1 files changed, 532 insertions, 335 deletions

diff --git a/apps/plugins/lua/lapi.c b/apps/plugins/lua/lapi.c
index 487d6b173a..d011431ead 100644
--- a/apps/plugins/lua/lapi.c
+++ b/apps/plugins/lua/lapi.c
@@ -1,12 +1,10 @@
 /*
-** $Id: lapi.c,v 2.55.1.5 2008/07/04 18:41:18 roberto Exp $
+** $Id: lapi.c,v 2.171.1.1 2013/04/12 18:48:47 roberto Exp $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
 
 
-/* #include <assert.h> */
-#include <math.h>
 #include <stdarg.h>
 #include <string.h>
 
@@ -32,76 +30,80 @@
 
 
 const char lua_ident[] =
-  "$Lua: " LUA_RELEASE " " LUA_COPYRIGHT " $\n"
-  "$Authors: " LUA_AUTHORS " $\n"
-  "$URL: www.lua.org $\n";
+  "$LuaVersion: " LUA_COPYRIGHT " $"
+  "$LuaAuthors: " LUA_AUTHORS " $";
 
 
+/* value at a non-valid index */
+#define NONVALIDVALUE           cast(TValue *, luaO_nilobject)
 
-#define api_checknelems(L, n)   api_check(L, (n) <= (L->top - L->base))
+/* corresponding test */
+#define isvalid(o)      ((o) != luaO_nilobject)
 
-#define api_checkvalidindex(L, i)       api_check(L, (i) != luaO_nilobject)
+/* test for pseudo index */
+#define ispseudo(i)             ((i) <= LUA_REGISTRYINDEX)
 
-#define api_incr_top(L)   {api_check(L, L->top < L->ci->top); L->top++;}
+/* 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 *index2adr (lua_State *L, int idx) {
+
+static TValue *index2addr (lua_State *L, int idx) {
+  CallInfo *ci = L->ci;
   if (idx > 0) {
-    TValue *o = L->base + (idx - 1);
-    api_check(L, idx <= L->ci->top - L->base);
-    if (o >= L->top) return cast(TValue *, luaO_nilobject);
+    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;
   }
-  else if (idx > LUA_REGISTRYINDEX) {
-    api_check(L, idx != 0 && -idx <= L->top - L->base);
+  else if (!ispseudo(idx)) {  /* negative index */
+    api_check(L, idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index");
     return L->top + idx;
   }
-  else switch (idx) {  /* pseudo-indices */
-    case LUA_REGISTRYINDEX: return registry(L);
-    case LUA_ENVIRONINDEX: {
-      Closure *func = curr_func(L);
-      sethvalue(L, &L->env, func->c.env);
-      return &L->env;
-    }
-    case LUA_GLOBALSINDEX: return gt(L);
-    default: {
-      Closure *func = curr_func(L);
-      idx = LUA_GLOBALSINDEX - idx;
-      return (idx <= func->c.nupvalues)
-                ? &func->c.upvalue[idx-1]
-                : cast(TValue *, luaO_nilobject);
+  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 */
+    else {
+      CClosure *func = clCvalue(ci->func);
+      return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE;
     }
   }
 }
 
 
-static Table *getcurrenv (lua_State *L) {
-  if (L->ci == L->base_ci)  /* no enclosing function? */
-    return hvalue(gt(L));  /* use global table as environment */
-  else {
-    Closure *func = curr_func(L);
-    return func->c.env;
-  }
-}
-
-
-void luaA_pushobject (lua_State *L, const TValue *o) {
-  setobj2s(L, L->top, o);
-  api_incr_top(L);
+/*
+** 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);
 }
 
 
 LUA_API int lua_checkstack (lua_State *L, int size) {
-  int res = 1;
+  int res;
+  CallInfo *ci = L->ci;
   lua_lock(L);
-  if (size > LUAI_MAXCSTACK || (L->top - L->base + size) > LUAI_MAXCSTACK)
-    res = 0;  /* stack overflow */
-  else if (size > 0) {
-    luaD_checkstack(L, size);
-    if (L->ci->top < L->top + size)
-      L->ci->top = L->top + size;
+  if (L->stack_last - L->top > size)  /* stack large enough? */
+    res = 1;  /* yes; check is OK */
+  else {  /* no; need to grow stack */
+    int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
+    if (inuse > LUAI_MAXSTACK - size)  /* can grow without overflow? */
+      res = 0;  /* no */
+    else  /* try to grow stack */
+      res = (luaD_rawrunprotected(L, &growstack, &size) == LUA_OK);
   }
+  if (res && ci->top < L->top + size)
+    ci->top = L->top + size;  /* adjust frame top */
   lua_unlock(L);
   return res;
 }
@@ -112,8 +114,8 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
   if (from == to) return;
   lua_lock(to);
   api_checknelems(from, n);
-  api_check(from, G(from) == G(to));
-  api_check(from, to->ci->top - to->top >= n);
+  api_check(from, G(from) == G(to), "moving among independent states");
+  api_check(from, to->ci->top - to->top >= n, "not enough elements to move");
   from->top -= n;
   for (i = 0; i < n; i++) {
     setobj2s(to, to->top++, from->top + i);
@@ -122,11 +124,6 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
 }
 
 
-LUA_API void lua_setlevel (lua_State *from, lua_State *to) {
-  to->nCcalls = from->nCcalls;
-}
-
-
 LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
   lua_CFunction old;
   lua_lock(L);
@@ -137,16 +134,10 @@ LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
 }
 
 
-LUA_API lua_State *lua_newthread (lua_State *L) {
-  lua_State *L1;
-  lua_lock(L);
-  luaC_checkGC(L);
-  L1 = luaE_newthread(L);
-  setthvalue(L, L->top, L1);
-  api_incr_top(L);
-  lua_unlock(L);
-  luai_userstatethread(L, L1);
-  return L1;
+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;
 }
 
