1/*
2** $Id: lvm.c,v 2.63.1.5 2011/08/17 20:43:11 roberto Exp $
3** Lua virtual machine
4** See Copyright Notice in lua.h
5*/
6
7
8#include <stdio.h>
9#include <stdlib.h>
10#include <string.h>
11
12#define lvm_c
13#define LUA_CORE
14
15#include "lua.h"
16
17#include "ldebug.h"
18#include "ldo.h"
19#include "lfunc.h"
20#include "lgc.h"
21#include "lobject.h"
22#include "lopcodes.h"
23#include "lstate.h"
24#include "lstring.h"
25#include "ltable.h"
26#include "ltm.h"
27#include "lvm.h"
28
29
30
31/* limit for table tag-method chains (to avoid loops) */
32#define MAXTAGLOOP 100
33
34
35const TValue *luaV_tonumber (const TValue *obj, TValue *n) {
36 lua_Number num;
37 if (ttisnumber(obj)) return obj;
38 if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
39 setnvalue(n, num);
40 return n;
41 }
42 else
43 return NULL;
44}
45
46
47int luaV_tostring (lua_State *L, StkId obj) {
48 if (!ttisnumber(obj))
49 return 0;
50 else {
51 char s[LUAI_MAXNUMBER2STR];
52 lua_Number n = nvalue(obj);
53 lua_number2str(s, n);
54 setsvalue2s(L, obj, luaS_new(L, s));
55 return 1;
56 }
57}
58
59
60static void traceexec (lua_State *L, const Instruction *pc) {
61 lu_byte mask = L->hookmask;
62 const Instruction *oldpc = L->savedpc;
63 L->savedpc = pc;
64 if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
65 resethookcount(L);
66 luaD_callhook(L, LUA_HOOKCOUNT, -1);
67 }
68 if (mask & LUA_MASKLINE) {
69 Proto *p = ci_func(L->ci)->l.p;
70 int npc = pcRel(pc, p);
71 int newline = getline(p, npc);
72 /* call linehook when enter a new function, when jump back (loop),
73 or when enter a new line */
74 if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p)))
75 luaD_callhook(L, LUA_HOOKLINE, newline);
76 }
77}
78
79
80static void callTMres (lua_State *L, StkId res, const TValue *f,
81 const TValue *p1, const TValue *p2) {
82 ptrdiff_t result = savestack(L, res);
83 setobj2s(L, L->top, f); /* push function */
84 setobj2s(L, L->top+1, p1); /* 1st argument */
85 setobj2s(L, L->top+2, p2); /* 2nd argument */
86 luaD_checkstack(L, 3);
87 L->top += 3;
88 luaD_call(L, L->top - 3, 1);
89 res = restorestack(L, result);
90 L->top--;
91 setobjs2s(L, res, L->top);
92}
93
94
95
96static void callTM (lua_State *L, const TValue *f, const TValue *p1,
97 const TValue *p2, const TValue *p3) {
98 setobj2s(L, L->top, f); /* push function */
99 setobj2s(L, L->top+1, p1); /* 1st argument */
100 setobj2s(L, L->top+2, p2); /* 2nd argument */
101 setobj2s(L, L->top+3, p3); /* 3th argument */
102 luaD_checkstack(L, 4);
103 L->top += 4;
104 luaD_call(L, L->top - 4, 0);
105}
106
107
108void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
109 int loop;
110 for (loop = 0; loop < MAXTAGLOOP; loop++) {
111 const TValue *tm;
112 if (ttistable(t)) { /* `t' is a table? */
113 Table *h = hvalue(t);
114 const TValue *res = luaH_get(h, key); /* do a primitive get */
115 if (!ttisnil(res) || /* result is no nil? */
116 (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
117 setobj2s(L, val, res);
118 return;
119 }
120 /* else will try the tag method */
121 }
122 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
123 luaG_typeerror(L, t, "index");
124 if (ttisfunction(tm)) {
125 callTMres(L, val, tm, t, key);
126 return;
127 }
128 t = tm; /* else repeat with `tm' */
129 }
130 luaG_runerror(L, "loop in gettable");
131}
132
133
134void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
135 int loop;
136 TValue temp;
137 for (loop = 0; loop < MAXTAGLOOP; loop++) {
138 const TValue *tm;
139 if (ttistable(t)) { /* `t' is a table? */
140 Table *h = hvalue(t);
141 if (h->readonly)
142 luaG_runerror(L, "Attempt to modify a readonly table");
143 TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
144 if (!ttisnil(oldval) || /* result is no nil? */
