1/*
2** $Id: lapi.c,v 2.55.1.5 2008/07/04 18:41:18 roberto Exp $
3** Lua API
4** See Copyright Notice in lua.h
5*/
6
7
8#include <assert.h>
9#include <math.h>
10#include <stdarg.h>
11#include <string.h>
12
13#define lapi_c
14#define LUA_CORE
15
16#include "lua.h"
17
18#include "lapi.h"
19#include "ldebug.h"
20#include "ldo.h"
21#include "lfunc.h"
22#include "lgc.h"
23#include "lmem.h"
24#include "lobject.h"
25#include "lstate.h"
26#include "lstring.h"
27#include "ltable.h"
28#include "ltm.h"
29#include "lundump.h"
30#include "lvm.h"
31
32
33
34const char lua_ident[] =
35 "$Lua: " LUA_RELEASE " " LUA_COPYRIGHT " $\n"
36 "$Authors: " LUA_AUTHORS " $\n"
37 "$URL: www.lua.org $\n";
38
39
40
41#define api_checknelems(L, n) api_check(L, (n) <= (L->top - L->base))
42
43#define api_checkvalidindex(L, i) api_check(L, (i) != luaO_nilobject)
44
45#define api_incr_top(L) {api_check(L, L->top < L->ci->top); L->top++;}
46
47
48
49static TValue *index2adr (lua_State *L, int idx) {
50 if (idx > 0) {
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);
54 else return o;
55 }
56 else if (idx > LUA_REGISTRYINDEX) {
57 api_check(L, idx != 0 && -idx <= L->top - L->base);
58 return L->top + idx;
59 }
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);
65 return &L->env;
66 }
67 case LUA_GLOBALSINDEX: return gt(L);
68 default: {
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);
74 }
75 }
76}
77
78
79static 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 */
82 else {
83 Closure *func = curr_func(L);
84 return func->c.env;
85 }
86}
87
88
89void luaA_pushobject (lua_State *L, const TValue *o) {
90 setobj2s(L, L->top, o);
91 api_incr_top(L);
92}
93
94
95LUA_API int lua_checkstack (lua_State *L, int size) {
96 int res = 1;
97 lua_lock(L);
98 if (size > LUAI_MAXCSTACK || (L->top - L->base + size) > LUAI_MAXCSTACK)
99 res = 0; /* stack overflow */
100 else if (size > 0) {
101 luaD_checkstack(L, size);
102 if (L->ci->top < L->top + size)
103 L->ci->top = L->top + size;
104 }
105 lua_unlock(L);
106 return res;
107}
108
109
110LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
111 int i;
112 if (from == to) return;
113 lua_lock(to);
114 api_checknelems(from, n);
115 api_check(from, G(from) == G(to));
116 api_check(from, to->ci->top - to->top >= n);
117 from->top -= n;
118 for (i = 0; i < n; i++) {
119 setobj2s(to, to->top++, from->top + i);
120 }
121 lua_unlock(to);
122}
123
124
125LUA_API void lua_setlevel (lua_State *from, lua_State *to) {
126 to->nCcalls = from->nCcalls;
127}
128
129
130LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) {
131 lua_CFunction old;
132 lua_lock(L);
133 old = G(L)->panic;
134 G(L)->panic = panicf;
135 lua_unlock(L);
136 return old;
137}
138
139
140LUA_API lua_State *lua_newthread (lua_State *L) {
141 lua_State *L1;
142 lua_lock(L);
143 luaC_checkGC(L);
144 L1 = luaE_newthread(L);
145 setthvalue(L, L->top, L1);
146 api_incr_top(L);
147 lua_unlock(L);
148 luai_userstatethread(L, L1);
149 return L1;
150}
151
152
153
154/*
155** basic stack manipulation
156*/
157
158
159LUA_API int lua_gettop (lua_State *L) {