 
@@ -156,21 +147,32 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
 */
 
 
+/*
+** convert an acceptable stack index into an absolute index
+*/
+LUA_API int lua_absindex (lua_State *L, int idx) {
+  return (idx > 0 || ispseudo(idx))
+         ? idx
+         : cast_int(L->top - L->ci->func + idx);
+}
+
+
 LUA_API int lua_gettop (lua_State *L) {
-  return cast_int(L->top - L->base);
+  return cast_int(L->top - (L->ci->func + 1));
 }
 
 
 LUA_API void lua_settop (lua_State *L, int idx) {
+  StkId func = L->ci->func;
   lua_lock(L);
   if (idx >= 0) {
-    api_check(L, idx <= L->stack_last - L->base);
-    while (L->top < L->base + idx)
+    api_check(L, idx <= L->stack_last - (func + 1), "new top too large");
+    while (L->top < (func + 1) + idx)
       setnilvalue(L->top++);
-    L->top = L->base + idx;
+    L->top = (func + 1) + idx;
   }
   else {
-    api_check(L, -(idx+1) <= (L->top - L->base));
+    api_check(L, -(idx+1) <= (L->top - (func + 1)), "invalid new top");
     L->top += idx+1;  /* `subtract' index (index is negative) */
   }
   lua_unlock(L);
@@ -180,8 +182,8 @@ LUA_API void lua_settop (lua_State *L, int idx) {
 LUA_API void lua_remove (lua_State *L, int idx) {
   StkId p;
   lua_lock(L);
-  p = index2adr(L, idx);
-  api_checkvalidindex(L, p);
+  p = index2addr(L, idx);
+  api_checkstackindex(L, idx, p);
   while (++p < L->top) setobjs2s(L, p-1, p);
   L->top--;
   lua_unlock(L);
@@ -192,42 +194,47 @@ LUA_API void lua_insert (lua_State *L, int idx) {
   StkId p;
   StkId q;
   lua_lock(L);
-  p = index2adr(L, idx);
-  api_checkvalidindex(L, p);
-  for (q = L->top; q>p; q--) setobjs2s(L, q, q-1);
+  p = index2addr(L, idx);
+  api_checkstackindex(L, idx, p);
+  for (q = L->top; q > p; q--)  /* use L->top as a temporary */
+    setobjs2s(L, q, q - 1);
   setobjs2s(L, p, L->top);
   lua_unlock(L);
 }
 
 
+static void moveto (lua_State *L, TValue *fr, int idx) {
+  TValue *to = index2addr(L, idx);
+  api_checkvalidindex(L, to);
+  setobj(L, to, fr);
+  if (idx < LUA_REGISTRYINDEX)  /* function upvalue? */
+    luaC_barrier(L, clCvalue(L->ci->func), fr);
+  /* LUA_REGISTRYINDEX does not need gc barrier
+     (collector revisits it before finishing collection) */
+}
+
+
 LUA_API void lua_replace (lua_State *L, int idx) {
-  StkId o;
   lua_lock(L);
-  /* explicit test for incompatible code */
-  if (idx == LUA_ENVIRONINDEX && L->ci == L->base_ci)
-    luaG_runerror(L, "no calling environment");
   api_checknelems(L, 1);
-  o = index2adr(L, idx);
-  api_checkvalidindex(L, o);
-  if (idx == LUA_ENVIRONINDEX) {
-    Closure *func = curr_func(L);
-    api_check(L, ttistable(L->top - 1)); 
-    func->c.env = hvalue(L->top - 1);
-    luaC_barrier(L, func, L->top - 1);
-  }
-  else {
-    setobj(L, o, L->top - 1);
-    if (idx < LUA_GLOBALSINDEX)  /* function upvalue? */
-      luaC_barrier(L, curr_func(L), L->top - 1);
-  }
+  moveto(L, L->top - 1, idx);
   L->top--;
   lua_unlock(L);
 }
 
 
+LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
+  TValue *fr;
+  lua_lock(L);
+  fr = index2addr(L, fromidx);
+  moveto(L, fr, toidx);
+  lua_unlock(L);
+}
+
+
 LUA_API void lua_pushvalue (lua_State *L, int idx) {
   lua_lock(L);
-  setobj2s(L, L->top, index2adr(L, idx));
+  setobj2s(L, L->top, index2addr(L, idx));
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -240,26 +247,26 @@ LUA_API void lua_pushvalue (lua_State *L, int idx) {
 
 
 LUA_API int lua_type (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
-  return (o == luaO_nilobject) ? LUA_TNONE : ttype(o);
+  StkId o = index2addr(L, idx);
+  return (isvalid(o) ? ttypenv(o) : LUA_TNONE);
 }
 
 
 LUA_API const char *lua_typename (lua_State *L, int t) {
   UNUSED(L);
-  return (t == LUA_TNONE) ? "no value" : luaT_typenames[t];
+  return ttypename(t);
 }
 
 
 LUA_API int lua_iscfunction (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
-  return iscfunction(o);
+  StkId o = index2addr(L, idx);
+  return (ttislcf(o) || (ttisCclosure(o)));
 }
 
 
 LUA_API int lua_isnumber (lua_State *L, int idx) {
   TValue n;
-  const TValue *o = index2adr(L, idx);
+  const TValue *o = index2addr(L, idx);
   return tonumber(o, &n);
 }
 
