+  int firstlabel;  /* index of first label (in 'dyd->label->arr') */
+  short ndebugvars;  /* number of elements in 'f->locvars' */
   lu_byte nactvar;  /* number of active local variables */
   lu_byte nups;  /* number of upvalues */
   lu_byte freereg;  /* first free register */
+  lu_byte iwthabs;  /* instructions issued since last absolute line info */
+  lu_byte needclose;  /* function needs to close upvalues when returning */
 } FuncState;
 
 
+LUAI_FUNC int luaY_nvarstack (FuncState *fs);
 LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
                                  Dyndata *dyd, const char *name, int firstchar);
 
diff --git a/libs/liblua/src/lprefix.h b/libs/liblua/src/lprefix.h
index 9a749a3f30..484f2ad6fb 100644
--- a/libs/liblua/src/lprefix.h
+++ b/libs/liblua/src/lprefix.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lprefix.h,v 1.2.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lprefix.h $
 ** Definitions for Lua code that must come before any other header file
 ** See Copyright Notice in lua.h
 */
@@ -33,7 +33,7 @@
 /*
 ** Windows stuff
 */
-#if defined(_WIN32) 	/* { */
+#if defined(_WIN32)	/* { */
 
 #if !defined(_CRT_SECURE_NO_WARNINGS)
 #define _CRT_SECURE_NO_WARNINGS  /* avoid warnings about ISO C functions */
diff --git a/libs/liblua/src/lstate.c b/libs/liblua/src/lstate.c
index 8815afb95f..b1b406ab15 100644
--- a/libs/liblua/src/lstate.c
+++ b/libs/liblua/src/lstate.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.c,v 2.133.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lstate.c $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -28,25 +28,6 @@
 #include "ltm.h"
 
 
-#if !defined(LUAI_GCPAUSE)
-#define LUAI_GCPAUSE	200  /* 200% */
-#endif
-
-#if !defined(LUAI_GCMUL)
-#define LUAI_GCMUL	200 /* GC runs 'twice the speed' of memory allocation */
-#endif
-
-
-/*
-** a macro to help the creation of a unique random seed when a state is
-** created; the seed is used to randomize hashes.
-*/
-#if !defined(luai_makeseed)
-#include <time.h>
-#define luai_makeseed()		cast(unsigned int, time(NULL))
-#endif
-
-
 
 /*
 ** thread state + extra space
@@ -71,25 +52,35 @@ typedef struct LG {
 
 
 /*
-** Compute an initial seed as random as possible. Rely on Address Space
-** Layout Randomization (if present) to increase randomness..
+** A macro to create a "random" seed when a state is created;
+** the seed is used to randomize string hashes.
+*/
+#if !defined(luai_makeseed)
+
+#include <time.h>
+
+/*
+** Compute an initial seed with some level of randomness.
+** Rely on Address Space Layout Randomization (if present) and
+** current time.
 */
 #define addbuff(b,p,e) \
-  { size_t t = cast(size_t, e); \
+  { size_t t = cast_sizet(e); \
     memcpy(b + p, &t, sizeof(t)); p += sizeof(t); }
 
-static unsigned int makeseed (lua_State *L) {
-  char buff[4 * sizeof(size_t)];
-  unsigned int h = luai_makeseed();
+static unsigned int luai_makeseed (lua_State *L) {
+  char buff[3 * sizeof(size_t)];
+  unsigned int h = cast_uint(time(NULL));
   int p = 0;
   addbuff(buff, p, L);  /* heap variable */
   addbuff(buff, p, &h);  /* local variable */
-  addbuff(buff, p, luaO_nilobject);  /* global variable */
   addbuff(buff, p, &lua_newstate);  /* public function */
   lua_assert(p == sizeof(buff));
-  return luaS_hash(buff, p, h);
+  return luaS_hash(buff, p, h, 1);
 }
 
+#endif
+
 
 /*
 ** set GCdebt to a new value keeping the value (totalbytes + GCdebt)
@@ -105,12 +96,73 @@ void luaE_setdebt (global_State *g, l_mem debt) {
 }
 
 
+LUA_API int lua_setcstacklimit (lua_State *L, unsigned int limit) {
+  global_State *g = G(L);
+  int ccalls;
+  luaE_freeCI(L);  /* release unused CIs */
+  ccalls = getCcalls(L);
+  if (limit >= 40000)
+    return 0;  /* out of bounds */
+  limit += CSTACKERR;
+  if (L != g-> mainthread)
+    return 0;  /* only main thread can change the C stack */
+  else if (ccalls <= CSTACKERR)
+    return 0;  /* handling overflow */
+  else {
+    int diff = limit - g->Cstacklimit;
+    if (ccalls + diff <= CSTACKERR)
+      return 0;  /* new limit would cause an overflow */
+    g->Cstacklimit = limit;  /* set new limit */
+    L->nCcalls += diff;  /* correct 'nCcalls' */
+    return limit - diff - CSTACKERR;  /* success; return previous limit */
+  }
+}
+
+
+/*
+** Decrement count of "C calls" and check for overflows. In case of
+** a stack overflow, check appropriate error ("regular" overflow or
+** overflow while handling stack overflow).  If 'nCcalls' is smaller
+** than CSTACKERR but larger than CSTACKMARK, it means it has just
+** entered the "overflow zone", so the function raises an overflow
+** error.  If 'nCcalls' is smaller than CSTACKMARK (which means it is
+** already handling an overflow) but larger than CSTACKERRMARK, does
+** not report an error (to allow message handling to work). Otherwise,
+** report a stack overflow while handling a stack overflow (probably
+** caused by a repeating error in the message handling function).
+*/
+
+void luaE_enterCcall (lua_State *L) {
+  int ncalls = getCcalls(L);
+  L->nCcalls--;
+  if (ncalls <= CSTACKERR) {  /* possible overflow? */
+    luaE_freeCI(L);  /* release unused CIs */
+    ncalls = getCcalls(L);  /* update call count */
+    if (ncalls <= CSTACKERR) {  /* still overflow? */
+      if (ncalls <= CSTACKERRMARK)  /* below error-handling zone? */
+        luaD_throw(L, LUA_ERRERR);  /* error while handling stack error */
+      else if (ncalls >= CSTACKMARK) {
+        /* not in error-handling zone; raise the error now */
+        L->nCcalls = (CSTACKMARK - 1);  /* enter error-handling zone */
+        luaG_runerror(L, "C stack overflow");
+      }
+      /* else stack is in the error-handling zone;
+         allow message handler to work */
+    }
+  }
+}
+
+
 CallInfo *luaE_extendCI (lua_State *L) {
-  CallInfo *ci = luaM_new(L, CallInfo);
+  CallInfo *ci;
+  lua_assert(L->ci->next == NULL);
+  luaE_enterCcall(L);
+  ci = luaM_new(L, CallInfo);
   lua_assert(L->ci->next == NULL);
   L->ci->next = ci;
   ci->previous = L->ci;
   ci->next = NULL;
+  ci->u.l.trap = 0;
   L->nci++;
   return ci;
 }
@@ -123,46 +175,60 @@ void luaE_freeCI (lua_State *L) {
   CallInfo *ci = L->ci;
   CallInfo *next = ci->next;
   ci->next = NULL;
+  L->nCcalls += L->nci;  /* add removed elements back to 'nCcalls' */
   while ((ci = next) != NULL) {
     next = ci->next;
     luaM_free(L, ci);
     L->nci--;
   }
+  L->nCcalls -= L->nci;  /* adjust result */
 }
 
 
 /*
-** free half of the CallInfo structures not in use by a thread
+** free half of the CallInfo structures not in use by a thread,
+** keeping the first one.
 */
 void luaE_shrinkCI (lua_State *L) {
-  CallInfo *ci = L->ci;
-  CallInfo *next2;  /* next's next */
-  /* while there are two nexts */
-  while (ci->next != NULL && (next2 = ci->next->next) != NULL) {
-    luaM_free(L, ci->next);  /* free next */
+  CallInfo *ci = L->ci->next;  /* first free CallInfo */
+  CallInfo *next;
+  if (ci == NULL)
+    return;  /* no extra elements */
+  L->nCcalls += L->nci;  /* add removed elements back to 'nCcalls' */
+  while ((next = ci->next) != NULL) {  /* two extra elements? */
+    CallInfo *next2 = next->next;  /* next's next */
+    ci->next = next2;  /* remove next from the list */
     L->nci--;
-    ci->next = next2;  /* remove 'next' from the list */
-    next2->previous = ci;
-    ci = next2;  /* keep next's next */
+    luaM_free(L, next);  /* free next */
+    if (next2 == NULL)
+      break;  /* no more elements */
+    else {
+      next2->previous = ci;
+      ci = next2;  /* continue */
+    }
   }
+  L->nCcalls -= L->nci;  /* adjust result */
 }
 
 
 static void stack_init (lua_State *L1, lua_State *L) {
   int i; CallInfo *ci;
   /* initialize stack array */
-  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue);
+  L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, StackValue);
   L1->stacksize = BASIC_STACK_SIZE;
   for (i = 0; i < BASIC_STACK_SIZE; i++)
-    setnilvalue(L1->stack + i);  /* erase new stack */
+    setnilvalue(s2v(L1->stack + i));  /* erase new stack */
   L1->top = L1->stack;
   L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK;
   /* initialize first ci */
   ci = &L1->base_ci;
   ci->next = ci->previous = NULL;
-  ci->callstatus = 0;
+  ci->callstatus = CIST_C;
   ci->func = L1->top;
-  setnilvalue(L1->top++);  /* 'function' entry for this 'ci' */
+  ci->u.c.k = NULL;
+  ci->nresults = 0;
+  setnilvalue(s2v(L1->top));  /* 'function' entry for this 'ci' */
+  L1->top++;
   ci->top = L1->top + LUA_MINSTACK;
   L1->ci = ci;
 }
@@ -198,7 +264,8 @@ static void init_registry (lua_State *L, global_State *g) {
 
 /*
 ** open parts of the state that may cause memory-allocation errors.
-** ('g->version' != NULL flags that the state was completely build)
+** ('g->nilvalue' being a nil value flags that the state was completely
+** build.)
 */
 static void f_luaopen (lua_State *L, void *ud) {
   global_State *g = G(L);
@@ -209,7 +276,7 @@ static void f_luaopen (lua_State *L, void *ud) {
   luaT_init(L);
   luaX_init(L);
   g->gcrunning = 1;  /* allow gc */
-  g->version = lua_version(NULL);
+  setnilvalue(&g->nilvalue);
   luai_userstateopen(L);
 }
 
@@ -226,14 +293,12 @@ static void preinit_thread (lua_State *L, global_State *g) {
   L->stacksize = 0;
   L->twups = L;  /* thread has no upvalues */
   L->errorJmp = NULL;
-  L->nCcalls = 0;
   L->hook = NULL;
   L->hookmask = 0;
   L->basehookcount = 0;
   L->allowhook = 1;
   resethookcount(L);
   L->openupval = NULL;
-  L->nny = 1;
   L->status = LUA_OK;
   L->errfunc = 0;
 }
@@ -241,9 +306,9 @@ static void preinit_thread (lua_State *L, global_State *g) {
 
 static void close_state (lua_State *L) {
   global_State *g = G(L);
-  luaF_close(L, L->stack);  /* close all upvalues for this thread */
+  luaF_close(L, L->stack, CLOSEPROTECT);  /* close all upvalues */
   luaC_freeallobjects(L);  /* collect all objects */
-  if (g->version)  /* closing a fully built state? */
+  if (ttisnil(&g->nilvalue))  /* closing a fully built state? */
     luai_userstateclose(L);
   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
   freestack(L);
@@ -260,14 +325,15 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
   /* create new thread */
   L1 = &cast(LX *, luaM_newobject(L, LUA_TTHREAD, sizeof(LX)))->l;
   L1->marked = luaC_white(g);
-  L1->tt = LUA_TTHREAD;
+  L1->tt = LUA_VTHREAD;
   /* link it on list 'allgc' */
   L1->next = g->allgc;
   g->allgc = obj2gco(L1);
   /* anchor it on L stack */
-  setthvalue(L, L->top, L1);
+  setthvalue2s(L, L->top, L1);
   api_incr_top(L);
   preinit_thread(L1, g);
+  L1->nCcalls = getCcalls(L);
   L1->hookmask = L->hookmask;
   L1->basehookcount = L->basehookcount;
   L1->hook = L->hook;
@@ -284,7 +350,7 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
 
 void luaE_freethread (lua_State *L, lua_State *L1) {
   LX *l = fromstate(L1);
-  luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
+  luaF_close(L1, L1->stack, NOCLOSINGMETH);  /* close all upvalues */
   lua_assert(L1->openupval == NULL);
   luai_userstatefree(L, L1);
   freestack(L1);
@@ -292,6 +358,28 @@ void luaE_freethread (lua_State *L, lua_State *L1) {
 }
 
 
+int lua_resetthread (lua_State *L) {
+  CallInfo *ci;
+  int status;
+  lua_lock(L);
+  L->ci = ci = &L->base_ci;  /* unwind CallInfo list */
+  setnilvalue(s2v(L->stack));  /* 'function' entry for basic 'ci' */
+  ci->func = L->stack;
+  ci->callstatus = CIST_C;
+  status = luaF_close(L, L->stack, CLOSEPROTECT);
+  if (status != CLOSEPROTECT)  /* real errors? */
+    luaD_seterrorobj(L, status, L->stack + 1);
+  else {
+    status = LUA_OK;
+    L->top = L->stack + 1;
+  }
+  ci->top = L->top + LUA_MINSTACK;
+  L->status = status;
+  lua_unlock(L);
+  return status;
+}
+
+
 LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   int i;
   lua_State *L;
@@ -300,34 +388,43 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   if (l == NULL) return NULL;
   L = &l->l.l;
   g = &l->g;
-  L->next = NULL;
-  L->tt = LUA_TTHREAD;
+  L->tt = LUA_VTHREAD;
   g->currentwhite = bitmask(WHITE0BIT);
   L->marked = luaC_white(g);
   preinit_thread(L, g);
+  g->allgc = obj2gco(L);  /* by now, only object is the main thread */
+  L->next = NULL;
+  g->Cstacklimit = L->nCcalls = LUAI_MAXCSTACK + CSTACKERR;
   g->frealloc = f;
   g->ud = ud;
+  g->warnf = NULL;
+  g->ud_warn = NULL;
   g->mainthread = L;
-  g->seed = makeseed(L);
+  g->seed = luai_makeseed(L);
   g->gcrunning = 0;  /* no GC while building state */
-  g->GCestimate = 0;
   g->strt.size = g->strt.nuse = 0;
   g->strt.hash = NULL;
   setnilvalue(&g->l_registry);
   g->panic = NULL;
-  g->version = NULL;
   g->gcstate = GCSpause;
-  g->gckind = KGC_NORMAL;
-  g->allgc = g->finobj = g->tobefnz = g->fixedgc = NULL;
+  g->gckind = KGC_INC;
+  g->gcemergency = 0;
+  g->finobj = g->tobefnz = g->fixedgc = NULL;
+  g->survival = g->old = g->reallyold = NULL;
+  g->finobjsur = g->finobjold = g->finobjrold = NULL;
   g->sweepgc = NULL;
   g->gray = g->grayagain = NULL;
   g->weak = g->ephemeron = g->allweak = NULL;
   g->twups = NULL;
   g->totalbytes = sizeof(LG);
   g->GCdebt = 0;
-  g->gcfinnum = 0;
-  g->gcpause = LUAI_GCPAUSE;
-  g->gcstepmul = LUAI_GCMUL;
+  g->lastatomic = 0;
+  setivalue(&g->nilvalue, 0);  /* to signal that state is not yet built */
+  setgcparam(g->gcpause, LUAI_GCPAUSE);
+  setgcparam(g->gcstepmul, LUAI_GCMUL);
+  g->gcstepsize = LUAI_GCSTEPSIZE;
+  setgcparam(g->genmajormul, LUAI_GENMAJORMUL);
+  g->genminormul = LUAI_GENMINORMUL;
   for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL;
   if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) {
     /* memory allocation error: free partial state */
@@ -348,3 +445,26 @@ LUA_API void lua_close (lua_State *L) {
 }
 
 
+void luaE_warning (lua_State *L, const char *msg, int tocont) {
+  lua_WarnFunction wf = G(L)->warnf;
+  if (wf != NULL)
+    wf(G(L)->ud_warn, msg, tocont);
+}
+
+
+/*
+** Generate a warning from an error message
+*/
+void luaE_warnerror (lua_State *L, const char *where) {
+  TValue *errobj = s2v(L->top - 1);  /* error object */
+  const char *msg = (ttisstring(errobj))
+                  ? svalue(errobj)
+                  : "error object is not a string";
+  /* produce warning "error in %s (%s)" (where, msg) */
+  luaE_warning(L, "error in ", 1);
+  luaE_warning(L, where, 1);
+  luaE_warning(L, " (", 1);
+  luaE_warning(L, msg, 1);
+  luaE_warning(L, ")", 0);
+}
+
diff --git a/libs/liblua/src/lstate.h b/libs/liblua/src/lstate.h
index 56b3741000..2e8bd6c486 100644
--- a/libs/liblua/src/lstate.h
+++ b/libs/liblua/src/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 2.133.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lstate.h $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -15,7 +15,6 @@
 
 
 /*
-
 ** Some notes about garbage-collected objects: All objects in Lua must
 ** be kept somehow accessible until being freed, so all objects always
 ** belong to one (and only one) of these lists, using field 'next' of
@@ -27,6 +26,22 @@
 ** 'fixedgc': all objects that are not to be collected (currently
 ** only small strings, such as reserved words).
 **
+** For the generational collector, some of these lists have marks for
+** generations. Each mark points to the first element in the list for
+** that particular generation; that generation goes until the next mark.
+**
+** 'allgc' -> 'survival': new objects;
+** 'survival' -> 'old': objects that survived one collection;
+** 'old' -> 'reallyold': objects that became old in last collection;
+** 'reallyold' -> NULL: objects old for more than one cycle.
+**
+** 'finobj' -> 'finobjsur': new objects marked for finalization;
+** 'finobjsur' -> 'finobjold': survived   """";
+** 'finobjold' -> 'finobjrold': just old  """";
+** 'finobjrold' -> NULL: really old       """".
+*/
+
+/*
 ** Moreover, there is another set of lists that control gray objects.
 ** These lists are linked by fields 'gclist'. (All objects that
 ** can become gray have such a field. The field is not the same
@@ -43,9 +58,77 @@
 ** 'weak': tables with weak values to be cleared;
 ** 'ephemeron': ephemeron tables with white->white entries;
 ** 'allweak': tables with weak keys and/or weak values to be cleared.
-** The last three lists are used only during the atomic phase.
+*/
+
+
 
+/*
+** About 'nCcalls': each thread in Lua (a lua_State) keeps a count of
+** how many "C calls" it still can do in the C stack, to avoid C-stack
+** overflow.  This count is very rough approximation; it considers only
+** recursive functions inside the interpreter, as non-recursive calls
+** can be considered using a fixed (although unknown) amount of stack
+** space.
+**
+** The count has two parts: the lower part is the count itself; the
+** higher part counts the number of non-yieldable calls in the stack.
+** (They are together so that we can change both with one instruction.)
+**
+** Because calls to external C functions can use an unknown amount
+** of space (e.g., functions using an auxiliary buffer), calls
+** to these functions add more than one to the count (see CSTACKCF).
+**
+** The proper count excludes the number of CallInfo structures allocated
+** by Lua, as a kind of "potential" calls. So, when Lua calls a function
+** (and "consumes" one CallInfo), it needs neither to decrement nor to
+** check 'nCcalls', as its use of C stack is already accounted for.
+*/
+
+/* number of "C stack slots" used by an external C function */
+#define CSTACKCF	10
+
+
+/*
+** The C-stack size is sliced in the following zones:
+** - larger than CSTACKERR: normal stack;
+** - [CSTACKMARK, CSTACKERR]: buffer zone to signal a stack overflow;
+** - [CSTACKCF, CSTACKERRMARK]: error-handling zone;
+** - below CSTACKERRMARK: buffer zone to signal overflow during overflow;
+** (Because the counter can be decremented CSTACKCF at once, we need
+** the so called "buffer zones", with at least that size, to properly
+** detect a change from one zone to the next.)
 */
+#define CSTACKERR	(8 * CSTACKCF)
+#define CSTACKMARK	(CSTACKERR - (CSTACKCF + 2))
+#define CSTACKERRMARK	(CSTACKCF + 2)
+
+
+/* initial limit for the C-stack of threads */
+#define CSTACKTHREAD	(2 * CSTACKERR)
+
+
+/* true if this thread does not have non-yieldable calls in the stack */
+#define yieldable(L)		(((L)->nCcalls & 0xffff0000) == 0)
+
+/* real number of C calls */
+#define getCcalls(L)	((L)->nCcalls & 0xffff)
+
+
+/* Increment the number of non-yieldable calls */
+#define incnny(L)	((L)->nCcalls += 0x10000)
+
+/* Decrement the number of non-yieldable calls */
+#define decnny(L)	((L)->nCcalls -= 0x10000)
+
+/* Increment the number of non-yieldable calls and decrement nCcalls */
+#define incXCcalls(L)	((L)->nCcalls += 0x10000 - CSTACKCF)
+
+/* Decrement the number of non-yieldable calls and increment nCcalls */
+#define decXCcalls(L)	((L)->nCcalls -= 0x10000 - CSTACKCF)
+
+
+
+
 
 
 struct lua_longjmp;  /* defined in ldo.c */
@@ -69,8 +152,8 @@ struct lua_longjmp;  /* defined in ldo.c */
 
 
 /* kinds of Garbage Collection */
-#define KGC_NORMAL	0
-#define KGC_EMERGENCY	1	/* gc was forced by an allocation failure */
+#define KGC_INC		0	/* incremental gc */
+#define KGC_GEN		1	/* generational gc */
 
 
 typedef struct stringtable {
@@ -82,12 +165,6 @@ typedef struct stringtable {
 
 /*
 ** Information about a call.
-** When a thread yields, 'func' is adjusted to pretend that the
-** top function has only the yielded values in its stack; in that
-** case, the actual 'func' value is saved in field 'extra'.
-** When a function calls another with a continuation, 'extra' keeps
-** the function index so that, in case of errors, the continuation
-** function can be called with the correct top.
 */
 typedef struct CallInfo {
   StkId func;  /* function index in the stack */
@@ -95,8 +172,9 @@ typedef struct CallInfo {
   struct CallInfo *previous, *next;  /* dynamic call link */
   union {
     struct {  /* only for Lua functions */
-      StkId base;  /* base for this function */
       const Instruction *savedpc;
+      volatile l_signalT trap;
+      int nextraargs;  /* # of extra arguments in vararg functions */
     } l;
     struct {  /* only for C functions */
       lua_KFunction k;  /* continuation in case of yields */
@@ -104,7 +182,14 @@ typedef struct CallInfo {
       lua_KContext ctx;  /* context info. in case of yields */
     } c;
   } u;
-  ptrdiff_t extra;
+  union {
+    int funcidx;  /* called-function index */
+    int nyield;  /* number of values yielded */
+    struct {  /* info about transferred values (for call/return hooks) */
+      unsigned short ftransfer;  /* offset of first value transferred */
+      unsigned short ntransfer;  /* number of values transferred */
+    } transferinfo;
+  } u2;
   short nresults;  /* expected number of results from this function */
   unsigned short callstatus;
 } CallInfo;
@@ -114,17 +199,22 @@ typedef struct CallInfo {
 ** Bits in CallInfo status
 */
 #define CIST_OAH	(1<<0)	/* original value of 'allowhook' */
-#define CIST_LUA	(1<<1)	/* call is running a Lua function */
+#define CIST_C		(1<<1)	/* call is running a C function */
 #define CIST_HOOKED	(1<<2)	/* call is running a debug hook */
-#define CIST_FRESH	(1<<3)	/* call is running on a fresh invocation
-                                   of luaV_execute */
-#define CIST_YPCALL	(1<<4)	/* call is a yieldable protected call */
-#define CIST_TAIL	(1<<5)	/* call was tail called */
-#define CIST_HOOKYIELD	(1<<6)	/* last hook called yielded */
-#define CIST_LEQ	(1<<7)  /* using __lt for __le */
-#define CIST_FIN	(1<<8)  /* call is running a finalizer */
+#define CIST_YPCALL	(1<<3)	/* call is a yieldable protected call */
+#define CIST_TAIL	(1<<4)	/* call was tail called */
+#define CIST_HOOKYIELD	(1<<5)	/* last hook called yielded */
+#define CIST_FIN	(1<<6)  /* call is running a finalizer */
+#define CIST_TRAN	(1<<7)	/* 'ci' has transfer information */
+#if defined(LUA_COMPAT_LT_LE)
+#define CIST_LEQ	(1<<8)  /* using __lt for __le */
+#endif
+
+/* active function is a Lua function */
+#define isLua(ci)	(!((ci)->callstatus & CIST_C))
 
-#define isLua(ci)	((ci)->callstatus & CIST_LUA)
+/* call is running Lua code (not a hook) */
+#define isLuacode(ci)	(!((ci)->callstatus & (CIST_C | CIST_HOOKED)))
 
 /* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */
 #define setoah(st,v)	((st) = ((st) & ~CIST_OAH) | (v))
@@ -139,15 +229,22 @@ typedef struct global_State {
   void *ud;         /* auxiliary data to 'frealloc' */
   l_mem totalbytes;  /* number of bytes currently allocated - GCdebt */
   l_mem GCdebt;  /* bytes allocated not yet compensated by the collector */
-  lu_mem GCmemtrav;  /* memory traversed by the GC */
   lu_mem GCestimate;  /* an estimate of the non-garbage memory in use */
+  lu_mem lastatomic;  /* see function 'genstep' in file 'lgc.c' */
   stringtable strt;  /* hash table for strings */
   TValue l_registry;
+  TValue nilvalue;  /* a nil value */
   unsigned int seed;  /* randomized seed for hashes */
   lu_byte currentwhite;
   lu_byte gcstate;  /* state of garbage collector */
   lu_byte gckind;  /* kind of GC running */
+  lu_byte genminormul;  /* control for minor generational collections */
+  lu_byte genmajormul;  /* control for major generational collections */
   lu_byte gcrunning;  /* true if GC is running */
+  lu_byte gcemergency;  /* true if this is an emergency collection */
+  lu_byte gcpause;  /* size of pause between successive GCs */
+  lu_byte gcstepmul;  /* GC "speed" */
+  lu_byte gcstepsize;  /* (log2 of) GC granularity */
   GCObject *allgc;  /* list of all collectable objects */
   GCObject **sweepgc;  /* current position of sweep in list */
   GCObject *finobj;  /* list of collectable objects with finalizers */
@@ -158,17 +255,23 @@ typedef struct global_State {
   GCObject *allweak;  /* list of all-weak tables */
   GCObject *tobefnz;  /* list of userdata to be GC */
   GCObject *fixedgc;  /* list of objects not to be collected */
+  /* fields for generational collector */
+  GCObject *survival;  /* start of objects that survived one GC cycle */
+  GCObject *old;  /* start of old objects */
+  GCObject *reallyold;  /* old objects with more than one cycle */
+  GCObject *finobjsur;  /* list of survival objects with finalizers */
+  GCObject *finobjold;  /* list of old objects with finalizers */
+  GCObject *finobjrold;  /* list of really old objects with finalizers */
   struct lua_State *twups;  /* list of threads with open upvalues */
-  unsigned int gcfinnum;  /* number of finalizers to call in each GC step */
-  int gcpause;  /* size of pause between successive GCs */
-  int gcstepmul;  /* GC 'granularity' */
   lua_CFunction panic;  /* to be called in unprotected errors */
   struct lua_State *mainthread;
-  const lua_Number *version;  /* pointer to version number */
-  TString *memerrmsg;  /* memory-error message */
+  TString *memerrmsg;  /* message for memory-allocation errors */
   TString *tmname[TM_N];  /* array with tag-method names */
   struct Table *mt[LUA_NUMTAGS];  /* metatables for basic types */
   TString *strcache[STRCACHE_N][STRCACHE_M];  /* cache for strings in API */
+  lua_WarnFunction warnf;  /* warning function */
+  void *ud_warn;         /* auxiliary data to 'warnf' */
+  unsigned int Cstacklimit;  /* current limit for the C stack */
 } global_State;
 
 
@@ -177,8 +280,9 @@ typedef struct global_State {
 */
 struct lua_State {
   CommonHeader;
-  unsigned short nci;  /* number of items in 'ci' list */
   lu_byte status;
+  lu_byte allowhook;
+  unsigned short nci;  /* number of items in 'ci' list */
   StkId top;  /* first free slot in the stack */
   global_State *l_G;
   CallInfo *ci;  /* call info for current function */
@@ -192,13 +296,11 @@ struct lua_State {
   CallInfo base_ci;  /* CallInfo for first level (C calling Lua) */
   volatile lua_Hook hook;
   ptrdiff_t errfunc;  /* current error handling function (stack index) */
+  l_uint32 nCcalls;  /* number of allowed nested C calls - 'nci' */
   int stacksize;
   int basehookcount;
   int hookcount;
-  unsigned short nny;  /* number of non-yieldable calls in stack */
-  unsigned short nCcalls;  /* number of nested C calls */
-  l_signalT hookmask;
-  lu_byte allowhook;
+  volatile l_signalT hookmask;
 };
 
 
@@ -216,6 +318,7 @@ union GCUnion {
   struct Table h;
   struct Proto p;
   struct lua_State th;  /* thread */
+  struct UpVal upv;
 };
 
 
@@ -224,19 +327,22 @@ union GCUnion {
 /* macros to convert a GCObject into a specific value */
 #define gco2ts(o)  \
 	check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts))
-#define gco2u(o)  check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u))
-#define gco2lcl(o)  check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l))
-#define gco2ccl(o)  check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c))
+#define gco2u(o)  check_exp((o)->tt == LUA_VUSERDATA, &((cast_u(o))->u))
+#define gco2lcl(o)  check_exp((o)->tt == LUA_VLCL, &((cast_u(o))->cl.l))
+#define gco2ccl(o)  check_exp((o)->tt == LUA_VCCL, &((cast_u(o))->cl.c))
 #define gco2cl(o)  \
 	check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl))
-#define gco2t(o)  check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h))
-#define gco2p(o)  check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p))
-#define gco2th(o)  check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th))
+#define gco2t(o)  check_exp((o)->tt == LUA_VTABLE, &((cast_u(o))->h))
+#define gco2p(o)  check_exp((o)->tt == LUA_VPROTO, &((cast_u(o))->p))
+#define gco2th(o)  check_exp((o)->tt == LUA_VTHREAD, &((cast_u(o))->th))
+#define gco2upv(o)	check_exp((o)->tt == LUA_VUPVAL, &((cast_u(o))->upv))
 
 
-/* macro to convert a Lua object into a GCObject */
-#define obj2gco(v) \
-	check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc)))
+/*
+** macro to convert a Lua object into a GCObject
+** (The access to 'tt' tries to ensure that 'v' is actually a Lua object.)
+*/
+#define obj2gco(v)	check_exp((v)->tt >= LUA_TSTRING, &(cast_u(v)->gc))
 
 
 /* actual number of total bytes allocated */
@@ -247,7 +353,12 @@ LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
 LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);
 LUAI_FUNC void luaE_freeCI (lua_State *L);
 LUAI_FUNC void luaE_shrinkCI (lua_State *L);
+LUAI_FUNC void luaE_enterCcall (lua_State *L);
+LUAI_FUNC void luaE_warning (lua_State *L, const char *msg, int tocont);
+LUAI_FUNC void luaE_warnerror (lua_State *L, const char *where);
+
 
+#define luaE_exitCcall(L)	((L)->nCcalls++)
 
 #endif
 
diff --git a/libs/liblua/src/lstring.c b/libs/liblua/src/lstring.c
index 6257f211d9..6f1574731b 100644
--- a/libs/liblua/src/lstring.c
+++ b/libs/liblua/src/lstring.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.c,v 2.56.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lstring.c $
 ** String table (keeps all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -22,11 +22,8 @@
 #include "lstring.h"
 
 
-#define MEMERRMSG       "not enough memory"
-
-
 /*
-** Lua will use at most ~(2^LUAI_HASHLIMIT) bytes from a string to
+** Lua will use at most ~(2^LUAI_HASHLIMIT) bytes from a long string to
 ** compute its hash
 */
 #if !defined(LUAI_HASHLIMIT)
@@ -34,21 +31,28 @@
 #endif
 
 
+
+/*
+** Maximum size for string table.
+*/
+#define MAXSTRTB	cast_int(luaM_limitN(MAX_INT, TString*))
+
+
 /*
 ** equality for long strings
 */
 int luaS_eqlngstr (TString *a, TString *b) {
   size_t len = a->u.lnglen;
-  lua_assert(a->tt == LUA_TLNGSTR && b->tt == LUA_TLNGSTR);
+  lua_assert(a->tt == LUA_VLNGSTR && b->tt == LUA_VLNGSTR);
   return (a == b) ||  /* same instance or... */
     ((len == b->u.lnglen) &&  /* equal length and ... */
      (memcmp(getstr(a), getstr(b), len) == 0));  /* equal contents */
 }
 
 
-unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
-  unsigned int h = seed ^ cast(unsigned int, l);
-  size_t step = (l >> LUAI_HASHLIMIT) + 1;
+unsigned int luaS_hash (const char *str, size_t l, unsigned int seed,
+                        size_t step) {
+  unsigned int h = seed ^ cast_uint(l);
   for (; l >= step; l -= step)
     h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1]));
   return h;
@@ -56,43 +60,58 @@ unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
 
 
 unsigned int luaS_hashlongstr (TString *ts) {
-  lua_assert(ts->tt == LUA_TLNGSTR);
+  lua_assert(ts->tt == LUA_VLNGSTR);
   if (ts->extra == 0) {  /* no hash? */
-    ts->hash = luaS_hash(getstr(ts), ts->u.lnglen, ts->hash);
+    size_t len = ts->u.lnglen;
+    size_t step = (len >> LUAI_HASHLIMIT) + 1;
+    ts->hash = luaS_hash(getstr(ts), len, ts->hash, step);
     ts->extra = 1;  /* now it has its hash */
   }
   return ts->hash;
 }
 
 
-/*
-** resizes the string table
-*/
-void luaS_resize (lua_State *L, int newsize) {
+static void tablerehash (TString **vect, int osize, int nsize) {
   int i;
-  stringtable *tb = &G(L)->strt;
-  if (newsize > tb->size) {  /* grow table if needed */
-    luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *);
-    for (i = tb->size; i < newsize; i++)
-      tb->hash[i] = NULL;
-  }
-  for (i = 0; i < tb->size; i++) {  /* rehash */
-    TString *p = tb->hash[i];
-    tb->hash[i] = NULL;
-    while (p) {  /* for each node in the list */
+  for (i = osize; i < nsize; i++)  /* clear new elements */
+    vect[i] = NULL;
+  for (i = 0; i < osize; i++) {  /* rehash old part of the array */
+    TString *p = vect[i];
+    vect[i] = NULL;
+    while (p) {  /* for each string in the list */
       TString *hnext = p->u.hnext;  /* save next */
-      unsigned int h = lmod(p->hash, newsize);  /* new position */
-      p->u.hnext = tb->hash[h];  /* chain it */
-      tb->hash[h] = p;
+      unsigned int h = lmod(p->hash, nsize);  /* new position */
+      p->u.hnext = vect[h];  /* chain it into array */
+      vect[h] = p;
       p = hnext;
     }
   }
-  if (newsize < tb->size) {  /* shrink table if needed */
-    /* vanishing slice should be empty */
-    lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL);
-    luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *);
+}
+
+
+/*
+** Resize the string table. If allocation fails, keep the current size.
+** (This can degrade performance, but any non-zero size should work
+** correctly.)
+*/
+void luaS_resize (lua_State *L, int nsize) {
+  stringtable *tb = &G(L)->strt;
+  int osize = tb->size;
+  TString **newvect;
+  if (nsize < osize)  /* shrinking table? */
+    tablerehash(tb->hash, osize, nsize);  /* depopulate shrinking part */
+  newvect = luaM_reallocvector(L, tb->hash, osize, nsize, TString*);
+  if (unlikely(newvect == NULL)) {  /* reallocation failed? */
+    if (nsize < osize)  /* was it shrinking table? */
+      tablerehash(tb->hash, nsize, osize);  /* restore to original size */
+    /* leave table as it was */
+  }
+  else {  /* allocation succeeded */
+    tb->hash = newvect;
+    tb->size = nsize;
+    if (nsize > osize)
+      tablerehash(newvect, osize, nsize);  /* rehash for new size */
   }
-  tb->size = newsize;
 }
 