160 return cast_int(L->top - L->base);
161}
162
163
164LUA_API void lua_settop (lua_State *L, int idx) {
165 lua_lock(L);
166 if (idx >= 0) {
167 api_check(L, idx <= L->stack_last - L->base);
168 while (L->top < L->base + idx)
169 setnilvalue(L->top++);
170 L->top = L->base + idx;
171 }
172 else {
173 api_check(L, -(idx+1) <= (L->top - L->base));
174 L->top += idx+1; /* `subtract' index (index is negative) */
175 }
176 lua_unlock(L);
177}
178
179
180LUA_API void lua_remove (lua_State *L, int idx) {
181 StkId p;
182 lua_lock(L);
183 p = index2adr(L, idx);
184 api_checkvalidindex(L, p);
185 while (++p < L->top) setobjs2s(L, p-1, p);
186 L->top--;
187 lua_unlock(L);
188}
189
190
191LUA_API void lua_insert (lua_State *L, int idx) {
192 StkId p;
193 StkId q;
194 lua_lock(L);
195 p = index2adr(L, idx);
196 api_checkvalidindex(L, p);
197 for (q = L->top; q>p; q--) setobjs2s(L, q, q-1);
198 setobjs2s(L, p, L->top);
199 lua_unlock(L);
200}
201
202
203LUA_API void lua_replace (lua_State *L, int idx) {
204 StkId o;
205 lua_lock(L);
206 /* explicit test for incompatible code */
207 if (idx == LUA_ENVIRONINDEX && L->ci == L->base_ci)
208 luaG_runerror(L, "no calling environment");
209 api_checknelems(L, 1);
210 o = index2adr(L, idx);
211 api_checkvalidindex(L, o);
212 if (idx == LUA_ENVIRONINDEX) {
213 Closure *func = curr_func(L);
214 api_check(L, ttistable(L->top - 1));
215 func->c.env = hvalue(L->top - 1);
216 luaC_barrier(L, func, L->top - 1);
217 }
218 else {
219 setobj(L, o, L->top - 1);
220 if (idx < LUA_GLOBALSINDEX) /* function upvalue? */
221 luaC_barrier(L, curr_func(L), L->top - 1);
222 }
223 L->top--;
224 lua_unlock(L);
225}
226
227
228LUA_API void lua_pushvalue (lua_State *L, int idx) {
229 lua_lock(L);
230 setobj2s(L, L->top, index2adr(L, idx));
231 api_incr_top(L);
232 lua_unlock(L);
233}
234
235
236
237/*
238** access functions (stack -> C)
239*/
240
241
242LUA_API int lua_type (lua_State *L, int idx) {
243 StkId o = index2adr(L, idx);
244 return (o == luaO_nilobject) ? LUA_TNONE : ttype(o);
245}
246
247
248LUA_API const char *lua_typename (lua_State *L, int t) {
249 UNUSED(L);
250 return (t == LUA_TNONE) ? "no value" : luaT_typenames[t];
251}
252
253
254LUA_API int lua_iscfunction (lua_State *L, int idx) {
255 StkId o = index2adr(L, idx);
256 return iscfunction(o);
257}
258
259
260LUA_API int lua_isnumber (lua_State *L, int idx) {
261 TValue n;
262 const TValue *o = index2adr(L, idx);
263 return tonumber(o, &n);
264}
265
266
267LUA_API int lua_isstring (lua_State *L, int idx) {
268 int t = lua_type(L, idx);
269 return (t == LUA_TSTRING || t == LUA_TNUMBER);
270}
271
272
273LUA_API int lua_isuserdata (lua_State *L, int idx) {
274 const TValue *o = index2adr(L, idx);
275 return (ttisuserdata(o) || ttislightuserdata(o));
276}
277
278
279LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
280 StkId o1 = index2adr(L, index1);
281 StkId o2 = index2adr(L, index2);
282 return (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
283 : luaO_rawequalObj(o1, o2);
284}
285
286
287LUA_API int lua_equal (lua_State *L, int index1, int index2) {
288 StkId o1, o2;
