diff -r 4cad87e11bf6 -r 0a24853de796 misc/liblua/lapi.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/liblua/lapi.c	Mon Feb 15 19:49:20 2010 +0000
@@ -0,0 +1,1087 @@
+/*
+** $Id: lapi.c,v 2.55.1.5 2008/07/04 18:41:18 roberto Exp $
+** Lua API
+** See Copyright Notice in lua.h
+*/
+
+
+#include <assert.h>
+#include <math.h>
+#include <stdarg.h>
+#include <string.h>
+
+#define lapi_c
+#define LUA_CORE
+
+#include "lua.h"
+
+#include "lapi.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lundump.h"
+#include "lvm.h"
+
+
+
+const char lua_ident[] =
+  "$Lua: " LUA_RELEASE " " LUA_COPYRIGHT " $\n"
+  "$Authors: " LUA_AUTHORS " $\n"
+  "$URL: www.lua.org $\n";
+
+
+
+#define api_checknelems(L, n)	api_check(L, (n) <= (L->top - L->base))
+
+#define api_checkvalidindex(L, i)	api_check(L, (i) != luaO_nilobject)
+
+#define api_incr_top(L)   {api_check(L, L->top < L->ci->top); L->top++;}
+
+
+
+static TValue *index2adr (lua_State *L, int idx) {
+  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);
+    else return o;
+  }
+  else if (idx > LUA_REGISTRYINDEX) {
+    api_check(L, idx != 0 && -idx <= L->top - L->base);
+    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);
+    }
+  }
+}
+
+
+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);
+}
+
+
+LUA_API int lua_checkstack (lua_State *L, int size) {
+  int res = 1;
+  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;
+  }
+  lua_unlock(L);
+  return res;
+}
+
+
+LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
+  int i;
+  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);
+  from->top -= n;
+  for (i = 0; i < n; i++) {
+    setobj2s(to, to->top++, from->top + i);
+  }
+  lua_unlock(to);
+}
+
+
+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);
+  old = G(L)->panic;
+  G(L)->panic = panicf;
+  lua_unlock(L);
+  return old;
+}
+
+
+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;
+}
+
+
+
+/*
+** basic stack manipulation
+*/
+
+
+LUA_API int lua_gettop (lua_State *L) {
+  return cast_int(L->top - L->base);
+}
+
+
+LUA_API void lua_settop (lua_State *L, int idx) {
+  lua_lock(L);
+  if (idx >= 0) {
+    api_check(L, idx <= L->stack_last - L->base);
+    while (L->top < L->base + idx)
+      setnilvalue(L->top++);
+    L->top = L->base + idx;
+  }
+  else {
+    api_check(L, -(idx+1) <= (L->top - L->base));
+    L->top += idx+1;  /* `subtract' index (index is negative) */
+  }
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_remove (lua_State *L, int idx) {
+  StkId p;
+  lua_lock(L);
+  p = index2adr(L, idx);
+  api_checkvalidindex(L, p);
+  while (++p < L->top) setobjs2s(L, p-1, p);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+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);
+  setobjs2s(L, p, L->top);
+  lua_unlock(L);
+}
+
+
+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);
+  }
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushvalue (lua_State *L, int idx) {
+  lua_lock(L);
+  setobj2s(L, L->top, index2adr(L, idx));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+
+/*
+** access functions (stack -> C)
+*/
+
+
+LUA_API int lua_type (lua_State *L, int idx) {
+  StkId o = index2adr(L, idx);
+  return (o == luaO_nilobject) ? LUA_TNONE : ttype(o);
+}
+
+
+LUA_API const char *lua_typename (lua_State *L, int t) {
+  UNUSED(L);
+  return (t == LUA_TNONE) ? "no value" : luaT_typenames[t];
+}
+
+
+LUA_API int lua_iscfunction (lua_State *L, int idx) {
+  StkId o = index2adr(L, idx);
+  return iscfunction(o);
+}
+
+
+LUA_API int lua_isnumber (lua_State *L, int idx) {
+  TValue n;
+  const TValue *o = index2adr(L, idx);
+  return tonumber(o, &n);
+}
+
+
+LUA_API int lua_isstring (lua_State *L, int idx) {
+  int t = lua_type(L, idx);
+  return (t == LUA_TSTRING || t == LUA_TNUMBER);
+}
+
+
+LUA_API int lua_isuserdata (lua_State *L, int idx) {