 
@@ -104,8 +123,8 @@ void luaS_clearcache (global_State *g) {
   int i, j;
   for (i = 0; i < STRCACHE_N; i++)
     for (j = 0; j < STRCACHE_M; j++) {
-    if (iswhite(g->strcache[i][j]))  /* will entry be collected? */
-      g->strcache[i][j] = g->memerrmsg;  /* replace it with something fixed */
+      if (iswhite(g->strcache[i][j]))  /* will entry be collected? */
+        g->strcache[i][j] = g->memerrmsg;  /* replace it with something fixed */
     }
 }
 
@@ -116,7 +135,10 @@ void luaS_clearcache (global_State *g) {
 void luaS_init (lua_State *L) {
   global_State *g = G(L);
   int i, j;
-  luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
+  stringtable *tb = &G(L)->strt;
+  tb->hash = luaM_newvector(L, MINSTRTABSIZE, TString*);
+  tablerehash(tb->hash, 0, MINSTRTABSIZE);  /* clear array */
+  tb->size = MINSTRTABSIZE;
   /* pre-create memory-error message */
   g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
   luaC_fix(L, obj2gco(g->memerrmsg));  /* it should never be collected */
@@ -145,7 +167,7 @@ static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) {
 
 
 TString *luaS_createlngstrobj (lua_State *L, size_t l) {
-  TString *ts = createstrobj(L, l, LUA_TLNGSTR, G(L)->seed);
+  TString *ts = createstrobj(L, l, LUA_VLNGSTR, G(L)->seed);
   ts->u.lnglen = l;
   return ts;
 }
@@ -161,34 +183,46 @@ void luaS_remove (lua_State *L, TString *ts) {
 }
 
 
+static void growstrtab (lua_State *L, stringtable *tb) {
+  if (unlikely(tb->nuse == MAX_INT)) {  /* too many strings? */
+    luaC_fullgc(L, 1);  /* try to free some... */
+    if (tb->nuse == MAX_INT)  /* still too many? */
+      luaM_error(L);  /* cannot even create a message... */
+  }
+  if (tb->size <= MAXSTRTB / 2)  /* can grow string table? */
+    luaS_resize(L, tb->size * 2);
+}
+
+
 /*
-** checks whether short string exists and reuses it or creates a new one
+** Checks whether short string exists and reuses it or creates a new one.
 */
 static TString *internshrstr (lua_State *L, const char *str, size_t l) {
   TString *ts;
   global_State *g = G(L);
-  unsigned int h = luaS_hash(str, l, g->seed);
-  TString **list = &g->strt.hash[lmod(h, g->strt.size)];
+  stringtable *tb = &g->strt;
+  unsigned int h = luaS_hash(str, l, g->seed, 1);
+  TString **list = &tb->hash[lmod(h, tb->size)];
   lua_assert(str != NULL);  /* otherwise 'memcmp'/'memcpy' are undefined */
   for (ts = *list; ts != NULL; ts = ts->u.hnext) {
-    if (l == ts->shrlen &&
-        (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
+    if (l == ts->shrlen && (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
       /* found! */
       if (isdead(g, ts))  /* dead (but not collected yet)? */
         changewhite(ts);  /* resurrect it */
       return ts;
     }
   }
-  if (g->strt.nuse >= g->strt.size && g->strt.size <= MAX_INT/2) {
-    luaS_resize(L, g->strt.size * 2);
-    list = &g->strt.hash[lmod(h, g->strt.size)];  /* recompute with new size */
+  /* else must create a new string */
+  if (tb->nuse >= tb->size) {  /* need to grow string table? */
+    growstrtab(L, tb);
+    list = &tb->hash[lmod(h, tb->size)];  /* rehash with new size */
   }
-  ts = createstrobj(L, l, LUA_TSHRSTR, h);
+  ts = createstrobj(L, l, LUA_VSHRSTR, h);
   memcpy(getstr(ts), str, l * sizeof(char));
   ts->shrlen = cast_byte(l);
   ts->u.hnext = *list;
   *list = ts;
-  g->strt.nuse++;
+  tb->nuse++;
   return ts;
 }
 
@@ -201,7 +235,7 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
     return internshrstr(L, str, l);
   else {
     TString *ts;
-    if (l >= (MAX_SIZE - sizeof(TString))/sizeof(char))
+    if (unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char)))
       luaM_toobig(L);
     ts = luaS_createlngstrobj(L, l);
     memcpy(getstr(ts), str, l * sizeof(char));
@@ -233,16 +267,19 @@ TString *luaS_new (lua_State *L, const char *str) {
 }
 
 
-Udata *luaS_newudata (lua_State *L, size_t s) {
+Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue) {
   Udata *u;
+  int i;
   GCObject *o;
-  if (s > MAX_SIZE - sizeof(Udata))
+  if (unlikely(s > MAX_SIZE - udatamemoffset(nuvalue)))
     luaM_toobig(L);
-  o = luaC_newobj(L, LUA_TUSERDATA, sizeludata(s));
+  o = luaC_newobj(L, LUA_VUSERDATA, sizeudata(nuvalue, s));
   u = gco2u(o);
   u->len = s;
+  u->nuvalue = nuvalue;
   u->metatable = NULL;
-  setuservalue(L, u, luaO_nilobject);
+  for (i = 0; i < nuvalue; i++)
+    setnilvalue(&u->uv[i].uv);
   return u;
 }
 
diff --git a/libs/liblua/src/lstring.h b/libs/liblua/src/lstring.h
index d612abd333..a413a9d3a0 100644
--- a/libs/liblua/src/lstring.h
+++ b/libs/liblua/src/lstring.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.h,v 1.61.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lstring.h $
 ** String table (keep all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -12,10 +12,18 @@
 #include "lstate.h"
 
 
-#define sizelstring(l)  (sizeof(union UTString) + ((l) + 1) * sizeof(char))
+/*
+** Memory-allocation error message must be preallocated (it cannot
+** be created after memory is exhausted)
+*/
+#define MEMERRMSG       "not enough memory"
+
 
-#define sizeludata(l)	(sizeof(union UUdata) + (l))
-#define sizeudata(u)	sizeludata((u)->len)
+/*
+** Size of a TString: Size of the header plus space for the string
+** itself (including final '\0').
+*/
+#define sizelstring(l)  (offsetof(TString, contents) + ((l) + 1) * sizeof(char))
 
 #define luaS_newliteral(L, s)	(luaS_newlstr(L, "" s, \
                                  (sizeof(s)/sizeof(char))-1))
@@ -24,23 +32,24 @@
 /*
 ** test whether a string is a reserved word
 */
-#define isreserved(s)	((s)->tt == LUA_TSHRSTR && (s)->extra > 0)
+#define isreserved(s)	((s)->tt == LUA_VSHRSTR && (s)->extra > 0)
 
 
 /*
 ** equality for short strings, which are always internalized
 */
-#define eqshrstr(a,b)	check_exp((a)->tt == LUA_TSHRSTR, (a) == (b))
+#define eqshrstr(a,b)	check_exp((a)->tt == LUA_VSHRSTR, (a) == (b))
 
 
-LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l, unsigned int seed);
+LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l,
+                                  unsigned int seed, size_t step);
 LUAI_FUNC unsigned int luaS_hashlongstr (TString *ts);
 LUAI_FUNC int luaS_eqlngstr (TString *a, TString *b);
 LUAI_FUNC void luaS_resize (lua_State *L, int newsize);
 LUAI_FUNC void luaS_clearcache (global_State *g);
 LUAI_FUNC void luaS_init (lua_State *L);
 LUAI_FUNC void luaS_remove (lua_State *L, TString *ts);
-LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s);
+LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue);
 LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l);
 LUAI_FUNC TString *luaS_new (lua_State *L, const char *str);
 LUAI_FUNC TString *luaS_createlngstrobj (lua_State *L, size_t l);
diff --git a/libs/liblua/src/lstrlib.c b/libs/liblua/src/lstrlib.c
index b4bed7e93d..2ba8bde47c 100644
--- a/libs/liblua/src/lstrlib.c
+++ b/libs/liblua/src/lstrlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstrlib.c,v 1.254.1.1 2017/04/19 17:29:57 roberto Exp $
+** $Id: lstrlib.c $
 ** Standard library for string operations and pattern-matching
 ** See Copyright Notice in lua.h
 */
@@ -14,6 +14,7 @@
 #include <float.h>
 #include <limits.h>
 #include <locale.h>
+#include <math.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -59,23 +60,50 @@ static int str_len (lua_State *L) {
 }
 
 
-/* translate a relative string position: negative means back from end */
-static lua_Integer posrelat (lua_Integer pos, size_t len) {
-  if (pos >= 0) return pos;
-  else if (0u - (size_t)pos > len) return 0;
-  else return (lua_Integer)len + pos + 1;
+/*
+** translate a relative initial string position
+** (negative means back from end): clip result to [1, inf).
+** The length of any string in Lua must fit in a lua_Integer,
+** so there are no overflows in the casts.
+** The inverted comparison avoids a possible overflow
+** computing '-pos'.
+*/
+static size_t posrelatI (lua_Integer pos, size_t len) {
+  if (pos > 0)
+    return (size_t)pos;
+  else if (pos == 0)
+    return 1;
+  else if (pos < -(lua_Integer)len)  /* inverted comparison */
+    return 1;  /* clip to 1 */
+  else return len + (size_t)pos + 1;
+}
+
+
+/*
+** Gets an optional ending string position from argument 'arg',
+** with default value 'def'.
+** Negative means back from end: clip result to [0, len]
+*/
+static size_t getendpos (lua_State *L, int arg, lua_Integer def,
+                         size_t len) {
+  lua_Integer pos = luaL_optinteger(L, arg, def);
+  if (pos > (lua_Integer)len)
+    return len;
+  else if (pos >= 0)
+    return (size_t)pos;
+  else if (pos < -(lua_Integer)len)
+    return 0;
+  else return len + (size_t)pos + 1;
 }
 
 
 static int str_sub (lua_State *L) {
   size_t l;
   const char *s = luaL_checklstring(L, 1, &l);
-  lua_Integer start = posrelat(luaL_checkinteger(L, 2), l);
-  lua_Integer end = posrelat(luaL_optinteger(L, 3, -1), l);
-  if (start < 1) start = 1;
-  if (end > (lua_Integer)l) end = l;
+  size_t start = posrelatI(luaL_checkinteger(L, 2), l);
+  size_t end = getendpos(L, 3, -1, l);
   if (start <= end)
-    lua_pushlstring(L, s + start - 1, (size_t)(end - start) + 1);
+    lua_pushlstring(L, s + start - 1, (end - start) + 1);
   else lua_pushliteral(L, "");
   return 1;
 }
@@ -148,13 +176,12 @@ static int str_rep (lua_State *L) {
 static int str_byte (lua_State *L) {
   size_t l;
   const char *s = luaL_checklstring(L, 1, &l);
-  lua_Integer posi = posrelat(luaL_optinteger(L, 2, 1), l);
-  lua_Integer pose = posrelat(luaL_optinteger(L, 3, posi), l);
+  lua_Integer pi = luaL_optinteger(L, 2, 1);
+  size_t posi = posrelatI(pi, l);
+  size_t pose = getendpos(L, 3, pi, l);
   int n, i;
-  if (posi < 1) posi = 1;
-  if (pose > (lua_Integer)l) pose = l;
   if (posi > pose) return 0;  /* empty interval; return no values */
-  if (pose - posi >= INT_MAX)  /* arithmetic overflow? */
+  if (pose - posi >= (size_t)INT_MAX)  /* arithmetic overflow? */
     return luaL_error(L, "string slice too long");
   n = (int)(pose -  posi) + 1;
   luaL_checkstack(L, n, "string slice too long");
@@ -170,8 +197,8 @@ static int str_char (lua_State *L) {
   luaL_Buffer b;
   char *p = luaL_buffinitsize(L, &b, n);
   for (i=1; i<=n; i++) {
-    lua_Integer c = luaL_checkinteger(L, i);
-    luaL_argcheck(L, uchar(c) == c, i, "value out of range");
+    lua_Unsigned c = (lua_Unsigned)luaL_checkinteger(L, i);
+    luaL_argcheck(L, c <= (lua_Unsigned)UCHAR_MAX, i, "value out of range");
     p[i - 1] = uchar(c);
   }
   luaL_pushresultsize(&b, n);
@@ -179,27 +206,142 @@ static int str_char (lua_State *L) {
 }
 
 
-static int writer (lua_State *L, const void *b, size_t size, void *B) {
-  (void)L;
-  luaL_addlstring((luaL_Buffer *) B, (const char *)b, size);
+/*
+** Buffer to store the result of 'string.dump'. It must be initialized
+** after the call to 'lua_dump', to ensure that the function is on the
+** top of the stack when 'lua_dump' is called. ('luaL_buffinit' might
+** push stuff.)
+*/
+struct str_Writer {
+  int init;  /* true iff buffer has been initialized */
+  luaL_Buffer B;
+};
+
+
+static int writer (lua_State *L, const void *b, size_t size, void *ud) {
+  struct str_Writer *state = (struct str_Writer *)ud;
+  if (!state->init) {
+    state->init = 1;
+    luaL_buffinit(L, &state->B);
+  }
+  luaL_addlstring(&state->B, (const char *)b, size);
   return 0;
 }
 
 
 static int str_dump (lua_State *L) {
-  luaL_Buffer b;
+  struct str_Writer state;
   int strip = lua_toboolean(L, 2);
   luaL_checktype(L, 1, LUA_TFUNCTION);
-  lua_settop(L, 1);
-  luaL_buffinit(L,&b);
-  if (lua_dump(L, writer, &b, strip) != 0)
+  lua_settop(L, 1);  /* ensure function is on the top of the stack */
+  state.init = 0;
+  if (lua_dump(L, writer, &state, strip) != 0)
     return luaL_error(L, "unable to dump given function");
-  luaL_pushresult(&b);
+  luaL_pushresult(&state.B);
   return 1;
 }
 
 
 
+/*
+** {======================================================
+** METAMETHODS
+** =======================================================
+*/
+
+#if defined(LUA_NOCVTS2N)	/* { */
+
+/* no coercion from strings to numbers */
+
+static const luaL_Reg stringmetamethods[] = {
+  {"__index", NULL},  /* placeholder */
+  {NULL, NULL}
+};
+
+#else		/* }{ */
+
+static int tonum (lua_State *L, int arg) {
+  if (lua_type(L, arg) == LUA_TNUMBER) {  /* already a number? */
+    lua_pushvalue(L, arg);
+    return 1;
+  }
+  else {  /* check whether it is a numerical string */
+    size_t len;
+    const char *s = lua_tolstring(L, arg, &len);
+    return (s != NULL && lua_stringtonumber(L, s) == len + 1);
+  }
+}
+
+
+static void trymt (lua_State *L, const char *mtname) {
+  lua_settop(L, 2);  /* back to the original arguments */
+  if (lua_type(L, 2) == LUA_TSTRING || !luaL_getmetafield(L, 2, mtname))
+    luaL_error(L, "attempt to %s a '%s' with a '%s'", mtname + 2,
+                  luaL_typename(L, -2), luaL_typename(L, -1));
+  lua_insert(L, -3);  /* put metamethod before arguments */
+  lua_call(L, 2, 1);  /* call metamethod */
+}
+
+
+static int arith (lua_State *L, int op, const char *mtname) {
+  if (tonum(L, 1) && tonum(L, 2))
+    lua_arith(L, op);  /* result will be on the top */
+  else
+    trymt(L, mtname);
+  return 1;
+}
+
+
+static int arith_add (lua_State *L) {
+  return arith(L, LUA_OPADD, "__add");
+}
+
+static int arith_sub (lua_State *L) {
+  return arith(L, LUA_OPSUB, "__sub");
+}
+
+static int arith_mul (lua_State *L) {
+  return arith(L, LUA_OPMUL, "__mul");
+}
+
+static int arith_mod (lua_State *L) {
+  return arith(L, LUA_OPMOD, "__mod");
+}
+
+static int arith_pow (lua_State *L) {
+  return arith(L, LUA_OPPOW, "__pow");
+}
+
+static int arith_div (lua_State *L) {
+  return arith(L, LUA_OPDIV, "__div");
+}
+
+static int arith_idiv (lua_State *L) {
+  return arith(L, LUA_OPIDIV, "__idiv");
+}
+
+static int arith_unm (lua_State *L) {
+  return arith(L, LUA_OPUNM, "__unm");
+}
+
+
+static const luaL_Reg stringmetamethods[] = {
+  {"__add", arith_add},
+  {"__sub", arith_sub},
+  {"__mul", arith_mul},
+  {"__mod", arith_mod},
+  {"__pow", arith_pow},
+  {"__div", arith_div},
+  {"__idiv", arith_idiv},
+  {"__unm", arith_unm},
+  {"__index", NULL},  /* placeholder */
+  {NULL, NULL}
+};
+
+#endif		/* } */
+
+/* }====================================================== */
+
 /*
 ** {======================================================
 ** PATTERN MATCHING
@@ -547,25 +689,46 @@ static const char *lmemfind (const char *s1, size_t l1,
 }
 
 
-static void push_onecapture (MatchState *ms, int i, const char *s,
-                                                    const char *e) {
+/*
+** get information about the i-th capture. If there are no captures
+** and 'i==0', return information about the whole match, which
+** is the range 's'..'e'. If the capture is a string, return
+** its length and put its address in '*cap'. If it is an integer
+** (a position), push it on the stack and return CAP_POSITION.
+*/
+static size_t get_onecapture (MatchState *ms, int i, const char *s,
+                              const char *e, const char **cap) {
   if (i >= ms->level) {
-    if (i == 0)  /* ms->level == 0, too */
-      lua_pushlstring(ms->L, s, e - s);  /* add whole match */
-    else
+    if (i != 0)
       luaL_error(ms->L, "invalid capture index %%%d", i + 1);
+    *cap = s;
+    return e - s;
   }
   else {
-    ptrdiff_t l = ms->capture[i].len;
-    if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture");
-    if (l == CAP_POSITION)
+    ptrdiff_t capl = ms->capture[i].len;
+    *cap = ms->capture[i].init;
+    if (capl == CAP_UNFINISHED)
+      luaL_error(ms->L, "unfinished capture");
+    else if (capl == CAP_POSITION)
       lua_pushinteger(ms->L, (ms->capture[i].init - ms->src_init) + 1);
-    else
-      lua_pushlstring(ms->L, ms->capture[i].init, l);
+    return capl;
   }
 }
 
 
+/*
+** Push the i-th capture on the stack.
+*/
+static void push_onecapture (MatchState *ms, int i, const char *s,
+                                                    const char *e) {
+  const char *cap;
+  ptrdiff_t l = get_onecapture(ms, i, s, e, &cap);
+  if (l != CAP_POSITION)
+    lua_pushlstring(ms->L, cap, l);
+  /* else position was already pushed */
+}
+
+
 static int push_captures (MatchState *ms, const char *s, const char *e) {
   int i;
   int nlevels = (ms->level == 0 && s) ? 1 : ms->level;
@@ -608,16 +771,15 @@ static int str_find_aux (lua_State *L, int find) {
   size_t ls, lp;
   const char *s = luaL_checklstring(L, 1, &ls);
   const char *p = luaL_checklstring(L, 2, &lp);
-  lua_Integer init = posrelat(luaL_optinteger(L, 3, 1), ls);
-  if (init < 1) init = 1;
-  else if (init > (lua_Integer)ls + 1) {  /* start after string's end? */
-    lua_pushnil(L);  /* cannot find anything */
+  size_t init = posrelatI(luaL_optinteger(L, 3, 1), ls) - 1;
+  if (init > ls) {  /* start after string's end? */
+    luaL_pushfail(L);  /* cannot find anything */
     return 1;
   }
   /* explicit request or no special characters? */
   if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) {
     /* do a plain search */
-    const char *s2 = lmemfind(s + init - 1, ls - (size_t)init + 1, p, lp);
+    const char *s2 = lmemfind(s + init, ls - init, p, lp);
     if (s2) {
       lua_pushinteger(L, (s2 - s) + 1);
       lua_pushinteger(L, (s2 - s) + lp);
@@ -626,7 +788,7 @@ static int str_find_aux (lua_State *L, int find) {
   }
   else {
     MatchState ms;
-    const char *s1 = s + init - 1;
+    const char *s1 = s + init;
     int anchor = (*p == '^');
     if (anchor) {
       p++; lp--;  /* skip anchor character */
@@ -646,7 +808,7 @@ static int str_find_aux (lua_State *L, int find) {
       }
     } while (s1++ < ms.src_end && !anchor);
   }
-  lua_pushnil(L);  /* not found */
+  luaL_pushfail(L);  /* not found */
   return 1;
 }
 
@@ -690,11 +852,14 @@ static int gmatch (lua_State *L) {
   size_t ls, lp;
   const char *s = luaL_checklstring(L, 1, &ls);
   const char *p = luaL_checklstring(L, 2, &lp);
+  size_t init = posrelatI(luaL_optinteger(L, 3, 1), ls) - 1;
   GMatchState *gm;
-  lua_settop(L, 2);  /* keep them on closure to avoid being collected */
-  gm = (GMatchState *)lua_newuserdata(L, sizeof(GMatchState));
+  lua_settop(L, 2);  /* keep strings on closure to avoid being collected */
+  gm = (GMatchState *)lua_newuserdatauv(L, sizeof(GMatchState), 0);
+  if (init > ls)  /* start after string's end? */
+    init = ls + 1;  /* avoid overflows in 's + init' */
   prepstate(&gm->ms, L, s, ls, p, lp);
-  gm->src = s; gm->p = p; gm->lastmatch = NULL;
+  gm->src = s + init; gm->p = p; gm->lastmatch = NULL;
   lua_pushcclosure(L, gmatch_aux, 3);
   return 1;
 }
@@ -702,60 +867,72 @@ static int gmatch (lua_State *L) {
 
 static void add_s (MatchState *ms, luaL_Buffer *b, const char *s,
                                                    const char *e) {
-  size_t l, i;
+  size_t l;
   lua_State *L = ms->L;
   const char *news = lua_tolstring(L, 3, &l);
-  for (i = 0; i < l; i++) {
-    if (news[i] != L_ESC)
-      luaL_addchar(b, news[i]);
-    else {
-      i++;  /* skip ESC */
-      if (!isdigit(uchar(news[i]))) {
-        if (news[i] != L_ESC)
-          luaL_error(L, "invalid use of '%c' in replacement string", L_ESC);
-        luaL_addchar(b, news[i]);
-      }
-      else if (news[i] == '0')
-          luaL_addlstring(b, s, e - s);
-      else {
-        push_onecapture(ms, news[i] - '1', s, e);
-        luaL_tolstring(L, -1, NULL);  /* if number, convert it to string */
-        lua_remove(L, -2);  /* remove original value */
-        luaL_addvalue(b);  /* add capture to accumulated result */
-      }
+  const char *p;
+  while ((p = (char *)memchr(news, L_ESC, l)) != NULL) {
+    luaL_addlstring(b, news, p - news);
+    p++;  /* skip ESC */
+    if (*p == L_ESC)  /* '%%' */
+      luaL_addchar(b, *p);
+    else if (*p == '0')  /* '%0' */
+        luaL_addlstring(b, s, e - s);
+    else if (isdigit(uchar(*p))) {  /* '%n' */
+      const char *cap;
+      ptrdiff_t resl = get_onecapture(ms, *p - '1', s, e, &cap);
+      if (resl == CAP_POSITION)
+        luaL_addvalue(b);  /* add position to accumulated result */
+      else
+        luaL_addlstring(b, cap, resl);
     }
+    else
+      luaL_error(L, "invalid use of '%c' in replacement string", L_ESC);
+    l -= p + 1 - news;
+    news = p + 1;
   }
+  luaL_addlstring(b, news, l);
 }
 
 
-static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
-                                       const char *e, int tr) {
+/*
+** Add the replacement value to the string buffer 'b'.
+** Return true if the original string was changed. (Function calls and
+** table indexing resulting in nil or false do not change the subject.)
+*/
+static int add_value (MatchState *ms, luaL_Buffer *b, const char *s,
+                                      const char *e, int tr) {
   lua_State *L = ms->L;
   switch (tr) {
-    case LUA_TFUNCTION: {
+    case LUA_TFUNCTION: {  /* call the function */
       int n;
-      lua_pushvalue(L, 3);
-      n = push_captures(ms, s, e);
-      lua_call(L, n, 1);
+      lua_pushvalue(L, 3);  /* push the function */
+      n = push_captures(ms, s, e);  /* all captures as arguments */
+      lua_call(L, n, 1);  /* call it */
       break;
     }
-    case LUA_TTABLE: {
-      push_onecapture(ms, 0, s, e);
+    case LUA_TTABLE: {  /* index the table */
+      push_onecapture(ms, 0, s, e);  /* first capture is the index */
       lua_gettable(L, 3);
       break;
     }
     default: {  /* LUA_TNUMBER or LUA_TSTRING */
-      add_s(ms, b, s, e);
-      return;
+      add_s(ms, b, s, e);  /* add value to the buffer */
+      return 1;  /* something changed */
     }
   }
   if (!lua_toboolean(L, -1)) {  /* nil or false? */
-    lua_pop(L, 1);
-    lua_pushlstring(L, s, e - s);  /* keep original text */
+    lua_pop(L, 1);  /* remove value */
+    luaL_addlstring(b, s, e - s);  /* keep original text */
+    return 0;  /* no changes */
   }
   else if (!lua_isstring(L, -1))
-    luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1));
-  luaL_addvalue(b);  /* add result to accumulator */
+    return luaL_error(L, "invalid replacement value (a %s)",
+                         luaL_typename(L, -1));
+  else {
+    luaL_addvalue(b);  /* add result to accumulator */
+    return 1;  /* something changed */
+  }
 }
 
 
@@ -768,11 +945,12 @@ static int str_gsub (lua_State *L) {
   lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1);  /* max replacements */
   int anchor = (*p == '^');
   lua_Integer n = 0;  /* replacement count */
+  int changed = 0;  /* change flag */
   MatchState ms;
   luaL_Buffer b;
-  luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
+  luaL_argexpected(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
                    tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3,
-                      "string/function/table expected");
+                      "string/function/table");
   luaL_buffinit(L, &b);
   if (anchor) {
     p++; lp--;  /* skip anchor character */
@@ -783,7 +961,7 @@ static int str_gsub (lua_State *L) {
     reprepstate(&ms);  /* (re)prepare state for new match */
     if ((e = match(&ms, src, p)) != NULL && e != lastmatch) {  /* match? */
       n++;
-      add_value(&ms, &b, src, e, tr);  /* add replacement to buffer */
+      changed = add_value(&ms, &b, src, e, tr) | changed;
       src = lastmatch = e;
     }
     else if (src < ms.src_end)  /* otherwise, skip one character */
@@ -791,8 +969,12 @@ static int str_gsub (lua_State *L) {
     else break;  /* end of subject */
     if (anchor) break;
   }
-  luaL_addlstring(&b, src, ms.src_end-src);
-  luaL_pushresult(&b);
+  if (!changed)  /* no changes? */
+    lua_pushvalue(L, 1);  /* return original string */
+  else {  /* something changed */
+    luaL_addlstring(&b, src, ms.src_end-src);
+    luaL_pushresult(&b);  /* create and return new string */
+  }
   lua_pushinteger(L, n);  /* number of substitutions */
   return 2;
 }
@@ -813,8 +995,6 @@ static int str_gsub (lua_State *L) {
 ** Hexadecimal floating-point formatter
 */
 
-#include <math.h>
-
 #define SIZELENMOD	(sizeof(LUA_NUMBER_FRMLEN)/sizeof(char))
 
 
@@ -824,7 +1004,7 @@ static int str_gsub (lua_State *L) {
 ** to nibble boundaries by making what is left after that first digit a
 ** multiple of 4.
 */
-#define L_NBFD		((l_mathlim(MANT_DIG) - 1)%4 + 1)
+#define L_NBFD		((l_floatatt(MANT_DIG) - 1)%4 + 1)
 
 
 /*
@@ -851,7 +1031,7 @@ static int num2straux (char *buff, int sz, lua_Number x) {
     lua_Number m = l_mathop(frexp)(x, &e);  /* 'x' fraction and exponent */
     int n = 0;  /* character count */
     if (m < 0) {  /* is number negative? */
-      buff[n++] = '-';  /* add signal */
+      buff[n++] = '-';  /* add sign */
       m = -m;  /* make it positive */
     }
     buff[n++] = '0'; buff[n++] = 'x';  /* add "0x" */
@@ -887,17 +1067,30 @@ static int lua_number2strx (lua_State *L, char *buff, int sz,
 
 
 /*
-** Maximum size of each formatted item. This maximum size is produced
+** Maximum size for items formatted with '%f'. This size is produced
 ** by format('%.99f', -maxfloat), and is equal to 99 + 3 ('-', '.',
 ** and '\0') + number of decimal digits to represent maxfloat (which
-** is maximum exponent + 1). (99+3+1 then rounded to 120 for "extra
-** expenses", such as locale-dependent stuff)
+** is maximum exponent + 1). (99+3+1, adding some extra, 110)
 */
-#define MAX_ITEM        (120 + l_mathlim(MAX_10_EXP))
+#define MAX_ITEMF	(110 + l_floatatt(MAX_10_EXP))
+
+
+/*
+** All formats except '%f' do not need that large limit.  The other
+** float formats use exponents, so that they fit in the 99 limit for
+** significant digits; 's' for large strings and 'q' add items directly
+** to the buffer; all integer formats also fit in the 99 limit.  The
+** worst case are floats: they may need 99 significant digits, plus
+** '0x', '-', '.', 'e+XXXX', and '\0'. Adding some extra, 120.
+*/
+#define MAX_ITEM	120
 
 
 /* valid flags in a format specification */
-#define FLAGS	"-+ #0"
+#if !defined(L_FMTFLAGS)
+#define L_FMTFLAGS	"-+ #0"
+#endif
+
 
 /*
 ** maximum size of each format specification (such as "%-099.99d")
@@ -929,14 +1122,32 @@ static void addquoted (luaL_Buffer *b, const char *s, size_t len) {
 
 
 /*
-** Ensures the 'buff' string uses a dot as the radix character.
+** Serialize a floating-point number in such a way that it can be
+** scanned back by Lua. Use hexadecimal format for "common" numbers
+** (to preserve precision); inf, -inf, and NaN are handled separately.
+** (NaN cannot be expressed as a numeral, so we write '(0/0)' for it.)
 */
-static void checkdp (char *buff, int nb) {
-  if (memchr(buff, '.', nb) == NULL) {  /* no dot? */
-    char point = lua_getlocaledecpoint();  /* try locale point */
-    char *ppoint = (char *)memchr(buff, point, nb);
-    if (ppoint) *ppoint = '.';  /* change it to a dot */
+static int quotefloat (lua_State *L, char *buff, lua_Number n) {
+  const char *s;  /* for the fixed representations */
+  if (n == (lua_Number)HUGE_VAL)  /* inf? */
+    s = "1e9999";
+  else if (n == -(lua_Number)HUGE_VAL)  /* -inf? */
+    s = "-1e9999";
+  else if (n != n)  /* NaN? */
+    s = "(0/0)";
+  else {  /* format number as hexadecimal */
+    int  nb = lua_number2strx(L, buff, MAX_ITEM,
+                                 "%" LUA_NUMBER_FRMLEN "a", n);
+    /* ensures that 'buff' string uses a dot as the radix character */
+    if (memchr(buff, '.', nb) == NULL) {  /* no dot? */
+      char point = lua_getlocaledecpoint();  /* try locale point */
+      char *ppoint = (char *)memchr(buff, point, nb);
+      if (ppoint) *ppoint = '.';  /* change it to a dot */
+    }
+    return nb;
   }
+  /* for the fixed representations */
+  return l_sprintf(buff, MAX_ITEM, "%s", s);
 }
 