289 int i;
290 lua_lock(L); /* may call tag method */
291 o1 = index2adr(L, index1);
292 o2 = index2adr(L, index2);
293 i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0 : equalobj(L, o1, o2);
294 lua_unlock(L);
295 return i;
296}
297
298
299LUA_API int lua_lessthan (lua_State *L, int index1, int index2) {
300 StkId o1, o2;
301 int i;
302 lua_lock(L); /* may call tag method */
303 o1 = index2adr(L, index1);
304 o2 = index2adr(L, index2);
305 i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
306 : luaV_lessthan(L, o1, o2);
307 lua_unlock(L);
308 return i;
309}
310
311
312
313LUA_API lua_Number lua_tonumber (lua_State *L, int idx) {
314 TValue n;
315 const TValue *o = index2adr(L, idx);
316 if (tonumber(o, &n))
317 return nvalue(o);
318 else
319 return 0;
320}
321
322
323LUA_API lua_Integer lua_tointeger (lua_State *L, int idx) {
324 TValue n;
325 const TValue *o = index2adr(L, idx);
326 if (tonumber(o, &n)) {
327 lua_Integer res;
328 lua_Number num = nvalue(o);
329 lua_number2integer(res, num);
330 return res;
331 }
332 else
333 return 0;
334}
335
336
337LUA_API int lua_toboolean (lua_State *L, int idx) {
338 const TValue *o = index2adr(L, idx);
339 return !l_isfalse(o);
340}
341
342
343LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
344 StkId o = index2adr(L, idx);
345 if (!ttisstring(o)) {
346 lua_lock(L); /* `luaV_tostring' may create a new string */
347 if (!luaV_tostring(L, o)) { /* conversion failed? */
348 if (len != NULL) *len = 0;
349 lua_unlock(L);
350 return NULL;
351 }
352 luaC_checkGC(L);
353 o = index2adr(L, idx); /* previous call may reallocate the stack */
354 lua_unlock(L);
355 }
356 if (len != NULL) *len = tsvalue(o)->len;
357 return svalue(o);
358}
359
360
361LUA_API size_t lua_objlen (lua_State *L, int idx) {
362 StkId o = index2adr(L, idx);
363 switch (ttype(o)) {
364 case LUA_TSTRING: return tsvalue(o)->len;
365 case LUA_TUSERDATA: return uvalue(o)->len;
366 case LUA_TTABLE: return luaH_getn(hvalue(o));
367 case LUA_TNUMBER: {
368 size_t l;
369 lua_lock(L); /* `luaV_tostring' may create a new string */
370 l = (luaV_tostring(L, o) ? tsvalue(o)->len : 0);
371 lua_unlock(L);
372 return l;
373 }
374 default: return 0;
375 }
376}
377
378
379LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) {
380 StkId o = index2adr(L, idx);
381 return (!iscfunction(o)) ? NULL : clvalue(o)->c.f;
382}
383
384
385LUA_API void *lua_touserdata (lua_State *L, int idx) {
386 StkId o = index2adr(L, idx);
387 switch (ttype(o)) {
388 case LUA_TUSERDATA: return (rawuvalue(o) + 1);
389 case LUA_TLIGHTUSERDATA: return pvalue(o);
390 default: return NULL;
391 }
392}
393
394
395LUA_API lua_State *lua_tothread (lua_State *L, int idx) {
396 StkId o = index2adr(L, idx);
397 return (!ttisthread(o)) ? NULL : thvalue(o);
398}
399
400
401LUA_API const void *lua_topointer (lua_State *L, int idx) {
402 StkId o = index2adr(L, idx);
403 switch (ttype(o)) {
404 case LUA_TTABLE: return hvalue(o);
405 case LUA_TFUNCTION: return clvalue(o);
406 case LUA_TTHREAD: return thvalue(o);
407 case LUA_TUSERDATA:
408 case LUA_TLIGHTUSERDATA:
