2 ** $Id: lapi.c,v 2.55.1.3 2008/01/03 15:20:39 roberto Exp $
4 ** See Copyright Notice in lua.h
34 const char lua_ident[] =
35 "$Lua: " LUA_RELEASE " " LUA_COPYRIGHT " $\n"
36 "$Authors: " LUA_AUTHORS " $\n"
37 "$URL: www.lua.org $\n";
41 #define api_checknelems(L, n) api_check(L, (n) <= (L->top - L->base))
43 #define api_checkvalidindex(L, i) api_check(L, (i) != luaO_nilobject)
45 #define api_incr_top(L) {api_check(L, L->top < L->ci->top); L->top++;}
49 static TValue *index2adr (lua_State *L, int idx) {
51 TValue *o = L->base + (idx - 1);
52 api_check(L, idx <= L->ci->top - L->base);
53 if (o >= L->top) return cast(TValue *, luaO_nilobject);
56 else if (idx > LUA_REGISTRYINDEX) {
57 api_check(L, idx != 0 && -idx <= L->top - L->base);
60 else switch (idx) { /* pseudo-indices */
61 case LUA_REGISTRYINDEX: return registry(L);
62 case LUA_ENVIRONINDEX: {
63 Closure *func = curr_func(L);
64 sethvalue(L, &L->env, func->c.env);
67 case LUA_GLOBALSINDEX: return gt(L);
69 Closure *func = curr_func(L);
70 idx = LUA_GLOBALSINDEX - idx;
71 return (idx <= func->c.nupvalues)
72 ? &func->c.upvalue[idx-1]
73 : cast(TValue *, luaO_nilobject);
79 static Table *getcurrenv (lua_State *L) {
80 if (L->ci == L->base_ci) /* no enclosing function? */
81 return hvalue(gt(L)); /* use global table as environment */
83 Closure *func = curr_func(L);
89 void luaA_pushobject (lua_State *L, const TValue *o) {
90 setobj2s(L, L->top, o);
95 LUA_API int lua_checkstack (lua_State *L, int size) {
98 if ((L->top - L->base + size) > LUAI_MAXCSTACK)
99 res = 0; /* stack overflow */
101 luaD_checkstack(L, size);
102 if (L->ci->top < L->top + size)
103 L->ci->top = L->top + size;
111 LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
113 if (from == to) return;
115 api_checknelems(from, n);
116 api_check(from, G(from) == G(to));
117 api_check(from, to->ci->top - to->top >= n);
119 for (i = 0; i < n; i++) {
120 setobj2s(to, to->top++, from->top + i);
126 LUA_API void lua_setlevel (lua_State *from, lua_State *to) {
127 to->nCcalls = from->nCcalls;
131 LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
135 G(L)->panic = panicf;
141 LUA_API lua_State *lua_newthread (lua_State *L) {
145 L1 = luaE_newthread(L);
146 setthvalue(L, L->top, L1);
149 luai_userstatethread(L, L1);
156 ** basic stack manipulation
160 LUA_API int lua_gettop (lua_State *L) {
161 return cast_int(L->top - L->base);
165 LUA_API void lua_settop (lua_State *L, int idx) {
168 api_check(L, idx <= L->stack_last - L->base);
169 while (L->top < L->base + idx)
170 setnilvalue(L->top++);
171 L->top = L->base + idx;
174 api_check(L, -(idx+1) <= (L->top - L->base));
175 L->top += idx+1; /* `subtract' index (index is negative) */
181 LUA_API void lua_remove (lua_State *L, int idx) {
184 p = index2adr(L, idx);
185 api_checkvalidindex(L, p);
186 while (++p < L->top) setobjs2s(L, p-1, p);
192 LUA_API void lua_insert (lua_State *L, int idx) {
196 p = index2adr(L, idx);
197 api_checkvalidindex(L, p);
198 for (q = L->top; q>p; q--) setobjs2s(L, q, q-1);
199 setobjs2s(L, p, L->top);
204 LUA_API void lua_replace (lua_State *L, int idx) {
207 /* explicit test for incompatible code */
208 if (idx == LUA_ENVIRONINDEX && L->ci == L->base_ci)
209 luaG_runerror(L, "no calling environment");
