/*** $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) {