409 return lua_touserdata(L, idx);
410 default: return NULL;
411 }
412}
413
414
415
416/*
417** push functions (C -> stack)
418*/
419
420
421LUA_API void lua_pushnil (lua_State *L) {
422 lua_lock(L);
423 setnilvalue(L->top);
424 api_incr_top(L);
425 lua_unlock(L);
426}
427
428
429LUA_API void lua_pushnumber (lua_State *L, lua_Number n) {
430 lua_lock(L);
431 setnvalue(L->top, n);
432 api_incr_top(L);
433 lua_unlock(L);
434}
435
436
437LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
438 lua_lock(L);
439 setnvalue(L->top, cast_num(n));
440 api_incr_top(L);
441 lua_unlock(L);
442}
443
444
445LUA_API void lua_pushlstring (lua_State *L, const char *s, size_t len) {
446 lua_lock(L);
447 luaC_checkGC(L);
448 setsvalue2s(L, L->top, luaS_newlstr(L, s, len));
449 api_incr_top(L);
450 lua_unlock(L);
451}
452
453
454LUA_API void lua_pushstring (lua_State *L, const char *s) {
455 if (s == NULL)
456 lua_pushnil(L);
457 else
458 lua_pushlstring(L, s, strlen(s));
459}
460
461
462LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
463 va_list argp) {
464 const char *ret;
465 lua_lock(L);
466 luaC_checkGC(L);
467 ret = luaO_pushvfstring(L, fmt, argp);
468 lua_unlock(L);
469 return ret;
470}
471
472
473LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
474 const char *ret;
475 va_list argp;
476 lua_lock(L);
477 luaC_checkGC(L);
478 va_start(argp, fmt);
479 ret = luaO_pushvfstring(L, fmt, argp);
480 va_end(argp);
481 lua_unlock(L);
482 return ret;
483}
484
485
486LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
487 Closure *cl;
488 lua_lock(L);
489 luaC_checkGC(L);
490 api_checknelems(L, n);
491 cl = luaF_newCclosure(L, n, getcurrenv(L));
492 cl->c.f = fn;
493 L->top -= n;
494 while (n--)
495 setobj2n(L, &cl->c.upvalue[n], L->top+n);
496 setclvalue(L, L->top, cl);
497 lua_assert(iswhite(obj2gco(cl)));
498 api_incr_top(L);
499 lua_unlock(L);
500}
501
502
503LUA_API void lua_pushboolean (lua_State *L, int b) {
504 lua_lock(L);
505 setbvalue(L->top, (b != 0)); /* ensure that true is 1 */
506 api_incr_top(L);
507 lua_unlock(L);
508}
509
510
511LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
512 lua_lock(L);
513 setpvalue(L->top, p);
514 api_incr_top(L);
515 lua_unlock(L);
516}
517
518
519LUA_API int lua_pushthread (lua_State *L) {
520 lua_lock(L);
521 setthvalue(L, L->top, L);
522 api_incr_top(L);
523 lua_unlock(L);
524 return (G(L)->mainthread == L);
525}
526
527
528
529/*
530** get functions (Lua -> stack)
531*/
532
533
534LUA_API void lua_gettable (lua_State *L, int idx) {
535 StkId t;
536 lua_lock(L);
537 t = index2adr(L, idx);
538 api_checkvalidindex(L, t);
539 luaV_gettable(L, t, L->top - 1, L->top - 1);
540 lua_unlock(L);
541}
542
543
544LUA_API void lua_getfield (lua_State *L, int idx, const char *k) {
545 StkId t;
546 TValue key;
547 lua_lock(L);
548 t = index2adr(L, idx);
549 api_checkvalidindex(L, t);
550 setsvalue(L, &key, luaS_new(L, k));
551 luaV_gettable(L, t, &key, L->top);
552 api_incr_top(L);
553 lua_unlock(L);
554}
555
556
557LUA_API void lua_rawget (lua_State *L, int idx) {
558 StkId t;
559 lua_lock(L);
560 t = index2adr(L, idx);
