fixes #2472 (Update liblua to 5.4)

1 files changed, 378 insertions, 266 deletions

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);
 }