+  const TValue *o = index2adr(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);
+}
+
+
+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_unlock(L);
+  return i;
+}
+
+
+LUA_API int lua_lessthan (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
+       : luaV_lessthan(L, o1, o2);
+  lua_unlock(L);
+  return i;
+}
+
+
+
+LUA_API lua_Number lua_tonumber (lua_State *L, int idx) {
+  TValue n;
+  const TValue *o = index2adr(L, idx);
+  if (tonumber(o, &n))
+    return nvalue(o);
+  else
+    return 0;
+}
+
+
+LUA_API lua_Integer lua_tointeger (lua_State *L, int idx) {
+  TValue n;
+  const TValue *o = index2adr(L, idx);
+  if (tonumber(o, &n)) {
+    lua_Integer res;
+    lua_Number num = nvalue(o);
+    lua_number2integer(res, num);
+    return res;
+  }
+  else
+    return 0;
+}
+
+
+LUA_API int lua_toboolean (lua_State *L, int idx) {
+  const TValue *o = index2adr(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);
+  if (!ttisstring(o)) {
+    lua_lock(L);  /* `luaV_tostring' may create a new string */
+    if (!luaV_tostring(L, o)) {  /* conversion failed? */
+      if (len != NULL) *len = 0;
+      lua_unlock(L);
+      return NULL;
+    }
+    luaC_checkGC(L);
+    o = index2adr(L, idx);  /* previous call may reallocate the stack */
+    lua_unlock(L);
+  }
+  if (len != NULL) *len = tsvalue(o)->len;
+  return svalue(o);
+}
+
+
+LUA_API size_t lua_objlen (lua_State *L, int idx) {
+  StkId o = index2adr(L, idx);
+  switch (ttype(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;
+}
+
+
+LUA_API void *lua_touserdata (lua_State *L, int idx) {
+  StkId o = index2adr(L, idx);
+  switch (ttype(o)) {
+    case LUA_TUSERDATA: return (rawuvalue(o) + 1);
+    case LUA_TLIGHTUSERDATA: return pvalue(o);
+    default: return NULL;
+  }
+}
+
+
+LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
+  StkId o = index2adr(L, idx);
+  return (!ttisthread(o)) ? NULL : thvalue(o);
+}
+
+
+LUA_API const void *lua_topointer (lua_State *L, int idx) {
+  StkId o = index2adr(L, idx);
+  switch (ttype(o)) {
+    case LUA_TTABLE: return hvalue(o);
+    case LUA_TFUNCTION: return clvalue(o);
+    case LUA_TTHREAD: return thvalue(o);
+    case LUA_TUSERDATA:
+    case LUA_TLIGHTUSERDATA:
+      return lua_touserdata(L, idx);
+    default: return NULL;
+  }
+}
+
+
+
+/*
+** push functions (C -> stack)
+*/
+
+
+LUA_API void lua_pushnil (lua_State *L) {
+  lua_lock(L);
+  setnilvalue(L->top);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
+  lua_lock(L);
+  setnvalue(L->top, n);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
+  lua_lock(L);
+  setnvalue(L->top, cast_num(n));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushlstring (lua_State *L, const char *s, size_t len) {
+  lua_lock(L);
+  luaC_checkGC(L);
+  setsvalue2s(L, L->top, luaS_newlstr(L, s, len));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushstring (lua_State *L, const char *s) {
+  if (s == NULL)
+    lua_pushnil(L);
+  else
+    lua_pushlstring(L, s, strlen(s));
+}
+
+
+LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
+                                      va_list argp) {
+  const char *ret;
+  lua_lock(L);
+  luaC_checkGC(L);
+  ret = luaO_pushvfstring(L, fmt, argp);
+  lua_unlock(L);
+  return ret;
+}
+
+
+LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
+  const char *ret;
+  va_list argp;
+  lua_lock(L);
+  luaC_checkGC(L);
+  va_start(argp, fmt);
+  ret = luaO_pushvfstring(L, fmt, argp);
+  va_end(argp);
+  lua_unlock(L);
+  return ret;
+}
+
+
+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)));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushboolean (lua_State *L, int b) {
+  lua_lock(L);
+  setbvalue(L->top, (b != 0));  /* ensure that true is 1 */
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
+  lua_lock(L);