210 api_checknelems(L, 1);
211 o = index2adr(L, idx);
212 api_checkvalidindex(L, o);
213 if (idx == LUA_ENVIRONINDEX) {
214 Closure *func = curr_func(L);
215 api_check(L, ttistable(L->top - 1));
216 func->c.env = hvalue(L->top - 1);
217 luaC_barrier(L, func, L->top - 1);
220 setobj(L, o, L->top - 1);
221 if (idx < LUA_GLOBALSINDEX) /* function upvalue? */
222 luaC_barrier(L, curr_func(L), L->top - 1);
229 LUA_API void lua_pushvalue (lua_State *L, int idx) {
231 setobj2s(L, L->top, index2adr(L, idx));
239 ** access functions (stack -> C)
243 LUA_API int lua_type (lua_State *L, int idx) {
244 StkId o = index2adr(L, idx);
245 return (o == luaO_nilobject) ? LUA_TNONE : ttype(o);
249 LUA_API const char *lua_typename (lua_State *L, int t) {
251 return (t == LUA_TNONE) ? "no value" : luaT_typenames[t];
255 LUA_API int lua_iscfunction (lua_State *L, int idx) {
256 StkId o = index2adr(L, idx);
257 return iscfunction(o);
261 LUA_API int lua_isnumber (lua_State *L, int idx) {
263 const TValue *o = index2adr(L, idx);
264 return tonumber(o, &n);
268 LUA_API int lua_isstring (lua_State *L, int idx) {
269 int t = lua_type(L, idx);
270 return (t == LUA_TSTRING || t == LUA_TNUMBER);
274 LUA_API int lua_isuserdata (lua_State *L, int idx) {
275 const TValue *o = index2adr(L, idx);
276 return (ttisuserdata(o) || ttislightuserdata(o));
280 LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
281 StkId o1 = index2adr(L, index1);
282 StkId o2 = index2adr(L, index2);
283 return (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
284 : luaO_rawequalObj(o1, o2);
288 LUA_API int lua_equal (lua_State *L, int index1, int index2) {
291 lua_lock(L); /* may call tag method */
292 o1 = index2adr(L, index1);
293 o2 = index2adr(L, index2);
294 i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0 : equalobj(L, o1, o2);
300 LUA_API int lua_lessthan (lua_State *L, int index1, int index2) {
303 lua_lock(L); /* may call tag method */
304 o1 = index2adr(L, index1);
305 o2 = index2adr(L, index2);
306 i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
307 : luaV_lessthan(L, o1, o2);
314 LUA_API lua_Number lua_tonumber (lua_State *L, int idx) {
316 const TValue *o = index2adr(L, idx);
324 LUA_API lua_Integer lua_tointeger (lua_State *L, int idx) {
326 const TValue *o = index2adr(L, idx);
327 if (tonumber(o, &n)) {
329 lua_Number num = nvalue(o);
330 lua_number2integer(res, num);
338 LUA_API int lua_toboolean (lua_State *L, int idx) {
339 const TValue *o = index2adr(L, idx);
340 return !l_isfalse(o);
344 LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
345 StkId o = index2adr(L, idx);
346 if (!ttisstring(o)) {
347 lua_lock(L); /* `luaV_tostring' may create a new string */
348 if (!luaV_tostring(L, o)) { /* conversion failed? */
349 if (len != NULL) *len = 0;
354 o = index2adr(L, idx); /* previous call may reallocate the stack */
357 if (len != NULL) *len = tsvalue(o)->len;
362 LUA_API size_t lua_objlen (lua_State *L, int idx) {
363 StkId o = index2adr(L, idx);
365 case LUA_TSTRING: return tsvalue(o)->len;
366 case LUA_TUSERDATA: return uvalue(o)->len;
367 case LUA_TTABLE: return luaH_getn(hvalue(o));
370 lua_lock(L); /* `luaV_tostring' may create a new string */
371 l = (luaV_tostring(L, o) ? tsvalue(o)->len : 0);