@@ -271,77 +278,116 @@ LUA_API int lua_isstring (lua_State *L, int idx) {
 
 
 LUA_API int lua_isuserdata (lua_State *L, int idx) {
-  const TValue *o = index2adr(L, idx);
+  const TValue *o = index2addr(L, idx);
   return (ttisuserdata(o) || ttislightuserdata(o));
 }
 
 
 LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
-  StkId o1 = index2adr(L, index1);
-  StkId o2 = index2adr(L, index2);
-  return (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
-         : luaO_rawequalObj(o1, o2);
+  StkId o1 = index2addr(L, index1);
+  StkId o2 = index2addr(L, index2);
+  return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0;
 }
 
 
-LUA_API int lua_equal (lua_State *L, int index1, int index2) {
-  StkId o1, o2;
-  int i;
-  lua_lock(L);  /* may call tag method */
-  o1 = index2adr(L, index1);
-  o2 = index2adr(L, index2);
-  i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0 : equalobj(L, o1, o2);
+LUA_API void lua_arith (lua_State *L, int op) {
+  StkId o1;  /* 1st operand */
+  StkId o2;  /* 2nd operand */
+  lua_lock(L);
+  if (op != LUA_OPUNM) /* all other operations expect two operands */
+    api_checknelems(L, 2);
+  else {  /* for unary minus, add fake 2nd operand */
+    api_checknelems(L, 1);
+    setobjs2s(L, L->top, L->top - 1);
+    L->top++;
+  }
+  o1 = L->top - 2;
+  o2 = L->top - 1;
+  if (ttisnumber(o1) && ttisnumber(o2)) {
+    setnvalue(o1, luaO_arith(op, nvalue(o1), nvalue(o2)));
+  }
+  else
+    luaV_arith(L, o1, o1, o2, cast(TMS, op - LUA_OPADD + TM_ADD));
+  L->top--;
   lua_unlock(L);
-  return i;
 }
 
 
-LUA_API int lua_lessthan (lua_State *L, int index1, int index2) {
+LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
   StkId o1, o2;
-  int i;
+  int i = 0;
   lua_lock(L);  /* may call tag method */
-  o1 = index2adr(L, index1);
-  o2 = index2adr(L, index2);
-  i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
-       : luaV_lessthan(L, o1, o2);
+  o1 = index2addr(L, index1);
+  o2 = index2addr(L, index2);
+  if (isvalid(o1) && isvalid(o2)) {
+    switch (op) {
+      case LUA_OPEQ: i = equalobj(L, o1, o2); break;
+      case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
+      case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break;
+      default: api_check(L, 0, "invalid option");
+    }
+  }
   lua_unlock(L);
   return i;
 }
 
 
-
-LUA_API lua_Number lua_tonumber (lua_State *L, int idx) {
+LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *isnum) {
   TValue n;
-  const TValue *o = index2adr(L, idx);
-  if (tonumber(o, &n))
+  const TValue *o = index2addr(L, idx);
+  if (tonumber(o, &n)) {
+    if (isnum) *isnum = 1;
     return nvalue(o);
-  else
+  }
+  else {
+    if (isnum) *isnum = 0;
     return 0;
+  }
 }
 
 
-LUA_API lua_Integer lua_tointeger (lua_State *L, int idx) {
+LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *isnum) {
   TValue n;
-  const TValue *o = index2adr(L, idx);
+  const TValue *o = index2addr(L, idx);
   if (tonumber(o, &n)) {
     lua_Integer res;
     lua_Number num = nvalue(o);
     lua_number2integer(res, num);
+    if (isnum) *isnum = 1;
     return res;
   }
-  else
+  else {
+    if (isnum) *isnum = 0;
+    return 0;
+  }
+}
+
+
+LUA_API lua_Unsigned lua_tounsignedx (lua_State *L, int idx, int *isnum) {
+  TValue n;
+  const TValue *o = index2addr(L, idx);
+  if (tonumber(o, &n)) {
+    lua_Unsigned res;
+    lua_Number num = nvalue(o);
+    lua_number2unsigned(res, num);
+    if (isnum) *isnum = 1;
+    return res;
+  }
+  else {
+    if (isnum) *isnum = 0;
     return 0;
+  }
 }
 
 
 LUA_API int lua_toboolean (lua_State *L, int idx) {
-  const TValue *o = index2adr(L, idx);
+  const TValue *o = index2addr(L, idx);
   return !l_isfalse(o);
 }
 
 
 LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
-  StkId o = index2adr(L, idx);
+  StkId o = index2addr(L, idx);
   if (!ttisstring(o)) {
     lua_lock(L);  /* `luaV_tostring' may create a new string */
     if (!luaV_tostring(L, o)) {  /* conversion failed? */
@@ -350,7 +396,7 @@ LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
       return NULL;
     }
     luaC_checkGC(L);
-    o = index2adr(L, idx);  /* previous call may reallocate the stack */
+    o = index2addr(L, idx);  /* previous call may reallocate the stack */
     lua_unlock(L);
   }
   if (len != NULL) *len = tsvalue(o)->len;
@@ -358,33 +404,29 @@ LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
 }
 
 
-LUA_API size_t lua_objlen (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
-  switch (ttype(o)) {
+LUA_API size_t lua_rawlen (lua_State *L, int idx) {
+  StkId o = index2addr(L, idx);
+  switch (ttypenv(o)) {
     case LUA_TSTRING: return tsvalue(o)->len;
     case LUA_TUSERDATA: return uvalue(o)->len;
     case LUA_TTABLE: return luaH_getn(hvalue(o));
-    case LUA_TNUMBER: {
-      size_t l;
-      lua_lock(L);  /* `luaV_tostring' may create a new string */
-      l = (luaV_tostring(L, o) ? tsvalue(o)->len : 0);
-      lua_unlock(L);
-      return l;
-    }
     default: return 0;
   }
 }
 