+  setpvalue(L->top, p);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_pushthread (lua_State *L) {
+  lua_lock(L);
+  setthvalue(L, L->top, L);
+  api_incr_top(L);
+  lua_unlock(L);
+  return (G(L)->mainthread == L);
+}
+
+
+
+/*
+** get functions (Lua -> stack)
+*/
+
+
+LUA_API void lua_gettable (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = index2adr(L, idx);
+  api_checkvalidindex(L, t);
+  luaV_gettable(L, t, L->top - 1, L->top - 1);
+  lua_unlock(L);
+}
+
+
+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);
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_rawget (lua_State *L, int idx) {
+  StkId t;
+  lua_lock(L);
+  t = index2adr(L, idx);
+  api_check(L, ttistable(t));
+  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;
+  lua_lock(L);
+  o = index2adr(L, idx);
+  api_check(L, ttistable(o));
+  setobj2s(L, L->top, luaH_getnum(hvalue(o), n));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
+  lua_lock(L);
+  luaC_checkGC(L);
+  sethvalue(L, L->top, luaH_new(L, narray, nrec));
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_getmetatable (lua_State *L, int objindex) {
+  const TValue *obj;
+  Table *mt = NULL;
+  int res;
+  lua_lock(L);
+  obj = index2adr(L, objindex);
+  switch (ttype(obj)) {
+    case LUA_TTABLE:
+      mt = hvalue(obj)->metatable;
+      break;
+    case LUA_TUSERDATA:
+      mt = uvalue(obj)->metatable;
+      break;
+    default:
+      mt = G(L)->mt[ttype(obj)];
+      break;
+  }
+  if (mt == NULL)
+    res = 0;
+  else {
+    sethvalue(L, L->top, mt);
+    api_incr_top(L);
+    res = 1;
+  }
+  lua_unlock(L);
+  return res;
+}
+
+
+LUA_API void lua_getfenv (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;
+  }
+  api_incr_top(L);
+  lua_unlock(L);
+}
+
+
+/*
+** set functions (stack -> Lua)
+*/
+
+
+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);
+  luaV_settable(L, t, L->top - 2, L->top - 1);
+  L->top -= 2;  /* pop index and value */
+  lua_unlock(L);
+}
+
+
+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 */
+  lua_unlock(L);
+}
+
+
+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));
+  setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
+  luaC_barriert(L, hvalue(t), L->top-1);
+  L->top -= 2;
+  lua_unlock(L);
+}
+
+
+LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
+  StkId o;
+  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);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_setmetatable (lua_State *L, int objindex) {
+  TValue *obj;
+  Table *mt;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  obj = index2adr(L, objindex);
+  api_checkvalidindex(L, obj);
+  if (ttisnil(L->top - 1))
+    mt = NULL;
+  else {
+    api_check(L, ttistable(L->top - 1));
+    mt = hvalue(L->top - 1);
+  }
+  switch (ttype(obj)) {
+    case LUA_TTABLE: {
+      hvalue(obj)->metatable = mt;
+      if (mt)
+        luaC_objbarriert(L, hvalue(obj), mt);
+      break;
+    }
+    case LUA_TUSERDATA: {
+      uvalue(obj)->metatable = mt;
+      if (mt)
+        luaC_objbarrier(L, rawuvalue(obj), mt);
+      break;
+    }
+    default: {
+      G(L)->mt[ttype(obj)] = mt;
+      break;
+    }
+  }
+  L->top--;
+  lua_unlock(L);
+  return 1;
+}
+
+
+LUA_API int lua_setfenv (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;
+  }
+  if (res) luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
+  L->top--;
+  lua_unlock(L);
+  return res;
+}
+
+
+/*
+** `load' and `call' functions (run Lua code)
+*/
+
+
+#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)))
+	
+
+LUA_API void lua_call (lua_State *L, int nargs, int nresults) {
+  StkId func;
+  lua_lock(L);
+  api_checknelems(L, nargs+1);
+  checkresults(L, nargs, nresults);
+  func = L->top - (nargs+1);
+  luaD_call(L, func, nresults);
+  adjustresults(L, nresults);
+  lua_unlock(L);
+}
+
+
+
+/*
+** Execute a protected call.