 
@@ -951,15 +1162,12 @@ static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
     case LUA_TNUMBER: {
       char *buff = luaL_prepbuffsize(b, MAX_ITEM);
       int nb;
-      if (!lua_isinteger(L, arg)) {  /* float? */
-        lua_Number n = lua_tonumber(L, arg);  /* write as hexa ('%a') */
-        nb = lua_number2strx(L, buff, MAX_ITEM, "%" LUA_NUMBER_FRMLEN "a", n);
-        checkdp(buff, nb);  /* ensure it uses a dot */
-      }
+      if (!lua_isinteger(L, arg))  /* float? */
+        nb = quotefloat(L, buff, lua_tonumber(L, arg));
       else {  /* integers */
         lua_Integer n = lua_tointeger(L, arg);
         const char *format = (n == LUA_MININTEGER)  /* corner case? */
-                           ? "0x%" LUA_INTEGER_FRMLEN "x"  /* use hexa */
+                           ? "0x%" LUA_INTEGER_FRMLEN "x"  /* use hex */
                            : LUA_INTEGER_FMT;  /* else use default format */
         nb = l_sprintf(buff, MAX_ITEM, format, (LUAI_UACINT)n);
       }
@@ -980,8 +1188,8 @@ static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
 
 static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
   const char *p = strfrmt;
-  while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++;  /* skip flags */
-  if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char))
+  while (*p != '\0' && strchr(L_FMTFLAGS, *p) != NULL) p++;  /* skip flags */
+  if ((size_t)(p - strfrmt) >= sizeof(L_FMTFLAGS)/sizeof(char))
     luaL_error(L, "invalid format (repeated flags)");
   if (isdigit(uchar(*p))) p++;  /* skip width */
   if (isdigit(uchar(*p))) p++;  /* (2 digits at most) */
@@ -1028,36 +1236,51 @@ static int str_format (lua_State *L) {
       luaL_addchar(&b, *strfrmt++);  /* %% */
     else { /* format item */
       char form[MAX_FORMAT];  /* to store the format ('%...') */
-      char *buff = luaL_prepbuffsize(&b, MAX_ITEM);  /* to put formatted item */
+      int maxitem = MAX_ITEM;
+      char *buff = luaL_prepbuffsize(&b, maxitem);  /* to put formatted item */
       int nb = 0;  /* number of bytes in added item */
       if (++arg > top)
-        luaL_argerror(L, arg, "no value");
+        return luaL_argerror(L, arg, "no value");
       strfrmt = scanformat(L, strfrmt, form);
       switch (*strfrmt++) {
         case 'c': {
-          nb = l_sprintf(buff, MAX_ITEM, form, (int)luaL_checkinteger(L, arg));
+          nb = l_sprintf(buff, maxitem, form, (int)luaL_checkinteger(L, arg));
           break;
         }
         case 'd': case 'i':
         case 'o': case 'u': case 'x': case 'X': {
           lua_Integer n = luaL_checkinteger(L, arg);
           addlenmod(form, LUA_INTEGER_FRMLEN);
-          nb = l_sprintf(buff, MAX_ITEM, form, (LUAI_UACINT)n);
+          nb = l_sprintf(buff, maxitem, form, (LUAI_UACINT)n);
           break;
         }
         case 'a': case 'A':
           addlenmod(form, LUA_NUMBER_FRMLEN);
-          nb = lua_number2strx(L, buff, MAX_ITEM, form,
+          nb = lua_number2strx(L, buff, maxitem, form,
                                   luaL_checknumber(L, arg));
           break;
-        case 'e': case 'E': case 'f':
-        case 'g': case 'G': {
+        case 'f':
+          maxitem = MAX_ITEMF;  /* extra space for '%f' */
+          buff = luaL_prepbuffsize(&b, maxitem);
+          /* FALLTHROUGH */
+        case 'e': case 'E': case 'g': case 'G': {
           lua_Number n = luaL_checknumber(L, arg);
           addlenmod(form, LUA_NUMBER_FRMLEN);
-          nb = l_sprintf(buff, MAX_ITEM, form, (LUAI_UACNUMBER)n);
+          nb = l_sprintf(buff, maxitem, form, (LUAI_UACNUMBER)n);
+          break;
+        }
+        case 'p': {
+          const void *p = lua_topointer(L, arg);
+          if (p == NULL) {  /* avoid calling 'printf' with argument NULL */
+            p = "(null)";  /* result */
+            form[strlen(form) - 1] = 's';  /* format it as a string */
+          }
+          nb = l_sprintf(buff, maxitem, form, p);
           break;
         }
         case 'q': {
+          if (form[2] != '\0')  /* modifiers? */
+            return luaL_error(L, "specifier '%%q' cannot have modifiers");
           addliteral(L, &b, arg);
           break;
         }
@@ -1073,18 +1296,17 @@ static int str_format (lua_State *L) {
               luaL_addvalue(&b);  /* keep entire string */
             }
             else {  /* format the string into 'buff' */
-              nb = l_sprintf(buff, MAX_ITEM, form, s);
+              nb = l_sprintf(buff, maxitem, form, s);
               lua_pop(L, 1);  /* remove result from 'luaL_tolstring' */
             }
           }
           break;
         }
         default: {  /* also treat cases 'pnLlh' */
-          return luaL_error(L, "invalid option '%%%c' to 'format'",
-                               *(strfrmt - 1));
+          return luaL_error(L, "invalid conversion '%s' to 'format'", form);
         }
       }
-      lua_assert(nb < MAX_ITEM);
+      lua_assert(nb < maxitem);
       luaL_addsize(&b, nb);
     }
   }
@@ -1422,17 +1644,12 @@ static int str_packsize (lua_State *L) {
   while (*fmt != '\0') {
     int size, ntoalign;
     KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign);
+    luaL_argcheck(L, opt != Kstring && opt != Kzstr, 1,
+                     "variable-length format");
     size += ntoalign;  /* total space used by option */
     luaL_argcheck(L, totalsize <= MAXSIZE - size, 1,
                      "format result too large");
     totalsize += size;
-    switch (opt) {
-      case Kstring:  /* strings with length count */
-      case Kzstr:    /* zero-terminated string */
-        luaL_argerror(L, 1, "variable-length format");
-        /* call never return, but to avoid warnings: *//* FALLTHROUGH */
-      default:  break;
-    }
   }
   lua_pushinteger(L, (lua_Integer)totalsize);
   return 1;
@@ -1478,15 +1695,15 @@ static int str_unpack (lua_State *L) {
   const char *fmt = luaL_checkstring(L, 1);
   size_t ld;
   const char *data = luaL_checklstring(L, 2, &ld);
-  size_t pos = (size_t)posrelat(luaL_optinteger(L, 3, 1), ld) - 1;
+  size_t pos = posrelatI(luaL_optinteger(L, 3, 1), ld) - 1;
   int n = 0;  /* number of results */
   luaL_argcheck(L, pos <= ld, 3, "initial position out of string");
   initheader(L, &h);
   while (*fmt != '\0') {
     int size, ntoalign;
     KOption opt = getdetails(&h, pos, &fmt, &size, &ntoalign);
-    if ((size_t)ntoalign + size > ~pos || pos + ntoalign + size > ld)
-      luaL_argerror(L, 2, "data string too short");
+    luaL_argcheck(L, (size_t)ntoalign + size <= ld - pos, 2,
+                    "data string too short");
     pos += ntoalign;  /* skip alignment */
     /* stack space for item + next position */
     luaL_checkstack(L, 2, "too many results");
@@ -1515,13 +1732,15 @@ static int str_unpack (lua_State *L) {
       }
       case Kstring: {
         size_t len = (size_t)unpackint(L, data + pos, h.islittle, size, 0);
-        luaL_argcheck(L, pos + len + size <= ld, 2, "data string too short");
+        luaL_argcheck(L, len <= ld - pos - size, 2, "data string too short");
         lua_pushlstring(L, data + pos + size, len);
         pos += len;  /* skip string */
         break;
       }
       case Kzstr: {
         size_t len = (int)strlen(data + pos);
+        luaL_argcheck(L, pos + len < ld, 2,
+                         "unfinished string for format 'z'");
         lua_pushlstring(L, data + pos, len);
         pos += len + 1;  /* skip string plus final '\0' */
         break;
@@ -1562,7 +1781,9 @@ static const luaL_Reg strlib[] = {
 
 
 static void createmetatable (lua_State *L) {
-  lua_createtable(L, 0, 1);  /* table to be metatable for strings */
+  /* table to be metatable for strings */
+  luaL_newlibtable(L, stringmetamethods);
+  luaL_setfuncs(L, stringmetamethods, 0);
   lua_pushliteral(L, "");  /* dummy string */
   lua_pushvalue(L, -2);  /* copy table */
   lua_setmetatable(L, -2);  /* set table as metatable for strings */
diff --git a/libs/liblua/src/ltable.c b/libs/liblua/src/ltable.c
index ea4fe7fcb3..d7eb69a2e1 100644
--- a/libs/liblua/src/ltable.c
+++ b/libs/liblua/src/ltable.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltable.c,v 2.118.1.4 2018/06/08 16:22:51 roberto Exp $
+** $Id: ltable.c $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
@@ -40,21 +40,34 @@
 
 
 /*
-** Maximum size of array part (MAXASIZE) is 2^MAXABITS. MAXABITS is
-** the largest integer such that MAXASIZE fits in an unsigned int.
+** MAXABITS is the largest integer such that MAXASIZE fits in an
+** unsigned int.
 */
 #define MAXABITS	cast_int(sizeof(int) * CHAR_BIT - 1)
-#define MAXASIZE	(1u << MAXABITS)
+
 
 /*
-** Maximum size of hash part is 2^MAXHBITS. MAXHBITS is the largest
-** integer such that 2^MAXHBITS fits in a signed int. (Note that the
-** maximum number of elements in a table, 2^MAXABITS + 2^MAXHBITS, still
-** fits comfortably in an unsigned int.)
+** MAXASIZE is the maximum size of the array part. It is the minimum
+** between 2^MAXABITS and the maximum size that, measured in bytes,
+** fits in a 'size_t'.
+*/
+#define MAXASIZE	luaM_limitN(1u << MAXABITS, TValue)
+
+/*
+** MAXHBITS is the largest integer such that 2^MAXHBITS fits in a
+** signed int.
 */
 #define MAXHBITS	(MAXABITS - 1)
 
 
+/*
+** MAXHSIZE is the maximum size of the hash part. It is the minimum
+** between 2^MAXHBITS and the maximum size such that, measured in bytes,
+** it fits in a 'size_t'.
+*/
+#define MAXHSIZE	luaM_limitN(1u << MAXHBITS, Node)
+
+
 #define hashpow2(t,n)		(gnode(t, lmod((n), sizenode(t))))
 
 #define hashstr(t,str)		hashpow2(t, (str)->hash)
@@ -75,11 +88,15 @@
 #define dummynode		(&dummynode_)
 
 static const Node dummynode_ = {
-  {NILCONSTANT},  /* value */
-  {{NILCONSTANT, 0}}  /* key */
+  {{NULL}, LUA_VEMPTY,  /* value's value and type */
+   LUA_VNIL, 0, {NULL}}  /* key type, next, and key value */
 };
 
 
+static const TValue absentkey = {ABSTKEYCONSTANT};
+
+
+
 /*
 ** Hash for floating-point numbers.
 ** The main computation should be just
@@ -103,51 +120,162 @@ static int l_hashfloat (lua_Number n) {
     return 0;
   }
   else {  /* normal case */
-    unsigned int u = cast(unsigned int, i) + cast(unsigned int, ni);
-    return cast_int(u <= cast(unsigned int, INT_MAX) ? u : ~u);
+    unsigned int u = cast_uint(i) + cast_uint(ni);
+    return cast_int(u <= cast_uint(INT_MAX) ? u : ~u);
   }
 }
 #endif
 
 
 /*
-** returns the 'main' position of an element in a table (that is, the index
-** of its hash value)
-*/
-static Node *mainposition (const Table *t, const TValue *key) {
-  switch (ttype(key)) {
-    case LUA_TNUMINT:
-      return hashint(t, ivalue(key));
-    case LUA_TNUMFLT:
-      return hashmod(t, l_hashfloat(fltvalue(key)));
-    case LUA_TSHRSTR:
-      return hashstr(t, tsvalue(key));
-    case LUA_TLNGSTR:
-      return hashpow2(t, luaS_hashlongstr(tsvalue(key)));
-    case LUA_TBOOLEAN:
-      return hashboolean(t, bvalue(key));
-    case LUA_TLIGHTUSERDATA:
-      return hashpointer(t, pvalue(key));
-    case LUA_TLCF:
-      return hashpointer(t, fvalue(key));
+** returns the 'main' position of an element in a table (that is,
+** the index of its hash value). The key comes broken (tag in 'ktt'
+** and value in 'vkl') so that we can call it on keys inserted into
+** nodes.
+*/
+static Node *mainposition (const Table *t, int ktt, const Value *kvl) {
+  switch (withvariant(ktt)) {
+    case LUA_VNUMINT:
+      return hashint(t, ivalueraw(*kvl));
+    case LUA_VNUMFLT:
+      return hashmod(t, l_hashfloat(fltvalueraw(*kvl)));
+    case LUA_VSHRSTR:
+      return hashstr(t, tsvalueraw(*kvl));
+    case LUA_VLNGSTR:
+      return hashpow2(t, luaS_hashlongstr(tsvalueraw(*kvl)));
+    case LUA_VFALSE:
+      return hashboolean(t, 0);
+    case LUA_VTRUE:
+      return hashboolean(t, 1);
+    case LUA_VLIGHTUSERDATA:
+      return hashpointer(t, pvalueraw(*kvl));
+    case LUA_VLCF:
+      return hashpointer(t, fvalueraw(*kvl));
     default:
-      lua_assert(!ttisdeadkey(key));
-      return hashpointer(t, gcvalue(key));
+      return hashpointer(t, gcvalueraw(*kvl));
+  }
+}
+
+
+/*
+** Returns the main position of an element given as a 'TValue'
+*/
+static Node *mainpositionTV (const Table *t, const TValue *key) {
+  return mainposition(t, rawtt(key), valraw(key));
+}
+
+
+/*
+** Check whether key 'k1' is equal to the key in node 'n2'.
+** This equality is raw, so there are no metamethods. Floats
+** with integer values have been normalized, so integers cannot
+** be equal to floats. It is assumed that 'eqshrstr' is simply
+** pointer equality, so that short strings are handled in the
+** default case.
+*/
+static int equalkey (const TValue *k1, const Node *n2) {
+  if (rawtt(k1) != keytt(n2))  /* not the same variants? */
+   return 0;  /* cannot be same key */
+  switch (ttypetag(k1)) {
+    case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE:
+      return 1;
+    case LUA_VNUMINT:
+      return (ivalue(k1) == keyival(n2));
+    case LUA_VNUMFLT:
+      return luai_numeq(fltvalue(k1), fltvalueraw(keyval(n2)));
+    case LUA_VLIGHTUSERDATA:
+      return pvalue(k1) == pvalueraw(keyval(n2));
+    case LUA_VLCF:
+      return fvalue(k1) == fvalueraw(keyval(n2));
+    case LUA_VLNGSTR:
+      return luaS_eqlngstr(tsvalue(k1), keystrval(n2));
+    default:
+      return gcvalue(k1) == gcvalueraw(keyval(n2));
+  }
+}
+
+
+/*
+** True if value of 'alimit' is equal to the real size of the array
+** part of table 't'. (Otherwise, the array part must be larger than
+** 'alimit'.)
+*/
+#define limitequalsasize(t)	(isrealasize(t) || ispow2((t)->alimit))
+
+
+/*
+** Returns the real size of the 'array' array
+*/
+LUAI_FUNC unsigned int luaH_realasize (const Table *t) {
+  if (limitequalsasize(t))
+    return t->alimit;  /* this is the size */
+  else {
+    unsigned int size = t->alimit;
+    /* compute the smallest power of 2 not smaller than 'n' */
+    size |= (size >> 1);
+    size |= (size >> 2);
+    size |= (size >> 4);
+    size |= (size >> 8);
+    size |= (size >> 16);
+#if (UINT_MAX >> 30) > 3
+    size |= (size >> 32);  /* unsigned int has more than 32 bits */
+#endif
+    size++;
+    lua_assert(ispow2(size) && size/2 < t->alimit && t->alimit < size);
+    return size;
   }
 }
 
 
 /*
-** returns the index for 'key' if 'key' is an appropriate key to live in
-** the array part of the table, 0 otherwise.
+** Check whether real size of the array is a power of 2.
+** (If it is not, 'alimit' cannot be changed to any other value
+** without changing the real size.)
+*/
+static int ispow2realasize (const Table *t) {
+  return (!isrealasize(t) || ispow2(t->alimit));
+}
+
+
+static unsigned int setlimittosize (Table *t) {
+  t->alimit = luaH_realasize(t);
+  setrealasize(t);
+  return t->alimit;
+}
+
+
+#define limitasasize(t)	check_exp(isrealasize(t), t->alimit)
+
+
+
+/*
+** "Generic" get version. (Not that generic: not valid for integers,
+** which may be in array part, nor for floats with integral values.)
 */
-static unsigned int arrayindex (const TValue *key) {
-  if (ttisinteger(key)) {
-    lua_Integer k = ivalue(key);
-    if (0 < k && (lua_Unsigned)k <= MAXASIZE)
-      return cast(unsigned int, k);  /* 'key' is an appropriate array index */
+static const TValue *getgeneric (Table *t, const TValue *key) {
+  Node *n = mainpositionTV(t, key);
+  for (;;) {  /* check whether 'key' is somewhere in the chain */
+    if (equalkey(key, n))
+      return gval(n);  /* that's it */
+    else {
+      int nx = gnext(n);
+      if (nx == 0)
+        return &absentkey;  /* not found */
+      n += nx;
+    }
   }
-  return 0;  /* 'key' did not match some condition */
+}
+
+
+/*
+** returns the index for 'k' if 'k' is an appropriate key to live in
+** the array part of a table, 0 otherwise.
+*/
+static unsigned int arrayindex (lua_Integer k) {
+  if (l_castS2U(k) - 1u < MAXASIZE)  /* 'k' in [1, MAXASIZE]? */
+    return cast_uint(k);  /* 'key' is an appropriate array index */
+  else
+    return 0;
 }
 
 
@@ -156,46 +284,39 @@ static unsigned int arrayindex (const TValue *key) {
 ** elements in the array part, then elements in the hash part. The
 ** beginning of a traversal is signaled by 0.
 */
-static unsigned int findindex (lua_State *L, Table *t, StkId key) {
+static unsigned int findindex (lua_State *L, Table *t, TValue *key,
+                               unsigned int asize) {
   unsigned int i;
   if (ttisnil(key)) return 0;  /* first iteration */
-  i = arrayindex(key);
-  if (i != 0 && i <= t->sizearray)  /* is 'key' inside array part? */
+  i = ttisinteger(key) ? arrayindex(ivalue(key)) : 0;
+  if (i - 1u < asize)  /* is 'key' inside array part? */
     return i;  /* yes; that's the index */
   else {
-    int nx;
-    Node *n = mainposition(t, key);
-    for (;;) {  /* check whether 'key' is somewhere in the chain */
-      /* key may be dead already, but it is ok to use it in 'next' */
-      if (luaV_rawequalobj(gkey(n), key) ||
-            (ttisdeadkey(gkey(n)) && iscollectable(key) &&
-             deadvalue(gkey(n)) == gcvalue(key))) {
-        i = cast_int(n - gnode(t, 0));  /* key index in hash table */
-        /* hash elements are numbered after array ones */
-        return (i + 1) + t->sizearray;
-      }
-      nx = gnext(n);
-      if (nx == 0)
-        luaG_runerror(L, "invalid key to 'next'");  /* key not found */
-      else n += nx;
-    }
+    const TValue *n = getgeneric(t, key);
+    if (unlikely(isabstkey(n)))
+      luaG_runerror(L, "invalid key to 'next'");  /* key not found */
+    i = cast_int(nodefromval(n) - gnode(t, 0));  /* key index in hash table */
+    /* hash elements are numbered after array ones */
+    return (i + 1) + asize;
   }
 }
 
 
 int luaH_next (lua_State *L, Table *t, StkId key) {
-  unsigned int i = findindex(L, t, key);  /* find original element */
-  for (; i < t->sizearray; i++) {  /* try first array part */
-    if (!ttisnil(&t->array[i])) {  /* a non-nil value? */
-      setivalue(key, i + 1);
-      setobj2s(L, key+1, &t->array[i]);
+  unsigned int asize = luaH_realasize(t);
+  unsigned int i = findindex(L, t, s2v(key), asize);  /* find original key */
+  for (; i < asize; i++) {  /* try first array part */
+    if (!isempty(&t->array[i])) {  /* a non-empty entry? */
+      setivalue(s2v(key), i + 1);
+      setobj2s(L, key + 1, &t->array[i]);
       return 1;
     }
   }
-  for (i -= t->sizearray; cast_int(i) < sizenode(t); i++) {  /* hash part */
-    if (!ttisnil(gval(gnode(t, i)))) {  /* a non-nil value? */
-      setobj2s(L, key, gkey(gnode(t, i)));
-      setobj2s(L, key+1, gval(gnode(t, i)));
+  for (i -= asize; cast_int(i) < sizenode(t); i++) {  /* hash part */
+    if (!isempty(gval(gnode(t, i)))) {  /* a non-empty entry? */
+      Node *n = gnode(t, i);
+      getnodekey(L, s2v(key), n);
+      setobj2s(L, key + 1, gval(n));
       return 1;
     }
   }
@@ -203,6 +324,12 @@ int luaH_next (lua_State *L, Table *t, StkId key) {
 }
 
 
+static void freehash (lua_State *L, Table *t) {
+  if (!isdummy(t))
+    luaM_freearray(L, t->node, cast_sizet(sizenode(t)));
+}
+
+
 /*
 ** {=============================================================
 ** Rehash
@@ -214,7 +341,8 @@ int luaH_next (lua_State *L, Table *t, StkId key) {
 ** "count array" where 'nums[i]' is the number of integers in the table
 ** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of
 ** integer keys in the table and leaves with the number of keys that
-** will go to the array part; return the optimal size.
+** will go to the array part; return the optimal size.  (The condition
+** 'twotoi > 0' in the for loop stops the loop if 'twotoi' overflows.)
 */
 static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
   int i;
@@ -226,12 +354,10 @@ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
   for (i = 0, twotoi = 1;
        twotoi > 0 && *pna > twotoi / 2;
        i++, twotoi *= 2) {
-    if (nums[i] > 0) {
-      a += nums[i];
-      if (a > twotoi/2) {  /* more than half elements present? */
-        optimal = twotoi;  /* optimal size (till now) */
-        na = a;  /* all elements up to 'optimal' will go to array part */
-      }
+    a += nums[i];
+    if (a > twotoi/2) {  /* more than half elements present? */
+      optimal = twotoi;  /* optimal size (till now) */
+      na = a;  /* all elements up to 'optimal' will go to array part */
     }
   }
   lua_assert((optimal == 0 || optimal / 2 < na) && na <= optimal);
@@ -240,7 +366,7 @@ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
 }
 
 
-static int countint (const TValue *key, unsigned int *nums) {
+static int countint (lua_Integer key, unsigned int *nums) {
   unsigned int k = arrayindex(key);
   if (k != 0) {  /* is 'key' an appropriate array index? */
     nums[luaO_ceillog2(k)]++;  /* count as such */
@@ -261,18 +387,19 @@ static unsigned int numusearray (const Table *t, unsigned int *nums) {
   unsigned int ttlg;  /* 2^lg */
   unsigned int ause = 0;  /* summation of 'nums' */
   unsigned int i = 1;  /* count to traverse all array keys */
+  unsigned int asize = limitasasize(t);  /* real array size */
   /* traverse each slice */
   for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) {
     unsigned int lc = 0;  /* counter */
     unsigned int lim = ttlg;
-    if (lim > t->sizearray) {
-      lim = t->sizearray;  /* adjust upper limit */
+    if (lim > asize) {
+      lim = asize;  /* adjust upper limit */
       if (i > lim)
         break;  /* no more elements to count */
     }
     /* count elements in range (2^(lg - 1), 2^lg] */
     for (; i <= lim; i++) {
-      if (!ttisnil(&t->array[i-1]))
+      if (!isempty(&t->array[i-1]))
         lc++;
     }
     nums[lg] += lc;
@@ -288,8 +415,9 @@ static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) {
   int i = sizenode(t);
   while (i--) {
     Node *n = &t->node[i];
-    if (!ttisnil(gval(n))) {
-      ause += countint(gkey(n), nums);
+    if (!isempty(gval(n))) {
+      if (keyisinteger(n))
+        ause += countint(keyival(n), nums);
       totaluse++;
     }
   }
@@ -298,15 +426,13 @@ static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) {
 }
 
 
-static void setarrayvector (lua_State *L, Table *t, unsigned int size) {
-  unsigned int i;
-  luaM_reallocvector(L, t->array, t->sizearray, size, TValue);
-  for (i=t->sizearray; i<size; i++)
-     setnilvalue(&t->array[i]);
-  t->sizearray = size;
-}
-
-
+/*
+** Creates an array for the hash part of a table with the given
+** size, or reuses the dummy node if size is zero.
+** The computation for size overflow is in two steps: the first
+** comparison ensures that the shift in the second one does not
+** overflow.
+*/
 static void setnodevector (lua_State *L, Table *t, unsigned int size) {
   if (size == 0) {  /* no elements to hash part? */
     t->node = cast(Node *, dummynode);  /* use common 'dummynode' */
@@ -316,15 +442,15 @@ static void setnodevector (lua_State *L, Table *t, unsigned int size) {
   else {
     int i;
     int lsize = luaO_ceillog2(size);
-    if (lsize > MAXHBITS)
+    if (lsize > MAXHBITS || (1u << lsize) > MAXHSIZE)
       luaG_runerror(L, "table overflow");
     size = twoto(lsize);
     t->node = luaM_newvector(L, size, Node);
     for (i = 0; i < (int)size; i++) {
       Node *n = gnode(t, i);
       gnext(n) = 0;
-      setnilvalue(wgkey(n));
-      setnilvalue(gval(n));
+      setnilkey(n);
+      setempty(gval(n));
     }
     t->lsizenode = cast_byte(lsize);
     t->lastfree = gnode(t, size);  /* all positions are free */
@@ -332,55 +458,88 @@ static void setnodevector (lua_State *L, Table *t, unsigned int size) {
 }
 
 
-typedef struct {
-  Table *t;
-  unsigned int nhsize;
-} AuxsetnodeT;
+/*
+** (Re)insert all elements from the hash part of 'ot' into table 't'.
+*/
+static void reinsert (lua_State *L, Table *ot, Table *t) {
+  int j;
+  int size = sizenode(ot);
+  for (j = 0; j < size; j++) {
+    Node *old = gnode(ot, j);
+    if (!isempty(gval(old))) {
+      /* doesn't need barrier/invalidate cache, as entry was
+         already present in the table */
+      TValue k;
+      getnodekey(L, &k, old);
+      setobjt2t(L, luaH_set(L, t, &k), gval(old));
+    }
+  }
+}
 
 
-static void auxsetnode (lua_State *L, void *ud) {
-  AuxsetnodeT *asn = cast(AuxsetnodeT *, ud);
-  setnodevector(L, asn->t, asn->nhsize);
+/*
+** Exchange the hash part of 't1' and 't2'.
+*/
+static void exchangehashpart (Table *t1, Table *t2) {
+  lu_byte lsizenode = t1->lsizenode;
+  Node *node = t1->node;
+  Node *lastfree = t1->lastfree;
+  t1->lsizenode = t2->lsizenode;
+  t1->node = t2->node;
+  t1->lastfree = t2->lastfree;
+  t2->lsizenode = lsizenode;
+  t2->node = node;
+  t2->lastfree = lastfree;
 }
 
 
-void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
+/*
+** Resize table 't' for the new given sizes. Both allocations (for
+** the hash part and for the array part) can fail, which creates some
+** subtleties. If the first allocation, for the hash part, fails, an
+** error is raised and that is it. Otherwise, it copies the elements from
+** the shrinking part of the array (if it is shrinking) into the new
+** hash. Then it reallocates the array part.  If that fails, the table
+** is in its original state; the function frees the new hash part and then
+** raises the allocation error. Otherwise, it sets the new hash part
+** into the table, initializes the new part of the array (if any) with
+** nils and reinserts the elements of the old hash back into the new
+** parts of the table.
+*/
+void luaH_resize (lua_State *L, Table *t, unsigned int newasize,
                                           unsigned int nhsize) {
   unsigned int i;
-  int j;
-  AuxsetnodeT asn;
-  unsigned int oldasize = t->sizearray;
-  int oldhsize = allocsizenode(t);
-  Node *nold = t->node;  /* save old hash ... */
-  if (nasize > oldasize)  /* array part must grow? */
-    setarrayvector(L, t, nasize);
-  /* create new hash part with appropriate size */
-  asn.t = t; asn.nhsize = nhsize;
-  if (luaD_rawrunprotected(L, auxsetnode, &asn) != LUA_OK) {  /* mem. error? */
-    setarrayvector(L, t, oldasize);  /* array back to its original size */
-    luaD_throw(L, LUA_ERRMEM);  /* rethrow memory error */
-  }
-  if (nasize < oldasize) {  /* array part must shrink? */
-    t->sizearray = nasize;
-    /* re-insert elements from vanishing slice */
-    for (i=nasize; i<oldasize; i++) {
-      if (!ttisnil(&t->array[i]))
+  Table newt;  /* to keep the new hash part */
+  unsigned int oldasize = setlimittosize(t);
+  TValue *newarray;
+  /* create new hash part with appropriate size into 'newt' */
+  setnodevector(L, &newt, nhsize);
+  if (newasize < oldasize) {  /* will array shrink? */
+    t->alimit = newasize;  /* pretend array has new size... */
+    exchangehashpart(t, &newt);  /* and new hash */
+    /* re-insert into the new hash the elements from vanishing slice */
+    for (i = newasize; i < oldasize; i++) {
+      if (!isempty(&t->array[i]))
         luaH_setint(L, t, i + 1, &t->array[i]);
     }
-    /* shrink array */
-    luaM_reallocvector(L, t->array, oldasize, nasize, TValue);
+    t->alimit = oldasize;  /* restore current size... */
+    exchangehashpart(t, &newt);  /* and hash (in case of errors) */
   }
-  /* re-insert elements from hash part */
-  for (j = oldhsize - 1; j >= 0; j--) {
-    Node *old = nold + j;
-    if (!ttisnil(gval(old))) {
-      /* doesn't need barrier/invalidate cache, as entry was
-         already present in the table */
-      setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old));
-    }
+  /* allocate new array */
+  newarray = luaM_reallocvector(L, t->array, oldasize, newasize, TValue);
+  if (unlikely(newarray == NULL && newasize > 0)) {  /* allocation failed? */
+    freehash(L, &newt);  /* release new hash part */
+    luaM_error(L);  /* raise error (with array unchanged) */
   }
-  if (oldhsize > 0)  /* not the dummy node? */
-    luaM_freearray(L, nold, cast(size_t, oldhsize)); /* free old hash */
+  /* allocation ok; initialize new part of the array */
+  exchangehashpart(t, &newt);  /* 't' has the new hash ('newt' has the old) */
+  t->array = newarray;  /* set new array part */
+  t->alimit = newasize;
+  for (i = oldasize; i < newasize; i++)  /* clear new slice of the array */
+     setempty(&t->array[i]);
+  /* re-insert elements from old hash part into new parts */
+  reinsert(L, &newt, t);  /* 'newt' now has the old hash */
+  freehash(L, &newt);  /* free old hash part */
 }
 
 
@@ -399,11 +558,13 @@ static void rehash (lua_State *L, Table *t, const TValue *ek) {
   int i;
   int totaluse;
   for (i = 0; i <= MAXABITS; i++) nums[i] = 0;  /* reset counts */
+  setlimittosize(t);
   na = numusearray(t, nums);  /* count keys in array part */
   totaluse = na;  /* all those keys are integer keys */
   totaluse += numusehash(t, nums, &na);  /* count keys in hash part */
   /* count extra key */
-  na += countint(ek, nums);
+  if (ttisinteger(ek))
+    na += countint(ivalue(ek), nums);
   totaluse++;
   /* compute new size for array part */
   asize = computesizes(nums, &na);
@@ -419,21 +580,20 @@ static void rehash (lua_State *L, Table *t, const TValue *ek) {
 
 
 Table *luaH_new (lua_State *L) {
-  GCObject *o = luaC_newobj(L, LUA_TTABLE, sizeof(Table));
+  GCObject *o = luaC_newobj(L, LUA_VTABLE, sizeof(Table));
   Table *t = gco2t(o);
   t->metatable = NULL;
   t->flags = cast_byte(~0);
   t->array = NULL;
-  t->sizearray = 0;
+  t->alimit = 0;
   setnodevector(L, t, 0);
   return t;
 }
 
 
 void luaH_free (lua_State *L, Table *t) {
-  if (!isdummy(t))
-    luaM_freearray(L, t->node, cast(size_t, sizenode(t)));
-  luaM_freearray(L, t->array, t->sizearray);
+  freehash(L, t);
+  luaM_freearray(L, t->array, luaH_realasize(t));
   luaM_free(L, t);
 }
 
@@ -442,7 +602,7 @@ static Node *getfreepos (Table *t) {
   if (!isdummy(t)) {
     while (t->lastfree > t->node) {
       t->lastfree--;
-      if (ttisnil(gkey(t->lastfree)))
+      if (keyisnil(t->lastfree))
         return t->lastfree;
     }
   }
@@ -461,18 +621,20 @@ static Node *getfreepos (Table *t) {
 TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
   Node *mp;
   TValue aux;
-  if (ttisnil(key)) luaG_runerror(L, "table index is nil");
+  if (unlikely(ttisnil(key)))
+    luaG_runerror(L, "table index is nil");
   else if (ttisfloat(key)) {
+    lua_Number f = fltvalue(key);
     lua_Integer k;
-    if (luaV_tointeger(key, &k, 0)) {  /* does index fit in an integer? */
+    if (luaV_flttointeger(f, &k, F2Ieq)) {  /* does key fit in an integer? */
       setivalue(&aux, k);
       key = &aux;  /* insert it as an integer */
     }
-    else if (luai_numisnan(fltvalue(key)))
+    else if (unlikely(luai_numisnan(f)))
       luaG_runerror(L, "table index is NaN");
   }
-  mp = mainposition(t, key);
-  if (!ttisnil(gval(mp)) || isdummy(t)) {  /* main position is taken? */
+  mp = mainpositionTV(t, key);
+  if (!isempty(gval(mp)) || isdummy(t)) {  /* main position is taken? */
     Node *othern;
     Node *f = getfreepos(t);  /* get a free place */
     if (f == NULL) {  /* cannot find a free place? */
@@ -481,7 +643,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
       return luaH_set(L, t, key);  /* insert key into grown table */
     }
     lua_assert(!isdummy(t));
-    othern = mainposition(t, gkey(mp));
+    othern = mainposition(t, keytt(mp), &keyval(mp));
     if (othern != mp) {  /* is colliding node out of its main position? */
       /* yes; move colliding node into free position */
       while (othern + gnext(othern) != mp)  /* find previous */
@@ -492,7 +654,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
         gnext(f) += cast_int(mp - f);  /* correct 'next' */
         gnext(mp) = 0;  /* now 'mp' is free */
       }
-      setnilvalue(gval(mp));
+      setempty(gval(mp));
     }
     else {  /* colliding node is in its own main position */
       /* new node will go into free position */
@@ -503,24 +665,34 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
       mp = f;
     }
   }
-  setnodekey(L, &mp->i_key, key);
-  luaC_barrierback(L, t, key);
-  lua_assert(ttisnil(gval(mp)));
+  setnodekey(L, mp, key);
+  luaC_barrierback(L, obj2gco(t), key);
+  lua_assert(isempty(gval(mp)));
   return gval(mp);
 }
 
 
 /*
-** search function for integers
+** Search function for integers. If integer is inside 'alimit', get it
+** directly from the array part. Otherwise, if 'alimit' is not equal to
+** the real size of the array, key still can be in the array part. In
+** this case, try to avoid a call to 'luaH_realasize' when key is just
+** one more than the limit (so that it can be incremented without
+** changing the real size of the array).
 */
 const TValue *luaH_getint (Table *t, lua_Integer key) {
-  /* (1 <= key && key <= t->sizearray) */
-  if (l_castS2U(key) - 1 < t->sizearray)
+  if (l_castS2U(key) - 1u < t->alimit)  /* 'key' in [1, t->alimit]? */
     return &t->array[key - 1];
+  else if (!limitequalsasize(t) &&  /* key still may be in the array part? */
+           (l_castS2U(key) == t->alimit + 1 ||
+            l_castS2U(key) - 1u < luaH_realasize(t))) {
+    t->alimit = cast_uint(key);  /* probably '#t' is here now */
+    return &t->array[key - 1];
+  }
   else {
     Node *n = hashint(t, key);
     for (;;) {  /* check whether 'key' is somewhere in the chain */
-      if (ttisinteger(gkey(n)) && ivalue(gkey(n)) == key)
+      if (keyisinteger(n) && keyival(n) == key)
         return gval(n);  /* that's it */
       else {
         int nx = gnext(n);
@@ -528,7 +700,7 @@ const TValue *luaH_getint (Table *t, lua_Integer key) {
         n += nx;
       }
     }
-    return luaO_nilobject;
+    return &absentkey;
   }
 }
 
@@ -538,34 +710,14 @@ const TValue *luaH_getint (Table *t, lua_Integer key) {
 */
 const TValue *luaH_getshortstr (Table *t, TString *key) {
   Node *n = hashstr(t, key);
-  lua_assert(key->tt == LUA_TSHRSTR);
-  for (;;) {  /* check whether 'key' is somewhere in the chain */
-    const TValue *k = gkey(n);
-    if (ttisshrstring(k) && eqshrstr(tsvalue(k), key))
-      return gval(n);  /* that's it */
-    else {
-      int nx = gnext(n);
-      if (nx == 0)
-        return luaO_nilobject;  /* not found */
-      n += nx;
-    }
-  }
-}
-
-
-/*
-** "Generic" get version. (Not that generic: not valid for integers,
-** which may be in array part, nor for floats with integral values.)
-*/
-static const TValue *getgeneric (Table *t, const TValue *key) {
-  Node *n = mainposition(t, key);
+  lua_assert(key->tt == LUA_VSHRSTR);
   for (;;) {  /* check whether 'key' is somewhere in the chain */
-    if (luaV_rawequalobj(gkey(n), key))
+    if (keyisshrstr(n) && eqshrstr(keystrval(n), key))
       return gval(n);  /* that's it */
     else {
       int nx = gnext(n);
       if (nx == 0)
-        return luaO_nilobject;  /* not found */
+        return &absentkey;  /* not found */
       n += nx;
     }
   }
@@ -573,7 +725,7 @@ static const TValue *getgeneric (Table *t, const TValue *key) {
 
 
 const TValue *luaH_getstr (Table *t, TString *key) {
-  if (key->tt == LUA_TSHRSTR)
+  if (key->tt == LUA_VSHRSTR)
     return luaH_getshortstr(t, key);
   else {  /* for long strings, use generic case */
     TValue ko;
@@ -587,13 +739,13 @@ const TValue *luaH_getstr (Table *t, TString *key) {
 ** main search function
 */
 const TValue *luaH_get (Table *t, const TValue *key) {
-  switch (ttype(key)) {
-    case LUA_TSHRSTR: return luaH_getshortstr(t, tsvalue(key));
-    case LUA_TNUMINT: return luaH_getint(t, ivalue(key));
-    case LUA_TNIL: return luaO_nilobject;
-    case LUA_TNUMFLT: {
+  switch (ttypetag(key)) {
+    case LUA_VSHRSTR: return luaH_getshortstr(t, tsvalue(key));
+    case LUA_VNUMINT: return luaH_getint(t, ivalue(key));
+    case LUA_VNIL: return &absentkey;
+    case LUA_VNUMFLT: {
       lua_Integer k;
-      if (luaV_tointeger(key, &k, 0)) /* index is int? */
+      if (luaV_flttointeger(fltvalue(key), &k, F2Ieq)) /* integral index? */
         return luaH_getint(t, k);  /* use specialized version */
       /* else... */
     }  /* FALLTHROUGH */
@@ -609,7 +761,7 @@ const TValue *luaH_get (Table *t, const TValue *key) {
 */
 TValue *luaH_set (lua_State *L, Table *t, const TValue *key) {
   const TValue *p = luaH_get(t, key);
-  if (p != luaO_nilobject)
+  if (!isabstkey(p))
     return cast(TValue *, p);
   else return luaH_newkey(L, t, key);
 }
@@ -618,7 +770,7 @@ TValue *luaH_set (lua_State *L, Table *t, const TValue *key) {
 void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
   const TValue *p = luaH_getint(t, key);
   TValue *cell;
-  if (p != luaO_nilobject)
+  if (!isabstkey(p))
     cell = cast(TValue *, p);
   else {
     TValue k;
@@ -629,24 +781,49 @@ void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
 }
 