561 api_check(L, ttistable(t));
562 setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
563 lua_unlock(L);
564}
565
566
567LUA_API void lua_rawgeti (lua_State *L, int idx, int n) {
568 StkId o;
569 lua_lock(L);
570 o = index2adr(L, idx);
571 api_check(L, ttistable(o));
572 setobj2s(L, L->top, luaH_getnum(hvalue(o), n));
573 api_incr_top(L);
574 lua_unlock(L);
575}
576
577
578LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
579 lua_lock(L);
580 luaC_checkGC(L);
581 sethvalue(L, L->top, luaH_new(L, narray, nrec));
582 api_incr_top(L);
583 lua_unlock(L);
584}
585
586
587LUA_API int lua_getmetatable (lua_State *L, int objindex) {
588 const TValue *obj;
589 Table *mt = NULL;
590 int res;
591 lua_lock(L);
592 obj = index2adr(L, objindex);
593 switch (ttype(obj)) {
594 case LUA_TTABLE:
595 mt = hvalue(obj)->metatable;
596 break;
597 case LUA_TUSERDATA:
598 mt = uvalue(obj)->metatable;
599 break;
600 default:
601 mt = G(L)->mt[ttype(obj)];
602 break;
603 }
604 if (mt == NULL)
605 res = 0;
606 else {
607 sethvalue(L, L->top, mt);
608 api_incr_top(L);
609 res = 1;
610 }
611 lua_unlock(L);
612 return res;
613}
614
615
616LUA_API void lua_getfenv (lua_State *L, int idx) {
617 StkId o;
618 lua_lock(L);
619 o = index2adr(L, idx);
620 api_checkvalidindex(L, o);
621 switch (ttype(o)) {
622 case LUA_TFUNCTION:
623 sethvalue(L, L->top, clvalue(o)->c.env);
624 break;
625 case LUA_TUSERDATA:
626 sethvalue(L, L->top, uvalue(o)->env);
627 break;
628 case LUA_TTHREAD:
629 setobj2s(L, L->top, gt(thvalue(o)));
630 break;
631 default:
632 setnilvalue(L->top);
633 break;
634 }
635 api_incr_top(L);
636 lua_unlock(L);
637}
638
639
640/*
641** set functions (stack -> Lua)
642*/
643
644
645LUA_API void lua_settable (lua_State *L, int idx) {
646 StkId t;
647 lua_lock(L);
648 api_checknelems(L, 2);
649 t = index2adr(L, idx);
650 api_checkvalidindex(L, t);
651 luaV_settable(L, t, L->top - 2, L->top - 1);
652 L->top -= 2; /* pop index and value */
653 lua_unlock(L);
654}
655
656
657LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
658 StkId t;
659 TValue key;
660 lua_lock(L);
661 api_checknelems(L, 1);
662 t = index2adr(L, idx);
663 api_checkvalidindex(L, t);
664 setsvalue(L, &key, luaS_new(L, k));
665 luaV_settable(L, t, &key, L->top - 1);
666 L->top--; /* pop value */
667 lua_unlock(L);
668}
669
670
671LUA_API void lua_rawset (lua_State *L, int idx) {
672 StkId t;
673 lua_lock(L);
674 api_checknelems(L, 2);
675 t = index2adr(L, idx);
676 api_check(L, ttistable(t));
677 if (hvalue(t)->readonly)
678 luaG_runerror(L, "Attempt to modify a readonly table");
679 setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
680 luaC_barriert(L, hvalue(t), L->top-1);
681 L->top -= 2;
682 lua_unlock(L);
683}
684
685
686LUA_API void lua_rawseti (lua_State *L, int idx, int n) {
687 StkId o;
688 lua_lock(L);
689 api_checknelems(L, 1);
690 o = index2adr(L, idx);
691 api_check(L, ttistable(o));
692 if (hvalue(o)->readonly)
693 luaG_runerror(L, "Attempt to modify a readonly table");
694 setobj2t(L, luaH_setnum(L, hvalue(o), n), L->top-1);
695 luaC_barriert(L, hvalue(o), L->top-1);