+*/
+struct CallS {  /* data to `f_call' */
+  StkId func;
+  int nresults;
+};
+
+
+static void f_call (lua_State *L, void *ud) {
+  struct CallS *c = cast(struct CallS *, ud);
+  luaD_call(L, c->func, c->nresults);
+}
+
+
+
+LUA_API int lua_pcall (lua_State *L, int nargs, int nresults, int errfunc) {
+  struct CallS c;
+  int status;
+  ptrdiff_t func;
+  lua_lock(L);
+  api_checknelems(L, nargs+1);
+  checkresults(L, nargs, nresults);
+  if (errfunc == 0)
+    func = 0;
+  else {
+    StkId o = index2adr(L, errfunc);
+    api_checkvalidindex(L, 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);
+  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) {
+  ZIO z;
+  int status;
+  lua_lock(L);
+  if (!chunkname) chunkname = "?";
+  luaZ_init(L, &z, reader, data);
+  status = luaD_protectedparser(L, &z, chunkname);
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data) {
+  int status;
+  TValue *o;
+  lua_lock(L);
+  api_checknelems(L, 1);
+  o = L->top - 1;
+  if (isLfunction(o))
+    status = luaU_dump(L, clvalue(o)->l.p, writer, data, 0);
+  else
+    status = 1;
+  lua_unlock(L);
+  return status;
+}
+
+
+LUA_API int  lua_status (lua_State *L) {
+  return L->status;
+}
+
+
+/*
+** Garbage-collection function
+*/
+
+LUA_API int lua_gc (lua_State *L, int what, int data) {
+  int res = 0;
+  global_State *g;
+  lua_lock(L);
+  g = G(L);
+  switch (what) {
+    case LUA_GCSTOP: {
+      g->GCthreshold = MAX_LUMEM;
+      break;
+    }
+    case LUA_GCRESTART: {
+      g->GCthreshold = g->totalbytes;
+      break;
+    }
+    case LUA_GCCOLLECT: {
+      luaC_fullgc(L);
+      break;
+    }
+    case LUA_GCCOUNT: {
+      /* GC values are expressed in Kbytes: #bytes/2^10 */
+      res = cast_int(g->totalbytes >> 10);
+      break;
+    }
+    case LUA_GCCOUNTB: {
+      res = cast_int(g->totalbytes & 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;
+        }
+      }
+      break;
+    }
+    case LUA_GCSETPAUSE: {
+      res = g->gcpause;
+      g->gcpause = data;
+      break;
+    }
+    case LUA_GCSETSTEPMUL: {
+      res = g->gcstepmul;
+      g->gcstepmul = data;
+      break;
+    }
+    default: res = -1;  /* invalid option */
+  }
+  lua_unlock(L);
+  return res;
+}
+
+
+
+/*
+** miscellaneous functions
+*/
+
+
+LUA_API int lua_error (lua_State *L) {
+  lua_lock(L);
+  api_checknelems(L, 1);
+  luaG_errormsg(L);
+  lua_unlock(L);
+  return 0;  /* to avoid warnings */
+}
+
+
+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));
+  more = luaH_next(L, hvalue(t), L->top - 1);
+  if (more) {
+    api_incr_top(L);
+  }
+  else  /* no more elements */
+    L->top -= 1;  /* remove key */
+  lua_unlock(L);
+  return more;
+}
+
+
+LUA_API void lua_concat (lua_State *L, int n) {
+  lua_lock(L);
+  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);
+  }
+  else if (n == 0) {  /* push empty string */
+    setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
+    api_incr_top(L);
+  }
+  /* else n == 1; nothing to do */
+  lua_unlock(L);
+}
+
+
+LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
+  lua_Alloc f;
+  lua_lock(L);
+  if (ud) *ud = G(L)->ud;
+  f = G(L)->frealloc;
+  lua_unlock(L);
+  return f;
+}
+
+
+LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
+  lua_lock(L);
+  G(L)->ud = ud;
+  G(L)->frealloc = f;
+  lua_unlock(L);
+}
+
+
+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));
+  setuvalue(L, L->top, u);
+  api_incr_top(L);
+  lua_unlock(L);
+  return u + 1;
+}
+
+
+
+
+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]);
+  }
+}
+
+
+LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
+  const char *name;
+  TValue *val;
+  lua_lock(L);
+  name = aux_upvalue(index2adr(L, funcindex), n, &val);
+  if (name) {
+    setobj2s(L, L->top, val);
+    api_incr_top(L);
+  }
+  lua_unlock(L);
+  return name;
+}
+
+
+LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
+  const char *name;
+  TValue *val;
+  StkId fi;
+  lua_lock(L);
+  fi = index2adr(L, funcindex);
+  api_checknelems(L, 1);
+  name = aux_upvalue(fi, n, &val);
+  if (name) {
+    L->top--;
+    setobj(L, val, L->top);
+    luaC_barrier(L, clvalue(fi), L->top);
+  }
+  lua_unlock(L);
+  return name;
+}
+