 
-static lua_Unsigned unbound_search (Table *t, lua_Unsigned j) {
-  lua_Unsigned i = j;  /* i is zero or a present index */
-  j++;
-  /* find 'i' and 'j' such that i is present and j is not */
-  while (!ttisnil(luaH_getint(t, j))) {
-    i = j;
-    if (j > l_castS2U(LUA_MAXINTEGER) / 2) {  /* overflow? */
-      /* table was built with bad purposes: resort to linear search */
-      i = 1;
-      while (!ttisnil(luaH_getint(t, i))) i++;
-      return i - 1;
+/*
+** Try to find a boundary in the hash part of table 't'. From the
+** caller, we know that 'j' is zero or present and that 'j + 1' is
+** present. We want to find a larger key that is absent from the
+** table, so that we can do a binary search between the two keys to
+** find a boundary. We keep doubling 'j' until we get an absent index.
+** If the doubling would overflow, we try LUA_MAXINTEGER. If it is
+** absent, we are ready for the binary search. ('j', being max integer,
+** is larger or equal to 'i', but it cannot be equal because it is
+** absent while 'i' is present; so 'j > i'.) Otherwise, 'j' is a
+** boundary. ('j + 1' cannot be a present integer key because it is
+** not a valid integer in Lua.)
+*/
+static lua_Unsigned hash_search (Table *t, lua_Unsigned j) {
+  lua_Unsigned i;
+  if (j == 0) j++;  /* the caller ensures 'j + 1' is present */
+  do {
+    i = j;  /* 'i' is a present index */
+    if (j <= l_castS2U(LUA_MAXINTEGER) / 2)
+      j *= 2;
+    else {
+      j = LUA_MAXINTEGER;
+      if (isempty(luaH_getint(t, j)))  /* t[j] not present? */
+        break;  /* 'j' now is an absent index */
+      else  /* weird case */
+        return j;  /* well, max integer is a boundary... */
     }
-    j *= 2;
+  } while (!isempty(luaH_getint(t, j)));  /* repeat until an absent t[j] */
+  /* i < j  &&  t[i] present  &&  t[j] absent */
+  while (j - i > 1u) {  /* do a binary search between them */
+    lua_Unsigned m = (i + j) / 2;
+    if (isempty(luaH_getint(t, m))) j = m;
+    else i = m;
   }
-  /* now do a binary search between them */
-  while (j - i > 1) {
-    lua_Unsigned m = (i+j)/2;
-    if (ttisnil(luaH_getint(t, m))) j = m;
+  return i;
+}
+
+
+static unsigned int binsearch (const TValue *array, unsigned int i,
+                                                    unsigned int j) {
+  while (j - i > 1u) {  /* binary search */
+    unsigned int m = (i + j) / 2;
+    if (isempty(&array[m - 1])) j = m;
     else i = m;
   }
   return i;
@@ -654,33 +831,92 @@ static lua_Unsigned unbound_search (Table *t, lua_Unsigned j) {
 
 
 /*
-** Try to find a boundary in table 't'. A 'boundary' is an integer index
-** such that t[i] is non-nil and t[i+1] is nil (and 0 if t[1] is nil).
+** Try to find a boundary in table 't'. (A 'boundary' is an integer index
+** such that t[i] is present and t[i+1] is absent, or 0 if t[1] is absent
+** and 'maxinteger' if t[maxinteger] is present.)
+** (In the next explanation, we use Lua indices, that is, with base 1.
+** The code itself uses base 0 when indexing the array part of the table.)
+** The code starts with 'limit = t->alimit', a position in the array
+** part that may be a boundary.
+**
+** (1) If 't[limit]' is empty, there must be a boundary before it.
+** As a common case (e.g., after 't[#t]=nil'), check whether 'limit-1'
+** is present. If so, it is a boundary. Otherwise, do a binary search
+** between 0 and limit to find a boundary. In both cases, try to
+** use this boundary as the new 'alimit', as a hint for the next call.
+**
+** (2) If 't[limit]' is not empty and the array has more elements
+** after 'limit', try to find a boundary there. Again, try first
+** the special case (which should be quite frequent) where 'limit+1'
+** is empty, so that 'limit' is a boundary. Otherwise, check the
+** last element of the array part. If it is empty, there must be a
+** boundary between the old limit (present) and the last element
+** (absent), which is found with a binary search. (This boundary always
+** can be a new limit.)
+**
+** (3) The last case is when there are no elements in the array part
+** (limit == 0) or its last element (the new limit) is present.
+** In this case, must check the hash part. If there is no hash part
+** or 'limit+1' is absent, 'limit' is a boundary.  Otherwise, call
+** 'hash_search' to find a boundary in the hash part of the table.
+** (In those cases, the boundary is not inside the array part, and
+** therefore cannot be used as a new limit.)
 */
 lua_Unsigned luaH_getn (Table *t) {
-  unsigned int j = t->sizearray;
-  if (j > 0 && ttisnil(&t->array[j - 1])) {
-    /* there is a boundary in the array part: (binary) search for it */
-    unsigned int i = 0;
-    while (j - i > 1) {
-      unsigned int m = (i+j)/2;
-      if (ttisnil(&t->array[m - 1])) j = m;
-      else i = m;
+  unsigned int limit = t->alimit;
+  if (limit > 0 && isempty(&t->array[limit - 1])) {  /* (1)? */
+    /* there must be a boundary before 'limit' */
+    if (limit >= 2 && !isempty(&t->array[limit - 2])) {
+      /* 'limit - 1' is a boundary; can it be a new limit? */
+      if (ispow2realasize(t) && !ispow2(limit - 1)) {
+        t->alimit = limit - 1;
+        setnorealasize(t);  /* now 'alimit' is not the real size */
+      }
+      return limit - 1;
+    }
+    else {  /* must search for a boundary in [0, limit] */
+      unsigned int boundary = binsearch(t->array, 0, limit);
+      /* can this boundary represent the real size of the array? */
+      if (ispow2realasize(t) && boundary > luaH_realasize(t) / 2) {
+        t->alimit = boundary;  /* use it as the new limit */
+        setnorealasize(t);
+      }
+      return boundary;
+    }
+  }
+  /* 'limit' is zero or present in table */
+  if (!limitequalsasize(t)) {  /* (2)? */
+    /* 'limit' > 0 and array has more elements after 'limit' */
+    if (isempty(&t->array[limit]))  /* 'limit + 1' is empty? */
+      return limit;  /* this is the boundary */
+    /* else, try last element in the array */
+    limit = luaH_realasize(t);
+    if (isempty(&t->array[limit - 1])) {  /* empty? */
+      /* there must be a boundary in the array after old limit,
+         and it must be a valid new limit */
+      unsigned int boundary = binsearch(t->array, t->alimit, limit);
+      t->alimit = boundary;
+      return boundary;
     }
-    return i;
+    /* else, new limit is present in the table; check the hash part */
   }
-  /* else must find a boundary in hash part */
-  else if (isdummy(t))  /* hash part is empty? */
-    return j;  /* that is easy... */
-  else return unbound_search(t, j);
+  /* (3) 'limit' is the last element and either is zero or present in table */
+  lua_assert(limit == luaH_realasize(t) &&
+             (limit == 0 || !isempty(&t->array[limit - 1])));
+  if (isdummy(t) || isempty(luaH_getint(t, cast(lua_Integer, limit + 1))))
+    return limit;  /* 'limit + 1' is absent */
+  else  /* 'limit + 1' is also present */
+    return hash_search(t, limit);
 }
 
 
 
 #if defined(LUA_DEBUG)
 
+/* export these functions for the test library */
+
 Node *luaH_mainposition (const Table *t, const TValue *key) {
-  return mainposition(t, key);
+  return mainpositionTV(t, key);
 }
 
 int luaH_isdummy (const Table *t) { return isdummy(t); }
diff --git a/libs/liblua/src/ltable.h b/libs/liblua/src/ltable.h
index 92db0ac7bf..ebd7f8ec3e 100644
--- a/libs/liblua/src/ltable.h
+++ b/libs/liblua/src/ltable.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltable.h,v 2.23.1.2 2018/05/24 19:39:05 roberto Exp $
+** $Id: ltable.h $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
@@ -12,18 +12,9 @@
 
 #define gnode(t,i)	(&(t)->node[i])
 #define gval(n)		(&(n)->i_val)
-#define gnext(n)	((n)->i_key.nk.next)
+#define gnext(n)	((n)->u.next)
 
 
-/* 'const' to avoid wrong writings that can mess up field 'next' */
-#define gkey(n)		cast(const TValue*, (&(n)->i_key.tvk))
-
-/*
-** writable version of 'gkey'; allows updates to individual fields,
-** but not to the whole (which has incompatible type)
-*/
-#define wgkey(n)		(&(n)->i_key.nk)
-
 #define invalidateTMcache(t)	((t)->flags = 0)
 
 
@@ -35,9 +26,8 @@
 #define allocsizenode(t)	(isdummy(t) ? 0 : sizenode(t))
 
 
-/* returns the key, given the value of a table entry */
-#define keyfromval(v) \
-  (gkey(cast(Node *, cast(char *, (v)) - offsetof(Node, i_val))))
+/* returns the Node, given the value of a table entry */
+#define nodefromval(v)	cast(Node *, (v))
 
 
 LUAI_FUNC const TValue *luaH_getint (Table *t, lua_Integer key);
@@ -55,6 +45,7 @@ LUAI_FUNC void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize);
 LUAI_FUNC void luaH_free (lua_State *L, Table *t);
 LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key);
 LUAI_FUNC lua_Unsigned luaH_getn (Table *t);
+LUAI_FUNC unsigned int luaH_realasize (const Table *t);
 
 
 #if defined(LUA_DEBUG)
diff --git a/libs/liblua/src/ltablib.c b/libs/liblua/src/ltablib.c
index c5349578ec..d344a47e9a 100644
--- a/libs/liblua/src/ltablib.c
+++ b/libs/liblua/src/ltablib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltablib.c,v 1.93.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ltablib.c $
 ** Library for Table Manipulation
 ** See Copyright Notice in lua.h
 */
@@ -58,24 +58,6 @@ static void checktab (lua_State *L, int arg, int what) {
 }
 
 
-#if defined(LUA_COMPAT_MAXN)
-static int maxn (lua_State *L) {
-  lua_Number max = 0;
-  luaL_checktype(L, 1, LUA_TTABLE);
-  lua_pushnil(L);  /* first key */
-  while (lua_next(L, 1)) {
-    lua_pop(L, 1);  /* remove value */
-    if (lua_type(L, -1) == LUA_TNUMBER) {
-      lua_Number v = lua_tonumber(L, -1);
-      if (v > max) max = v;
-    }
-  }
-  lua_pushnumber(L, max);
-  return 1;
-}
-#endif
-
-
 static int tinsert (lua_State *L) {
   lua_Integer e = aux_getn(L, 1, TAB_RW) + 1;  /* first empty element */
   lua_Integer pos;  /* where to insert new element */
@@ -87,7 +69,9 @@ static int tinsert (lua_State *L) {
     case 3: {
       lua_Integer i;
       pos = luaL_checkinteger(L, 2);  /* 2nd argument is the position */
-      luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
+      /* check whether 'pos' is in [1, e] */
+      luaL_argcheck(L, (lua_Unsigned)pos - 1u < (lua_Unsigned)e, 2,
+                       "position out of bounds");
       for (i = e; i > pos; i--) {  /* move up elements */
         lua_geti(L, 1, i - 1);
         lua_seti(L, 1, i);  /* t[i] = t[i - 1] */
@@ -107,14 +91,16 @@ static int tremove (lua_State *L) {
   lua_Integer size = aux_getn(L, 1, TAB_RW);
   lua_Integer pos = luaL_optinteger(L, 2, size);
   if (pos != size)  /* validate 'pos' if given */
-    luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
+    /* check whether 'pos' is in [1, size + 1] */
+    luaL_argcheck(L, (lua_Unsigned)pos - 1u <= (lua_Unsigned)size, 1,
+                     "position out of bounds");
   lua_geti(L, 1, pos);  /* result = t[pos] */
   for ( ; pos < size; pos++) {
     lua_geti(L, 1, pos + 1);
     lua_seti(L, 1, pos);  /* t[pos] = t[pos + 1] */
   }
   lua_pushnil(L);
-  lua_seti(L, 1, pos);  /* t[pos] = nil */
+  lua_seti(L, 1, pos);  /* remove entry t[pos] */
   return 1;
 }
 
@@ -191,7 +177,7 @@ static int tconcat (lua_State *L) {
 ** =======================================================
 */
 
-static int pack (lua_State *L) {
+static int tpack (lua_State *L) {
   int i;
   int n = lua_gettop(L);  /* number of elements to pack */
   lua_createtable(L, n, 1);  /* create result table */
@@ -204,7 +190,7 @@ static int pack (lua_State *L) {
 }
 
 
-static int unpack (lua_State *L) {
+static int tunpack (lua_State *L) {
   lua_Unsigned n;
   lua_Integer i = luaL_optinteger(L, 2, 1);
   lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
@@ -313,14 +299,14 @@ static IdxT partition (lua_State *L, IdxT lo, IdxT up) {
   /* loop invariant: a[lo .. i] <= P <= a[j .. up] */
   for (;;) {
     /* next loop: repeat ++i while a[i] < P */
-    while (lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
+    while ((void)lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
       if (i == up - 1)  /* a[i] < P  but a[up - 1] == P  ?? */
         luaL_error(L, "invalid order function for sorting");
       lua_pop(L, 1);  /* remove a[i] */
     }
     /* after the loop, a[i] >= P and a[lo .. i - 1] < P */
     /* next loop: repeat --j while P < a[j] */
-    while (lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
+    while ((void)lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
       if (j < i)  /* j < i  but  a[j] > P ?? */
         luaL_error(L, "invalid order function for sorting");
       lua_pop(L, 1);  /* remove a[j] */
@@ -352,7 +338,7 @@ static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) {
 
 
 /*
-** QuickSort algorithm (recursive function)
+** Quicksort algorithm (recursive function)
 */
 static void auxsort (lua_State *L, IdxT lo, IdxT up,
                                    unsigned int rnd) {
@@ -425,12 +411,9 @@ static int sort (lua_State *L) {
 
 static const luaL_Reg tab_funcs[] = {
   {"concat", tconcat},
-#if defined(LUA_COMPAT_MAXN)
-  {"maxn", maxn},
-#endif
   {"insert", tinsert},
-  {"pack", pack},
-  {"unpack", unpack},
+  {"pack", tpack},
+  {"unpack", tunpack},
   {"remove", tremove},
   {"move", tmove},
   {"sort", sort},
@@ -440,11 +423,6 @@ static const luaL_Reg tab_funcs[] = {
 
 LUAMOD_API int luaopen_table (lua_State *L) {
   luaL_newlib(L, tab_funcs);
-#if defined(LUA_COMPAT_UNPACK)
-  /* _G.unpack = table.unpack */
-  lua_getfield(L, -1, "unpack");
-  lua_setglobal(L, "unpack");
-#endif
   return 1;
 }
 
diff --git a/libs/liblua/src/ltm.c b/libs/liblua/src/ltm.c
index 0e7c713214..ae60983f25 100644
--- a/libs/liblua/src/ltm.c
+++ b/libs/liblua/src/ltm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.c,v 2.38.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: ltm.c $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -16,6 +16,7 @@
 
 #include "ldebug.h"
 #include "ldo.h"
+#include "lgc.h"
 #include "lobject.h"
 #include "lstate.h"
 #include "lstring.h"
@@ -26,11 +27,11 @@
 
 static const char udatatypename[] = "userdata";
 
-LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = {
+LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTYPES] = {
   "no value",
   "nil", "boolean", udatatypename, "number",
   "string", "table", "function", udatatypename, "thread",
-  "proto" /* this last case is used for tests only */
+  "upvalue", "proto" /* these last cases are used for tests only */
 };
 
 
@@ -42,7 +43,7 @@ void luaT_init (lua_State *L) {
     "__div", "__idiv",
     "__band", "__bor", "__bxor", "__shl", "__shr",
     "__unm", "__bnot", "__lt", "__le",
-    "__concat", "__call"
+    "__concat", "__call", "__close"
   };
   int i;
   for (i=0; i<TM_N; i++) {
@@ -59,7 +60,7 @@ void luaT_init (lua_State *L) {
 const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
   const TValue *tm = luaH_getshortstr(events, ename);
   lua_assert(event <= TM_EQ);
-  if (ttisnil(tm)) {  /* no tag method? */
+  if (notm(tm)) {  /* no tag method? */
     events->flags |= cast_byte(1u<<event);  /* cache this fact */
     return NULL;
   }
@@ -69,7 +70,7 @@ const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
 
 const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
   Table *mt;
-  switch (ttnov(o)) {
+  switch (ttype(o)) {
     case LUA_TTABLE:
       mt = hvalue(o)->metatable;
       break;
@@ -77,9 +78,9 @@ const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
       mt = uvalue(o)->metatable;
       break;
     default:
-      mt = G(L)->mt[ttnov(o)];
+      mt = G(L)->mt[ttype(o)];
   }
-  return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : luaO_nilobject);
+  return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : &G(L)->nilvalue);
 }
 
 
@@ -95,54 +96,62 @@ const char *luaT_objtypename (lua_State *L, const TValue *o) {
     if (ttisstring(name))  /* is '__name' a string? */
       return getstr(tsvalue(name));  /* use it as type name */
   }
-  return ttypename(ttnov(o));  /* else use standard type name */
+  return ttypename(ttype(o));  /* else use standard type name */
 }
 
 
 void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
-                  const TValue *p2, TValue *p3, int hasres) {
-  ptrdiff_t result = savestack(L, p3);
+                  const TValue *p2, const TValue *p3) {
+  StkId func = L->top;
+  setobj2s(L, func, f);  /* push function (assume EXTRA_STACK) */
+  setobj2s(L, func + 1, p1);  /* 1st argument */
+  setobj2s(L, func + 2, p2);  /* 2nd argument */
+  setobj2s(L, func + 3, p3);  /* 3rd argument */
+  L->top = func + 4;
+  /* metamethod may yield only when called from Lua code */
+  if (isLuacode(L->ci))
+    luaD_call(L, func, 0);
+  else
+    luaD_callnoyield(L, func, 0);
+}
+
+
+void luaT_callTMres (lua_State *L, const TValue *f, const TValue *p1,
+                     const TValue *p2, StkId res) {
+  ptrdiff_t result = savestack(L, res);
   StkId func = L->top;
   setobj2s(L, func, f);  /* push function (assume EXTRA_STACK) */
   setobj2s(L, func + 1, p1);  /* 1st argument */
   setobj2s(L, func + 2, p2);  /* 2nd argument */
   L->top += 3;
-  if (!hasres)  /* no result? 'p3' is third argument */
-    setobj2s(L, L->top++, p3);  /* 3rd argument */
   /* metamethod may yield only when called from Lua code */
-  if (isLua(L->ci))
-    luaD_call(L, func, hasres);
+  if (isLuacode(L->ci))
+    luaD_call(L, func, 1);
   else
-    luaD_callnoyield(L, func, hasres);
-  if (hasres) {  /* if has result, move it to its place */
-    p3 = restorestack(L, result);
-    setobjs2s(L, p3, --L->top);
-  }
+    luaD_callnoyield(L, func, 1);
+  res = restorestack(L, result);
+  setobjs2s(L, res, --L->top);  /* move result to its place */
 }
 
 
-int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
-                    StkId res, TMS event) {
+static int callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
+                      StkId res, TMS event) {
   const TValue *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
-  if (ttisnil(tm))
+  if (notm(tm))
     tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
-  if (ttisnil(tm)) return 0;
-  luaT_callTM(L, tm, p1, p2, res, 1);
+  if (notm(tm)) return 0;
+  luaT_callTMres(L, tm, p1, p2, res);
   return 1;
 }
 
 
 void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
                     StkId res, TMS event) {
-  if (!luaT_callbinTM(L, p1, p2, res, event)) {
+  if (!callbinTM(L, p1, p2, res, event)) {
     switch (event) {
-      case TM_CONCAT:
-        luaG_concaterror(L, p1, p2);
-      /* call never returns, but to avoid warnings: *//* FALLTHROUGH */
       case TM_BAND: case TM_BOR: case TM_BXOR:
       case TM_SHL: case TM_SHR: case TM_BNOT: {
-        lua_Number dummy;
-        if (tonumber(p1, &dummy) && tonumber(p2, &dummy))
+        if (ttisnumber(p1) && ttisnumber(p2))
           luaG_tointerror(L, p1, p2);
         else
           luaG_opinterror(L, p1, p2, "perform bitwise operation on");
@@ -155,11 +164,107 @@ void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
 }
 
 
+void luaT_tryconcatTM (lua_State *L) {
+  StkId top = L->top;
+  if (!callbinTM(L, s2v(top - 2), s2v(top - 1), top - 2, TM_CONCAT))
+    luaG_concaterror(L, s2v(top - 2), s2v(top - 1));
+}
+
+
+void luaT_trybinassocTM (lua_State *L, const TValue *p1, const TValue *p2,
+                                       int flip, StkId res, TMS event) {
+  if (flip)
+    luaT_trybinTM(L, p2, p1, res, event);
+  else
+    luaT_trybinTM(L, p1, p2, res, event);
+}
+
+
+void luaT_trybiniTM (lua_State *L, const TValue *p1, lua_Integer i2,
+                                   int flip, StkId res, TMS event) {
+  TValue aux;
+  setivalue(&aux, i2);
+  luaT_trybinassocTM(L, p1, &aux, flip, res, event);
+}
+
+
+/*
+** Calls an order tag method.
+** For lessequal, LUA_COMPAT_LT_LE keeps compatibility with old
+** behavior: if there is no '__le', try '__lt', based on l <= r iff
+** !(r < l) (assuming a total order). If the metamethod yields during
+** this substitution, the continuation has to know about it (to negate
+** the result of r<l); bit CIST_LEQ in the call status keeps that
+** information.
+*/
 int luaT_callorderTM (lua_State *L, const TValue *p1, const TValue *p2,
                       TMS event) {
-  if (!luaT_callbinTM(L, p1, p2, L->top, event))
-    return -1;  /* no metamethod */
+  if (callbinTM(L, p1, p2, L->top, event))  /* try original event */
+    return !l_isfalse(s2v(L->top));
+#if defined(LUA_COMPAT_LT_LE)
+  else if (event == TM_LE) {
+      /* try '!(p2 < p1)' for '(p1 <= p2)' */
+      L->ci->callstatus |= CIST_LEQ;  /* mark it is doing 'lt' for 'le' */
+      if (callbinTM(L, p2, p1, L->top, TM_LT)) {
+        L->ci->callstatus ^= CIST_LEQ;  /* clear mark */
+        return l_isfalse(s2v(L->top));
+      }
+      /* else error will remove this 'ci'; no need to clear mark */
+  }
+#endif
+  luaG_ordererror(L, p1, p2);  /* no metamethod found */
+  return 0;  /* to avoid warnings */
+}
+
+
+int luaT_callorderiTM (lua_State *L, const TValue *p1, int v2,
+                       int flip, int isfloat, TMS event) {
+  TValue aux; const TValue *p2;
+  if (isfloat) {
+    setfltvalue(&aux, cast_num(v2));
+  }
+  else
+    setivalue(&aux, v2);
+  if (flip) {  /* arguments were exchanged? */
+    p2 = p1; p1 = &aux;  /* correct them */
+  }
   else
-    return !l_isfalse(L->top);
+    p2 = &aux;
+  return luaT_callorderTM(L, p1, p2, event);
+}
+
+
+void luaT_adjustvarargs (lua_State *L, int nfixparams, CallInfo *ci,
+                         const Proto *p) {
+  int i;
+  int actual = cast_int(L->top - ci->func) - 1;  /* number of arguments */
+  int nextra = actual - nfixparams;  /* number of extra arguments */
+  ci->u.l.nextraargs = nextra;
+  checkstackGC(L, p->maxstacksize + 1);
+  /* copy function to the top of the stack */
+  setobjs2s(L, L->top++, ci->func);
+  /* move fixed parameters to the top of the stack */
+  for (i = 1; i <= nfixparams; i++) {
+    setobjs2s(L, L->top++, ci->func + i);
+    setnilvalue(s2v(ci->func + i));  /* erase original parameter (for GC) */
+  }
+  ci->func += actual + 1;
+  ci->top += actual + 1;
+  lua_assert(L->top <= ci->top && ci->top <= L->stack_last);
+}
+
+
+void luaT_getvarargs (lua_State *L, CallInfo *ci, StkId where, int wanted) {
+  int i;
+  int nextra = ci->u.l.nextraargs;
+  if (wanted < 0) {
+    wanted = nextra;  /* get all extra arguments available */
+    checkstackp(L, nextra, where);  /* ensure stack space */
+    L->top = where + nextra;  /* next instruction will need top */
+  }
+  for (i = 0; i < wanted && i < nextra; i++)
+    setobjs2s(L, where + i, ci->func - nextra + i);
+  for (; i < wanted; i++)   /* complete required results with nil */
+    setnilvalue(s2v(where + i));
 }
 
diff --git a/libs/liblua/src/ltm.h b/libs/liblua/src/ltm.h
index 8170688dae..99b545e766 100644
--- a/libs/liblua/src/ltm.h
+++ b/libs/liblua/src/ltm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.h,v 2.22.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: ltm.h $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -40,10 +40,17 @@ typedef enum {
   TM_LE,
   TM_CONCAT,
   TM_CALL,
+  TM_CLOSE,
   TM_N		/* number of elements in the enum */
 } TMS;
 
 
+/*
+** Test whether there is no tagmethod.
+** (Because tagmethods use raw accesses, the result may be an "empty" nil.)
+*/
+#define notm(tm)	ttisnil(tm)
+
 
 #define gfasttm(g,et,e) ((et) == NULL ? NULL : \
   ((et)->flags & (1u<<(e))) ? NULL : luaT_gettm(et, e, (g)->tmname[e]))
@@ -52,7 +59,7 @@ typedef enum {
 
 #define ttypename(x)	luaT_typenames_[(x) + 1]
 
-LUAI_DDEC const char *const luaT_typenames_[LUA_TOTALTAGS];
+LUAI_DDEC(const char *const luaT_typenames_[LUA_TOTALTYPES];)
 
 
 LUAI_FUNC const char *luaT_objtypename (lua_State *L, const TValue *o);
@@ -63,14 +70,25 @@ LUAI_FUNC const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o,
 LUAI_FUNC void luaT_init (lua_State *L);
 
 LUAI_FUNC void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
-                            const TValue *p2, TValue *p3, int hasres);
-LUAI_FUNC int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2,
-                              StkId res, TMS event);
+                            const TValue *p2, const TValue *p3);
+LUAI_FUNC void luaT_callTMres (lua_State *L, const TValue *f,
+                            const TValue *p1, const TValue *p2, StkId p3);
 LUAI_FUNC void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2,
                               StkId res, TMS event);
+LUAI_FUNC void luaT_tryconcatTM (lua_State *L);
+LUAI_FUNC void luaT_trybinassocTM (lua_State *L, const TValue *p1,
+       const TValue *p2, int inv, StkId res, TMS event);
+LUAI_FUNC void luaT_trybiniTM (lua_State *L, const TValue *p1, lua_Integer i2,
+                               int inv, StkId res, TMS event);
 LUAI_FUNC int luaT_callorderTM (lua_State *L, const TValue *p1,
                                 const TValue *p2, TMS event);
+LUAI_FUNC int luaT_callorderiTM (lua_State *L, const TValue *p1, int v2,
+                                 int inv, int isfloat, TMS event);
 
+LUAI_FUNC void luaT_adjustvarargs (lua_State *L, int nfixparams,
+                                   struct CallInfo *ci, const Proto *p);
+LUAI_FUNC void luaT_getvarargs (lua_State *L, struct CallInfo *ci,
+                                              StkId where, int wanted);
 
 
 #endif
diff --git a/libs/liblua/src/lua.h b/libs/liblua/src/lua.h
index c236e36095..b348c147fc 100644
--- a/libs/liblua/src/lua.h
+++ b/libs/liblua/src/lua.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.h,v 1.332.1.2 2018/06/13 16:58:17 roberto Exp $
+** $Id: lua.h $
 ** Lua - A Scripting Language
 ** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
@@ -17,13 +17,15 @@
 
 
 #define LUA_VERSION_MAJOR	"5"
-#define LUA_VERSION_MINOR	"3"
-#define LUA_VERSION_NUM		503
-#define LUA_VERSION_RELEASE	"5"
+#define LUA_VERSION_MINOR	"4"
+#define LUA_VERSION_RELEASE	"0"
+
+#define LUA_VERSION_NUM			504
+#define LUA_VERSION_RELEASE_NUM		(LUA_VERSION_NUM * 100 + 0)
 
 #define LUA_VERSION	"Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
 #define LUA_RELEASE	LUA_VERSION "." LUA_VERSION_RELEASE
-#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2018 Lua.org, PUC-Rio"
+#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2020 Lua.org, PUC-Rio"
 #define LUA_AUTHORS	"R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
 
 
@@ -49,8 +51,7 @@
 #define LUA_ERRRUN	2
 #define LUA_ERRSYNTAX	3
 #define LUA_ERRMEM	4
-#define LUA_ERRGCMM	5
-#define LUA_ERRERR	6
+#define LUA_ERRERR	5
 
 
 typedef struct lua_State lua_State;
@@ -71,7 +72,7 @@ typedef struct lua_State lua_State;
 #define LUA_TUSERDATA		7
 #define LUA_TTHREAD		8
 
-#define LUA_NUMTAGS		9
+#define LUA_NUMTYPES		9
 
 
 
@@ -124,6 +125,13 @@ typedef int (*lua_Writer) (lua_State *L, const void *p, size_t sz, void *ud);
 typedef void * (*lua_Alloc) (void *ud, void *ptr, size_t osize, size_t nsize);
 
 
+/*
+** Type for warning functions
+*/
+typedef void (*lua_WarnFunction) (void *ud, const char *msg, int tocont);
+
+
+
 
 /*
 ** generic extra include file
@@ -145,11 +153,12 @@ extern const char lua_ident[];
 LUA_API lua_State *(lua_newstate) (lua_Alloc f, void *ud);
 LUA_API void       (lua_close) (lua_State *L);
 LUA_API lua_State *(lua_newthread) (lua_State *L);
+LUA_API int        (lua_resetthread) (lua_State *L);
 
 LUA_API lua_CFunction (lua_atpanic) (lua_State *L, lua_CFunction panicf);
 
 
-LUA_API const lua_Number *(lua_version) (lua_State *L);
+LUA_API lua_Number (lua_version) (lua_State *L);
 
 
 /*
@@ -182,7 +191,7 @@ LUA_API lua_Number      (lua_tonumberx) (lua_State *L, int idx, int *isnum);
 LUA_API lua_Integer     (lua_tointegerx) (lua_State *L, int idx, int *isnum);
 LUA_API int             (lua_toboolean) (lua_State *L, int idx);
 LUA_API const char     *(lua_tolstring) (lua_State *L, int idx, size_t *len);
-LUA_API size_t          (lua_rawlen) (lua_State *L, int idx);
+LUA_API lua_Unsigned    (lua_rawlen) (lua_State *L, int idx);
 LUA_API lua_CFunction   (lua_tocfunction) (lua_State *L, int idx);
 LUA_API void	       *(lua_touserdata) (lua_State *L, int idx);
 LUA_API lua_State      *(lua_tothread) (lua_State *L, int idx);
@@ -247,9 +256,9 @@ LUA_API int (lua_rawgeti) (lua_State *L, int idx, lua_Integer n);
 LUA_API int (lua_rawgetp) (lua_State *L, int idx, const void *p);
 
 LUA_API void  (lua_createtable) (lua_State *L, int narr, int nrec);
-LUA_API void *(lua_newuserdata) (lua_State *L, size_t sz);
+LUA_API void *(lua_newuserdatauv) (lua_State *L, size_t sz, int nuvalue);
 LUA_API int   (lua_getmetatable) (lua_State *L, int objindex);
-LUA_API int  (lua_getuservalue) (lua_State *L, int idx);
+LUA_API int  (lua_getiuservalue) (lua_State *L, int idx, int n);
 
 
 /*
@@ -263,7 +272,7 @@ LUA_API void  (lua_rawset) (lua_State *L, int idx);
 LUA_API void  (lua_rawseti) (lua_State *L, int idx, lua_Integer n);
 LUA_API void  (lua_rawsetp) (lua_State *L, int idx, const void *p);
 LUA_API int   (lua_setmetatable) (lua_State *L, int objindex);
-LUA_API void  (lua_setuservalue) (lua_State *L, int idx);
+LUA_API int   (lua_setiuservalue) (lua_State *L, int idx, int n);
 
 
 /*
@@ -288,13 +297,21 @@ LUA_API int (lua_dump) (lua_State *L, lua_Writer writer, void *data, int strip);
 */
 LUA_API int  (lua_yieldk)     (lua_State *L, int nresults, lua_KContext ctx,
                                lua_KFunction k);
-LUA_API int  (lua_resume)     (lua_State *L, lua_State *from, int narg);
+LUA_API int  (lua_resume)     (lua_State *L, lua_State *from, int narg,
+                               int *nres);
 LUA_API int  (lua_status)     (lua_State *L);
 LUA_API int (lua_isyieldable) (lua_State *L);
 
 #define lua_yield(L,n)		lua_yieldk(L, (n), 0, NULL)
 
 
+/*
+** Warning-related functions
+*/
+LUA_API void (lua_setwarnf) (lua_State *L, lua_WarnFunction f, void *ud);
+LUA_API void (lua_warning)  (lua_State *L, const char *msg, int tocont);
+
+
 /*
 ** garbage-collection function and options
 */
@@ -308,8 +325,10 @@ LUA_API int (lua_isyieldable) (lua_State *L);
 #define LUA_GCSETPAUSE		6
 #define LUA_GCSETSTEPMUL	7
 #define LUA_GCISRUNNING		9
+#define LUA_GCGEN		10
+#define LUA_GCINC		11
 
-LUA_API int (lua_gc) (lua_State *L, int what, int data);
+LUA_API int (lua_gc) (lua_State *L, int what, ...);
 
 
 /*
@@ -328,6 +347,7 @@ LUA_API size_t   (lua_stringtonumber) (lua_State *L, const char *s);
 LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud);
 LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 
+LUA_API void  (lua_toclose) (lua_State *L, int idx);
 
 
 /*
@@ -377,7 +397,7 @@ LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 
 /*
 ** {==============================================================
-** compatibility macros for unsigned conversions
+** compatibility macros
 ** ===============================================================
 */
 #if defined(LUA_COMPAT_APIINTCASTS)
@@ -387,6 +407,13 @@ LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 #define lua_tounsigned(L,i)	lua_tounsignedx(L,(i),NULL)
 
 #endif
+
+#define lua_newuserdata(L,s)	lua_newuserdatauv(L,s,1)
+#define lua_getuservalue(L,idx)	lua_getiuservalue(L,idx,1)
+#define lua_setuservalue(L,idx)	lua_setiuservalue(L,idx,1)
+
+#define LUA_NUMTAGS		LUA_NUMTYPES
+
 /* }============================================================== */
 
 /*
@@ -437,6 +464,7 @@ LUA_API lua_Hook (lua_gethook) (lua_State *L);
 LUA_API int (lua_gethookmask) (lua_State *L);
 LUA_API int (lua_gethookcount) (lua_State *L);
 
+LUA_API int (lua_setcstacklimit) (lua_State *L, unsigned int limit);
 
 struct lua_Debug {
   int event;
@@ -444,6 +472,7 @@ struct lua_Debug {
   const char *namewhat;	/* (n) 'global', 'local', 'field', 'method' */
   const char *what;	/* (S) 'Lua', 'C', 'main', 'tail' */
   const char *source;	/* (S) */
+  size_t srclen;	/* (S) */
   int currentline;	/* (l) */
   int linedefined;	/* (S) */
   int lastlinedefined;	/* (S) */
@@ -451,6 +480,8 @@ struct lua_Debug {
   unsigned char nparams;/* (u) number of parameters */
   char isvararg;        /* (u) */
   char istailcall;	/* (t) */
+  unsigned short ftransfer;   /* (r) index of first value transferred */
+  unsigned short ntransfer;   /* (r) number of transferred values */
   char short_src[LUA_IDSIZE]; /* (S) */
   /* private part */
   struct CallInfo *i_ci;  /* active function */
@@ -460,7 +491,7 @@ struct lua_Debug {
 