696 L->top--;
697 lua_unlock(L);
698}
699
700
701LUA_API int lua_setmetatable (lua_State *L, int objindex) {
702 TValue *obj;
703 Table *mt;
704 lua_lock(L);
705 api_checknelems(L, 1);
706 obj = index2adr(L, objindex);
707 api_checkvalidindex(L, obj);
708 if (ttisnil(L->top - 1))
709 mt = NULL;
710 else {
711 api_check(L, ttistable(L->top - 1));
712 mt = hvalue(L->top - 1);
713 }
714 switch (ttype(obj)) {
715 case LUA_TTABLE: {
716 if (hvalue(obj)->readonly)
717 luaG_runerror(L, "Attempt to modify a readonly table");
718 hvalue(obj)->metatable = mt;
719 if (mt)
720 luaC_objbarriert(L, hvalue(obj), mt);
721 break;
722 }
723 case LUA_TUSERDATA: {
724 uvalue(obj)->metatable = mt;
725 if (mt)
726 luaC_objbarrier(L, rawuvalue(obj), mt);
727 break;
728 }
729 default: {
730 G(L)->mt[ttype(obj)] = mt;
731 break;
732 }
733 }
734 L->top--;
735 lua_unlock(L);
736 return 1;
737}
738
739
740LUA_API int lua_setfenv (lua_State *L, int idx) {
741 StkId o;
742 int res = 1;
743 lua_lock(L);
744 api_checknelems(L, 1);
745 o = index2adr(L, idx);
746 api_checkvalidindex(L, o);
747 api_check(L, ttistable(L->top - 1));
748 switch (ttype(o)) {
749 case LUA_TFUNCTION:
750 clvalue(o)->c.env = hvalue(L->top - 1);
751 break;
752 case LUA_TUSERDATA:
753 uvalue(o)->env = hvalue(L->top - 1);
754 break;
755 case LUA_TTHREAD:
756 sethvalue(L, gt(thvalue(o)), hvalue(L->top - 1));
757 break;
758 default:
759 res = 0;
760 break;
761 }
762 if (res) luaC_objbarrier(L, gcvalue(o), hvalue(L->top - 1));
763 L->top--;
764 lua_unlock(L);
765 return res;
766}
767
768
769/*
770** `load' and `call' functions (run Lua code)
771*/
772
773
774#define adjustresults(L,nres) \
775 { if (nres == LUA_MULTRET && L->top >= L->ci->top) L->ci->top = L->top; }
776
777
778#define checkresults(L,na,nr) \
779 api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)))
780
781
782LUA_API void lua_call (lua_State *L, int nargs, int nresults) {
783 StkId func;
784 lua_lock(L);
785 api_checknelems(L, nargs+1);
786 checkresults(L, nargs, nresults);
787 func = L->top - (nargs+1);
788 luaD_call(L, func, nresults);
789 adjustresults(L, nresults);
790 lua_unlock(L);
791}
792
793
794
795/*
796** Execute a protected call.
797*/
798struct CallS { /* data to `f_call' */
799 StkId func;
800 int nresults;
801};
802
803
804static void f_call (lua_State *L, void *ud) {
805 struct CallS *c = cast(struct CallS *, ud);
806 luaD_call(L, c->func, c->nresults);
807}
808
809
810
811LUA_API int lua_pcall (lua_State *L, int nargs, int nresults, int errfunc) {
812 struct CallS c;
813 int status;
814 ptrdiff_t func;
815 lua_lock(L);
816 api_checknelems(L, nargs+1);
817 checkresults(L, nargs, nresults);
818 if (errfunc == 0)
819 func = 0;
820 else {
821 StkId o = index2adr(L, errfunc);
822 api_checkvalidindex(L, o);
823 func = savestack(L, o);
824 }
825 c.func = L->top - (nargs+1); /* function to be called */
826 c.nresults = nresults;
827 status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
828 adjustresults(L, nresults);
829 lua_unlock(L);
830 return status;
831}
832
833
834/*
835** Execute a protected C call.