 
 LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
-  return (!iscfunction(o)) ? NULL : clvalue(o)->c.f;
+  StkId o = index2addr(L, idx);
+  if (ttislcf(o)) return fvalue(o);
+  else if (ttisCclosure(o))
+    return clCvalue(o)->f;
+  else return NULL;  /* not a C function */
 }
 
 
 LUA_API void *lua_touserdata (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
-  switch (ttype(o)) {
+  StkId o = index2addr(L, idx);
+  switch (ttypenv(o)) {
     case LUA_TUSERDATA: return (rawuvalue(o) + 1);
     case LUA_TLIGHTUSERDATA: return pvalue(o);
     default: return NULL;
@@ -393,16 +435,18 @@ LUA_API void *lua_touserdata (lua_State *L, int idx) {
 
 
 LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
+  StkId o = index2addr(L, idx);
   return (!ttisthread(o)) ? NULL : thvalue(o);
 }
 
 
 LUA_API const void *lua_topointer (lua_State *L, int idx) {
-  StkId o = index2adr(L, idx);
+  StkId o = index2addr(L, idx);
   switch (ttype(o)) {
     case LUA_TTABLE: return hvalue(o);
-    case LUA_TFUNCTION: return clvalue(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:
     case LUA_TLIGHTUSERDATA:
@@ -429,6 +473,8 @@ LUA_API void lua_pushnil (lua_State *L) {
 LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
   lua_lock(L);
   setnvalue(L->top, n);
+  luai_checknum(L, L->top,
+    luaG_runerror(L, "C API - attempt to push a signaling NaN"));
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -442,20 +488,43 @@ LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
 }
 
 
-LUA_API void lua_pushlstring (lua_State *L, const char *s, size_t len) {
+LUA_API void lua_pushunsigned (lua_State *L, lua_Unsigned u) {
+  lua_Number n;
+  lua_lock(L);
+  n = lua_unsigned2number(u);
+  setnvalue(L->top, n);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
+  TString *ts;
   lua_lock(L);
   luaC_checkGC(L);
-  setsvalue2s(L, L->top, luaS_newlstr(L, s, len));
+  ts = luaS_newlstr(L, s, len);
+  setsvalue2s(L, L->top, ts);
   api_incr_top(L);
   lua_unlock(L);
+  return getstr(ts);
 }
 
 
-LUA_API void lua_pushstring (lua_State *L, const char *s) {
-  if (s == NULL)
+LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
+  if (s == NULL) {
     lua_pushnil(L);
-  else
-    lua_pushlstring(L, s, strlen(s));
+    return NULL;
+  }
+  else {
+    TString *ts;
+    lua_lock(L);
+    luaC_checkGC(L);
+    ts = luaS_new(L, s);
+    setsvalue2s(L, L->top, ts);
+    api_incr_top(L);
+    lua_unlock(L);
+    return getstr(ts);
+  }
 }
 
 
@@ -484,17 +553,22 @@ 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) {
-  Closure *cl;
   lua_lock(L);
-  luaC_checkGC(L);
-  api_checknelems(L, n);
-  cl = luaF_newCclosure(L, n, getcurrenv(L));
-  cl->c.f = fn;
-  L->top -= n;
-  while (n--)
-    setobj2n(L, &cl->c.upvalue[n], L->top+n);
-  setclvalue(L, L->top, cl);
-  lua_assert(iswhite(obj2gco(cl)));
+  if (n == 0) {
+    setfvalue(L->top, fn);
+  }
+  else {
+    Closure *cl;
+    api_checknelems(L, n);
+    api_check(L, n <= MAXUPVAL, "upvalue index too large");
+    luaC_checkGC(L);
+    cl = luaF_newCclosure(L, n);
+    cl->c.f = fn;
+    L->top -= n;
+    while (n--)
+      setobj2n(L, &cl->c.upvalue[n], L->top + n);
+    setclCvalue(L, L->top, cl);
+  }
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -531,11 +605,21 @@ LUA_API int lua_pushthread (lua_State *L) {
 */
 
 
+LUA_API void lua_getglobal (lua_State *L, const char *var) {
+  Table *reg = hvalue(&G(L)->l_registry);
+  const TValue *gt;  /* global table */
+  lua_lock(L);
+  gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
+  setsvalue2s(L, L->top++, luaS_new(L, var));
+  luaV_gettable(L, gt, L->top - 1, L->top - 1);
+  lua_unlock(L);
+}
+
+
 LUA_API void lua_gettable (lua_State *L, int idx) {
   StkId t;
   lua_lock(L);
-  t = index2adr(L, idx);
-  api_checkvalidindex(L, t);
+  t = index2addr(L, idx);
   luaV_gettable(L, t, L->top - 1, L->top - 1);
   lua_unlock(L);
 }
@@ -543,13 +627,11 @@ LUA_API void lua_gettable (lua_State *L, int idx) {
 
 LUA_API void lua_getfield (lua_State *L, int idx, const char *k) {
   StkId t;
-  TValue key;
   lua_lock(L);
-  t = index2adr(L, idx);
-  api_checkvalidindex(L, t);
-  setsvalue(L, &key, luaS_new(L, k));
-  luaV_gettable(L, t, &key, L->top);
+  t = index2addr(L, idx);
+  setsvalue2s(L, L->top, luaS_new(L, k));
   api_incr_top(L);
+  luaV_gettable(L, t, L->top - 1, L->top - 1);
   lua_unlock(L);
 }
 
@@ -557,29 +639,46 @@ LUA_API void lua_getfield (lua_State *L, int idx, const char *k) {
 LUA_API void lua_rawget (lua_State *L, int idx) {
   StkId t;
   lua_lock(L);
-  t = index2adr(L, idx);
-  api_check(L, ttistable(t));
+  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);
 }
 