 
 /******************************************************************************
-* Copyright (C) 1994-2018 Lua.org, PUC-Rio.
+* Copyright (C) 1994-2020 Lua.org, PUC-Rio.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
diff --git a/libs/liblua/src/luaconf.h b/libs/liblua/src/luaconf.h
index 9eeeea69e2..bdf927e77e 100644
--- a/libs/liblua/src/luaconf.h
+++ b/libs/liblua/src/luaconf.h
@@ -1,5 +1,5 @@
 /*
-** $Id: luaconf.h,v 1.259.1.1 2017/04/19 17:29:57 roberto Exp $
+** $Id: luaconf.h $
 ** Configuration file for Lua
 ** See Copyright Notice in lua.h
 */
@@ -14,6 +14,16 @@
 
 /*
 ** ===================================================================
+** General Configuration File for Lua
+**
+** Some definitions here can be changed externally, through the
+** compiler (e.g., with '-D' options). Those are protected by
+** '#if !defined' guards. However, several other definitions should
+** be changed directly here, either because they affect the Lua
+** ABI (by making the changes here, you ensure that all software
+** connected to Lua, such as C libraries, will be compiled with the
+** same configuration); or because they are seldom changed.
+**
 ** Search for "@@" to find all configurable definitions.
 ** ===================================================================
 */
@@ -22,18 +32,23 @@
 /*
 ** {====================================================================
 ** System Configuration: macros to adapt (if needed) Lua to some
-** particular platform, for instance compiling it with 32-bit numbers or
-** restricting it to C89.
+** particular platform, for instance restricting it to C89.
 ** =====================================================================
 */
 
 /*
-@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats. You
-** can also define LUA_32BITS in the make file, but changing here you
-** ensure that all software connected to Lua will be compiled with the
-** same configuration.
+@@ LUAI_MAXCSTACK defines the maximum depth for nested calls and
+** also limits the maximum depth of other recursive algorithms in
+** the implementation, such as syntactic analysis. A value too
+** large may allow the interpreter to crash (C-stack overflow).
+** The default value seems ok for regular machines, but may be
+** too high for restricted hardware.
+** The test file 'cstack.lua' may help finding a good limit.
+** (It will crash with a limit too high.)
 */
-/* #define LUA_32BITS */
+#if !defined(LUAI_MAXCSTACK)
+#define LUAI_MAXCSTACK		2000
+#endif
 
 
 /*
@@ -61,45 +76,51 @@
 #if defined(LUA_USE_LINUX)
 #define LUA_USE_POSIX
 #define LUA_USE_DLOPEN		/* needs an extra library: -ldl */
-#define LUA_USE_READLINE	/* needs some extra libraries */
 #endif
 
 
 #if defined(LUA_USE_MACOSX)
 #define LUA_USE_POSIX
 #define LUA_USE_DLOPEN		/* MacOS does not need -ldl */
-#define LUA_USE_READLINE	/* needs an extra library: -lreadline */
 #endif
 
 
 /*
-@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for
-** C89 ('long' and 'double'); Windows always has '__int64', so it does
-** not need to use this case.
+@@ LUAI_IS32INT is true iff 'int' has (at least) 32 bits.
 */
-#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS)
-#define LUA_C89_NUMBERS
-#endif
+#define LUAI_IS32INT	((UINT_MAX >> 30) >= 3)
+
+/* }================================================================== */
 
 
 
 /*
-@@ LUAI_BITSINT defines the (minimum) number of bits in an 'int'.
+** {==================================================================
+** Configuration for Number types.
+** ===================================================================
 */
-/* avoid undefined shifts */
-#if ((INT_MAX >> 15) >> 15) >= 1
-#define LUAI_BITSINT	32
-#else
-/* 'int' always must have at least 16 bits */
-#define LUAI_BITSINT	16
+
+/*
+@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats.
+*/
+/* #define LUA_32BITS */
+
+
+/*
+@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for
+** C89 ('long' and 'double'); Windows always has '__int64', so it does
+** not need to use this case.
+*/
+#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS)
+#define LUA_C89_NUMBERS
 #endif
 
 
 /*
 @@ LUA_INT_TYPE defines the type for Lua integers.
 @@ LUA_FLOAT_TYPE defines the type for Lua floats.
-** Lua should work fine with any mix of these options (if supported
-** by your C compiler). The usual configurations are 64-bit integers
+** Lua should work fine with any mix of these options supported
+** by your C compiler. The usual configurations are 64-bit integers
 ** and 'double' (the default), 32-bit integers and 'float' (for
 ** restricted platforms), and 'long'/'double' (for C compilers not
 ** compliant with C99, which may not have support for 'long long').
@@ -119,7 +140,7 @@
 /*
 ** 32-bit integers and 'float'
 */
-#if LUAI_BITSINT >= 32  /* use 'int' if big enough */
+#if LUAI_IS32INT  /* use 'int' if big enough */
 #define LUA_INT_TYPE	LUA_INT_INT
 #else  /* otherwise use 'long' */
 #define LUA_INT_TYPE	LUA_INT_LONG
@@ -151,7 +172,6 @@
 
 
 
-
 /*
 ** {==================================================================
 ** Configuration for Paths.
@@ -179,6 +199,7 @@
 ** hierarchy or if you want to install your libraries in
 ** non-conventional directories.
 */
+
 #define LUA_VDIR	LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
 #if defined(_WIN32)	/* { */
 /*
@@ -188,27 +209,40 @@
 #define LUA_LDIR	"!\\lua\\"
 #define LUA_CDIR	"!\\"
 #define LUA_SHRDIR	"!\\..\\share\\lua\\" LUA_VDIR "\\"
+
+#if !defined(LUA_PATH_DEFAULT)
 #define LUA_PATH_DEFAULT  \
 		LUA_LDIR"?.lua;"  LUA_LDIR"?\\init.lua;" \
 		LUA_CDIR"?.lua;"  LUA_CDIR"?\\init.lua;" \
 		LUA_SHRDIR"?.lua;" LUA_SHRDIR"?\\init.lua;" \
 		".\\?.lua;" ".\\?\\init.lua"
+#endif
+
+#if !defined(LUA_CPATH_DEFAULT)
 #define LUA_CPATH_DEFAULT \
 		LUA_CDIR"?.dll;" \
 		LUA_CDIR"..\\lib\\lua\\" LUA_VDIR "\\?.dll;" \
 		LUA_CDIR"loadall.dll;" ".\\?.dll"
+#endif
 
 #else			/* }{ */
 
 #define LUA_ROOT	"/usr/local/"
 #define LUA_LDIR	LUA_ROOT "share/lua/" LUA_VDIR "/"
 #define LUA_CDIR	LUA_ROOT "lib/lua/" LUA_VDIR "/"
+
+#if !defined(LUA_PATH_DEFAULT)
 #define LUA_PATH_DEFAULT  \
 		LUA_LDIR"?.lua;"  LUA_LDIR"?/init.lua;" \
 		LUA_CDIR"?.lua;"  LUA_CDIR"?/init.lua;" \
 		"./?.lua;" "./?/init.lua"
+#endif
+
+#if !defined(LUA_CPATH_DEFAULT)
 #define LUA_CPATH_DEFAULT \
 		LUA_CDIR"?.so;" LUA_CDIR"loadall.so;" "./?.so"
+#endif
+
 #endif			/* } */
 
 
@@ -217,12 +251,16 @@
 ** CHANGE it if your machine does not use "/" as the directory separator
 ** and is not Windows. (On Windows Lua automatically uses "\".)
 */
+#if !defined(LUA_DIRSEP)
+
 #if defined(_WIN32)
 #define LUA_DIRSEP	"\\"
 #else
 #define LUA_DIRSEP	"/"
 #endif
 
+#endif
+
 /* }================================================================== */
 
 
@@ -256,16 +294,18 @@
 #endif				/* } */
 
 
-/* more often than not the libs go together with the core */
+/*
+** More often than not the libs go together with the core.
+*/
 #define LUALIB_API	LUA_API
-#define LUAMOD_API	LUALIB_API
+#define LUAMOD_API	LUA_API
 
 
 /*
 @@ LUAI_FUNC is a mark for all extern functions that are not to be
 ** exported to outside modules.
-@@ LUAI_DDEF and LUAI_DDEC are marks for all extern (const) variables
-** that are not to be exported to outside modules (LUAI_DDEF for
+@@ LUAI_DDEF and LUAI_DDEC are marks for all extern (const) variables,
+** none of which to be exported to outside modules (LUAI_DDEF for
 ** definitions and LUAI_DDEC for declarations).
 ** CHANGE them if you need to mark them in some special way. Elf/gcc
 ** (versions 3.2 and later) mark them as "hidden" to optimize access
@@ -277,12 +317,12 @@
 */
 #if defined(__GNUC__) && ((__GNUC__*100 + __GNUC_MINOR__) >= 302) && \
     defined(__ELF__)		/* { */
-#define LUAI_FUNC	__attribute__((visibility("hidden"))) extern
+#define LUAI_FUNC	__attribute__((visibility("internal"))) extern
 #else				/* }{ */
 #define LUAI_FUNC	extern
 #endif				/* } */
 
-#define LUAI_DDEC	LUAI_FUNC
+#define LUAI_DDEC(dec)	LUAI_FUNC dec
 #define LUAI_DDEF	/* empty */
 
 /* }================================================================== */
@@ -295,88 +335,43 @@
 */
 
 /*
-@@ LUA_COMPAT_5_2 controls other macros for compatibility with Lua 5.2.
-@@ LUA_COMPAT_5_1 controls other macros for compatibility with Lua 5.1.
+@@ LUA_COMPAT_5_3 controls other macros for compatibility with Lua 5.3.
 ** You can define it to get all options, or change specific options
 ** to fit your specific needs.
 */
-#if defined(LUA_COMPAT_5_2)	/* { */
+#if defined(LUA_COMPAT_5_3)	/* { */
 
 /*
 @@ LUA_COMPAT_MATHLIB controls the presence of several deprecated
 ** functions in the mathematical library.
+** (These functions were already officially removed in 5.3;
+** nevertheless they are still available here.)
 */
 #define LUA_COMPAT_MATHLIB
 
-/*
-@@ LUA_COMPAT_BITLIB controls the presence of library 'bit32'.
-*/
-#define LUA_COMPAT_BITLIB
-
-/*
-@@ LUA_COMPAT_IPAIRS controls the effectiveness of the __ipairs metamethod.
-*/
-#define LUA_COMPAT_IPAIRS
-
 /*
 @@ LUA_COMPAT_APIINTCASTS controls the presence of macros for
 ** manipulating other integer types (lua_pushunsigned, lua_tounsigned,
 ** luaL_checkint, luaL_checklong, etc.)
+** (These macros were also officially removed in 5.3, but they are still
+** available here.)
 */
 #define LUA_COMPAT_APIINTCASTS
 
-#endif				/* } */
-
-
-#if defined(LUA_COMPAT_5_1)	/* { */
-
-/* Incompatibilities from 5.2 -> 5.3 */
-#define LUA_COMPAT_MATHLIB
-#define LUA_COMPAT_APIINTCASTS
 
 /*
-@@ LUA_COMPAT_UNPACK controls the presence of global 'unpack'.
-** You can replace it with 'table.unpack'.
+@@ LUA_COMPAT_LT_LE controls the emulation of the '__le' metamethod
+** using '__lt'.
 */
-#define LUA_COMPAT_UNPACK
+#define LUA_COMPAT_LT_LE
 
-/*
-@@ LUA_COMPAT_LOADERS controls the presence of table 'package.loaders'.
-** You can replace it with 'package.searchers'.
-*/
-#define LUA_COMPAT_LOADERS
-
-/*
-@@ macro 'lua_cpcall' emulates deprecated function lua_cpcall.
-** You can call your C function directly (with light C functions).
-*/
-#define lua_cpcall(L,f,u)  \
-	(lua_pushcfunction(L, (f)), \
-	 lua_pushlightuserdata(L,(u)), \
-	 lua_pcall(L,1,0,0))
-
-
-/*
-@@ LUA_COMPAT_LOG10 defines the function 'log10' in the math library.
-** You can rewrite 'log10(x)' as 'log(x, 10)'.
-*/
-#define LUA_COMPAT_LOG10
-
-/*
-@@ LUA_COMPAT_LOADSTRING defines the function 'loadstring' in the base
-** library. You can rewrite 'loadstring(s)' as 'load(s)'.
-*/
-#define LUA_COMPAT_LOADSTRING
-
-/*
-@@ LUA_COMPAT_MAXN defines the function 'maxn' in the table library.
-*/
-#define LUA_COMPAT_MAXN
 
 /*
 @@ The following macros supply trivial compatibility for some
 ** changes in the API. The macros themselves document how to
 ** change your code to avoid using them.
+** (Once more, these macros were officially removed in 5.3, but they are
+** still available here.)
 */
 #define lua_strlen(L,i)		lua_rawlen(L, (i))
 
@@ -385,23 +380,8 @@
 #define lua_equal(L,idx1,idx2)		lua_compare(L,(idx1),(idx2),LUA_OPEQ)
 #define lua_lessthan(L,idx1,idx2)	lua_compare(L,(idx1),(idx2),LUA_OPLT)
 
-/*
-@@ LUA_COMPAT_MODULE controls compatibility with previous
-** module functions 'module' (Lua) and 'luaL_register' (C).
-*/
-#define LUA_COMPAT_MODULE
-
 #endif				/* } */
 
-
-/*
-@@ LUA_COMPAT_FLOATSTRING makes Lua format integral floats without a
-@@ a float mark ('.0').
-** This macro is not on by default even in compatibility mode,
-** because this is not really an incompatibility.
-*/
-/* #define LUA_COMPAT_FLOATSTRING */
-
 /* }================================================================== */
 
 
@@ -418,14 +398,14 @@
 @@ LUA_NUMBER is the floating-point type used by Lua.
 @@ LUAI_UACNUMBER is the result of a 'default argument promotion'
 @@ over a floating number.
-@@ l_mathlim(x) corrects limit name 'x' to the proper float type
+@@ l_floatatt(x) corrects float attribute 'x' to the proper float type
 ** by prefixing it with one of FLT/DBL/LDBL.
 @@ LUA_NUMBER_FRMLEN is the length modifier for writing floats.
 @@ LUA_NUMBER_FMT is the format for writing floats.
 @@ lua_number2str converts a float to a string.
 @@ l_mathop allows the addition of an 'l' or 'f' to all math operations.
 @@ l_floor takes the floor of a float.
-@@ lua_str2number converts a decimal numeric string to a number.
+@@ lua_str2number converts a decimal numeral to a number.
 */
 
 
@@ -437,12 +417,13 @@
 	l_sprintf((s), sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)(n))
 
 /*
-@@ lua_numbertointeger converts a float number to an integer, or
-** returns 0 if float is not within the range of a lua_Integer.
-** (The range comparisons are tricky because of rounding. The tests
-** here assume a two-complement representation, where MININTEGER always
-** has an exact representation as a float; MAXINTEGER may not have one,
-** and therefore its conversion to float may have an ill-defined value.)
+@@ lua_numbertointeger converts a float number with an integral value
+** to an integer, or returns 0 if float is not within the range of
+** a lua_Integer.  (The range comparisons are tricky because of
+** rounding. The tests here assume a two-complement representation,
+** where MININTEGER always has an exact representation as a float;
+** MAXINTEGER may not have one, and therefore its conversion to float
+** may have an ill-defined value.)
 */
 #define lua_numbertointeger(n,p) \
   ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \
@@ -456,7 +437,7 @@
 
 #define LUA_NUMBER	float
 
-#define l_mathlim(n)		(FLT_##n)
+#define l_floatatt(n)		(FLT_##n)
 
 #define LUAI_UACNUMBER	double
 
@@ -472,7 +453,7 @@
 
 #define LUA_NUMBER	long double
 
-#define l_mathlim(n)		(LDBL_##n)
+#define l_floatatt(n)		(LDBL_##n)
 
 #define LUAI_UACNUMBER	long double
 
@@ -487,7 +468,7 @@
 
 #define LUA_NUMBER	double
 
-#define l_mathlim(n)		(DBL_##n)
+#define l_floatatt(n)		(DBL_##n)
 
 #define LUAI_UACNUMBER	double
 
@@ -512,11 +493,13 @@
 @@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER.
 **
 @@ LUAI_UACINT is the result of a 'default argument promotion'
-@@ over a lUA_INTEGER.
+@@ over a LUA_INTEGER.
 @@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers.
 @@ LUA_INTEGER_FMT is the format for writing integers.
 @@ LUA_MAXINTEGER is the maximum value for a LUA_INTEGER.
 @@ LUA_MININTEGER is the minimum value for a LUA_INTEGER.
+@@ LUA_MAXUNSIGNED is the maximum value for a LUA_UNSIGNED.
+@@ LUA_UNSIGNEDBITS is the number of bits in a LUA_UNSIGNED.
 @@ lua_integer2str converts an integer to a string.
 */
 
@@ -537,6 +520,9 @@
 #define LUA_UNSIGNED		unsigned LUAI_UACINT
 
 
+#define LUA_UNSIGNEDBITS	(sizeof(LUA_UNSIGNED) * CHAR_BIT)
+
+
 /* now the variable definitions */
 
 #if LUA_INT_TYPE == LUA_INT_INT		/* { int */
@@ -547,6 +533,8 @@
 #define LUA_MAXINTEGER		INT_MAX
 #define LUA_MININTEGER		INT_MIN
 
+#define LUA_MAXUNSIGNED		UINT_MAX
+
 #elif LUA_INT_TYPE == LUA_INT_LONG	/* }{ long */
 
 #define LUA_INTEGER		long
@@ -555,6 +543,8 @@
 #define LUA_MAXINTEGER		LONG_MAX
 #define LUA_MININTEGER		LONG_MIN
 
+#define LUA_MAXUNSIGNED		ULONG_MAX
+
 #elif LUA_INT_TYPE == LUA_INT_LONGLONG	/* }{ long long */
 
 /* use presence of macro LLONG_MAX as proxy for C99 compliance */
@@ -567,6 +557,8 @@
 #define LUA_MAXINTEGER		LLONG_MAX
 #define LUA_MININTEGER		LLONG_MIN
 
+#define LUA_MAXUNSIGNED		ULLONG_MAX
+
 #elif defined(LUA_USE_WINDOWS) /* }{ */
 /* in Windows, can use specific Windows types */
 
@@ -576,6 +568,8 @@
 #define LUA_MAXINTEGER		_I64_MAX
 #define LUA_MININTEGER		_I64_MIN
 
+#define LUA_MAXUNSIGNED		_UI64_MAX
+
 #else				/* }{ */
 
 #error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' \
@@ -610,7 +604,7 @@
 
 
 /*
-@@ lua_strx2number converts an hexadecimal numeric string to a number.
+@@ lua_strx2number converts a hexadecimal numeral to a number.
 ** In C99, 'strtod' does that conversion. Otherwise, you can
 ** leave 'lua_strx2number' undefined and Lua will provide its own
 ** implementation.
@@ -628,7 +622,7 @@
 
 
 /*
-@@ lua_number2strx converts a float to an hexadecimal numeric string.
+@@ lua_number2strx converts a float to a hexadecimal numeral.
 ** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that.
 ** Otherwise, you can leave 'lua_number2strx' undefined and Lua will
 ** provide its own implementation.
@@ -674,7 +668,7 @@
 /*
 @@ lua_getlocaledecpoint gets the locale "radix character" (decimal point).
 ** Change that if you do not want to use C locales. (Code using this
-** macro must include header 'locale.h'.)
+** macro must include the header 'locale.h'.)
 */
 #if !defined(lua_getlocaledecpoint)
 #define lua_getlocaledecpoint()		(localeconv()->decimal_point[0])
@@ -715,7 +709,7 @@
 ** {==================================================================
 ** Macros that affect the API and must be stable (that is, must be the
 ** same when you compile Lua and when you compile code that links to
-** Lua). You probably do not want/need to change them.
+** Lua).
 ** =====================================================================
 */
 
@@ -724,8 +718,9 @@
 ** CHANGE it if you need a different limit. This limit is arbitrary;
 ** its only purpose is to stop Lua from consuming unlimited stack
 ** space (and to reserve some numbers for pseudo-indices).
+** (It must fit into max(size_t)/32.)
 */
-#if LUAI_BITSINT >= 32
+#if LUAI_IS32INT
 #define LUAI_MAXSTACK		1000000
 #else
 #define LUAI_MAXSTACK		15000
@@ -750,27 +745,18 @@
 
 /*
 @@ LUAL_BUFFERSIZE is the buffer size used by the lauxlib buffer system.
-** CHANGE it if it uses too much C-stack space. (For long double,
-** 'string.format("%.99f", -1e4932)' needs 5034 bytes, so a
-** smaller buffer would force a memory allocation for each call to
-** 'string.format'.)
 */
-#if LUA_FLOAT_TYPE == LUA_FLOAT_LONGDOUBLE
-#define LUAL_BUFFERSIZE		8192
-#else
-#define LUAL_BUFFERSIZE   ((int)(0x80 * sizeof(void*) * sizeof(lua_Integer)))
-#endif
-
-/* }================================================================== */
+#define LUAL_BUFFERSIZE   ((int)(16 * sizeof(void*) * sizeof(lua_Number)))
 
 
 /*
-@@ LUA_QL describes how error messages quote program elements.
-** Lua does not use these macros anymore; they are here for
-** compatibility only.
+@@ LUAI_MAXALIGN defines fields that, when used in a union, ensure
+** maximum alignment for the other items in that union.
 */
-#define LUA_QL(x)	"'" x "'"
-#define LUA_QS		LUA_QL("%s")
+#define LUAI_MAXALIGN  lua_Number n; double u; void *s; lua_Integer i; long l
+
+/* }================================================================== */
+
 
 
 
diff --git a/libs/liblua/src/lualib.h b/libs/liblua/src/lualib.h
index f5304aa0dd..eb08b530a6 100644
--- a/libs/liblua/src/lualib.h
+++ b/libs/liblua/src/lualib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lualib.h,v 1.45.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lualib.h $
 ** Lua standard libraries
 ** See Copyright Notice in lua.h
 */
@@ -35,9 +35,6 @@ LUAMOD_API int (luaopen_string) (lua_State *L);
 #define LUA_UTF8LIBNAME	"utf8"
 LUAMOD_API int (luaopen_utf8) (lua_State *L);
 
-#define LUA_BITLIBNAME	"bit32"
-LUAMOD_API int (luaopen_bit32) (lua_State *L);
-
 #define LUA_MATHLIBNAME	"math"
 LUAMOD_API int (luaopen_math) (lua_State *L);
 
diff --git a/libs/liblua/src/lundump.c b/libs/liblua/src/lundump.c
index 7a67d75aaa..4243678a72 100644
--- a/libs/liblua/src/lundump.c
+++ b/libs/liblua/src/lundump.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.c,v 2.44.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lundump.c $
 ** load precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -10,6 +10,7 @@
 #include "lprefix.h"
 
 
+#include <limits.h>
 #include <string.h>
 
 #include "lua.h"
@@ -25,7 +26,7 @@
 
 
 #if !defined(luai_verifycode)
-#define luai_verifycode(L,b,f)  /* empty */
+#define luai_verifycode(L,f)  /* empty */
 #endif
 
 
@@ -36,224 +37,266 @@ typedef struct {
 } LoadState;
 
 
-static l_noret error(LoadState *S, const char *why) {
-  luaO_pushfstring(S->L, "%s: %s precompiled chunk", S->name, why);
+static l_noret error (LoadState *S, const char *why) {
+  luaO_pushfstring(S->L, "%s: bad binary format (%s)", S->name, why);
   luaD_throw(S->L, LUA_ERRSYNTAX);
 }
 
 
 /*
-** All high-level loads go through LoadVector; you can change it to
+** All high-level loads go through loadVector; you can change it to
 ** adapt to the endianness of the input
 */
-#define LoadVector(S,b,n)	LoadBlock(S,b,(n)*sizeof((b)[0]))
+#define loadVector(S,b,n)	loadBlock(S,b,(n)*sizeof((b)[0]))
 
-static void LoadBlock (LoadState *S, void *b, size_t size) {
+static void loadBlock (LoadState *S, void *b, size_t size) {
   if (luaZ_read(S->Z, b, size) != 0)
-    error(S, "truncated");
+    error(S, "truncated chunk");
 }
 
 
-#define LoadVar(S,x)		LoadVector(S,&x,1)
+#define loadVar(S,x)		loadVector(S,&x,1)
 
 
-static lu_byte LoadByte (LoadState *S) {
-  lu_byte x;
-  LoadVar(S, x);
-  return x;
+static lu_byte loadByte (LoadState *S) {
+  int b = zgetc(S->Z);
+  if (b == EOZ)
+    error(S, "truncated chunk");
+  return cast_byte(b);
 }
 
 
-static int LoadInt (LoadState *S) {
-  int x;
-  LoadVar(S, x);
+static size_t loadUnsigned (LoadState *S, size_t limit) {
+  size_t x = 0;
+  int b;
+  limit >>= 7;
+  do {
+    b = loadByte(S);
+    if (x >= limit)
+      error(S, "integer overflow");
+    x = (x << 7) | (b & 0x7f);
+  } while ((b & 0x80) == 0);
   return x;
 }
 
 
-static lua_Number LoadNumber (LoadState *S) {
+static size_t loadSize (LoadState *S) {
+  return loadUnsigned(S, ~(size_t)0);
+}
+
+
+static int loadInt (LoadState *S) {
+  return cast_int(loadUnsigned(S, INT_MAX));
+}
+
+
+static lua_Number loadNumber (LoadState *S) {
   lua_Number x;
-  LoadVar(S, x);
+  loadVar(S, x);
   return x;
 }
 
 
-static lua_Integer LoadInteger (LoadState *S) {
+static lua_Integer loadInteger (LoadState *S) {
   lua_Integer x;
-  LoadVar(S, x);
+  loadVar(S, x);
   return x;
 }
 
 
-static TString *LoadString (LoadState *S) {
-  size_t size = LoadByte(S);
-  if (size == 0xFF)
-    LoadVar(S, size);
-  if (size == 0)
+/*
+** Load a nullable string into prototype 'p'.
+*/
+static TString *loadStringN (LoadState *S, Proto *p) {
+  lua_State *L = S->L;
+  TString *ts;
+  size_t size = loadSize(S);
+  if (size == 0)  /* no string? */
     return NULL;
   else if (--size <= LUAI_MAXSHORTLEN) {  /* short string? */
     char buff[LUAI_MAXSHORTLEN];
-    LoadVector(S, buff, size);
-    return luaS_newlstr(S->L, buff, size);
+    loadVector(S, buff, size);  /* load string into buffer */
+    ts = luaS_newlstr(L, buff, size);  /* create string */
   }
   else {  /* long string */
-    TString *ts = luaS_createlngstrobj(S->L, size);
-    LoadVector(S, getstr(ts), size);  /* load directly in final place */
-    return ts;
+    ts = luaS_createlngstrobj(L, size);  /* create string */
+    loadVector(S, getstr(ts), size);  /* load directly in final place */
   }
+  luaC_objbarrier(L, p, ts);
+  return ts;
 }
 
 
-static void LoadCode (LoadState *S, Proto *f) {
-  int n = LoadInt(S);
-  f->code = luaM_newvector(S->L, n, Instruction);
+/*
+** Load a non-nullable string into prototype 'p'.
+*/
+static TString *loadString (LoadState *S, Proto *p) {
+  TString *st = loadStringN(S, p);
+  if (st == NULL)
+    error(S, "bad format for constant string");
+  return st;
+}
+
+
+static void loadCode (LoadState *S, Proto *f) {
+  int n = loadInt(S);
+  f->code = luaM_newvectorchecked(S->L, n, Instruction);
   f->sizecode = n;
-  LoadVector(S, f->code, n);
+  loadVector(S, f->code, n);
 }
 
 
-static void LoadFunction(LoadState *S, Proto *f, TString *psource);
+static void loadFunction(LoadState *S, Proto *f, TString *psource);
 
 
-static void LoadConstants (LoadState *S, Proto *f) {
+static void loadConstants (LoadState *S, Proto *f) {
   int i;
-  int n = LoadInt(S);
-  f->k = luaM_newvector(S->L, n, TValue);
+  int n = loadInt(S);
+  f->k = luaM_newvectorchecked(S->L, n, TValue);
   f->sizek = n;
   for (i = 0; i < n; i++)
     setnilvalue(&f->k[i]);
   for (i = 0; i < n; i++) {
     TValue *o = &f->k[i];
-    int t = LoadByte(S);
+    int t = loadByte(S);
     switch (t) {
-    case LUA_TNIL:
-      setnilvalue(o);
-      break;
-    case LUA_TBOOLEAN:
-      setbvalue(o, LoadByte(S));
-      break;
-    case LUA_TNUMFLT:
-      setfltvalue(o, LoadNumber(S));
-      break;
-    case LUA_TNUMINT:
-      setivalue(o, LoadInteger(S));
-      break;
-    case LUA_TSHRSTR:
-    case LUA_TLNGSTR:
-      setsvalue2n(S->L, o, LoadString(S));
-      break;
-    default:
-      lua_assert(0);
+      case LUA_VNIL:
+        setnilvalue(o);
+        break;
+      case LUA_VFALSE:
+        setbfvalue(o);
+        break;
+      case LUA_VTRUE:
+        setbtvalue(o);
+        break;
+      case LUA_VNUMFLT:
+        setfltvalue(o, loadNumber(S));
+        break;
+      case LUA_VNUMINT:
+        setivalue(o, loadInteger(S));
+        break;
+      case LUA_VSHRSTR:
+      case LUA_VLNGSTR:
+        setsvalue2n(S->L, o, loadString(S, f));
+        break;
+      default: lua_assert(0);
     }
   }
 }
 
 
-static void LoadProtos (LoadState *S, Proto *f) {
+static void loadProtos (LoadState *S, Proto *f) {
   int i;
-  int n = LoadInt(S);
-  f->p = luaM_newvector(S->L, n, Proto *);
+  int n = loadInt(S);
+  f->p = luaM_newvectorchecked(S->L, n, Proto *);
   f->sizep = n;
   for (i = 0; i < n; i++)
     f->p[i] = NULL;
   for (i = 0; i < n; i++) {
     f->p[i] = luaF_newproto(S->L);
-    LoadFunction(S, f->p[i], f->source);
+    luaC_objbarrier(S->L, f, f->p[i]);
+    loadFunction(S, f->p[i], f->source);
   }
 }
 
 
-static void LoadUpvalues (LoadState *S, Proto *f) {
+static void loadUpvalues (LoadState *S, Proto *f) {
   int i, n;
-  n = LoadInt(S);
-  f->upvalues = luaM_newvector(S->L, n, Upvaldesc);
+  n = loadInt(S);
+  f->upvalues = luaM_newvectorchecked(S->L, n, Upvaldesc);
   f->sizeupvalues = n;
-  for (i = 0; i < n; i++)
-    f->upvalues[i].name = NULL;
   for (i = 0; i < n; i++) {
-    f->upvalues[i].instack = LoadByte(S);
-    f->upvalues[i].idx = LoadByte(S);
+    f->upvalues[i].name = NULL;
+    f->upvalues[i].instack = loadByte(S);
+    f->upvalues[i].idx = loadByte(S);
+    f->upvalues[i].kind = loadByte(S);
   }
 }
 
 
-static void LoadDebug (LoadState *S, Proto *f) {
+static void loadDebug (LoadState *S, Proto *f) {
   int i, n;
-  n = LoadInt(S);
-  f->lineinfo = luaM_newvector(S->L, n, int);
+  n = loadInt(S);
+  f->lineinfo = luaM_newvectorchecked(S->L, n, ls_byte);
   f->sizelineinfo = n;
-  LoadVector(S, f->lineinfo, n);
-  n = LoadInt(S);
-  f->locvars = luaM_newvector(S->L, n, LocVar);
+  loadVector(S, f->lineinfo, n);
+  n = loadInt(S);
+  f->abslineinfo = luaM_newvectorchecked(S->L, n, AbsLineInfo);
+  f->sizeabslineinfo = n;
+  for (i = 0; i < n; i++) {
+    f->abslineinfo[i].pc = loadInt(S);
+    f->abslineinfo[i].line = loadInt(S);
+  }
+  n = loadInt(S);
+  f->locvars = luaM_newvectorchecked(S->L, n, LocVar);
   f->sizelocvars = n;
   for (i = 0; i < n; i++)
     f->locvars[i].varname = NULL;
   for (i = 0; i < n; i++) {
-    f->locvars[i].varname = LoadString(S);
-    f->locvars[i].startpc = LoadInt(S);
-    f->locvars[i].endpc = LoadInt(S);
+    f->locvars[i].varname = loadStringN(S, f);
+    f->locvars[i].startpc = loadInt(S);
+    f->locvars[i].endpc = loadInt(S);
   }
-  n = LoadInt(S);
+  n = loadInt(S);
   for (i = 0; i < n; i++)
-    f->upvalues[i].name = LoadString(S);
+    f->upvalues[i].name = loadStringN(S, f);
 }
 
 
-static void LoadFunction (LoadState *S, Proto *f, TString *psource) {
-  f->source = LoadString(S);
+static void loadFunction (LoadState *S, Proto *f, TString *psource) {
+  f->source = loadStringN(S, f);
   if (f->source == NULL)  /* no source in dump? */
     f->source = psource;  /* reuse parent's source */
-  f->linedefined = LoadInt(S);
-  f->lastlinedefined = LoadInt(S);
-  f->numparams = LoadByte(S);
-  f->is_vararg = LoadByte(S);
-  f->maxstacksize = LoadByte(S);
-  LoadCode(S, f);
-  LoadConstants(S, f);
-  LoadUpvalues(S, f);
-  LoadProtos(S, f);
-  LoadDebug(S, f);
+  f->linedefined = loadInt(S);
+  f->lastlinedefined = loadInt(S);
+  f->numparams = loadByte(S);
+  f->is_vararg = loadByte(S);
+  f->maxstacksize = loadByte(S);
+  loadCode(S, f);
+  loadConstants(S, f);
+  loadUpvalues(S, f);
+  loadProtos(S, f);
+  loadDebug(S, f);
 }
 
 
 static void checkliteral (LoadState *S, const char *s, const char *msg) {
   char buff[sizeof(LUA_SIGNATURE) + sizeof(LUAC_DATA)]; /* larger than both */
   size_t len = strlen(s);
-  LoadVector(S, buff, len);
+  loadVector(S, buff, len);
   if (memcmp(s, buff, len) != 0)
     error(S, msg);
 }
 
 
 static void fchecksize (LoadState *S, size_t size, const char *tname) {
-  if (LoadByte(S) != size)
-    error(S, luaO_pushfstring(S->L, "%s size mismatch in", tname));
+  if (loadByte(S) != size)
+    error(S, luaO_pushfstring(S->L, "%s size mismatch", tname));
 }
 
 
 #define checksize(S,t)	fchecksize(S,sizeof(t),#t)
 
 static void checkHeader (LoadState *S) {
-  checkliteral(S, LUA_SIGNATURE + 1, "not a");  /* 1st char already checked */
-  if (LoadByte(S) != LUAC_VERSION)
-    error(S, "version mismatch in");
-  if (LoadByte(S) != LUAC_FORMAT)
-    error(S, "format mismatch in");
-  checkliteral(S, LUAC_DATA, "corrupted");
-  checksize(S, int);
-  checksize(S, size_t);
+  /* skip 1st char (already read and checked) */
+  checkliteral(S, &LUA_SIGNATURE[1], "not a binary chunk");
+  if (loadByte(S) != LUAC_VERSION)
+    error(S, "version mismatch");
+  if (loadByte(S) != LUAC_FORMAT)
+    error(S, "format mismatch");
+  checkliteral(S, LUAC_DATA, "corrupted chunk");
   checksize(S, Instruction);
   checksize(S, lua_Integer);
   checksize(S, lua_Number);
-  if (LoadInteger(S) != LUAC_INT)
-    error(S, "endianness mismatch in");
-  if (LoadNumber(S) != LUAC_NUM)
-    error(S, "float format mismatch in");
+  if (loadInteger(S) != LUAC_INT)
+    error(S, "integer format mismatch");
+  if (loadNumber(S) != LUAC_NUM)
+    error(S, "float format mismatch");
 }
 
