fixes #2472 (Update liblua to 5.4)

1 files changed, 486 insertions, 248 deletions

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;
 
 
@@ -402,11 +507,26 @@ typedef struct 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