 
 LUA_API void lua_rawgeti (lua_State *L, int idx, int n) {
-  StkId o;
+  StkId t;
   lua_lock(L);
-  o = index2adr(L, idx);
-  api_check(L, ttistable(o));
-  setobj2s(L, L->top, luaH_getnum(hvalue(o), n));
+  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);
+}
+
+
+LUA_API void lua_rawgetp (lua_State *L, int idx, const void *p) {
+  StkId 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);
 }
 
 
 LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
+  Table *t;
   lua_lock(L);
   luaC_checkGC(L);
-  sethvalue(L, L->top, luaH_new(L, narray, nrec));
+  t = luaH_new(L);
+  sethvalue(L, L->top, t);
   api_incr_top(L);
+  if (narray > 0 || nrec > 0)
+    luaH_resize(L, t, narray, nrec);
   lua_unlock(L);
 }
 
@@ -589,8 +688,8 @@ LUA_API int lua_getmetatable (lua_State *L, int objindex) {
   Table *mt = NULL;
   int res;
   lua_lock(L);
-  obj = index2adr(L, objindex);
-  switch (ttype(obj)) {
+  obj = index2addr(L, objindex);
+  switch (ttypenv(obj)) {
     case LUA_TTABLE:
       mt = hvalue(obj)->metatable;
       break;
@@ -598,7 +697,7 @@ LUA_API int lua_getmetatable (lua_State *L, int objindex) {
       mt = uvalue(obj)->metatable;
       break;
     default:
-      mt = G(L)->mt[ttype(obj)];
+      mt = G(L)->mt[ttypenv(obj)];
       break;
   }
   if (mt == NULL)
@@ -613,25 +712,15 @@ LUA_API int lua_getmetatable (lua_State *L, int objindex) {
 }
 
 
-LUA_API void lua_getfenv (lua_State *L, int idx) {
+LUA_API void lua_getuservalue (lua_State *L, int idx) {
   StkId o;
   lua_lock(L);
-  o = index2adr(L, idx);
-  api_checkvalidindex(L, o);
-  switch (ttype(o)) {
-    case LUA_TFUNCTION:
-      sethvalue(L, L->top, clvalue(o)->c.env);
-      break;
-    case LUA_TUSERDATA:
-      sethvalue(L, L->top, uvalue(o)->env);
-      break;
-    case LUA_TTHREAD:
-      setobj2s(L, L->top,  gt(thvalue(o)));
-      break;
-    default:
-      setnilvalue(L->top);
-      break;
-  }
+  o = index2addr(L, idx);
+  api_check(L, ttisuserdata(o), "userdata expected");
+  if (uvalue(o)->env) {
+    sethvalue(L, L->top, uvalue(o)->env);
+  } else
+    setnilvalue(L->top);
   api_incr_top(L);
   lua_unlock(L);
 }
@@ -642,12 +731,24 @@ LUA_API void lua_getfenv (lua_State *L, int idx) {
 */
 
 
+LUA_API void lua_setglobal (lua_State *L, const char *var) {
+  Table *reg = hvalue(&G(L)->l_registry);
+  const TValue *gt;  /* global table */
+  lua_lock(L);
+  api_checknelems(L, 1);
+  gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
+  setsvalue2s(L, L->top++, luaS_new(L, var));
+  luaV_settable(L, gt, L->top - 1, L->top - 2);
+  L->top -= 2;  /* pop value and key */
+  lua_unlock(L);
+}
+
+
 LUA_API void lua_settable (lua_State *L, int idx) {
   StkId t;
   lua_lock(L);
   api_checknelems(L, 2);
-  t = index2adr(L, idx);
-  api_checkvalidindex(L, t);
+  t = index2addr(L, idx);
   luaV_settable(L, t, L->top - 2, L->top - 1);
   L->top -= 2;  /* pop index and value */
   lua_unlock(L);
@@ -656,14 +757,12 @@ LUA_API void lua_settable (lua_State *L, int idx) {
 
 LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
   StkId t;
-  TValue key;
   lua_lock(L);
   api_checknelems(L, 1);
-  t = index2adr(L, idx);
-  api_checkvalidindex(L, t);
-  setsvalue(L, &key, luaS_new(L, k));
-  luaV_settable(L, t, &key, L->top - 1);
-  L->top--;  /* pop value */
+  t = index2addr(L, idx);
+  setsvalue2s(L, L->top++, luaS_new(L, k));
+  luaV_settable(L, t, L->top - 1, L->top - 2);
+  L->top -= 2;  /* pop value and key */
   lua_unlock(L);
 }
 
@@ -672,23 +771,39 @@ LUA_API void lua_rawset (lua_State *L, int idx) {
   StkId t;
   lua_lock(L);
   api_checknelems(L, 2);
-  t = index2adr(L, idx);
-  api_check(L, ttistable(t));
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
   setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
-  luaC_barriert(L, hvalue(t), L->top-1);
+  invalidateTMcache(hvalue(t));
+  luaC_barrierback(L, gcvalue(t), L->top-1);
   L->top -= 2;
   lua_unlock(L);
 }
 