836*/
837struct CCallS { /* data to `f_Ccall' */
838 lua_CFunction func;
839 void *ud;
840};
841
842
843static void f_Ccall (lua_State *L, void *ud) {
844 struct CCallS *c = cast(struct CCallS *, ud);
845 Closure *cl;
846 cl = luaF_newCclosure(L, 0, getcurrenv(L));
847 cl->c.f = c->func;
848 setclvalue(L, L->top, cl); /* push function */
849 api_incr_top(L);
850 setpvalue(L->top, c->ud); /* push only argument */
851 api_incr_top(L);
852 luaD_call(L, L->top - 2, 0);
853}
854
855
856LUA_API int lua_cpcall (lua_State *L, lua_CFunction func, void *ud) {
857 struct CCallS c;
858 int status;
859 lua_lock(L);
860 c.func = func;
861 c.ud = ud;
862 status = luaD_pcall(L, f_Ccall, &c, savestack(L, L->top), 0);
863 lua_unlock(L);
864 return status;
865}
866
867
868LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
869 const char *chunkname) {
870 ZIO z;
871 int status;
872 lua_lock(L);
873 if (!chunkname) chunkname = "?";
874 luaZ_init(L, &z, reader, data);
875 status = luaD_protectedparser(L, &z, chunkname);
876 lua_unlock(L);
877 return status;
878}
879
880
881LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data) {
882 int status;
883 TValue *o;
884 lua_lock(L);
885 api_checknelems(L, 1);
886 o = L->top - 1;
887 if (isLfunction(o))
888 status = luaU_dump(L, clvalue(o)->l.p, writer, data, 0);
889 else
890 status = 1;
891 lua_unlock(L);
892 return status;
893}
894
895
896LUA_API int lua_status (lua_State *L) {
897 return L->status;
898}
899
900
901/*
902** Garbage-collection function
903*/
904
905LUA_API int lua_gc (lua_State *L, int what, int data) {
906 int res = 0;
907 global_State *g;
908 lua_lock(L);
909 g = G(L);
910 switch (what) {
911 case LUA_GCSTOP: {
912 g->GCthreshold = MAX_LUMEM;
913 break;
914 }
915 case LUA_GCRESTART: {
916 g->GCthreshold = g->totalbytes;
917 break;
918 }
919 case LUA_GCCOLLECT: {
920 luaC_fullgc(L);
921 break;
922 }
923 case LUA_GCCOUNT: {
924 /* GC values are expressed in Kbytes: #bytes/2^10 */
925 res = cast_int(g->totalbytes >> 10);
926 break;
927 }
928 case LUA_GCCOUNTB: {
929 res = cast_int(g->totalbytes & 0x3ff);
930 break;
931 }
932 case LUA_GCSTEP: {
933 lu_mem a = (cast(lu_mem, data) << 10);
934 if (a <= g->totalbytes)
935 g->GCthreshold = g->totalbytes - a;
936 else
937 g->GCthreshold = 0;
938 while (g->GCthreshold <= g->totalbytes) {
939 luaC_step(L);
940 if (g->gcstate == GCSpause) { /* end of cycle? */
941 res = 1; /* signal it */
942 break;
943 }
944 }
945 break;
946 }
947 case LUA_GCSETPAUSE: {
948 res = g->gcpause;
949 g->gcpause = data;
950 break;
951 }
952 case LUA_GCSETSTEPMUL: {
953 res = g->gcstepmul;
954 g->gcstepmul = data;
955 break;
956 }
957 default: res = -1; /* invalid option */
958 }
959 lua_unlock(L);
960 return res;
961}
962
963
964
965/*
966** miscellaneous functions
967*/
968
969
970LUA_API int lua_error (lua_State *L) {
971 lua_lock(L);
972 api_checknelems(L, 1);
973 luaG_errormsg(L);
974 lua_unlock(L);
975 return 0; /* to avoid warnings */
976}
977
978
979LUA_API int lua_next (lua_State *L, int idx) {
980 StkId t;
981 int more;