380 LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
381 StkId o = index2adr(L, idx);
382 return (!iscfunction(o)) ? NULL : clvalue(o)->c.f;
386 LUA_API void *lua_touserdata (lua_State *L, int idx) {
387 StkId o = index2adr(L, idx);
389 case LUA_TUSERDATA: return (rawuvalue(o) + 1);
390 case LUA_TLIGHTUSERDATA: return pvalue(o);
391 default: return NULL;
396 LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
397 StkId o = index2adr(L, idx);
398 return (!ttisthread(o)) ? NULL : thvalue(o);
402 LUA_API const void *lua_topointer (lua_State *L, int idx) {
403 StkId o = index2adr(L, idx);
405 case LUA_TTABLE: return hvalue(o);
406 case LUA_TFUNCTION: return clvalue(o);
407 case LUA_TTHREAD: return thvalue(o);
409 case LUA_TLIGHTUSERDATA:
410 return lua_touserdata(L, idx);
411 default: return NULL;
418 ** push functions (C -> stack)
422 LUA_API void lua_pushnil (lua_State *L) {
430 LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
432 setnvalue(L->top, n);
438 LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
440 setnvalue(L->top, cast_num(n));
446 LUA_API void lua_pushlstring (lua_State *L, const char *s, size_t len) {
449 setsvalue2s(L, L->top, luaS_newlstr(L, s, len));
455 LUA_API void lua_pushstring (lua_State *L, const char *s) {
459 lua_pushlstring(L, s, strlen(s));
463 LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
468 ret = luaO_pushvfstring(L, fmt, argp);
474 LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
480 ret = luaO_pushvfstring(L, fmt, argp);
487 LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
491 api_checknelems(L, n);
492 cl = luaF_newCclosure(L, n, getcurrenv(L));
496 setobj2n(L, &cl->c.upvalue[n], L->top+n);
497 setclvalue(L, L->top, cl);
498 lua_assert(iswhite(obj2gco(cl)));
504 LUA_API void lua_pushboolean (lua_State *L, int b) {
506 setbvalue(L->top, (b != 0)); /* ensure that true is 1 */
512 LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
514 setpvalue(L->top, p);
520 LUA_API int lua_pushthread (lua_State *L) {
522 setthvalue(L, L->top, L);
525 return (G(L)->mainthread == L);
531 ** get functions (Lua -> stack)
535 LUA_API void lua_gettable (lua_State *L, int idx) {
538 t = index2adr(L, idx);
539 api_checkvalidindex(L, t);
540 luaV_gettable(L, t, L->top - 1, L->top - 1);
545 LUA_API void lua_getfield (lua_State *L, int idx, const char *k) {
549 t = index2adr(L, idx);
550 api_checkvalidindex(L, t);
551 setsvalue(L, &key, luaS_new(L, k));
552 luaV_gettable(L, t, &key, L->top);
558 LUA_API void lua_rawget (lua_State *L, int idx) {
561 t = index2adr(L, idx);
562 api_check(L, ttistable(t));
563 setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
568 LUA_API void lua_rawgeti (lua_State *L, int idx, int n) {
571 o = index2adr(L, idx);
572 api_check(L, ttistable(o));
573 setobj2s(L, L->top, luaH_getnum(hvalue(o), n));
579 LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
582 sethvalue(L, L->top, luaH_new(L, narray, nrec));
588 LUA_API int lua_getmetatable (lua_State *L, int objindex) {
593 obj = index2adr(L, objindex);
594 switch (ttype(obj)) {
596 mt = hvalue(obj)->metatable;
599 mt = uvalue(obj)->metatable;
602 mt = G(L)->mt[ttype(obj)];
608 sethvalue(L, L->top, mt);
617 LUA_API void lua_getfenv (lua_State *L, int idx) {