 
 LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
-  StkId o;
+  StkId t;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  luaH_setint(L, hvalue(t), n, L->top - 1);
+  luaC_barrierback(L, gcvalue(t), L->top-1);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
+  StkId t;
+  TValue k;
   lua_lock(L);
   api_checknelems(L, 1);
-  o = index2adr(L, idx);
-  api_check(L, ttistable(o));
-  setobj2t(L, luaH_setnum(L, hvalue(o), n), L->top-1);
-  luaC_barriert(L, hvalue(o), L->top-1);
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
+  setpvalue(&k, cast(void *, p));
+  setobj2t(L, luaH_set(L, hvalue(t), &k), L->top - 1);
+  luaC_barrierback(L, gcvalue(t), L->top - 1);
   L->top--;
   lua_unlock(L);
 }
@@ -699,29 +814,32 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
   Table *mt;
   lua_lock(L);
   api_checknelems(L, 1);
-  obj = index2adr(L, objindex);
-  api_checkvalidindex(L, obj);
+  obj = index2addr(L, objindex);
   if (ttisnil(L->top - 1))
     mt = NULL;
   else {
-    api_check(L, ttistable(L->top - 1));
+    api_check(L, ttistable(L->top - 1), "table expected");
     mt = hvalue(L->top - 1);
   }
-  switch (ttype(obj)) {
+  switch (ttypenv(obj)) {
     case LUA_TTABLE: {
       hvalue(obj)->metatable = mt;
-      if (mt)
-        luaC_objbarriert(L, hvalue(obj), mt);
+      if (mt) {
+        luaC_objbarrierback(L, gcvalue(obj), mt);
+        luaC_checkfinalizer(L, gcvalue(obj), mt);
+      }
       break;
     }
     case LUA_TUSERDATA: {
       uvalue(obj)->metatable = mt;
-      if (mt)
+      if (mt) {
         luaC_objbarrier(L, rawuvalue(obj), mt);
+        luaC_checkfinalizer(L, gcvalue(obj), mt);
+      }
       break;
     }
     default: {
-      G(L)->mt[ttype(obj)] = mt;
+      G(L)->mt[ttypenv(obj)] = mt;
       break;
     }
   }
@@ -731,32 +849,21 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
 }
 
 
-LUA_API int lua_setfenv (lua_State *L, int idx) {
+LUA_API void lua_setuservalue (lua_State *L, int idx) {
   StkId o;
-  int res = 1;
   lua_lock(L);
   api_checknelems(L, 1);
-  o = index2adr(L, idx);
-  api_checkvalidindex(L, o);
-  api_check(L, ttistable(L->top - 1));
-  switch (ttype(o)) {
-    case LUA_TFUNCTION:
-      clvalue(o)->c.env = hvalue(L->top - 1);
-      break;
-    case LUA_TUSERDATA:
-      uvalue(o)->env = hvalue(L->top - 1);
-      break;
-    case LUA_TTHREAD:
-      sethvalue(L, gt(thvalue(o)), hvalue(L->top - 1));
-      break;
-    default:
-      res = 0;
-      break;
+  o = index2addr(L, idx);
+  api_check(L, ttisuserdata(o), "userdata expected");
+  if (ttisnil(L->top - 1))
+    uvalue(o)->env = NULL;
+  else {
+    api_check(L, ttistable(L->top - 1), "table expected");
+    uvalue(o)->env = hvalue(L->top - 1);
+    luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
   }
-  if (res) luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
   L->top--;
   lua_unlock(L);
-  return res;
 }
 
 
@@ -765,21 +872,37 @@ LUA_API int lua_setfenv (lua_State *L, int idx) {
 */
 
 
-#define adjustresults(L,nres) \
-    { if (nres == LUA_MULTRET && L->top >= L->ci->top) L->ci->top = L->top; }
+#define checkresults(L,na,nr) \
+     api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \
+        "results from function overflow current stack size")
 
 
-#define checkresults(L,na,nr) \
-     api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)))
-        
+LUA_API int lua_getctx (lua_State *L, int *ctx) {
+  if (L->ci->callstatus & CIST_YIELDED) {
+    if (ctx) *ctx = L->ci->u.c.ctx;
+    return L->ci->u.c.status;
+  }
+  else return LUA_OK;
+}
 
-LUA_API void lua_call (lua_State *L, int nargs, int nresults) {
+
+LUA_API void lua_callk (lua_State *L, int nargs, int nresults, int ctx,
+                        lua_CFunction k) {
   StkId func;
   lua_lock(L);
+  api_check(L, k == NULL || !isLua(L->ci),
+    "cannot use continuations inside hooks");
   api_checknelems(L, nargs+1);
+  api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
   checkresults(L, nargs, nresults);
   func = L->top - (nargs+1);
-  luaD_call(L, func, nresults);
+  if (k != NULL && L->nny == 0) {  /* 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, 1);  /* do the call */
+  }
+  else  /* no continuation or no yieldable */
+    luaD_call(L, func, nresults, 0);  /* just do the call */
   adjustresults(L, nresults);
   lua_unlock(L);
 }
@@ -797,76 +920,75 @@ struct CallS {  /* data to `f_call' */
 
 static void f_call (lua_State *L, void *ud) {
   struct CallS *c = cast(struct CallS *, ud);
-  luaD_call(L, c->func, c->nresults);
+  luaD_call(L, c->func, c->nresults, 0);
 }
 
 
 