982 lua_lock(L);
983 t = index2adr(L, idx);
984 api_check(L, ttistable(t));
985 more = luaH_next(L, hvalue(t), L->top - 1);
986 if (more) {
987 api_incr_top(L);
988 }
989 else /* no more elements */
990 L->top -= 1; /* remove key */
991 lua_unlock(L);
992 return more;
993}
994
995
996LUA_API void lua_concat (lua_State *L, int n) {
997 lua_lock(L);
998 api_checknelems(L, n);
999 if (n >= 2) {
1000 luaC_checkGC(L);
1001 luaV_concat(L, n, cast_int(L->top - L->base) - 1);
1002 L->top -= (n-1);
1003 }
1004 else if (n == 0) { /* push empty string */
1005 setsvalue2s(L, L->top, luaS_newlstr(L, "", 0));
1006 api_incr_top(L);
1007 }
1008 /* else n == 1; nothing to do */
1009 lua_unlock(L);
1010}
1011
1012
1013LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) {
1014 lua_Alloc f;
1015 lua_lock(L);
1016 if (ud) *ud = G(L)->ud;
1017 f = G(L)->frealloc;
1018 lua_unlock(L);
1019 return f;
1020}
1021
1022
1023LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
1024 lua_lock(L);
1025 G(L)->ud = ud;
1026 G(L)->frealloc = f;
1027 lua_unlock(L);
1028}
1029
1030
1031LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
1032 Udata *u;
1033 lua_lock(L);
1034 luaC_checkGC(L);
1035 u = luaS_newudata(L, size, getcurrenv(L));
1036 setuvalue(L, L->top, u);
1037 api_incr_top(L);
1038 lua_unlock(L);
1039 return u + 1;
1040}
1041
1042
1043
1044
1045static const char *aux_upvalue (StkId fi, int n, TValue **val) {
1046 Closure *f;
1047 if (!ttisfunction(fi)) return NULL;
1048 f = clvalue(fi);
1049 if (f->c.isC) {
1050 if (!(1 <= n && n <= f->c.nupvalues)) return NULL;
1051 *val = &f->c.upvalue[n-1];
1052 return "";
1053 }
1054 else {
1055 Proto *p = f->l.p;
1056 if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
1057 *val = f->l.upvals[n-1]->v;
1058 return getstr(p->upvalues[n-1]);
1059 }
1060}
1061
1062
1063LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
1064 const char *name;
1065 TValue *val;
1066 lua_lock(L);
1067 name = aux_upvalue(index2adr(L, funcindex), n, &val);
1068 if (name) {
1069 setobj2s(L, L->top, val);
1070 api_incr_top(L);
1071 }
1072 lua_unlock(L);
1073 return name;
1074}
1075
1076
1077LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
1078 const char *name;
1079 TValue *val;
1080 StkId fi;
1081 lua_lock(L);
1082 fi = index2adr(L, funcindex);
1083 api_checknelems(L, 1);
1084 name = aux_upvalue(fi, n, &val);
1085 if (name) {
1086 L->top--;
1087 setobj(L, val, L->top);
1088 luaC_barrier(L, clvalue(fi), L->top);
1089 }
1090 lua_unlock(L);
1091 return name;
1092}
1093
1094LUA_API void lua_enablereadonlytable (lua_State *L, int objindex, int enabled) {
1095 const TValue* o = index2adr(L, objindex);
1096 api_check(L, ttistable(o));
1097 Table* t = hvalue(o);
1098 api_check(L, t != hvalue(registry(L)));
1099 t->readonly = enabled;
1100}
1101
1102LUA_API int lua_isreadonlytable (lua_State *L, int objindex) {
1103 const TValue* o = index2adr(L, objindex);
1104 api_check(L, ttistable(o));
1105 Table* t = hvalue(o);
1106 api_check(L, t != hvalue(registry(L)));
1107 return t->readonly;
1108}
1109
1110