620 o = index2adr(L, idx);
621 api_checkvalidindex(L, o);
624 sethvalue(L, L->top, clvalue(o)->c.env);
627 sethvalue(L, L->top, uvalue(o)->env);
630 setobj2s(L, L->top, gt(thvalue(o)));
642 ** set functions (stack -> Lua)
646 LUA_API void lua_settable (lua_State *L, int idx) {
649 api_checknelems(L, 2);
650 t = index2adr(L, idx);
651 api_checkvalidindex(L, t);
652 luaV_settable(L, t, L->top - 2, L->top - 1);
653 L->top -= 2; /* pop index and value */
658 LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
662 api_checknelems(L, 1);
663 t = index2adr(L, idx);
664 api_checkvalidindex(L, t);
665 setsvalue(L, &key, luaS_new(L, k));
666 luaV_settable(L, t, &key, L->top - 1);
667 L->top--; /* pop value */
672 LUA_API void lua_rawset (lua_State *L, int idx) {
675 api_checknelems(L, 2);
676 t = index2adr(L, idx);
677 api_check(L, ttistable(t));
678 setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
679 luaC_barriert(L, hvalue(t), L->top-1);
685 LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
688 api_checknelems(L, 1);
689 o = index2adr(L, idx);
690 api_check(L, ttistable(o));
691 setobj2t(L, luaH_setnum(L, hvalue(o), n), L->top-1);
692 luaC_barriert(L, hvalue(o), L->top-1);
698 LUA_API int lua_setmetatable (lua_State *L, int objindex) {
702 api_checknelems(L, 1);
703 obj = index2adr(L, objindex);
704 api_checkvalidindex(L, obj);
705 if (ttisnil(L->top - 1))
708 api_check(L, ttistable(L->top - 1));
709 mt = hvalue(L->top - 1);
711 switch (ttype(obj)) {
713 hvalue(obj)->metatable = mt;
715 luaC_objbarriert(L, hvalue(obj), mt);
718 case LUA_TUSERDATA: {
719 uvalue(obj)->metatable = mt;
721 luaC_objbarrier(L, rawuvalue(obj), mt);
725 G(L)->mt[ttype(obj)] = mt;
735 LUA_API int lua_setfenv (lua_State *L, int idx) {
739 api_checknelems(L, 1);
740 o = index2adr(L, idx);
741 api_checkvalidindex(L, o);
742 api_check(L, ttistable(L->top - 1));
745 clvalue(o)->c.env = hvalue(L->top - 1);
748 uvalue(o)->env = hvalue(L->top - 1);
751 sethvalue(L, gt(thvalue(o)), hvalue(L->top - 1));
757 if (res) luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
765 ** `load' and `call' functions (run Lua code)
769 #define adjustresults(L,nres) \
770 { if (nres == LUA_MULTRET && L->top >= L->ci->top) L->ci->top = L->top; }
773 #define checkresults(L,na,nr) \
774 api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)))
777 LUA_API void lua_call (lua_State *L, int nargs, int nresults) {
780 api_checknelems(L, nargs+1);
781 checkresults(L, nargs, nresults);
782 func = L->top - (nargs+1);
783 luaD_call(L, func, nresults);
784 adjustresults(L, nresults);
791 ** Execute a protected call.
793 struct CallS { /* data to `f_call' */
799 static void f_call (lua_State *L, void *ud) {
800 struct CallS *c = cast(struct CallS *, ud);
801 luaD_call(L, c->func, c->nresults);
806 LUA_API int lua_pcall (lua_State *L, int nargs, int nresults, int errfunc) {
811 api_checknelems(L, nargs+1);
812 checkresults(L, nargs, nresults);
816 StkId o = index2adr(L, errfunc);
817 api_checkvalidindex(L, o);
818 func = savestack(L, o);
820 c.func = L->top - (nargs+1); /* function to be called */
821 c.nresults = nresults;
822 status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
823 adjustresults(L, nresults);
830 ** Execute a protected C call.