-LUA_API int lua_pcall (lua_State *L, int nargs, int nresults, int errfunc) {
+LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
+                        int ctx, lua_CFunction k) {
   struct CallS c;
   int status;
   ptrdiff_t func;
   lua_lock(L);
+  api_check(L, k == NULL || !isLua(L->ci),
+    "cannot use continuations inside hooks");
   api_checknelems(L, nargs+1);
+  api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
   checkresults(L, nargs, nresults);
   if (errfunc == 0)
     func = 0;
   else {
-    StkId o = index2adr(L, errfunc);
-    api_checkvalidindex(L, o);
+    StkId o = index2addr(L, errfunc);
+    api_checkstackindex(L, errfunc, o);
     func = savestack(L, o);
   }
   c.func = L->top - (nargs+1);  /* function to be called */
-  c.nresults = nresults;
-  status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
+  if (k == NULL || L->nny > 0) {  /* 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);
+  }
+  else {  /* prepare continuation (call is already protected by 'resume') */
+    CallInfo *ci = L->ci;
+    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->u.c.old_allowhook = L->allowhook;
+    ci->u.c.old_errfunc = L->errfunc;
+    L->errfunc = func;
+    /* mark that function may do error recovery */
+    ci->callstatus |= CIST_YPCALL;
+    luaD_call(L, c.func, nresults, 1);  /* do the call */
+    ci->callstatus &= ~CIST_YPCALL;
+    L->errfunc = ci->u.c.old_errfunc;
+    status = LUA_OK;  /* if it is here, there were no errors */
+  }
   adjustresults(L, nresults);
   lua_unlock(L);
   return status;
 }
 
 
-/*
-** Execute a protected C call.
-*/
-struct CCallS {  /* data to `f_Ccall' */
-  lua_CFunction func;
-  void *ud;
-};
-
-
-static void f_Ccall (lua_State *L, void *ud) {
-  struct CCallS *c = cast(struct CCallS *, ud);
-  Closure *cl;
-  cl = luaF_newCclosure(L, 0, getcurrenv(L));
-  cl->c.f = c->func;
-  setclvalue(L, L->top, cl);  /* push function */
-  api_incr_top(L);
-  setpvalue(L->top, c->ud);  /* push only argument */
-  api_incr_top(L);
-  luaD_call(L, L->top - 2, 0);
-}
-
-
-LUA_API int lua_cpcall (lua_State *L, lua_CFunction func, void *ud) {
-  struct CCallS c;
-  int status;
-  lua_lock(L);
-  c.func = func;
-  c.ud = ud;
-  status = luaD_pcall(L, f_Ccall, &c, savestack(L, L->top), 0);
-  lua_unlock(L);
-  return status;
-}
-
-
 LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
-                      const char *chunkname) {
+                      const char *chunkname, const char *mode) {
   ZIO z;
   int status;
   lua_lock(L);
   if (!chunkname) chunkname = "?";
   luaZ_init(L, &z, reader, data);
-  status = luaD_protectedparser(L, &z, chunkname);
+  status = luaD_protectedparser(L, &z, chunkname, mode);
+  if (status == LUA_OK) {  /* no errors? */
+    LClosure *f = clLvalue(L->top - 1);  /* get newly created function */
+    if (f->nupvalues == 1) {  /* does it have one 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_barrier(L, f->upvals[0], gt);
+    }
+  }
   lua_unlock(L);
   return status;
 }
@@ -879,7 +1001,7 @@ LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data) {
   api_checknelems(L, 1);
   o = L->top - 1;
   if (isLfunction(o))
-    status = luaU_dump(L, clvalue(o)->l.p, writer, data, 0);
+    status = luaU_dump(L, getproto(o), writer, data, 0);
   else
     status = 1;
   lua_unlock(L);
@@ -887,7 +1009,7 @@ LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data) {
 }
 
 
-LUA_API int  lua_status (lua_State *L) {
+LUA_API int lua_status (lua_State *L) {
   return L->status;
 }
 
@@ -903,38 +1025,40 @@ LUA_API int lua_gc (lua_State *L, int what, int data) {
   g = G(L);
   switch (what) {
     case LUA_GCSTOP: {
-      g->GCthreshold = MAX_LUMEM;
+      g->gcrunning = 0;
       break;
     }
     case LUA_GCRESTART: {
-      g->GCthreshold = g->totalbytes;
+      luaE_setdebt(g, 0);
+      g->gcrunning = 1;
       break;
     }
     case LUA_GCCOLLECT: {
-      luaC_fullgc(L);
+      luaC_fullgc(L, 0);
       break;
     }
     case LUA_GCCOUNT: {
       /* GC values are expressed in Kbytes: #bytes/2^10 */
-      res = cast_int(g->totalbytes >> 10);
+      res = cast_int(gettotalbytes(g) >> 10);
       break;
     }
     case LUA_GCCOUNTB: {
-      res = cast_int(g->totalbytes & 0x3ff);
+      res = cast_int(gettotalbytes(g) & 0x3ff);
       break;
     }
     case LUA_GCSTEP: {
-      lu_mem a = (cast(lu_mem, data) << 10);
-      if (a <= g->totalbytes)
-        g->GCthreshold = g->totalbytes - a;
-      else
-        g->GCthreshold = 0;
-      while (g->GCthreshold <= g->totalbytes) {
-        luaC_step(L);
-        if (g->gcstate == GCSpause) {  /* end of cycle? */
-          res = 1;  /* signal it */
-          break;
-        }
+      if (g->gckind == KGC_GEN) {  /* generational mode? */
+        res = (g->GCestimate == 0);  /* true if it will do major collection */
+        luaC_forcestep(L);  /* do a single step */
+      }
+      else {
+       lu_mem debt = cast(lu_mem, data) * 1024 - GCSTEPSIZE;
+       if (g->gcrunning)
+         debt += g->GCdebt;  /* include current debt */
+       luaE_setdebt(g, debt);
+       luaC_forcestep(L);
+       if (g->gcstate == GCSpause)  /* end of cycle? */
+         res = 1;  /* signal it */
       }
       break;
     }
@@ -943,11 +1067,28 @@ LUA_API int lua_gc (lua_State *L, int what, int data) {
       g->gcpause = data;
       break;
     }
+    case LUA_GCSETMAJORINC: {
+      res = g->gcmajorinc;
+      g->gcmajorinc = data;
+      break;
+    }
     case LUA_GCSETSTEPMUL: {
       res = g->gcstepmul;
       g->gcstepmul = data;
       break;
     }
+    case LUA_GCISRUNNING: {
+      res = g->gcrunning;
+      break;
+    }
+    case LUA_GCGEN: {  /* change collector to generational mode */
+      luaC_changemode(L, KGC_GEN);
+      break;
+    }
+    case LUA_GCINC: {  /* change collector to incremental mode */
+      luaC_changemode(L, KGC_NORMAL);
+      break;
+    }
     default: res = -1;  /* invalid option */
   }
   lua_unlock(L);
@@ -965,7 +1106,7 @@ LUA_API int lua_error (lua_State *L) {
   lua_lock(L);
   api_checknelems(L, 1);
   luaG_errormsg(L);
-  lua_unlock(L);
+  /* code unreachable; will unlock when control actually leaves the kernel */
   return 0;  /* to avoid warnings */
 }
 