 
 /*
-** load precompiled chunk
+** Load precompiled chunk.
 */
 LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
   LoadState S;
@@ -267,13 +310,14 @@ LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
   S.L = L;
   S.Z = Z;
   checkHeader(&S);
-  cl = luaF_newLclosure(L, LoadByte(&S));
-  setclLvalue(L, L->top, cl);
+  cl = luaF_newLclosure(L, loadByte(&S));
+  setclLvalue2s(L, L->top, cl);
   luaD_inctop(L);
   cl->p = luaF_newproto(L);
-  LoadFunction(&S, cl->p, NULL);
+  luaC_objbarrier(L, cl, cl->p);
+  loadFunction(&S, cl->p, NULL);
   lua_assert(cl->nupvalues == cl->p->sizeupvalues);
-  luai_verifycode(L, buff, cl->p);
+  luai_verifycode(L, cl->p);
   return cl;
 }
 
diff --git a/libs/liblua/src/lundump.h b/libs/liblua/src/lundump.h
index ce492d689c..f3748a9980 100644
--- a/libs/liblua/src/lundump.h
+++ b/libs/liblua/src/lundump.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.h,v 1.45.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lundump.h $
 ** load precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -18,8 +18,12 @@
 #define LUAC_INT	0x5678
 #define LUAC_NUM	cast_num(370.5)
 
-#define MYINT(s)	(s[0]-'0')
+/*
+** Encode major-minor version in one byte, one nibble for each
+*/
+#define MYINT(s)	(s[0]-'0')  /* assume one-digit numerals */
 #define LUAC_VERSION	(MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR))
+
 #define LUAC_FORMAT	0	/* this is the official format */
 
 /* load one chunk; from lundump.c */
diff --git a/libs/liblua/src/lutf8lib.c b/libs/liblua/src/lutf8lib.c
index 10bd238a71..901d985f8d 100644
--- a/libs/liblua/src/lutf8lib.c
+++ b/libs/liblua/src/lutf8lib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lutf8lib.c,v 1.16.1.1 2017/04/19 17:29:57 roberto Exp $
+** $Id: lutf8lib.c $
 ** Standard library for UTF-8 manipulation
 ** See Copyright Notice in lua.h
 */
@@ -20,7 +20,20 @@
 #include "lauxlib.h"
 #include "lualib.h"
 
-#define MAXUNICODE	0x10FFFF
+
+#define MAXUNICODE	0x10FFFFu
+
+#define MAXUTF		0x7FFFFFFFu
+
+/*
+** Integer type for decoded UTF-8 values; MAXUTF needs 31 bits.
+*/
+#if (UINT_MAX >> 30) >= 1
+typedef unsigned int utfint;
+#else
+typedef unsigned long utfint;
+#endif
+
 
 #define iscont(p)	((*(p) & 0xC0) == 0x80)
 
@@ -35,53 +48,62 @@ static lua_Integer u_posrelat (lua_Integer pos, size_t len) {
 
 
 /*
-** Decode one UTF-8 sequence, returning NULL if byte sequence is invalid.
+** Decode one UTF-8 sequence, returning NULL if byte sequence is
+** invalid.  The array 'limits' stores the minimum value for each
+** sequence length, to check for overlong representations. Its first
+** entry forces an error for non-ascii bytes with no continuation
+** bytes (count == 0).
 */
-static const char *utf8_decode (const char *o, int *val) {
-  static const unsigned int limits[] = {0xFF, 0x7F, 0x7FF, 0xFFFF};
-  const unsigned char *s = (const unsigned char *)o;
-  unsigned int c = s[0];
-  unsigned int res = 0;  /* final result */
+static const char *utf8_decode (const char *s, utfint *val, int strict) {
+  static const utfint limits[] =
+        {~(utfint)0, 0x80, 0x800, 0x10000u, 0x200000u, 0x4000000u};
+  unsigned int c = (unsigned char)s[0];
+  utfint res = 0;  /* final result */
   if (c < 0x80)  /* ascii? */
     res = c;
   else {
     int count = 0;  /* to count number of continuation bytes */
-    while (c & 0x40) {  /* still have continuation bytes? */
-      int cc = s[++count];  /* read next byte */
+    for (; c & 0x40; c <<= 1) {  /* while it needs continuation bytes... */
+      unsigned int cc = (unsigned char)s[++count];  /* read next byte */
       if ((cc & 0xC0) != 0x80)  /* not a continuation byte? */
         return NULL;  /* invalid byte sequence */
       res = (res << 6) | (cc & 0x3F);  /* add lower 6 bits from cont. byte */
-      c <<= 1;  /* to test next bit */
     }
-    res |= ((c & 0x7F) << (count * 5));  /* add first byte */
-    if (count > 3 || res > MAXUNICODE || res <= limits[count])
+    res |= ((utfint)(c & 0x7F) << (count * 5));  /* add first byte */
+    if (count > 5 || res > MAXUTF || res < limits[count])
       return NULL;  /* invalid byte sequence */
     s += count;  /* skip continuation bytes read */
   }
+  if (strict) {
+    /* check for invalid code points; too large or surrogates */
+    if (res > MAXUNICODE || (0xD800u <= res && res <= 0xDFFFu))
+      return NULL;
+  }
   if (val) *val = res;
-  return (const char *)s + 1;  /* +1 to include first byte */
+  return s + 1;  /* +1 to include first byte */
 }
 
 
 /*
-** utf8len(s [, i [, j]]) --> number of characters that start in the
-** range [i,j], or nil + current position if 's' is not well formed in
-** that interval
+** utf8len(s [, i [, j [, lax]]]) --> number of characters that
+** start in the range [i,j], or nil + current position if 's' is not
+** well formed in that interval
 */
 static int utflen (lua_State *L) {
-  int n = 0;
-  size_t len;
+  lua_Integer n = 0;  /* counter for the number of characters */
+  size_t len;  /* string length in bytes */
   const char *s = luaL_checklstring(L, 1, &len);
   lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
   lua_Integer posj = u_posrelat(luaL_optinteger(L, 3, -1), len);
+  int lax = lua_toboolean(L, 4);
   luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,
-                   "initial position out of string");
+                   "initial position out of bounds");
   luaL_argcheck(L, --posj < (lua_Integer)len, 3,
-                   "final position out of string");
+                   "final position out of bounds");
   while (posi <= posj) {
-    const char *s1 = utf8_decode(s + posi, NULL);
+    const char *s1 = utf8_decode(s + posi, NULL, !lax);
     if (s1 == NULL) {  /* conversion error? */
-      lua_pushnil(L);  /* return nil ... */
+      luaL_pushfail(L);  /* return fail ... */
       lua_pushinteger(L, posi + 1);  /* ... and current position */
       return 2;
     }
@@ -94,28 +116,29 @@ static int utflen (lua_State *L) {
 
 
 /*
-** codepoint(s, [i, [j]])  -> returns codepoints for all characters
-** that start in the range [i,j]
+** codepoint(s, [i, [j [, lax]]]) -> returns codepoints for all
+** characters that start in the range [i,j]
 */
 static int codepoint (lua_State *L) {
   size_t len;
   const char *s = luaL_checklstring(L, 1, &len);
   lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);
   lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len);
+  int lax = lua_toboolean(L, 4);
   int n;
   const char *se;
-  luaL_argcheck(L, posi >= 1, 2, "out of range");
-  luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of range");
+  luaL_argcheck(L, posi >= 1, 2, "out of bounds");
+  luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of bounds");
   if (posi > pose) return 0;  /* empty interval; return no values */
   if (pose - posi >= INT_MAX)  /* (lua_Integer -> int) overflow? */
     return luaL_error(L, "string slice too long");
-  n = (int)(pose -  posi) + 1;
+  n = (int)(pose -  posi) + 1;  /* upper bound for number of returns */
   luaL_checkstack(L, n, "string slice too long");
-  n = 0;
-  se = s + pose;
+  n = 0;  /* count the number of returns */
+  se = s + pose;  /* string end */
   for (s += posi - 1; s < se;) {
-    int code;
-    s = utf8_decode(s, &code);
+    utfint code;
+    s = utf8_decode(s, &code, !lax);
     if (s == NULL)
       return luaL_error(L, "invalid UTF-8 code");
     lua_pushinteger(L, code);
@@ -126,8 +149,8 @@ static int codepoint (lua_State *L) {
 
 
 static void pushutfchar (lua_State *L, int arg) {
-  lua_Integer code = luaL_checkinteger(L, arg);
-  luaL_argcheck(L, 0 <= code && code <= MAXUNICODE, arg, "value out of range");
+  lua_Unsigned code = (lua_Unsigned)luaL_checkinteger(L, arg);
+  luaL_argcheck(L, code <= MAXUTF, arg, "value out of range");
   lua_pushfstring(L, "%U", (long)code);
 }
 
@@ -164,7 +187,7 @@ static int byteoffset (lua_State *L) {
   lua_Integer posi = (n >= 0) ? 1 : len + 1;
   posi = u_posrelat(luaL_optinteger(L, 3, posi), len);
   luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3,
-                   "position out of range");
+                   "position out of bounds");
   if (n == 0) {
     /* find beginning of current byte sequence */
     while (posi > 0 && iscont(s + posi)) posi--;
@@ -193,12 +216,12 @@ static int byteoffset (lua_State *L) {
   if (n == 0)  /* did it find given character? */
     lua_pushinteger(L, posi + 1);
   else  /* no such character */
-    lua_pushnil(L);
+    luaL_pushfail(L);
   return 1;
 }
 
 
-static int iter_aux (lua_State *L) {
+static int iter_aux (lua_State *L, int strict) {
   size_t len;
   const char *s = luaL_checklstring(L, 1, &len);
   lua_Integer n = lua_tointeger(L, 2) - 1;
@@ -211,9 +234,9 @@ static int iter_aux (lua_State *L) {
   if (n >= (lua_Integer)len)
     return 0;  /* no more codepoints */
   else {
-    int code;
-    const char *next = utf8_decode(s + n, &code);
-    if (next == NULL || iscont(next))
+    utfint code;
+    const char *next = utf8_decode(s + n, &code, strict);
+    if (next == NULL)
       return luaL_error(L, "invalid UTF-8 code");
     lua_pushinteger(L, n + 1);
     lua_pushinteger(L, code);
@@ -222,9 +245,19 @@ static int iter_aux (lua_State *L) {
 }
 
 
+static int iter_auxstrict (lua_State *L) {
+  return iter_aux(L, 1);
+}
+
+static int iter_auxlax (lua_State *L) {
+  return iter_aux(L, 0);
+}
+
+
 static int iter_codes (lua_State *L) {
+  int lax = lua_toboolean(L, 2);
   luaL_checkstring(L, 1);
-  lua_pushcfunction(L, iter_aux);
+  lua_pushcfunction(L, lax ? iter_auxlax : iter_auxstrict);
   lua_pushvalue(L, 1);
   lua_pushinteger(L, 0);
   return 3;
@@ -232,7 +265,7 @@ static int iter_codes (lua_State *L) {
 
 
 /* pattern to match a single UTF-8 character */
-#define UTF8PATT	"[\0-\x7F\xC2-\xF4][\x80-\xBF]*"
+#define UTF8PATT	"[\0-\x7F\xC2-\xFD][\x80-\xBF]*"
 
 
 static const luaL_Reg funcs[] = {
diff --git a/libs/liblua/src/lvm.c b/libs/liblua/src/lvm.c
index cc43d8714d..e7781dbf25 100644
--- a/libs/liblua/src/lvm.c
+++ b/libs/liblua/src/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.268.1.1 2017/04/19 17:39:34 roberto Exp $
+** $Id: lvm.c $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -31,39 +31,70 @@
 #include "lvm.h"
 
 
-/* limit for table tag-method chains (to avoid loops) */
-#define MAXTAGLOOP	2000
+/*
+** By default, use jump tables in the main interpreter loop on gcc
+** and compatible compilers.
+*/
+#if !defined(LUA_USE_JUMPTABLE)
+#if defined(__GNUC__)
+#define LUA_USE_JUMPTABLE	1
+#else
+#define LUA_USE_JUMPTABLE	0
+#endif
+#endif
+
 
 
+/* limit for table tag-method chains (to avoid infinite loops) */
+#define MAXTAGLOOP	2000
+
 
 /*
-** 'l_intfitsf' checks whether a given integer can be converted to a
-** float without rounding. Used in comparisons. Left undefined if
-** all integers fit in a float precisely.
+** 'l_intfitsf' checks whether a given integer is in the range that
+** can be converted to a float without rounding. Used in comparisons.
 */
-#if !defined(l_intfitsf)
 
 /* number of bits in the mantissa of a float */
-#define NBM		(l_mathlim(MANT_DIG))
+#define NBM		(l_floatatt(MANT_DIG))
 
 /*
-** Check whether some integers may not fit in a float, that is, whether
-** (maxinteger >> NBM) > 0 (that implies (1 << NBM) <= maxinteger).
-** (The shifts are done in parts to avoid shifting by more than the size
+** Check whether some integers may not fit in a float, testing whether
+** (maxinteger >> NBM) > 0. (That implies (1 << NBM) <= maxinteger.)
+** (The shifts are done in parts, to avoid shifting by more than the size
 ** of an integer. In a worst case, NBM == 113 for long double and
-** sizeof(integer) == 32.)
+** sizeof(long) == 32.)
 */
 #if ((((LUA_MAXINTEGER >> (NBM / 4)) >> (NBM / 4)) >> (NBM / 4)) \
 	>> (NBM - (3 * (NBM / 4))))  >  0
 
-#define l_intfitsf(i)  \
-  (-((lua_Integer)1 << NBM) <= (i) && (i) <= ((lua_Integer)1 << NBM))
+/* limit for integers that fit in a float */
+#define MAXINTFITSF	((lua_Unsigned)1 << NBM)
 
-#endif
+/* check whether 'i' is in the interval [-MAXINTFITSF, MAXINTFITSF] */
+#define l_intfitsf(i)	((MAXINTFITSF + l_castS2U(i)) <= (2 * MAXINTFITSF))
+
+#else  /* all integers fit in a float precisely */
+
+#define l_intfitsf(i)	1
 
 #endif
 
 
+/*
+** Try to convert a value from string to a number value.
+** If the value is not a string or is a string not representing
+** a valid numeral (or if coercions from strings to numbers
+** are disabled via macro 'cvt2num'), do not modify 'result'
+** and return 0.
+*/
+static int l_strton (const TValue *obj, TValue *result) {
+  lua_assert(obj != result);
+  if (!cvt2num(obj))  /* is object not a string? */
+    return 0;
+  else
+    return (luaO_str2num(svalue(obj), result) == vslen(obj) + 1);
+}
+
 
 /*
 ** Try to convert a value to a float. The float case is already handled
@@ -75,8 +106,7 @@ int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
     *n = cast_num(ivalue(obj));
     return 1;
   }
-  else if (cvt2num(obj) &&  /* string convertible to number? */
-            luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
+  else if (l_strton(obj, &v)) {  /* string coercible to number? */
     *n = nvalue(&v);  /* convert result of 'luaO_str2num' to a float */
     return 1;
   }
@@ -86,76 +116,173 @@ int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
 
 
 /*
-** try to convert a value to an integer, rounding according to 'mode':
-** mode == 0: accepts only integral values
-** mode == 1: takes the floor of the number
-** mode == 2: takes the ceil of the number
+** try to convert a float to an integer, rounding according to 'mode'.
 */
-int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode) {
-  TValue v;
- again:
-  if (ttisfloat(obj)) {
-    lua_Number n = fltvalue(obj);
-    lua_Number f = l_floor(n);
-    if (n != f) {  /* not an integral value? */
-      if (mode == 0) return 0;  /* fails if mode demands integral value */
-      else if (mode > 1)  /* needs ceil? */
-        f += 1;  /* convert floor to ceil (remember: n != f) */
-    }
-    return lua_numbertointeger(f, p);
+int luaV_flttointeger (lua_Number n, lua_Integer *p, F2Imod mode) {
+  lua_Number f = l_floor(n);
+  if (n != f) {  /* not an integral value? */
+    if (mode == F2Ieq) return 0;  /* fails if mode demands integral value */
+    else if (mode == F2Iceil)  /* needs ceil? */
+      f += 1;  /* convert floor to ceil (remember: n != f) */
   }
+  return lua_numbertointeger(f, p);
+}
+
+
+/*
+** try to convert a value to an integer, rounding according to 'mode',
+** without string coercion.
+** ("Fast track" handled by macro 'tointegerns'.)
+*/
+int luaV_tointegerns (const TValue *obj, lua_Integer *p, F2Imod mode) {
+  if (ttisfloat(obj))
+    return luaV_flttointeger(fltvalue(obj), p, mode);
   else if (ttisinteger(obj)) {
     *p = ivalue(obj);
     return 1;
   }
-  else if (cvt2num(obj) &&
-            luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
-    obj = &v;
-    goto again;  /* convert result from 'luaO_str2num' to an integer */
+  else
+    return 0;
+}
+
+
+/*
+** try to convert a value to an integer.
+*/
+int luaV_tointeger (const TValue *obj, lua_Integer *p, F2Imod mode) {
+  TValue v;
+  if (l_strton(obj, &v))  /* does 'obj' point to a numerical string? */
+    obj = &v;  /* change it to point to its corresponding number */
+  return luaV_tointegerns(obj, p, mode);
+}
+
+
+/*
+** Try to convert a 'for' limit to an integer, preserving the semantics
+** of the loop. Return true if the loop must not run; otherwise, '*p'
+** gets the integer limit.
+** (The following explanation assumes a positive step; it is valid for
+** negative steps mutatis mutandis.)
+** If the limit is an integer or can be converted to an integer,
+** rounding down, that is the limit.
+** Otherwise, check whether the limit can be converted to a float. If
+** the float is too large, clip it to LUA_MAXINTEGER.  If the float
+** is too negative, the loop should not run, because any initial
+** integer value is greater than such limit; so, the function returns
+** true to signal that. (For this latter case, no integer limit would be
+** correct; even a limit of LUA_MININTEGER would run the loop once for
+** an initial value equal to LUA_MININTEGER.)
+*/
+static int forlimit (lua_State *L, lua_Integer init, const TValue *lim,
+                                   lua_Integer *p, lua_Integer step) {
+  if (!luaV_tointeger(lim, p, (step < 0 ? F2Iceil : F2Ifloor))) {
+    /* not coercible to in integer */
+    lua_Number flim;  /* try to convert to float */
+    if (!tonumber(lim, &flim)) /* cannot convert to float? */
+      luaG_forerror(L, lim, "limit");
+    /* else 'flim' is a float out of integer bounds */
+    if (luai_numlt(0, flim)) {  /* if it is positive, it is too large */
+      if (step < 0) return 1;  /* initial value must be less than it */
+      *p = LUA_MAXINTEGER;  /* truncate */
+    }
+    else {  /* it is less than min integer */
+      if (step > 0) return 1;  /* initial value must be greater than it */
+      *p = LUA_MININTEGER;  /* truncate */
+    }
   }
-  return 0;  /* conversion failed */
+  return (step > 0 ? init > *p : init < *p);  /* not to run? */
 }
 
 
 /*
-** Try to convert a 'for' limit to an integer, preserving the
-** semantics of the loop.
-** (The following explanation assumes a non-negative step; it is valid
-** for negative steps mutatis mutandis.)
-** If the limit can be converted to an integer, rounding down, that is
-** it.
-** Otherwise, check whether the limit can be converted to a number.  If
-** the number is too large, it is OK to set the limit as LUA_MAXINTEGER,
-** which means no limit.  If the number is too negative, the loop
-** should not run, because any initial integer value is larger than the
-** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects
-** the extreme case when the initial value is LUA_MININTEGER, in which
-** case the LUA_MININTEGER limit would still run the loop once.
+** Prepare a numerical for loop (opcode OP_FORPREP).
+** Return true to skip the loop. Otherwise,
+** after preparation, stack will be as follows:
+**   ra : internal index (safe copy of the control variable)
+**   ra + 1 : loop counter (integer loops) or limit (float loops)
+**   ra + 2 : step
+**   ra + 3 : control variable
 */
-static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
-                     int *stopnow) {
-  *stopnow = 0;  /* usually, let loops run */
-  if (!luaV_tointeger(obj, p, (step < 0 ? 2 : 1))) {  /* not fit in integer? */
-    lua_Number n;  /* try to convert to float */
-    if (!tonumber(obj, &n)) /* cannot convert to float? */
-      return 0;  /* not a number */
-    if (luai_numlt(0, n)) {  /* if true, float is larger than max integer */
-      *p = LUA_MAXINTEGER;
-      if (step < 0) *stopnow = 1;
+static int forprep (lua_State *L, StkId ra) {
+  TValue *pinit = s2v(ra);
+  TValue *plimit = s2v(ra + 1);
+  TValue *pstep = s2v(ra + 2);
+  if (ttisinteger(pinit) && ttisinteger(pstep)) { /* integer loop? */
+    lua_Integer init = ivalue(pinit);
+    lua_Integer step = ivalue(pstep);
+    lua_Integer limit;
+    if (step == 0)
+      luaG_runerror(L, "'for' step is zero");
+    setivalue(s2v(ra + 3), init);  /* control variable */
+    if (forlimit(L, init, plimit, &limit, step))
+      return 1;  /* skip the loop */
+    else {  /* prepare loop counter */
+      lua_Unsigned count;
+      if (step > 0) {  /* ascending loop? */
+        count = l_castS2U(limit) - l_castS2U(init);
+        if (step != 1)  /* avoid division in the too common case */
+          count /= l_castS2U(step);
+      }
+      else {  /* step < 0; descending loop */
+        count = l_castS2U(init) - l_castS2U(limit);
+        /* 'step+1' avoids negating 'mininteger' */
+        count /= l_castS2U(-(step + 1)) + 1u;
+      }
+      /* store the counter in place of the limit (which won't be
+         needed anymore */
+      setivalue(plimit, l_castU2S(count));
     }
-    else {  /* float is smaller than min integer */
-      *p = LUA_MININTEGER;
-      if (step >= 0) *stopnow = 1;
+  }
+  else {  /* try making all values floats */
+    lua_Number init; lua_Number limit; lua_Number step;
+    if (unlikely(!tonumber(plimit, &limit)))
+      luaG_forerror(L, plimit, "limit");
+    if (unlikely(!tonumber(pstep, &step)))
+      luaG_forerror(L, pstep, "step");
+    if (unlikely(!tonumber(pinit, &init)))
+      luaG_forerror(L, pinit, "initial value");
+    if (step == 0)
+      luaG_runerror(L, "'for' step is zero");
+    if (luai_numlt(0, step) ? luai_numlt(limit, init)
+                            : luai_numlt(init, limit))
+      return 1;  /* skip the loop */
+    else {
+      /* make sure internal values are all floats */
+      setfltvalue(plimit, limit);
+      setfltvalue(pstep, step);
+      setfltvalue(s2v(ra), init);  /* internal index */
+      setfltvalue(s2v(ra + 3), init);  /* control variable */
     }
   }
-  return 1;
+  return 0;
+}
+
+
+/*
+** Execute a step of a float numerical for loop, returning
+** true iff the loop must continue. (The integer case is
+** written online with opcode OP_FORLOOP, for performance.)
+*/
+static int floatforloop (StkId ra) {
+  lua_Number step = fltvalue(s2v(ra + 2));
+  lua_Number limit = fltvalue(s2v(ra + 1));
+  lua_Number idx = fltvalue(s2v(ra));  /* internal index */
+  idx = luai_numadd(L, idx, step);  /* increment index */
+  if (luai_numlt(0, step) ? luai_numle(idx, limit)
+                          : luai_numle(limit, idx)) {
+    chgfltvalue(s2v(ra), idx);  /* update internal index */
+    setfltvalue(s2v(ra + 3), idx);  /* and control variable */
+    return 1;  /* jump back */
+  }
+  else
+    return 0;  /* finish the loop */
 }
 
 
 /*
 ** Finish the table access 'val = t[key]'.
 ** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to
-** t[k] entry (which must be nil).
+** t[k] entry (which must be empty).
 */
 void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
                       const TValue *slot) {
@@ -165,25 +292,25 @@ void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
     if (slot == NULL) {  /* 't' is not a table? */
       lua_assert(!ttistable(t));
       tm = luaT_gettmbyobj(L, t, TM_INDEX);
-      if (ttisnil(tm))
+      if (unlikely(notm(tm)))
         luaG_typeerror(L, t, "index");  /* no metamethod */
       /* else will try the metamethod */
     }
     else {  /* 't' is a table */
-      lua_assert(ttisnil(slot));
+      lua_assert(isempty(slot));
       tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);  /* table's metamethod */
       if (tm == NULL) {  /* no metamethod? */
-        setnilvalue(val);  /* result is nil */
+        setnilvalue(s2v(val));  /* result is nil */
         return;
       }
       /* else will try the metamethod */
     }
     if (ttisfunction(tm)) {  /* is metamethod a function? */
-      luaT_callTM(L, tm, t, key, val, 1);  /* call it */
+      luaT_callTMres(L, tm, t, key, val);  /* call it */
       return;
     }
     t = tm;  /* else try to access 'tm[key]' */
-    if (luaV_fastget(L,t,key,slot,luaH_get)) {  /* fast track? */
+    if (luaV_fastget(L, t, key, slot, luaH_get)) {  /* fast track? */
       setobj2s(L, val, slot);  /* done */
       return;
     }
@@ -196,51 +323,54 @@ void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
 /*
 ** Finish a table assignment 't[key] = val'.
 ** If 'slot' is NULL, 't' is not a table.  Otherwise, 'slot' points
-** to the entry 't[key]', or to 'luaO_nilobject' if there is no such
-** entry.  (The value at 'slot' must be nil, otherwise 'luaV_fastset'
-** would have done the job.)
+** to the entry 't[key]', or to a value with an absent key if there
+** is no such entry.  (The value at 'slot' must be empty, otherwise
+** 'luaV_fastget' would have done the job.)
 */
 void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
-                     StkId val, const TValue *slot) {
+                     TValue *val, const TValue *slot) {
   int loop;  /* counter to avoid infinite loops */
   for (loop = 0; loop < MAXTAGLOOP; loop++) {
     const TValue *tm;  /* '__newindex' metamethod */
     if (slot != NULL) {  /* is 't' a table? */
       Table *h = hvalue(t);  /* save 't' table */
-      lua_assert(ttisnil(slot));  /* old value must be nil */
+      lua_assert(isempty(slot));  /* slot must be empty */
       tm = fasttm(L, h->metatable, TM_NEWINDEX);  /* get metamethod */
       if (tm == NULL) {  /* no metamethod? */
-        if (slot == luaO_nilobject)  /* no previous entry? */
+        if (isabstkey(slot))  /* no previous entry? */
           slot = luaH_newkey(L, h, key);  /* create one */
         /* no metamethod and (now) there is an entry with given key */
         setobj2t(L, cast(TValue *, slot), val);  /* set its new value */
         invalidateTMcache(h);
-        luaC_barrierback(L, h, val);
+        luaC_barrierback(L, obj2gco(h), val);
         return;
       }
       /* else will try the metamethod */
     }
     else {  /* not a table; check metamethod */
-      if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
+      tm = luaT_gettmbyobj(L, t, TM_NEWINDEX);
+      if (unlikely(notm(tm)))
         luaG_typeerror(L, t, "index");
     }
     /* try the metamethod */
     if (ttisfunction(tm)) {
-      luaT_callTM(L, tm, t, key, val, 0);
+      luaT_callTM(L, tm, t, key, val);
       return;
     }
     t = tm;  /* else repeat assignment over 'tm' */
-    if (luaV_fastset(L, t, key, slot, luaH_get, val))
+    if (luaV_fastget(L, t, key, slot, luaH_get)) {
+      luaV_finishfastset(L, t, slot, val);
       return;  /* done */
-    /* else loop */
+    }
+    /* else 'return luaV_finishset(L, t, key, val, slot)' (loop) */
   }
   luaG_runerror(L, "'__newindex' chain too long; possible loop");
 }
 
 
 /*
-** Compare two strings 'ls' x 'rs', returning an integer smaller-equal-
-** -larger than zero if 'ls' is smaller-equal-larger than 'rs'.
+** Compare two strings 'ls' x 'rs', returning an integer less-equal-
+** -greater than zero if 'ls' is less-equal-greater than 'rs'.
 ** The code is a little tricky because it allows '\0' in the strings
 ** and it uses 'strcoll' (to respect locales) for each segments
 ** of the strings.
@@ -259,7 +389,7 @@ static int l_strcmp (const TString *ls, const TString *rs) {
       if (len == lr)  /* 'rs' is finished? */
         return (len == ll) ? 0 : 1;  /* check 'ls' */
       else if (len == ll)  /* 'ls' is finished? */
-        return -1;  /* 'ls' is smaller than 'rs' ('rs' is not finished) */
+        return -1;  /* 'ls' is less than 'rs' ('rs' is not finished) */
       /* both strings longer than 'len'; go on comparing after the '\0' */
       len++;
       l += len; ll -= len; r += len; lr -= len;
@@ -271,25 +401,24 @@ static int l_strcmp (const TString *ls, const TString *rs) {
 /*
 ** Check whether integer 'i' is less than float 'f'. If 'i' has an
 ** exact representation as a float ('l_intfitsf'), compare numbers as
-** floats. Otherwise, if 'f' is outside the range for integers, result
-** is trivial. Otherwise, compare them as integers. (When 'i' has no
-** float representation, either 'f' is "far away" from 'i' or 'f' has
-** no precision left for a fractional part; either way, how 'f' is
-** truncated is irrelevant.) When 'f' is NaN, comparisons must result
-** in false.
+** floats. Otherwise, use the equivalence 'i < f <=> i < ceil(f)'.
+** If 'ceil(f)' is out of integer range, either 'f' is greater than
+** all integers or less than all integers.
+** (The test with 'l_intfitsf' is only for performance; the else
+** case is correct for all values, but it is slow due to the conversion
+** from float to int.)
+** When 'f' is NaN, comparisons must result in false.
 */
 static int LTintfloat (lua_Integer i, lua_Number f) {
-#if defined(l_intfitsf)
-  if (!l_intfitsf(i)) {
-    if (f >= -cast_num(LUA_MININTEGER))  /* -minint == maxint + 1 */
-      return 1;  /* f >= maxint + 1 > i */
-    else if (f > cast_num(LUA_MININTEGER))  /* minint < f <= maxint ? */
-      return (i < cast(lua_Integer, f));  /* compare them as integers */
-    else  /* f <= minint <= i (or 'f' is NaN)  -->  not(i < f) */
-      return 0;
+  if (l_intfitsf(i))
+    return luai_numlt(cast_num(i), f);  /* compare them as floats */
+  else {  /* i < f <=> i < ceil(f) */
+    lua_Integer fi;
+    if (luaV_flttointeger(f, &fi, F2Iceil))  /* fi = ceil(f) */
+      return i < fi;   /* compare them as integers */
+    else  /* 'f' is either greater or less than all integers */
+      return f > 0;  /* greater? */
   }
-#endif
-  return luai_numlt(cast_num(i), f);  /* compare them as floats */
 }
 
 
@@ -298,17 +427,49 @@ static int LTintfloat (lua_Integer i, lua_Number f) {
 ** See comments on previous function.
 */
 static int LEintfloat (lua_Integer i, lua_Number f) {
-#if defined(l_intfitsf)
-  if (!l_intfitsf(i)) {
-    if (f >= -cast_num(LUA_MININTEGER))  /* -minint == maxint + 1 */
-      return 1;  /* f >= maxint + 1 > i */
-    else if (f >= cast_num(LUA_MININTEGER))  /* minint <= f <= maxint ? */
-      return (i <= cast(lua_Integer, f));  /* compare them as integers */
-    else  /* f < minint <= i (or 'f' is NaN)  -->  not(i <= f) */
-      return 0;
+  if (l_intfitsf(i))
+    return luai_numle(cast_num(i), f);  /* compare them as floats */
+  else {  /* i <= f <=> i <= floor(f) */
+    lua_Integer fi;
+    if (luaV_flttointeger(f, &fi, F2Ifloor))  /* fi = floor(f) */
+      return i <= fi;   /* compare them as integers */
+    else  /* 'f' is either greater or less than all integers */
+      return f > 0;  /* greater? */
+  }
+}
+
+
+/*
+** Check whether float 'f' is less than integer 'i'.
+** See comments on previous function.
+*/
+static int LTfloatint (lua_Number f, lua_Integer i) {
+  if (l_intfitsf(i))
+    return luai_numlt(f, cast_num(i));  /* compare them as floats */
+  else {  /* f < i <=> floor(f) < i */
+    lua_Integer fi;
+    if (luaV_flttointeger(f, &fi, F2Ifloor))  /* fi = floor(f) */
+      return fi < i;   /* compare them as integers */
+    else  /* 'f' is either greater or less than all integers */
+      return f < 0;  /* less? */
+  }
+}
+
+
+/*
+** Check whether float 'f' is less than or equal to integer 'i'.
+** See comments on previous function.
+*/
+static int LEfloatint (lua_Number f, lua_Integer i) {
+  if (l_intfitsf(i))
+    return luai_numle(f, cast_num(i));  /* compare them as floats */
+  else {  /* f <= i <=> ceil(f) <= i */
+    lua_Integer fi;
+    if (luaV_flttointeger(f, &fi, F2Iceil))  /* fi = ceil(f) */
+      return fi <= i;   /* compare them as integers */
+    else  /* 'f' is either greater or less than all integers */
+      return f < 0;  /* less? */
   }
-#endif
-  return luai_numle(cast_num(i), f);  /* compare them as floats */
 }
 
 
@@ -316,6 +477,7 @@ static int LEintfloat (lua_Integer i, lua_Number f) {
 ** Return 'l < r', for numbers.
 */
 static int LTnum (const TValue *l, const TValue *r) {
+  lua_assert(ttisnumber(l) && ttisnumber(r));
   if (ttisinteger(l)) {
     lua_Integer li = ivalue(l);
     if (ttisinteger(r))
@@ -327,10 +489,8 @@ static int LTnum (const TValue *l, const TValue *r) {
     lua_Number lf = fltvalue(l);  /* 'l' must be float */
     if (ttisfloat(r))
       return luai_numlt(lf, fltvalue(r));  /* both are float */
-    else if (luai_numisnan(lf))  /* 'r' is int and 'l' is float */
-      return 0;  /* NaN < i is always false */
-    else  /* without NaN, (l < r)  <-->  not(r <= l) */
-      return !LEintfloat(ivalue(r), lf);  /* not (r <= l) ? */
+    else  /* 'l' is float and 'r' is int */
+      return LTfloatint(lf, ivalue(r));
   }
 }
 
@@ -339,6 +499,7 @@ static int LTnum (const TValue *l, const TValue *r) {
 ** Return 'l <= r', for numbers.
 */
 static int LEnum (const TValue *l, const TValue *r) {
+  lua_assert(ttisnumber(l) && ttisnumber(r));
   if (ttisinteger(l)) {
     lua_Integer li = ivalue(l);
     if (ttisinteger(r))
@@ -350,53 +511,53 @@ static int LEnum (const TValue *l, const TValue *r) {
     lua_Number lf = fltvalue(l);  /* 'l' must be float */
     if (ttisfloat(r))
       return luai_numle(lf, fltvalue(r));  /* both are float */
-    else if (luai_numisnan(lf))  /* 'r' is int and 'l' is float */
-      return 0;  /*  NaN <= i is always false */
-    else  /* without NaN, (l <= r)  <-->  not(r < l) */
-      return !LTintfloat(ivalue(r), lf);  /* not (r < l) ? */
+    else  /* 'l' is float and 'r' is int */
+      return LEfloatint(lf, ivalue(r));
   }
 }
 