832 struct CCallS { /* data to `f_Ccall' */
838 static void f_Ccall (lua_State *L, void *ud) {
839 struct CCallS *c = cast(struct CCallS *, ud);
841 cl = luaF_newCclosure(L, 0, getcurrenv(L));
843 setclvalue(L, L->top, cl); /* push function */
845 setpvalue(L->top, c->ud); /* push only argument */
847 luaD_call(L, L->top - 2, 0);
851 LUA_API int lua_cpcall (lua_State *L, lua_CFunction func, void *ud) {
857 status = luaD_pcall(L, f_Ccall, &c, savestack(L, L->top), 0);
863 LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
864 const char *chunkname) {
868 if (!chunkname) chunkname = "?";
869 luaZ_init(L, &z, reader, data);
870 status = luaD_protectedparser(L, &z, chunkname);
876 LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data) {
880 api_checknelems(L, 1);
883 status = luaU_dump(L, clvalue(o)->l.p, writer, data, 0);
891 LUA_API int lua_status (lua_State *L) {
897 ** Garbage-collection function
900 LUA_API int lua_gc (lua_State *L, int what, int data) {
907 g->GCthreshold = MAX_LUMEM;
910 case LUA_GCRESTART: {
911 g->GCthreshold = g->totalbytes;
914 case LUA_GCCOLLECT: {
919 /* GC values are expressed in Kbytes: #bytes/2^10 */
920 res = cast_int(g->totalbytes >> 10);
924 res = cast_int(g->totalbytes & 0x3ff);
928 lu_mem a = (cast(lu_mem, data) << 10);
929 if (a <= g->totalbytes)
930 g->GCthreshold = g->totalbytes - a;
933 while (g->GCthreshold <= g->totalbytes)
935 if (g->gcstate == GCSpause) /* end of cycle? */
936 res = 1; /* signal it */
939 case LUA_GCSETPAUSE: {
944 case LUA_GCSETSTEPMUL: {
949 default: res = -1; /* invalid option */
958 ** miscellaneous functions
962 LUA_API int lua_error (lua_State *L) {
964 api_checknelems(L, 1);
967 return 0; /* to avoid warnings */
971 LUA_API int lua_next (lua_State *L, int idx) {
975 t = index2adr(L, idx);
976 api_check(L, ttistable(t));
977 more = luaH_next(L, hvalue(t), L->top - 1);
981 else /* no more elements */
982 L->top -= 1; /* remove key */
988 LUA_API void lua_concat (lua_State *L, int n) {
990 api_checknelems(L, n);
993 luaV_concat(L, n, cast_int(L->top - L->base) - 1);
996 else if (n == 0) { /* push empty string */
997 setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
1000 /* else n == 1; nothing to do */
1005 LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
1008 if (ud) *ud = G(L)->ud;
1015 LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
1023 LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
1027 u = luaS_newudata(L, size, getcurrenv(L));
1028 setuvalue(L, L->top, u);
1037 static const char *aux_upvalue (StkId fi, int n, TValue **val) {
1039 if (!ttisfunction(fi)) return NULL;
1042 if (!(1 <= n && n <= f->c.nupvalues)) return NULL;
1043 *val = &f->c.upvalue[n-1];
1048 if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
1049 *val = f->l.upvals[n-1]->v;
1050 return getstr(p->upvalues[n-1]);
1055 LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
1059 name = aux_upvalue(index2adr(L, funcindex), n, &val);
1061 setobj2s(L, L->top, val);
1069 LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
1074 fi = index2adr(L, funcindex);
1075 api_checknelems(L, 1);
1076 name = aux_upvalue(fi, n, &val);
1079 setobj(L, val, L->top);
1080 luaC_barrier(L, clvalue(fi), L->top);