@@ -974,8 +1115,8 @@ LUA_API int lua_next (lua_State *L, int idx) {
   StkId t;
   int more;
   lua_lock(L);
-  t = index2adr(L, idx);
-  api_check(L, ttistable(t));
+  t = index2addr(L, idx);
+  api_check(L, ttistable(t), "table expected");
   more = luaH_next(L, hvalue(t), L->top - 1);
   if (more) {
     api_incr_top(L);
@@ -992,8 +1133,7 @@ LUA_API void lua_concat (lua_State *L, int n) {
   api_checknelems(L, n);
   if (n >= 2) {
     luaC_checkGC(L);
-    luaV_concat(L, n, cast_int(L->top - L->base) - 1);
-    L->top -= (n-1);
+    luaV_concat(L, n);
   }
   else if (n == 0) {  /* push empty string */
     setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
@@ -1004,6 +1144,16 @@ LUA_API void lua_concat (lua_State *L, int n) {
 }
 
 
+LUA_API void lua_len (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = index2addr(L, idx);
+  luaV_objlen(L, L->top, t);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
 LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
   lua_Alloc f;
   lua_lock(L);
@@ -1026,7 +1176,7 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
   Udata *u;
   lua_lock(L);
   luaC_checkGC(L);
-  u = luaS_newudata(L, size, getcurrenv(L));
+  u = luaS_newudata(L, size, NULL);
   setuvalue(L, L->top, u);
   api_incr_top(L);
   lua_unlock(L);
@@ -1035,30 +1185,36 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
 
 
 
-
-static const char *aux_upvalue (StkId fi, int n, TValue **val) {
-  Closure *f;
-  if (!ttisfunction(fi)) return NULL;
-  f = clvalue(fi);
-  if (f->c.isC) {
-    if (!(1 <= n && n <= f->c.nupvalues)) return NULL;
-    *val = &f->c.upvalue[n-1];
-    return "";
-  }
-  else {
-    Proto *p = f->l.p;
-    if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
-    *val = f->l.upvals[n-1]->v;
-    return getstr(p->upvalues[n-1]);
+static const char *aux_upvalue (StkId fi, int n, TValue **val,
+                                GCObject **owner) {
+  switch (ttype(fi)) {
+    case LUA_TCCL: {  /* C closure */
+      CClosure *f = clCvalue(fi);
+      if (!(1 <= n && n <= f->nupvalues)) return NULL;
+      *val = &f->upvalue[n-1];
+      if (owner) *owner = obj2gco(f);
+      return "";
+    }
+    case LUA_TLCL: {  /* Lua closure */
+      LClosure *f = clLvalue(fi);
+      TString *name;
+      Proto *p = f->p;
+      if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
+      *val = f->upvals[n-1]->v;
+      if (owner) *owner = obj2gco(f->upvals[n - 1]);
+      name = p->upvalues[n-1].name;
+      return (name == NULL) ? "" : getstr(name);
+    }
+    default: return NULL;  /* not a closure */
   }
 }
 
 
 LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
   const char *name;
-  TValue *val;
+  TValue *val = NULL;  /* to avoid warnings */
   lua_lock(L);
-  name = aux_upvalue(index2adr(L, funcindex), n, &val);
+  name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL);
   if (name) {
     setobj2s(L, L->top, val);
     api_incr_top(L);
@@ -1070,18 +1226,59 @@ 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;
+  TValue *val = NULL;  /* to avoid warnings */
+  GCObject *owner = NULL;  /* to avoid warnings */
   StkId fi;
   lua_lock(L);
-  fi = index2adr(L, funcindex);
+  fi = index2addr(L, funcindex);
   api_checknelems(L, 1);
-  name = aux_upvalue(fi, n, &val);
+  name = aux_upvalue(fi, n, &val, &owner);
   if (name) {
     L->top--;
     setobj(L, val, L->top);
-    luaC_barrier(L, clvalue(fi), L->top);
+    luaC_barrier(L, owner, L->top);
   }
   lua_unlock(L);
   return name;
 }
 
+
+static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
+  LClosure *f;
+  StkId fi = index2addr(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");
+  if (pf) *pf = f;
+  return &f->upvals[n - 1];  /* get its upvalue pointer */
+}
+
+
+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 */
+      return *getupvalref(L, fidx, n, NULL);
+    }
+    case LUA_TCCL: {  /* C closure */
+      CClosure *f = clCvalue(fi);
+      api_check(L, 1 <= n && n <= f->nupvalues, "invalid upvalue index");
+      return &f->upvalue[n - 1];
+    }
+    default: {
+      api_check(L, 0, "closure expected");
+      return NULL;
+    }
+  }
+}
+
+
+LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
+                                            int fidx2, int n2) {
+  LClosure *f1;
+  UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
+  UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
+  *up1 = *up2;
+  luaC_objbarrier(L, f1, *up2);
+}
+