 
+/*
+** return 'l < r' for non-numbers.
+*/
+static int lessthanothers (lua_State *L, const TValue *l, const TValue *r) {
+  lua_assert(!ttisnumber(l) || !ttisnumber(r));
+  if (ttisstring(l) && ttisstring(r))  /* both are strings? */
+    return l_strcmp(tsvalue(l), tsvalue(r)) < 0;
+  else
+    return luaT_callorderTM(L, l, r, TM_LT);
+}
+
+
 /*
 ** Main operation less than; return 'l < r'.
 */
 int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
-  int res;
   if (ttisnumber(l) && ttisnumber(r))  /* both operands are numbers? */
     return LTnum(l, r);
-  else if (ttisstring(l) && ttisstring(r))  /* both are strings? */
-    return l_strcmp(tsvalue(l), tsvalue(r)) < 0;
-  else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0)  /* no metamethod? */
-    luaG_ordererror(L, l, r);  /* error */
-  return res;
+  else return lessthanothers(L, l, r);
+}
+
+
+/*
+** return 'l <= r' for non-numbers.
+*/
+static int lessequalothers (lua_State *L, const TValue *l, const TValue *r) {
+  lua_assert(!ttisnumber(l) || !ttisnumber(r));
+  if (ttisstring(l) && ttisstring(r))  /* both are strings? */
+    return l_strcmp(tsvalue(l), tsvalue(r)) <= 0;
+  else
+    return luaT_callorderTM(L, l, r, TM_LE);
 }
 
 
 /*
-** Main operation less than or equal to; return 'l <= r'. If it needs
-** a metamethod and there is no '__le', try '__lt', based on
-** l <= r iff !(r < l) (assuming a total order). If the metamethod
-** yields during this substitution, the continuation has to know
-** about it (to negate the result of r<l); bit CIST_LEQ in the call
-** status keeps that information.
+** Main operation less than or equal to; return 'l <= r'.
 */
 int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
-  int res;
   if (ttisnumber(l) && ttisnumber(r))  /* both operands are numbers? */
     return LEnum(l, r);
-  else if (ttisstring(l) && ttisstring(r))  /* both are strings? */
-    return l_strcmp(tsvalue(l), tsvalue(r)) <= 0;
-  else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0)  /* try 'le' */
-    return res;
-  else {  /* try 'lt': */
-    L->ci->callstatus |= CIST_LEQ;  /* mark it is doing 'lt' for 'le' */
-    res = luaT_callorderTM(L, r, l, TM_LT);
-    L->ci->callstatus ^= CIST_LEQ;  /* clear mark */
-    if (res < 0)
-      luaG_ordererror(L, l, r);
-    return !res;  /* result is negated */
-  }
+  else return lessequalothers(L, l, r);
 }
 
 
@@ -406,25 +567,24 @@ int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
 */
 int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
   const TValue *tm;
-  if (ttype(t1) != ttype(t2)) {  /* not the same variant? */
-    if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER)
+  if (ttypetag(t1) != ttypetag(t2)) {  /* not the same variant? */
+    if (ttype(t1) != ttype(t2) || ttype(t1) != LUA_TNUMBER)
       return 0;  /* only numbers can be equal with different variants */
     else {  /* two numbers with different variants */
       lua_Integer i1, i2;  /* compare them as integers */
-      return (tointeger(t1, &i1) && tointeger(t2, &i2) && i1 == i2);
+      return (tointegerns(t1, &i1) && tointegerns(t2, &i2) && i1 == i2);
     }
   }
   /* values have same type and same variant */
-  switch (ttype(t1)) {
-    case LUA_TNIL: return 1;
-    case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2));
-    case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2));
-    case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
-    case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
-    case LUA_TLCF: return fvalue(t1) == fvalue(t2);
-    case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2));
-    case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2));
-    case LUA_TUSERDATA: {
+  switch (ttypetag(t1)) {
+    case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE: return 1;
+    case LUA_VNUMINT: return (ivalue(t1) == ivalue(t2));
+    case LUA_VNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2));
+    case LUA_VLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
+    case LUA_VLCF: return fvalue(t1) == fvalue(t2);
+    case LUA_VSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2));
+    case LUA_VLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2));
+    case LUA_VUSERDATA: {
       if (uvalue(t1) == uvalue(t2)) return 1;
       else if (L == NULL) return 0;
       tm = fasttm(L, uvalue(t1)->metatable, TM_EQ);
@@ -432,7 +592,7 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
         tm = fasttm(L, uvalue(t2)->metatable, TM_EQ);
       break;  /* will try TM */
     }
-    case LUA_TTABLE: {
+    case LUA_VTABLE: {
       if (hvalue(t1) == hvalue(t2)) return 1;
       else if (L == NULL) return 0;
       tm = fasttm(L, hvalue(t1)->metatable, TM_EQ);
@@ -445,8 +605,10 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
   }
   if (tm == NULL)  /* no TM? */
     return 0;  /* objects are different */
-  luaT_callTM(L, tm, t1, t2, L->top, 1);  /* call TM */
-  return !l_isfalse(L->top);
+  else {
+    luaT_callTMres(L, tm, t1, t2, L->top);  /* call TM */
+    return !l_isfalse(s2v(L->top));
+  }
 }
 
 
@@ -460,8 +622,8 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
 static void copy2buff (StkId top, int n, char *buff) {
   size_t tl = 0;  /* size already copied */
   do {
-    size_t l = vslen(top - n);  /* length of string being copied */
-    memcpy(buff + tl, svalue(top - n), l * sizeof(char));
+    size_t l = vslen(s2v(top - n));  /* length of string being copied */
+    memcpy(buff + tl, svalue(s2v(top - n)), l * sizeof(char));
     tl += l;
   } while (--n > 0);
 }
@@ -476,21 +638,22 @@ void luaV_concat (lua_State *L, int total) {
   do {
     StkId top = L->top;
     int n = 2;  /* number of elements handled in this pass (at least 2) */
-    if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1))
-      luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT);
-    else if (isemptystr(top - 1))  /* second operand is empty? */
-      cast_void(tostring(L, top - 2));  /* result is first operand */
-    else if (isemptystr(top - 2)) {  /* first operand is an empty string? */
+    if (!(ttisstring(s2v(top - 2)) || cvt2str(s2v(top - 2))) ||
+        !tostring(L, s2v(top - 1)))
+      luaT_tryconcatTM(L);
+    else if (isemptystr(s2v(top - 1)))  /* second operand is empty? */
+      cast_void(tostring(L, s2v(top - 2)));  /* result is first operand */
+    else if (isemptystr(s2v(top - 2))) {  /* first operand is empty string? */
       setobjs2s(L, top - 2, top - 1);  /* result is second op. */
     }
     else {
       /* at least two non-empty string values; get as many as possible */
-      size_t tl = vslen(top - 1);
+      size_t tl = vslen(s2v(top - 1));
       TString *ts;
       /* collect total length and number of strings */
-      for (n = 1; n < total && tostring(L, top - n - 1); n++) {
-        size_t l = vslen(top - n - 1);
-        if (l >= (MAX_SIZE/sizeof(char)) - tl)
+      for (n = 1; n < total && tostring(L, s2v(top - n - 1)); n++) {
+        size_t l = vslen(s2v(top - n - 1));
+        if (unlikely(l >= (MAX_SIZE/sizeof(char)) - tl))
           luaG_runerror(L, "string length overflow");
         tl += l;
       }
@@ -512,34 +675,34 @@ void luaV_concat (lua_State *L, int total) {
 
 
 /*
-** Main operation 'ra' = #rb'.
+** Main operation 'ra = #rb'.
 */
 void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
   const TValue *tm;
-  switch (ttype(rb)) {
-    case LUA_TTABLE: {
+  switch (ttypetag(rb)) {
+    case LUA_VTABLE: {
       Table *h = hvalue(rb);
       tm = fasttm(L, h->metatable, TM_LEN);
       if (tm) break;  /* metamethod? break switch to call it */
-      setivalue(ra, luaH_getn(h));  /* else primitive len */
+      setivalue(s2v(ra), luaH_getn(h));  /* else primitive len */
       return;
     }
-    case LUA_TSHRSTR: {
-      setivalue(ra, tsvalue(rb)->shrlen);
+    case LUA_VSHRSTR: {
+      setivalue(s2v(ra), tsvalue(rb)->shrlen);
       return;
     }
-    case LUA_TLNGSTR: {
-      setivalue(ra, tsvalue(rb)->u.lnglen);
+    case LUA_VLNGSTR: {
+      setivalue(s2v(ra), tsvalue(rb)->u.lnglen);
       return;
     }
     default: {  /* try metamethod */
       tm = luaT_gettmbyobj(L, rb, TM_LEN);
-      if (ttisnil(tm))  /* no metamethod? */
+      if (unlikely(notm(tm)))  /* no metamethod? */
         luaG_typeerror(L, rb, "get length of");
       break;
     }
   }
-  luaT_callTM(L, tm, rb, rb, ra, 1);
+  luaT_callTMres(L, tm, rb, rb, ra);
 }
 
 
@@ -549,8 +712,8 @@ void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
 ** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer,
 ** otherwise 'floor(q) == trunc(q) - 1'.
 */
-lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) {
-  if (l_castS2U(n) + 1u <= 1u) {  /* special cases: -1 or 0 */
+lua_Integer luaV_idiv (lua_State *L, lua_Integer m, lua_Integer n) {
+  if (unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
     if (n == 0)
       luaG_runerror(L, "attempt to divide by zero");
     return intop(-, 0, m);   /* n==-1; avoid overflow with 0x80000...//-1 */
@@ -567,29 +730,41 @@ lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) {
 /*
 ** Integer modulus; return 'm % n'. (Assume that C '%' with
 ** negative operands follows C99 behavior. See previous comment
-** about luaV_div.)
+** about luaV_idiv.)
 */
 lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
-  if (l_castS2U(n) + 1u <= 1u) {  /* special cases: -1 or 0 */
+  if (unlikely(l_castS2U(n) + 1u <= 1u)) {  /* special cases: -1 or 0 */
     if (n == 0)
       luaG_runerror(L, "attempt to perform 'n%%0'");
     return 0;   /* m % -1 == 0; avoid overflow with 0x80000...%-1 */
   }
   else {
     lua_Integer r = m % n;
-    if (r != 0 && (m ^ n) < 0)  /* 'm/n' would be non-integer negative? */
+    if (r != 0 && (r ^ n) < 0)  /* 'm/n' would be non-integer negative? */
       r += n;  /* correct result for different rounding */
     return r;
   }
 }
 
 
+/*
+** Float modulus
+*/
+lua_Number luaV_modf (lua_State *L, lua_Number m, lua_Number n) {
+  lua_Number r;
+  luai_nummod(L, m, n, r);
+  return r;
+}
+
+
 /* number of bits in an integer */
 #define NBITS	cast_int(sizeof(lua_Integer) * CHAR_BIT)
 
 /*
 ** Shift left operation. (Shift right just negates 'y'.)
 */
+#define luaV_shiftr(x,y)	luaV_shiftl(x,-(y))
+
 lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) {
   if (y < 0) {  /* shift right? */
     if (y <= -NBITS) return 0;
@@ -602,32 +777,9 @@ lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) {
 }
 
 
-/*
-** check whether cached closure in prototype 'p' may be reused, that is,
-** whether there is a cached closure with the same upvalues needed by
-** new closure to be created.
-*/
-static LClosure *getcached (Proto *p, UpVal **encup, StkId base) {
-  LClosure *c = p->cache;
-  if (c != NULL) {  /* is there a cached closure? */
-    int nup = p->sizeupvalues;
-    Upvaldesc *uv = p->upvalues;
-    int i;
-    for (i = 0; i < nup; i++) {  /* check whether it has right upvalues */
-      TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v;
-      if (c->upvals[i]->v != v)
-        return NULL;  /* wrong upvalue; cannot reuse closure */
-    }
-  }
-  return c;  /* return cached closure (or NULL if no cached closure) */
-}
-
-
 /*
 ** create a new Lua closure, push it in the stack, and initialize
-** its upvalues. Note that the closure is not cached if prototype is
-** already black (which means that 'cache' was already cleared by the
-** GC).
+** its upvalues.
 */
 static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
                          StkId ra) {
@@ -636,77 +788,71 @@ static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
   int i;
   LClosure *ncl = luaF_newLclosure(L, nup);
   ncl->p = p;
-  setclLvalue(L, ra, ncl);  /* anchor new closure in stack */
+  setclLvalue2s(L, ra, ncl);  /* anchor new closure in stack */
   for (i = 0; i < nup; i++) {  /* fill in its upvalues */
     if (uv[i].instack)  /* upvalue refers to local variable? */
       ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx);
     else  /* get upvalue from enclosing function */
       ncl->upvals[i] = encup[uv[i].idx];
-    ncl->upvals[i]->refcount++;
-    /* new closure is white, so we do not need a barrier here */
+    luaC_objbarrier(L, ncl, ncl->upvals[i]);
   }
-  if (!isblack(p))  /* cache will not break GC invariant? */
-    p->cache = ncl;  /* save it on cache for reuse */
 }
 
 
 /*
-** finish execution of an opcode interrupted by an yield
+** finish execution of an opcode interrupted by a yield
 */
 void luaV_finishOp (lua_State *L) {
   CallInfo *ci = L->ci;
-  StkId base = ci->u.l.base;
+  StkId base = ci->func + 1;
   Instruction inst = *(ci->u.l.savedpc - 1);  /* interrupted instruction */
   OpCode op = GET_OPCODE(inst);
   switch (op) {  /* finish its execution */
-    case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV: case OP_IDIV:
-    case OP_BAND: case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR:
-    case OP_MOD: case OP_POW:
+    case OP_MMBIN: case OP_MMBINI: case OP_MMBINK: {
+      setobjs2s(L, base + GETARG_A(*(ci->u.l.savedpc - 2)), --L->top);
+      break;
+    }
     case OP_UNM: case OP_BNOT: case OP_LEN:
-    case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: {
+    case OP_GETTABUP: case OP_GETTABLE: case OP_GETI:
+    case OP_GETFIELD: case OP_SELF: {
       setobjs2s(L, base + GETARG_A(inst), --L->top);
       break;
     }
-    case OP_LE: case OP_LT: case OP_EQ: {
-      int res = !l_isfalse(L->top - 1);
+    case OP_LT: case OP_LE:
+    case OP_LTI: case OP_LEI:
+    case OP_GTI: case OP_GEI:
+    case OP_EQ: {  /* note that 'OP_EQI'/'OP_EQK' cannot yield */
+      int res = !l_isfalse(s2v(L->top - 1));
       L->top--;
+#if defined(LUA_COMPAT_LT_LE)
       if (ci->callstatus & CIST_LEQ) {  /* "<=" using "<" instead? */
-        lua_assert(op == OP_LE);
         ci->callstatus ^= CIST_LEQ;  /* clear mark */
         res = !res;  /* negate result */
       }
+#endif
       lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
-      if (res != GETARG_A(inst))  /* condition failed? */
+      if (res != GETARG_k(inst))  /* condition failed? */
         ci->u.l.savedpc++;  /* skip jump instruction */
       break;
     }
     case OP_CONCAT: {
-      StkId top = L->top - 1;  /* top when 'luaT_trybinTM' was called */
-      int b = GETARG_B(inst);      /* first element to concatenate */
-      int total = cast_int(top - 1 - (base + b));  /* yet to concatenate */
-      setobj2s(L, top - 2, top);  /* put TM result in proper position */
+      StkId top = L->top - 1;  /* top when 'luaT_tryconcatTM' was called */
+      int a = GETARG_A(inst);      /* first element to concatenate */
+      int total = cast_int(top - 1 - (base + a));  /* yet to concatenate */
+      setobjs2s(L, top - 2, top);  /* put TM result in proper position */
       if (total > 1) {  /* are there elements to concat? */
         L->top = top - 1;  /* top is one after last element (at top-2) */
         luaV_concat(L, total);  /* concat them (may yield again) */
       }
-      /* move final result to final position */
-      setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1);
-      L->top = ci->top;  /* restore top */
-      break;
-    }
-    case OP_TFORCALL: {
-      lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP);
-      L->top = ci->top;  /* correct top */
       break;
     }
-    case OP_CALL: {
-      if (GETARG_C(inst) - 1 >= 0)  /* nresults >= 0? */
-        L->top = ci->top;  /* adjust results */
+    default: {
+      /* only these other opcodes can yield */
+      lua_assert(op == OP_TFORCALL || op == OP_CALL ||
+           op == OP_TAILCALL || op == OP_SETTABUP || op == OP_SETTABLE ||
+           op == OP_SETI || op == OP_SETFIELD);
       break;
     }
-    case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE:
-      break;
-    default: lua_assert(0);
   }
 }
 
@@ -715,10 +861,172 @@ void luaV_finishOp (lua_State *L) {
 
 /*
 ** {==================================================================
-** Function 'luaV_execute': main interpreter loop
+** Macros for arithmetic/bitwise/comparison opcodes in 'luaV_execute'
 ** ===================================================================
 */
 
+#define l_addi(L,a,b)	intop(+, a, b)
+#define l_subi(L,a,b)	intop(-, a, b)
+#define l_muli(L,a,b)	intop(*, a, b)
+#define l_band(a,b)	intop(&, a, b)
+#define l_bor(a,b)	intop(|, a, b)
+#define l_bxor(a,b)	intop(^, a, b)
+
+#define l_lti(a,b)	(a < b)
+#define l_lei(a,b)	(a <= b)
+#define l_gti(a,b)	(a > b)
+#define l_gei(a,b)	(a >= b)
+
+
+/*
+** Arithmetic operations with immediate operands. 'iop' is the integer
+** operation, 'fop' is the float operation.
+*/
+#define op_arithI(L,iop,fop) {  \
+  TValue *v1 = vRB(i);  \
+  int imm = GETARG_sC(i);  \
+  if (ttisinteger(v1)) {  \
+    lua_Integer iv1 = ivalue(v1);  \
+    pc++; setivalue(s2v(ra), iop(L, iv1, imm));  \
+  }  \
+  else if (ttisfloat(v1)) {  \
+    lua_Number nb = fltvalue(v1);  \
+    lua_Number fimm = cast_num(imm);  \
+    pc++; setfltvalue(s2v(ra), fop(L, nb, fimm)); \
+  }}
+
+
+/*
+** Auxiliary function for arithmetic operations over floats and others
+** with two register operands.
+*/
+#define op_arithf_aux(L,v1,v2,fop) {  \
+  lua_Number n1; lua_Number n2;  \
+  if (tonumberns(v1, n1) && tonumberns(v2, n2)) {  \
+    pc++; setfltvalue(s2v(ra), fop(L, n1, n2));  \
+  }}
+
+
+/*
+** Arithmetic operations over floats and others with register operands.
+*/
+#define op_arithf(L,fop) {  \
+  TValue *v1 = vRB(i);  \
+  TValue *v2 = vRC(i);  \
+  op_arithf_aux(L, v1, v2, fop); }
+
+
+/*
+** Arithmetic operations with K operands for floats.
+*/
+#define op_arithfK(L,fop) {  \
+  TValue *v1 = vRB(i);  \
+  TValue *v2 = KC(i);  \
+  op_arithf_aux(L, v1, v2, fop); }
+
+
+/*
+** Arithmetic operations over integers and floats.
+*/
+#define op_arith_aux(L,v1,v2,iop,fop) {  \
+  if (ttisinteger(v1) && ttisinteger(v2)) {  \
+    lua_Integer i1 = ivalue(v1); lua_Integer i2 = ivalue(v2);  \
+    pc++; setivalue(s2v(ra), iop(L, i1, i2));  \
+  }  \
+  else op_arithf_aux(L, v1, v2, fop); }
+
+
+/*
+** Arithmetic operations with register operands.
+*/
+#define op_arith(L,iop,fop) {  \
+  TValue *v1 = vRB(i);  \
+  TValue *v2 = vRC(i);  \
+  op_arith_aux(L, v1, v2, iop, fop); }
+
+
+/*
+** Arithmetic operations with K operands.
+*/
+#define op_arithK(L,iop,fop) {  \
+  TValue *v1 = vRB(i);  \
+  TValue *v2 = KC(i);  \
+  op_arith_aux(L, v1, v2, iop, fop); }
+
+
+/*
+** Bitwise operations with constant operand.
+*/
+#define op_bitwiseK(L,op) {  \
+  TValue *v1 = vRB(i);  \
+  TValue *v2 = KC(i);  \
+  lua_Integer i1;  \
+  lua_Integer i2 = ivalue(v2);  \
+  if (tointegerns(v1, &i1)) {  \
+    pc++; setivalue(s2v(ra), op(i1, i2));  \
+  }}
+
+
+/*
+** Bitwise operations with register operands.
+*/
+#define op_bitwise(L,op) {  \
+  TValue *v1 = vRB(i);  \
+  TValue *v2 = vRC(i);  \
+  lua_Integer i1; lua_Integer i2;  \
+  if (tointegerns(v1, &i1) && tointegerns(v2, &i2)) {  \
+    pc++; setivalue(s2v(ra), op(i1, i2));  \
+  }}
+
+
+/*
+** Order operations with register operands. 'opn' actually works
+** for all numbers, but the fast track improves performance for
+** integers.
+*/
+#define op_order(L,opi,opn,other) {  \
+        int cond;  \
+        TValue *rb = vRB(i);  \
+        if (ttisinteger(s2v(ra)) && ttisinteger(rb)) {  \
+          lua_Integer ia = ivalue(s2v(ra));  \
+          lua_Integer ib = ivalue(rb);  \
+          cond = opi(ia, ib);  \
+        }  \
+        else if (ttisnumber(s2v(ra)) && ttisnumber(rb))  \
+          cond = opn(s2v(ra), rb);  \
+        else  \
+          Protect(cond = other(L, s2v(ra), rb));  \
+        docondjump(); }
+
+
+/*
+** Order operations with immediate operand. (Immediate operand is
+** always small enough to have an exact representation as a float.)
+*/
+#define op_orderI(L,opi,opf,inv,tm) {  \
+        int cond;  \
+        int im = GETARG_sB(i);  \
+        if (ttisinteger(s2v(ra)))  \
+          cond = opi(ivalue(s2v(ra)), im);  \
+        else if (ttisfloat(s2v(ra))) {  \
+          lua_Number fa = fltvalue(s2v(ra));  \
+          lua_Number fim = cast_num(im);  \
+          cond = opf(fa, fim);  \
+        }  \
+        else {  \
+          int isf = GETARG_C(i);  \
+          Protect(cond = luaT_callorderiTM(L, s2v(ra), im, inv, isf, tm));  \
+        }  \
+        docondjump(); }
+
+/* }================================================================== */
+
+
+/*
+** {==================================================================
+** Function 'luaV_execute': main interpreter loop
+** ===================================================================
+*/
 
 /*
 ** some macros for common tasks in 'luaV_execute'
@@ -726,40 +1034,89 @@ void luaV_finishOp (lua_State *L) {
 
 
 #define RA(i)	(base+GETARG_A(i))
-#define RB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
-#define RC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
-#define RKB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
-	ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
-#define RKC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
-	ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
+#define RB(i)	(base+GETARG_B(i))
+#define vRB(i)	s2v(RB(i))
+#define KB(i)	(k+GETARG_B(i))
+#define RC(i)	(base+GETARG_C(i))
+#define vRC(i)	s2v(RC(i))
+#define KC(i)	(k+GETARG_C(i))
+#define RKC(i)	((TESTARG_k(i)) ? k + GETARG_C(i) : s2v(base + GETARG_C(i)))
+
+
+
+#define updatetrap(ci)  (trap = ci->u.l.trap)
+
+#define updatebase(ci)	(base = ci->func + 1)
+
 
+#define updatestack(ci) { if (trap) { updatebase(ci); ra = RA(i); } }
+
+
+/*
+** Execute a jump instruction. The 'updatetrap' allows signals to stop
+** tight loops. (Without it, the local copy of 'trap' could never change.)
+*/
+#define dojump(ci,i,e)	{ pc += GETARG_sJ(i) + e; updatetrap(ci); }
 
-/* execute a jump instruction */
-#define dojump(ci,i,e) \
-  { int a = GETARG_A(i); \
-    if (a != 0) luaF_close(L, ci->u.l.base + a - 1); \
-    ci->u.l.savedpc += GETARG_sBx(i) + e; }
 
 /* for test instructions, execute the jump instruction that follows it */
-#define donextjump(ci)	{ i = *ci->u.l.savedpc; dojump(ci, i, 1); }
+#define donextjump(ci)	{ Instruction ni = *pc; dojump(ci, ni, 1); }
+
+/*
+** do a conditional jump: skip next instruction if 'cond' is not what
+** was expected (parameter 'k'), else do next instruction, which must
+** be a jump.
+*/
+#define docondjump()	if (cond != GETARG_k(i)) pc++; else donextjump(ci);
+
+
+/*
+** Correct global 'pc'.
+*/
+#define savepc(L)	(ci->u.l.savedpc = pc)
+
+
+/*
+** Whenever code can raise errors, the global 'pc' and the global
+** 'top' must be correct to report occasional errors.
+*/
+#define savestate(L,ci)		(savepc(L), L->top = ci->top)
+
+
+/*
+** Protect code that, in general, can raise errors, reallocate the
+** stack, and change the hooks.
+*/
+#define Protect(exp)  (savestate(L,ci), (exp), updatetrap(ci))
+
+/* special version that does not change the top */
+#define ProtectNT(exp)  (savepc(L), (exp), updatetrap(ci))
+
+/*
+** Protect code that will finish the loop (returns) or can only raise
+** errors. (That is, it will not return to the interpreter main loop
+** after changing the stack or hooks.)
+*/
+#define halfProtect(exp)  (savestate(L,ci), (exp))
 
+/* idem, but without changing the stack */
+#define halfProtectNT(exp)  (savepc(L), (exp))
 
-#define Protect(x)	{ {x;}; base = ci->u.l.base; }
 
 #define checkGC(L,c)  \
 	{ luaC_condGC(L, L->top = (c),  /* limit of live values */ \
-                         Protect(L->top = ci->top));  /* restore top */ \
+                         updatetrap(ci)); \
            luai_threadyield(L); }
 
 
 /* fetch an instruction and prepare its execution */
 #define vmfetch()	{ \
-  i = *(ci->u.l.savedpc++); \
-  if (L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) \
-    Protect(luaG_traceexec(L)); \
+  if (trap) {  /* stack reallocation or hooks? */ \
+    trap = luaG_traceexec(L, pc);  /* handle hooks */ \
+    updatebase(ci);  /* correct stack */ \
+  } \
+  i = *(pc++); \
   ra = RA(i); /* WARNING: any stack reallocation invalidates 'ra' */ \
-  lua_assert(base == ci->u.l.base); \
-  lua_assert(base <= L->top && L->top < L->stack + L->stacksize); \
 }
 
 #define vmdispatch(o)	switch(o)
@@ -767,43 +1124,52 @@ void luaV_finishOp (lua_State *L) {
 #define vmbreak		break
 
