/*** $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;}