 
-/*
-** copy of 'luaV_gettable', but protecting the call to potential
-** metamethod (which can reallocate the stack)
-*/
-#define gettableProtected(L,t,k,v)  { const TValue *slot; \
-  if (luaV_fastget(L,t,k,slot,luaH_get)) { setobj2s(L, v, slot); } \
-  else Protect(luaV_finishget(L,t,k,v,slot)); }
-
-
-/* same for 'luaV_settable' */
-#define settableProtected(L,t,k,v) { const TValue *slot; \
-  if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
-    Protect(luaV_finishset(L,t,k,v,slot)); }
-
-
-
-void luaV_execute (lua_State *L) {
-  CallInfo *ci = L->ci;
+void luaV_execute (lua_State *L, CallInfo *ci) {
   LClosure *cl;
   TValue *k;
   StkId base;
-  ci->callstatus |= CIST_FRESH;  /* fresh invocation of 'luaV_execute" */
- newframe:  /* reentry point when frame changes (call/return) */
-  lua_assert(ci == L->ci);
-  cl = clLvalue(ci->func);  /* local reference to function's closure */
-  k = cl->p->k;  /* local reference to function's constant table */
-  base = ci->u.l.base;  /* local copy of function's base */
+  const Instruction *pc;
+  int trap;
+#if LUA_USE_JUMPTABLE
+#include "ljumptab.h"
+#endif
+ tailcall:
+  trap = L->hookmask;
+  cl = clLvalue(s2v(ci->func));
+  k = cl->p->k;
+  pc = ci->u.l.savedpc;
+  if (trap) {
+    if (cl->p->is_vararg)
+      trap = 0;  /* hooks will start after VARARGPREP instruction */
+    else if (pc == cl->p->code)  /* first instruction (not resuming)? */
+      luaD_hookcall(L, ci);
+    ci->u.l.trap = 1;  /* there may be other hooks */
+  }
+  base = ci->func + 1;
   /* main loop of interpreter */
   for (;;) {
-    Instruction i;
-    StkId ra;
+    Instruction i;  /* instruction being executed */
+    StkId ra;  /* instruction's A register */
     vmfetch();
+    lua_assert(base == ci->func + 1);
+    lua_assert(base <= L->top && L->top < L->stack + L->stacksize);
+    /* invalidate top for instructions not expecting it */
+    lua_assert(isIT(i) || (cast_void(L->top = base), 1));
     vmdispatch (GET_OPCODE(i)) {
       vmcase(OP_MOVE) {
         setobjs2s(L, ra, RB(i));
         vmbreak;
       }
+      vmcase(OP_LOADI) {
+        lua_Integer b = GETARG_sBx(i);
+        setivalue(s2v(ra), b);
+        vmbreak;
+      }
+      vmcase(OP_LOADF) {
+        int b = GETARG_sBx(i);
+        setfltvalue(s2v(ra), cast_num(b));
+        vmbreak;
+      }
       vmcase(OP_LOADK) {
         TValue *rb = k + GETARG_Bx(i);
         setobj2s(L, ra, rb);
@@ -811,20 +1177,27 @@ void luaV_execute (lua_State *L) {
       }
       vmcase(OP_LOADKX) {
         TValue *rb;
-        lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
-        rb = k + GETARG_Ax(*ci->u.l.savedpc++);
+        rb = k + GETARG_Ax(*pc); pc++;
         setobj2s(L, ra, rb);
         vmbreak;
       }
-      vmcase(OP_LOADBOOL) {
-        setbvalue(ra, GETARG_B(i));
-        if (GETARG_C(i)) ci->u.l.savedpc++;  /* skip next instruction (if C) */
+      vmcase(OP_LOADFALSE) {
+        setbfvalue(s2v(ra));
+        vmbreak;
+      }
+      vmcase(OP_LFALSESKIP) {
+        setbfvalue(s2v(ra));
+        pc++;  /* skip next instruction */
+        vmbreak;
+      }
+      vmcase(OP_LOADTRUE) {
+        setbtvalue(s2v(ra));
         vmbreak;
       }
       vmcase(OP_LOADNIL) {
         int b = GETARG_B(i);
         do {
-          setnilvalue(ra++);
+          setnilvalue(s2v(ra++));
         } while (b--);
         vmbreak;
       }
@@ -833,248 +1206,335 @@ void luaV_execute (lua_State *L) {
         setobj2s(L, ra, cl->upvals[b]->v);
         vmbreak;
       }
+      vmcase(OP_SETUPVAL) {
+        UpVal *uv = cl->upvals[GETARG_B(i)];
+        setobj(L, uv->v, s2v(ra));
+        luaC_barrier(L, uv, s2v(ra));
+        vmbreak;
+      }
       vmcase(OP_GETTABUP) {
+        const TValue *slot;
         TValue *upval = cl->upvals[GETARG_B(i)]->v;
-        TValue *rc = RKC(i);
-        gettableProtected(L, upval, rc, ra);
+        TValue *rc = KC(i);
+        TString *key = tsvalue(rc);  /* key must be a string */
+        if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) {
+          setobj2s(L, ra, slot);
+        }
+        else
+          Protect(luaV_finishget(L, upval, rc, ra, slot));
         vmbreak;
       }
       vmcase(OP_GETTABLE) {
-        StkId rb = RB(i);
-        TValue *rc = RKC(i);
-        gettableProtected(L, rb, rc, ra);
+        const TValue *slot;
+        TValue *rb = vRB(i);
+        TValue *rc = vRC(i);
+        lua_Unsigned n;
+        if (ttisinteger(rc)  /* fast track for integers? */
+            ? (cast_void(n = ivalue(rc)), luaV_fastgeti(L, rb, n, slot))
+            : luaV_fastget(L, rb, rc, slot, luaH_get)) {
+          setobj2s(L, ra, slot);
+        }
+        else
+          Protect(luaV_finishget(L, rb, rc, ra, slot));
+        vmbreak;
+      }
+      vmcase(OP_GETI) {
+        const TValue *slot;
+        TValue *rb = vRB(i);
+        int c = GETARG_C(i);
+        if (luaV_fastgeti(L, rb, c, slot)) {
+          setobj2s(L, ra, slot);
+        }
+        else {
+          TValue key;
+          setivalue(&key, c);
+          Protect(luaV_finishget(L, rb, &key, ra, slot));
+        }
+        vmbreak;
+      }
+      vmcase(OP_GETFIELD) {
+        const TValue *slot;
+        TValue *rb = vRB(i);
+        TValue *rc = KC(i);
+        TString *key = tsvalue(rc);  /* key must be a string */
+        if (luaV_fastget(L, rb, key, slot, luaH_getshortstr)) {
+          setobj2s(L, ra, slot);
+        }
+        else
+          Protect(luaV_finishget(L, rb, rc, ra, slot));
         vmbreak;
       }
       vmcase(OP_SETTABUP) {
+        const TValue *slot;
         TValue *upval = cl->upvals[GETARG_A(i)]->v;
-        TValue *rb = RKB(i);
+        TValue *rb = KB(i);
         TValue *rc = RKC(i);
-        settableProtected(L, upval, rb, rc);
+        TString *key = tsvalue(rb);  /* key must be a string */
+        if (luaV_fastget(L, upval, key, slot, luaH_getshortstr)) {
+          luaV_finishfastset(L, upval, slot, rc);
+        }
+        else
+          Protect(luaV_finishset(L, upval, rb, rc, slot));
         vmbreak;
       }
-      vmcase(OP_SETUPVAL) {
-        UpVal *uv = cl->upvals[GETARG_B(i)];
-        setobj(L, uv->v, ra);
-        luaC_upvalbarrier(L, uv);
+      vmcase(OP_SETTABLE) {
+        const TValue *slot;
+        TValue *rb = vRB(i);  /* key (table is in 'ra') */
+        TValue *rc = RKC(i);  /* value */
+        lua_Unsigned n;
+        if (ttisinteger(rb)  /* fast track for integers? */
+            ? (cast_void(n = ivalue(rb)), luaV_fastgeti(L, s2v(ra), n, slot))
+            : luaV_fastget(L, s2v(ra), rb, slot, luaH_get)) {
+          luaV_finishfastset(L, s2v(ra), slot, rc);
+        }
+        else
+          Protect(luaV_finishset(L, s2v(ra), rb, rc, slot));
         vmbreak;
       }
-      vmcase(OP_SETTABLE) {
-        TValue *rb = RKB(i);
+      vmcase(OP_SETI) {
+        const TValue *slot;
+        int c = GETARG_B(i);
+        TValue *rc = RKC(i);
+        if (luaV_fastgeti(L, s2v(ra), c, slot)) {
+          luaV_finishfastset(L, s2v(ra), slot, rc);
+        }
+        else {
+          TValue key;
+          setivalue(&key, c);
+          Protect(luaV_finishset(L, s2v(ra), &key, rc, slot));
+        }
+        vmbreak;
+      }
+      vmcase(OP_SETFIELD) {
+        const TValue *slot;
+        TValue *rb = KB(i);
         TValue *rc = RKC(i);
-        settableProtected(L, ra, rb, rc);
+        TString *key = tsvalue(rb);  /* key must be a string */
+        if (luaV_fastget(L, s2v(ra), key, slot, luaH_getshortstr)) {
+          luaV_finishfastset(L, s2v(ra), slot, rc);
+        }
+        else
+          Protect(luaV_finishset(L, s2v(ra), rb, rc, slot));
         vmbreak;
       }
       vmcase(OP_NEWTABLE) {
-        int b = GETARG_B(i);
-        int c = GETARG_C(i);
-        Table *t = luaH_new(L);
-        sethvalue(L, ra, t);
+        int b = GETARG_B(i);  /* log2(hash size) + 1 */
+        int c = GETARG_C(i);  /* array size */
+        Table *t;
+        if (b > 0)
+          b = 1 << (b - 1);  /* size is 2^(b - 1) */
+        lua_assert((!TESTARG_k(i)) == (GETARG_Ax(*pc) == 0));
+        if (TESTARG_k(i))  /* non-zero extra argument? */
+          c += GETARG_Ax(*pc) * (MAXARG_C + 1);  /* add it to size */
+        pc++;  /* skip extra argument */
+        L->top = ra + 1;  /* correct top in case of emergency GC */
+        t = luaH_new(L);  /* memory allocation */
+        sethvalue2s(L, ra, t);
         if (b != 0 || c != 0)
-          luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c));
+          luaH_resize(L, t, c, b);  /* idem */
         checkGC(L, ra + 1);
         vmbreak;
       }
       vmcase(OP_SELF) {
-        const TValue *aux;
-        StkId rb = RB(i);
+        const TValue *slot;
+        TValue *rb = vRB(i);
         TValue *rc = RKC(i);
         TString *key = tsvalue(rc);  /* key must be a string */
-        setobjs2s(L, ra + 1, rb);
-        if (luaV_fastget(L, rb, key, aux, luaH_getstr)) {
-          setobj2s(L, ra, aux);
+        setobj2s(L, ra + 1, rb);
+        if (luaV_fastget(L, rb, key, slot, luaH_getstr)) {
+          setobj2s(L, ra, slot);
         }
-        else Protect(luaV_finishget(L, rb, rc, ra, aux));
+        else
+          Protect(luaV_finishget(L, rb, rc, ra, slot));
         vmbreak;
       }
-      vmcase(OP_ADD) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (ttisinteger(rb) && ttisinteger(rc)) {
-          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
-          setivalue(ra, intop(+, ib, ic));
+      vmcase(OP_ADDI) {
+        op_arithI(L, l_addi, luai_numadd);
+        vmbreak;
+      }
+      vmcase(OP_ADDK) {
+        op_arithK(L, l_addi, luai_numadd);
+        vmbreak;
+      }
+      vmcase(OP_SUBK) {
+        op_arithK(L, l_subi, luai_numsub);
+        vmbreak;
+      }
+      vmcase(OP_MULK) {
+        op_arithK(L, l_muli, luai_nummul);
+        vmbreak;
+      }
+      vmcase(OP_MODK) {
+        op_arithK(L, luaV_mod, luaV_modf);
+        vmbreak;
+      }
+      vmcase(OP_POWK) {
+        op_arithfK(L, luai_numpow);
+        vmbreak;
+      }
+      vmcase(OP_DIVK) {
+        op_arithfK(L, luai_numdiv);
+        vmbreak;
+      }
+      vmcase(OP_IDIVK) {
+        op_arithK(L, luaV_idiv, luai_numidiv);
+        vmbreak;
+      }
+      vmcase(OP_BANDK) {
+        op_bitwiseK(L, l_band);
+        vmbreak;
+      }
+      vmcase(OP_BORK) {
+        op_bitwiseK(L, l_bor);
+        vmbreak;
+      }
+      vmcase(OP_BXORK) {
+        op_bitwiseK(L, l_bxor);
+        vmbreak;
+      }
+      vmcase(OP_SHRI) {
+        TValue *rb = vRB(i);
+        int ic = GETARG_sC(i);
+        lua_Integer ib;
+        if (tointegerns(rb, &ib)) {
+          pc++; setivalue(s2v(ra), luaV_shiftl(ib, -ic));
         }
-        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          setfltvalue(ra, luai_numadd(L, nb, nc));
+        vmbreak;
+      }
+      vmcase(OP_SHLI) {
+        TValue *rb = vRB(i);
+        int ic = GETARG_sC(i);
+        lua_Integer ib;
+        if (tointegerns(rb, &ib)) {
+          pc++; setivalue(s2v(ra), luaV_shiftl(ic, ib));
         }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_ADD)); }
+        vmbreak;
+      }
+      vmcase(OP_ADD) {
+        op_arith(L, l_addi, luai_numadd);
         vmbreak;
       }
       vmcase(OP_SUB) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (ttisinteger(rb) && ttisinteger(rc)) {
-          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
-          setivalue(ra, intop(-, ib, ic));
-        }
-        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          setfltvalue(ra, luai_numsub(L, nb, nc));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SUB)); }
+        op_arith(L, l_subi, luai_numsub);
         vmbreak;
       }
       vmcase(OP_MUL) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (ttisinteger(rb) && ttisinteger(rc)) {
-          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
-          setivalue(ra, intop(*, ib, ic));
-        }
-        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          setfltvalue(ra, luai_nummul(L, nb, nc));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MUL)); }
+        op_arith(L, l_muli, luai_nummul);
+        vmbreak;
+      }
+      vmcase(OP_MOD) {
+        op_arith(L, luaV_mod, luaV_modf);
+        vmbreak;
+      }
+      vmcase(OP_POW) {
+        op_arithf(L, luai_numpow);
         vmbreak;
       }
       vmcase(OP_DIV) {  /* float division (always with floats) */
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          setfltvalue(ra, luai_numdiv(L, nb, nc));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_DIV)); }
+        op_arithf(L, luai_numdiv);
+        vmbreak;
+      }
+      vmcase(OP_IDIV) {  /* floor division */
+        op_arith(L, luaV_idiv, luai_numidiv);
         vmbreak;
       }
       vmcase(OP_BAND) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Integer ib; lua_Integer ic;
-        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
-          setivalue(ra, intop(&, ib, ic));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BAND)); }
+        op_bitwise(L, l_band);
         vmbreak;
       }
       vmcase(OP_BOR) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Integer ib; lua_Integer ic;
-        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
-          setivalue(ra, intop(|, ib, ic));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BOR)); }
+        op_bitwise(L, l_bor);
         vmbreak;
       }
       vmcase(OP_BXOR) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Integer ib; lua_Integer ic;
-        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
-          setivalue(ra, intop(^, ib, ic));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BXOR)); }
+        op_bitwise(L, l_bxor);
         vmbreak;
       }
-      vmcase(OP_SHL) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Integer ib; lua_Integer ic;
-        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
-          setivalue(ra, luaV_shiftl(ib, ic));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHL)); }
+      vmcase(OP_SHR) {
+        op_bitwise(L, luaV_shiftr);
         vmbreak;
       }
-      vmcase(OP_SHR) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Integer ib; lua_Integer ic;
-        if (tointeger(rb, &ib) && tointeger(rc, &ic)) {
-          setivalue(ra, luaV_shiftl(ib, -ic));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHR)); }
+      vmcase(OP_SHL) {
+        op_bitwise(L, luaV_shiftl);
         vmbreak;
       }
-      vmcase(OP_MOD) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (ttisinteger(rb) && ttisinteger(rc)) {
-          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
-          setivalue(ra, luaV_mod(L, ib, ic));
-        }
-        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          lua_Number m;
-          luai_nummod(L, nb, nc, m);
-          setfltvalue(ra, m);
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MOD)); }
+      vmcase(OP_MMBIN) {
+        Instruction pi = *(pc - 2);  /* original arith. expression */
+        TValue *rb = vRB(i);
+        TMS tm = (TMS)GETARG_C(i);
+        StkId result = RA(pi);
+        lua_assert(OP_ADD <= GET_OPCODE(pi) && GET_OPCODE(pi) <= OP_SHR);
+        Protect(luaT_trybinTM(L, s2v(ra), rb, result, tm));
         vmbreak;
       }
-      vmcase(OP_IDIV) {  /* floor division */
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (ttisinteger(rb) && ttisinteger(rc)) {
-          lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc);
-          setivalue(ra, luaV_div(L, ib, ic));
-        }
-        else if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          setfltvalue(ra, luai_numidiv(L, nb, nc));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_IDIV)); }
+      vmcase(OP_MMBINI) {
+        Instruction pi = *(pc - 2);  /* original arith. expression */
+        int imm = GETARG_sB(i);
+        TMS tm = (TMS)GETARG_C(i);
+        int flip = GETARG_k(i);
+        StkId result = RA(pi);
+        Protect(luaT_trybiniTM(L, s2v(ra), imm, flip, result, tm));
         vmbreak;
       }
-      vmcase(OP_POW) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        lua_Number nb; lua_Number nc;
-        if (tonumber(rb, &nb) && tonumber(rc, &nc)) {
-          setfltvalue(ra, luai_numpow(L, nb, nc));
-        }
-        else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_POW)); }
+      vmcase(OP_MMBINK) {
+        Instruction pi = *(pc - 2);  /* original arith. expression */
+        TValue *imm = KB(i);
+        TMS tm = (TMS)GETARG_C(i);
+        int flip = GETARG_k(i);
+        StkId result = RA(pi);
+        Protect(luaT_trybinassocTM(L, s2v(ra), imm, flip, result, tm));
         vmbreak;
       }
       vmcase(OP_UNM) {
-        TValue *rb = RB(i);
+        TValue *rb = vRB(i);
         lua_Number nb;
         if (ttisinteger(rb)) {
           lua_Integer ib = ivalue(rb);
-          setivalue(ra, intop(-, 0, ib));
+          setivalue(s2v(ra), intop(-, 0, ib));
         }
-        else if (tonumber(rb, &nb)) {
-          setfltvalue(ra, luai_numunm(L, nb));
+        else if (tonumberns(rb, nb)) {
+          setfltvalue(s2v(ra), luai_numunm(L, nb));
         }
-        else {
+        else
           Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM));
-        }
         vmbreak;
       }
       vmcase(OP_BNOT) {
-        TValue *rb = RB(i);
+        TValue *rb = vRB(i);
         lua_Integer ib;
-        if (tointeger(rb, &ib)) {
-          setivalue(ra, intop(^, ~l_castS2U(0), ib));
+        if (tointegerns(rb, &ib)) {
+          setivalue(s2v(ra), intop(^, ~l_castS2U(0), ib));
         }
-        else {
+        else
           Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT));
-        }
         vmbreak;
       }
       vmcase(OP_NOT) {
-        TValue *rb = RB(i);
-        int res = l_isfalse(rb);  /* next assignment may change this value */
-        setbvalue(ra, res);
+        TValue *rb = vRB(i);
+        if (l_isfalse(rb))
+          setbtvalue(s2v(ra));
+        else
+          setbfvalue(s2v(ra));
         vmbreak;
       }
       vmcase(OP_LEN) {
-        Protect(luaV_objlen(L, ra, RB(i)));
+        Protect(luaV_objlen(L, ra, vRB(i)));
         vmbreak;
       }
       vmcase(OP_CONCAT) {
-        int b = GETARG_B(i);
-        int c = GETARG_C(i);
-        StkId rb;
-        L->top = base + c + 1;  /* mark the end of concat operands */
-        Protect(luaV_concat(L, c - b + 1));
-        ra = RA(i);  /* 'luaV_concat' may invoke TMs and move the stack */
-        rb = base + b;
-        setobjs2s(L, ra, rb);
-        checkGC(L, (ra >= rb ? ra + 1 : rb));
-        L->top = ci->top;  /* restore top */
+        int n = GETARG_B(i);  /* number of elements to concatenate */
+        L->top = ra + n;  /* mark the end of concat operands */
+        ProtectNT(luaV_concat(L, n));
+        checkGC(L, L->top); /* 'luaV_concat' ensures correct top */
+        vmbreak;
+      }
+      vmcase(OP_CLOSE) {
+        Protect(luaF_close(L, ra, LUA_OK));
+        vmbreak;
+      }
+      vmcase(OP_TBC) {
+        /* create new to-be-closed upvalue */
+        halfProtect(luaF_newtbcupval(L, ra));
         vmbreak;
       }
       vmcase(OP_JMP) {
@@ -1082,47 +1542,66 @@ void luaV_execute (lua_State *L) {
         vmbreak;
       }
       vmcase(OP_EQ) {
-        TValue *rb = RKB(i);
-        TValue *rc = RKC(i);
-        Protect(
-          if (luaV_equalobj(L, rb, rc) != GETARG_A(i))
-            ci->u.l.savedpc++;
-          else
-            donextjump(ci);
-        )
+        int cond;
+        TValue *rb = vRB(i);
+        Protect(cond = luaV_equalobj(L, s2v(ra), rb));
+        docondjump();
         vmbreak;
       }
       vmcase(OP_LT) {
-        Protect(
-          if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i))
-            ci->u.l.savedpc++;
-          else
-            donextjump(ci);
-        )
+        op_order(L, l_lti, LTnum, lessthanothers);
         vmbreak;
       }
       vmcase(OP_LE) {
-        Protect(
-          if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i))
-            ci->u.l.savedpc++;
-          else
-            donextjump(ci);
-        )
+        op_order(L, l_lei, LEnum, lessequalothers);
+        vmbreak;
+      }
+      vmcase(OP_EQK) {
+        TValue *rb = KB(i);
+        /* basic types do not use '__eq'; we can use raw equality */
+        int cond = luaV_rawequalobj(s2v(ra), rb);
+        docondjump();
+        vmbreak;
+      }
+      vmcase(OP_EQI) {
+        int cond;
+        int im = GETARG_sB(i);
+        if (ttisinteger(s2v(ra)))
+          cond = (ivalue(s2v(ra)) == im);
+        else if (ttisfloat(s2v(ra)))
+          cond = luai_numeq(fltvalue(s2v(ra)), cast_num(im));
+        else
+          cond = 0;  /* other types cannot be equal to a number */
+        docondjump();
+        vmbreak;
+      }
+      vmcase(OP_LTI) {
+        op_orderI(L, l_lti, luai_numlt, 0, TM_LT);
+        vmbreak;
+      }
+      vmcase(OP_LEI) {
+        op_orderI(L, l_lei, luai_numle, 0, TM_LE);
+        vmbreak;
+      }
+      vmcase(OP_GTI) {
+        op_orderI(L, l_gti, luai_numgt, 1, TM_LT);
+        vmbreak;
+      }
+      vmcase(OP_GEI) {
+        op_orderI(L, l_gei, luai_numge, 1, TM_LE);
         vmbreak;
       }
       vmcase(OP_TEST) {
-        if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra))
-            ci->u.l.savedpc++;
-          else
-          donextjump(ci);
+        int cond = !l_isfalse(s2v(ra));
+        docondjump();
         vmbreak;
       }
       vmcase(OP_TESTSET) {
-        TValue *rb = RB(i);
-        if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb))
-          ci->u.l.savedpc++;
+        TValue *rb = vRB(i);
+        if (l_isfalse(rb) == GETARG_k(i))
+          pc++;
         else {
-          setobjs2s(L, ra, rb);
+          setobj2s(L, ra, rb);
           donextjump(ci);
         }
         vmbreak;
@@ -1130,184 +1609,196 @@ void luaV_execute (lua_State *L) {
       vmcase(OP_CALL) {
         int b = GETARG_B(i);
         int nresults = GETARG_C(i) - 1;
-        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
-        if (luaD_precall(L, ra, nresults)) {  /* C function? */
-          if (nresults >= 0)
-            L->top = ci->top;  /* adjust results */
-          Protect((void)0);  /* update 'base' */
-        }
-        else {  /* Lua function */
-          ci = L->ci;
-          goto newframe;  /* restart luaV_execute over new Lua function */
-        }
+        if (b != 0)  /* fixed number of arguments? */
+          L->top = ra + b;  /* top signals number of arguments */
+        /* else previous instruction set top */
+        ProtectNT(luaD_call(L, ra, nresults));
         vmbreak;
       }
       vmcase(OP_TAILCALL) {
-        int b = GETARG_B(i);
-        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
-        lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
-        if (luaD_precall(L, ra, LUA_MULTRET)) {  /* C function? */
-          Protect((void)0);  /* update 'base' */
+        int b = GETARG_B(i);  /* number of arguments + 1 (function) */
+        int nparams1 = GETARG_C(i);
+        /* delat is virtual 'func' - real 'func' (vararg functions) */
+        int delta = (nparams1) ? ci->u.l.nextraargs + nparams1 : 0;
+        if (b != 0)
+          L->top = ra + b;
+        else  /* previous instruction set top */
+          b = cast_int(L->top - ra);
+        savepc(ci);  /* some calls here can raise errors */
+        if (TESTARG_k(i)) {
+          /* close upvalues from current call; the compiler ensures
+             that there are no to-be-closed variables here, so this
+             call cannot change the stack */
+          luaF_close(L, base, NOCLOSINGMETH);
+          lua_assert(base == ci->func + 1);
         }
-        else {
-          /* tail call: put called frame (n) in place of caller one (o) */
-          CallInfo *nci = L->ci;  /* called frame */
-          CallInfo *oci = nci->previous;  /* caller frame */
-          StkId nfunc = nci->func;  /* called function */
-          StkId ofunc = oci->func;  /* caller function */
-          /* last stack slot filled by 'precall' */
-          StkId lim = nci->u.l.base + getproto(nfunc)->numparams;
-          int aux;
-          /* close all upvalues from previous call */
-          if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base);
-          /* move new frame into old one */
-          for (aux = 0; nfunc + aux < lim; aux++)
-            setobjs2s(L, ofunc + aux, nfunc + aux);
-          oci->u.l.base = ofunc + (nci->u.l.base - nfunc);  /* correct base */
-          oci->top = L->top = ofunc + (L->top - nfunc);  /* correct top */
-          oci->u.l.savedpc = nci->u.l.savedpc;
-          oci->callstatus |= CIST_TAIL;  /* function was tail called */
-          ci = L->ci = oci;  /* remove new frame */
-          lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize);
-          goto newframe;  /* restart luaV_execute over new Lua function */
+        while (!ttisfunction(s2v(ra))) {  /* not a function? */
+          luaD_tryfuncTM(L, ra);  /* try '__call' metamethod */
+          b++;  /* there is now one extra argument */
+          checkstackp(L, 1, ra);
         }
-        vmbreak;
+        if (!ttisLclosure(s2v(ra))) {  /* C function? */
+          luaD_call(L, ra, LUA_MULTRET);  /* call it */
+          updatetrap(ci);
+          updatestack(ci);  /* stack may have been relocated */
+          ci->func -= delta;
+          luaD_poscall(L, ci, cast_int(L->top - ra));
+          return;
+        }
+        ci->func -= delta;
+        luaD_pretailcall(L, ci, ra, b);  /* prepare call frame */
+        goto tailcall;
       }
       vmcase(OP_RETURN) {
-        int b = GETARG_B(i);
-        if (cl->p->sizep > 0) luaF_close(L, base);
-        b = luaD_poscall(L, ci, ra, (b != 0 ? b - 1 : cast_int(L->top - ra)));
-        if (ci->callstatus & CIST_FRESH)  /* local 'ci' still from callee */
-          return;  /* external invocation: return */
-        else {  /* invocation via reentry: continue execution */
-          ci = L->ci;
-          if (b) L->top = ci->top;
-          lua_assert(isLua(ci));
-          lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL);
-          goto newframe;  /* restart luaV_execute over new Lua function */
+        int n = GETARG_B(i) - 1;  /* number of results */
+        int nparams1 = GETARG_C(i);
+        if (n < 0)  /* not fixed? */
+          n = cast_int(L->top - ra);  /* get what is available */
+        savepc(ci);
+        if (TESTARG_k(i)) {  /* may there be open upvalues? */
+          if (L->top < ci->top)
+            L->top = ci->top;
+          luaF_close(L, base, LUA_OK);
+          updatetrap(ci);
+          updatestack(ci);
         }
+        if (nparams1)  /* vararg function? */
+          ci->func -= ci->u.l.nextraargs + nparams1;
+        L->top = ra + n;  /* set call for 'luaD_poscall' */
+        luaD_poscall(L, ci, n);
+        return;
       }
-      vmcase(OP_FORLOOP) {
-        if (ttisinteger(ra)) {  /* integer loop? */
-          lua_Integer step = ivalue(ra + 2);
-          lua_Integer idx = intop(+, ivalue(ra), step); /* increment index */
-          lua_Integer limit = ivalue(ra + 1);
-          if ((0 < step) ? (idx <= limit) : (limit <= idx)) {
-            ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
-            chgivalue(ra, idx);  /* update internal index... */
-            setivalue(ra + 3, idx);  /* ...and external index */
+      vmcase(OP_RETURN0) {
+        if (L->hookmask) {
+          L->top = ra;
+          halfProtectNT(luaD_poscall(L, ci, 0));  /* no hurry... */
+        }
+        else {  /* do the 'poscall' here */
+          int nres = ci->nresults;
+          L->ci = ci->previous;  /* back to caller */
+          L->top = base - 1;
+          while (nres-- > 0)
+            setnilvalue(s2v(L->top++));  /* all results are nil */
+        }
+        return;
+      }
+      vmcase(OP_RETURN1) {
+        if (L->hookmask) {
+          L->top = ra + 1;
+          halfProtectNT(luaD_poscall(L, ci, 1));  /* no hurry... */
+        }
+        else {  /* do the 'poscall' here */
+          int nres = ci->nresults;
+          L->ci = ci->previous;  /* back to caller */
+          if (nres == 0)
+            L->top = base - 1;  /* asked for no results */
+          else {
+            setobjs2s(L, base - 1, ra);  /* at least this result */
+            L->top = base;
+            while (--nres > 0)  /* complete missing results */
+              setnilvalue(s2v(L->top++));
           }
         }
-        else {  /* floating loop */
-          lua_Number step = fltvalue(ra + 2);
-          lua_Number idx = luai_numadd(L, fltvalue(ra), step); /* inc. index */
-          lua_Number limit = fltvalue(ra + 1);
-          if (luai_numlt(0, step) ? luai_numle(idx, limit)
-                                  : luai_numle(limit, idx)) {
-            ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
-            chgfltvalue(ra, idx);  /* update internal index... */
-            setfltvalue(ra + 3, idx);  /* ...and external index */
+        return;
+      }
+      vmcase(OP_FORLOOP) {
+        if (ttisinteger(s2v(ra + 2))) {  /* integer loop? */
+          lua_Unsigned count = l_castS2U(ivalue(s2v(ra + 1)));
+          if (count > 0) {  /* still more iterations? */
+            lua_Integer step = ivalue(s2v(ra + 2));
+            lua_Integer idx = ivalue(s2v(ra));  /* internal index */
+            chgivalue(s2v(ra + 1), count - 1);  /* update counter */
+            idx = intop(+, idx, step);  /* add step to index */
+            chgivalue(s2v(ra), idx);  /* update internal index */
+            setivalue(s2v(ra + 3), idx);  /* and control variable */
+            pc -= GETARG_Bx(i);  /* jump back */
           }
         }
+        else if (floatforloop(ra))  /* float loop */
+          pc -= GETARG_Bx(i);  /* jump back */
+        updatetrap(ci);  /* allows a signal to break the loop */
         vmbreak;
       }
       vmcase(OP_FORPREP) {
-        TValue *init = ra;
-        TValue *plimit = ra + 1;
-        TValue *pstep = ra + 2;
-        lua_Integer ilimit;
-        int stopnow;
-        if (ttisinteger(init) && ttisinteger(pstep) &&
-            forlimit(plimit, &ilimit, ivalue(pstep), &stopnow)) {
-          /* all values are integer */
-          lua_Integer initv = (stopnow ? 0 : ivalue(init));
-          setivalue(plimit, ilimit);
-          setivalue(init, intop(-, initv, ivalue(pstep)));
-        }
-        else {  /* try making all values floats */
-          lua_Number ninit; lua_Number nlimit; lua_Number nstep;
-          if (!tonumber(plimit, &nlimit))
-            luaG_runerror(L, "'for' limit must be a number");
-          setfltvalue(plimit, nlimit);
-          if (!tonumber(pstep, &nstep))
-            luaG_runerror(L, "'for' step must be a number");
-          setfltvalue(pstep, nstep);
-          if (!tonumber(init, &ninit))
-            luaG_runerror(L, "'for' initial value must be a number");
-          setfltvalue(init, luai_numsub(L, ninit, nstep));
-        }
-        ci->u.l.savedpc += GETARG_sBx(i);
+        savestate(L, ci);  /* in case of errors */
+        if (forprep(L, ra))
+          pc += GETARG_Bx(i) + 1;  /* skip the loop */
         vmbreak;
       }
+      vmcase(OP_TFORPREP) {
+        /* create to-be-closed upvalue (if needed) */
+        halfProtect(luaF_newtbcupval(L, ra + 3));
+        pc += GETARG_Bx(i);
+        i = *(pc++);  /* go to next instruction */
+        lua_assert(GET_OPCODE(i) == OP_TFORCALL && ra == RA(i));
+        goto l_tforcall;
+      }
       vmcase(OP_TFORCALL) {
-        StkId cb = ra + 3;  /* call base */
-        setobjs2s(L, cb+2, ra+2);
-        setobjs2s(L, cb+1, ra+1);
-        setobjs2s(L, cb, ra);
-        L->top = cb + 3;  /* func. + 2 args (state and index) */
-        Protect(luaD_call(L, cb, GETARG_C(i)));
-        L->top = ci->top;
-        i = *(ci->u.l.savedpc++);  /* go to next instruction */
-        ra = RA(i);
-        lua_assert(GET_OPCODE(i) == OP_TFORLOOP);
+       l_tforcall:
+        /* 'ra' has the iterator function, 'ra + 1' has the state,
+           'ra + 2' has the control variable, and 'ra + 3' has the
+           to-be-closed variable. The call will use the stack after
+           these values (starting at 'ra + 4')
+        */
+        /* push function, state, and control variable */
+        memcpy(ra + 4, ra, 3 * sizeof(*ra));
+        L->top = ra + 4 + 3;
+        ProtectNT(luaD_call(L, ra + 4, GETARG_C(i)));  /* do the call */
+        updatestack(ci);  /* stack may have changed */
+        i = *(pc++);  /* go to next instruction */
+        lua_assert(GET_OPCODE(i) == OP_TFORLOOP && ra == RA(i));
         goto l_tforloop;
       }
       vmcase(OP_TFORLOOP) {
         l_tforloop:
-        if (!ttisnil(ra + 1)) {  /* continue loop? */
-          setobjs2s(L, ra, ra + 1);  /* save control variable */
-           ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
+        if (!ttisnil(s2v(ra + 4))) {  /* continue loop? */
+          setobjs2s(L, ra + 2, ra + 4);  /* save control variable */
+          pc -= GETARG_Bx(i);  /* jump back */
         }
         vmbreak;
       }
       vmcase(OP_SETLIST) {
         int n = GETARG_B(i);
-        int c = GETARG_C(i);
-        unsigned int last;
-        Table *h;
-        if (n == 0) n = cast_int(L->top - ra) - 1;
-        if (c == 0) {
-          lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
-          c = GETARG_Ax(*ci->u.l.savedpc++);
+        unsigned int last = GETARG_C(i);
+        Table *h = hvalue(s2v(ra));
+        if (n == 0)
+          n = cast_int(L->top - ra) - 1;  /* get up to the top */
+        else
+          L->top = ci->top;  /* correct top in case of emergency GC */
+        last += n;
+        if (TESTARG_k(i)) {
+          last += GETARG_Ax(*pc) * (MAXARG_C + 1);
+          pc++;
         }
-        h = hvalue(ra);
-        last = ((c-1)*LFIELDS_PER_FLUSH) + n;
-        if (last > h->sizearray)  /* needs more space? */
+        if (last > luaH_realasize(h))  /* needs more space? */
           luaH_resizearray(L, h, last);  /* preallocate it at once */
         for (; n > 0; n--) {
-          TValue *val = ra+n;
-          luaH_setint(L, h, last--, val);
-          luaC_barrierback(L, h, val);
+          TValue *val = s2v(ra + n);
+          setobj2t(L, &h->array[last - 1], val);
+          last--;
+          luaC_barrierback(L, obj2gco(h), val);
         }
-        L->top = ci->top;  /* correct top (in case of previous open call) */
         vmbreak;
       }
       vmcase(OP_CLOSURE) {
         Proto *p = cl->p->p[GETARG_Bx(i)];
-        LClosure *ncl = getcached(p, cl->upvals, base);  /* cached closure */
-        if (ncl == NULL)  /* no match? */
-          pushclosure(L, p, cl->upvals, base, ra);  /* create a new one */
-        else
-          setclLvalue(L, ra, ncl);  /* push cashed closure */
+        halfProtect(pushclosure(L, p, cl->upvals, base, ra));
         checkGC(L, ra + 1);
         vmbreak;
       }
       vmcase(OP_VARARG) {
-        int b = GETARG_B(i) - 1;  /* required results */
-        int j;
-        int n = cast_int(base - ci->func) - cl->p->numparams - 1;
-        if (n < 0)  /* less arguments than parameters? */
-          n = 0;  /* no vararg arguments */
-        if (b < 0) {  /* B == 0? */
-          b = n;  /* get all var. arguments */
-          Protect(luaD_checkstack(L, n));
-          ra = RA(i);  /* previous call may change the stack */
-          L->top = ra + n;
+        int n = GETARG_C(i) - 1;  /* required results */
+        Protect(luaT_getvarargs(L, ci, ra, n));
+        vmbreak;
+      }
+      vmcase(OP_VARARGPREP) {
+        luaT_adjustvarargs(L, GETARG_A(i), ci, cl->p);
+        updatetrap(ci);
+        if (trap) {
+          luaD_hookcall(L, ci);
+          L->oldpc = pc + 1;  /* next opcode will be seen as a "new" line */
         }
-        for (j = 0; j < b && j < n; j++)
-          setobjs2s(L, ra + j, base - n + j);
-        for (; j < b; j++)  /* complete required results with nil */
-          setnilvalue(ra + j);
+        updatebase(ci);  /* function has new base after adjustment */
         vmbreak;
       }
       vmcase(OP_EXTRAARG) {
@@ -1319,4 +1810,3 @@ void luaV_execute (lua_State *L) {
 }
 
 /* }================================================================== */
-
diff --git a/libs/liblua/src/lvm.h b/libs/liblua/src/lvm.h
index a8f954f04c..2d4ac160fe 100644
--- a/libs/liblua/src/lvm.h
+++ b/libs/liblua/src/lvm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.h,v 2.41.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lvm.h $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -33,15 +33,40 @@
 ** integral values)
 */
 #if !defined(LUA_FLOORN2I)
-#define LUA_FLOORN2I		0
+#define LUA_FLOORN2I		F2Ieq
 #endif
 
 
+/*
+** Rounding modes for float->integer coercion
+ */
+typedef enum {
+  F2Ieq,     /* no rounding; accepts only integral values */
+  F2Ifloor,  /* takes the floor of the number */
+  F2Iceil    /* takes the ceil of the number */
+} F2Imod;
+
+
+/* convert an object to a float (including string coercion) */
 #define tonumber(o,n) \
 	(ttisfloat(o) ? (*(n) = fltvalue(o), 1) : luaV_tonumber_(o,n))
 
+
+/* convert an object to a float (without string coercion) */
+#define tonumberns(o,n) \
+	(ttisfloat(o) ? ((n) = fltvalue(o), 1) : \
+	(ttisinteger(o) ? ((n) = cast_num(ivalue(o)), 1) : 0))
+
+
+/* convert an object to an integer (including string coercion) */
 #define tointeger(o,i) \
-    (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointeger(o,i,LUA_FLOORN2I))
+  (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointeger(o,i,LUA_FLOORN2I))
+
+
+/* convert an object to an integer (without string coercion) */
+#define tointegerns(o,i) \
+  (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointegerns(o,i,LUA_FLOORN2I))
+
 
 #define intop(op,v1,v2) l_castU2S(l_castS2U(v1) op l_castS2U(v2))
 
@@ -49,47 +74,39 @@
 
 
 /*
-** fast track for 'gettable': if 't' is a table and 't[k]' is not nil,
-** return 1 with 'slot' pointing to 't[k]' (final result).  Otherwise,
-** return 0 (meaning it will have to check metamethod) with 'slot'
-** pointing to a nil 't[k]' (if 't' is a table) or NULL (otherwise).
-** 'f' is the raw get function to use.
+** fast track for 'gettable': if 't' is a table and 't[k]' is present,
+** return 1 with 'slot' pointing to 't[k]' (position of final result).
+** Otherwise, return 0 (meaning it will have to check metamethod)
+** with 'slot' pointing to an empty 't[k]' (if 't' is a table) or NULL
+** (otherwise). 'f' is the raw get function to use.
 */
 #define luaV_fastget(L,t,k,slot,f) \
   (!ttistable(t)  \
    ? (slot = NULL, 0)  /* not a table; 'slot' is NULL and result is 0 */  \
    : (slot = f(hvalue(t), k),  /* else, do raw access */  \
-      !ttisnil(slot)))  /* result not nil? */
+      !isempty(slot)))  /* result not empty? */
+
 
 /*
-** standard implementation for 'gettable'
+** Special case of 'luaV_fastget' for integers, inlining the fast case
+** of 'luaH_getint'.
 */
-#define luaV_gettable(L,t,k,v) { const TValue *slot; \
-  if (luaV_fastget(L,t,k,slot,luaH_get)) { setobj2s(L, v, slot); } \
-  else luaV_finishget(L,t,k,v,slot); }
+#define luaV_fastgeti(L,t,k,slot) \
+  (!ttistable(t)  \
+   ? (slot = NULL, 0)  /* not a table; 'slot' is NULL and result is 0 */  \
+   : (slot = (l_castS2U(k) - 1u < hvalue(t)->alimit) \
+              ? &hvalue(t)->array[k - 1] : luaH_getint(hvalue(t), k), \
+      !isempty(slot)))  /* result not empty? */
 
 
 /*
-** Fast track for set table. If 't' is a table and 't[k]' is not nil,
-** call GC barrier, do a raw 't[k]=v', and return true; otherwise,
-** return false with 'slot' equal to NULL (if 't' is not a table) or
-** 'nil'. (This is needed by 'luaV_finishget'.) Note that, if the macro
-** returns true, there is no need to 'invalidateTMcache', because the
-** call is not creating a new entry.
+** Finish a fast set operation (when fast get succeeds). In that case,
+** 'slot' points to the place to put the value.
 */
-#define luaV_fastset(L,t,k,slot,f,v) \
-  (!ttistable(t) \
-   ? (slot = NULL, 0) \
-   : (slot = f(hvalue(t), k), \
-     ttisnil(slot) ? 0 \
-     : (luaC_barrierback(L, hvalue(t), v), \
-        setobj2t(L, cast(TValue *,slot), v), \
-        1)))
-
+#define luaV_finishfastset(L,t,slot,v) \
+    { setobj2t(L, cast(TValue *,slot), v); \
+      luaC_barrierback(L, gcvalue(t), v); }
 
-#define luaV_settable(L,t,k,v) { const TValue *slot; \
-  if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
-    luaV_finishset(L,t,k,v,slot); }
 
 
 
@@ -97,16 +114,20 @@ LUAI_FUNC int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2);
 LUAI_FUNC int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r);
 LUAI_FUNC int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r);
 LUAI_FUNC int luaV_tonumber_ (const TValue *obj, lua_Number *n);
-LUAI_FUNC int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode);
+LUAI_FUNC int luaV_tointeger (const TValue *obj, lua_Integer *p, F2Imod mode);
+LUAI_FUNC int luaV_tointegerns (const TValue *obj, lua_Integer *p,
+                                F2Imod mode);
+LUAI_FUNC int luaV_flttointeger (lua_Number n, lua_Integer *p, F2Imod mode);
 LUAI_FUNC void luaV_finishget (lua_State *L, const TValue *t, TValue *key,
                                StkId val, const TValue *slot);
 LUAI_FUNC void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
-                               StkId val, const TValue *slot);
+                               TValue *val, const TValue *slot);
 LUAI_FUNC void luaV_finishOp (lua_State *L);
-LUAI_FUNC void luaV_execute (lua_State *L);
+LUAI_FUNC void luaV_execute (lua_State *L, CallInfo *ci);
 LUAI_FUNC void luaV_concat (lua_State *L, int total);
-LUAI_FUNC lua_Integer luaV_div (lua_State *L, lua_Integer x, lua_Integer y);
+LUAI_FUNC lua_Integer luaV_idiv (lua_State *L, lua_Integer x, lua_Integer y);
 LUAI_FUNC lua_Integer luaV_mod (lua_State *L, lua_Integer x, lua_Integer y);
+LUAI_FUNC lua_Number luaV_modf (lua_State *L, lua_Number x, lua_Number y);
 LUAI_FUNC lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y);
 LUAI_FUNC void luaV_objlen (lua_State *L, StkId ra, const TValue *rb);
 
diff --git a/libs/liblua/src/lzio.c b/libs/liblua/src/lzio.c
index 6f79094410..cd0a02d5f9 100644
--- a/libs/liblua/src/lzio.c
+++ b/libs/liblua/src/lzio.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lzio.c,v 1.37.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lzio.c $
 ** Buffered streams
 ** See Copyright Notice in lua.h
 */
diff --git a/libs/liblua/src/lzio.h b/libs/liblua/src/lzio.h
index d897870815..38f397fd28 100644
--- a/libs/liblua/src/lzio.h
+++ b/libs/liblua/src/lzio.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lzio.h,v 1.31.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lzio.h $
 ** Buffered streams
 ** See Copyright Notice in lua.h
 */
-- 
cgit v1.2.3