145 (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
146 setobj2t(L, oldval, val);
147 h->flags = 0;
148 luaC_barriert(L, h, val);
149 return;
150 }
151 /* else will try the tag method */
152 }
153 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
154 luaG_typeerror(L, t, "index");
155 if (ttisfunction(tm)) {
156 callTM(L, tm, t, key, val);
157 return;
158 }
159 /* else repeat with `tm' */
160 setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
161 t = &temp;
162 }
163 luaG_runerror(L, "loop in settable");
164}
165
166
167static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
168 StkId res, TMS event) {
169 const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
170 if (ttisnil(tm))
171 tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
172 if (ttisnil(tm)) return 0;
173 callTMres(L, res, tm, p1, p2);
174 return 1;
175}
176
177
178static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
179 TMS event) {
180 const TValue *tm1 = fasttm(L, mt1, event);
181 const TValue *tm2;
182 if (tm1 == NULL) return NULL; /* no metamethod */
183 if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
184 tm2 = fasttm(L, mt2, event);
185 if (tm2 == NULL) return NULL; /* no metamethod */
186 if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
187 return tm1;
188 return NULL;
189}
190
191
192static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
193 TMS event) {
194 const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
195 const TValue *tm2;
196 if (ttisnil(tm1)) return -1; /* no metamethod? */
197 tm2 = luaT_gettmbyobj(L, p2, event);
198 if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
199 return -1;
200 callTMres(L, L->top, tm1, p1, p2);
201 return !l_isfalse(L->top);
202}
203
204
205static int l_strcmp (const TString *ls, const TString *rs) {
206 const char *l = getstr(ls);
207 size_t ll = ls->tsv.len;
208 const char *r = getstr(rs);
209 size_t lr = rs->tsv.len;
210 for (;;) {
211 int temp = strcoll(l, r);
212 if (temp != 0) return temp;
213 else { /* strings are equal up to a `\0' */
214 size_t len = strlen(l); /* index of first `\0' in both strings */
215 if (len == lr) /* r is finished? */
216 return (len == ll) ? 0 : 1;
217 else if (len == ll) /* l is finished? */
218 return -1; /* l is smaller than r (because r is not finished) */
219 /* both strings longer than `len'; go on comparing (after the `\0') */
220 len++;
221 l += len; ll -= len; r += len; lr -= len;
222 }
223 }
224}
225
226
227int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
228 int res;
229 if (ttype(l) != ttype(r))
230 return luaG_ordererror(L, l, r);
231 else if (ttisnumber(l))
232 return luai_numlt(nvalue(l), nvalue(r));
233 else if (ttisstring(l))
234 return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
235 else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
236 return res;
237 return luaG_ordererror(L, l, r);
238}
239
240
241static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
242 int res;
243 if (ttype(l) != ttype(r))
244 return luaG_ordererror(L, l, r);
245 else if (ttisnumber(l))
246 return luai_numle(nvalue(l), nvalue(r));
247 else if (ttisstring(l))
248 return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
249 else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
250 return res;
251 else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
252 return !res;
253 return luaG_ordererror(L, l, r);
254}
255
256
257int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
258 const TValue *tm;
259 lua_assert(ttype(t1) == ttype(t2));
260 switch (ttype(t1)) {
261 case LUA_TNIL: return 1;
262 case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
263 case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
264 case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
265 case LUA_TUSERDATA: {
266 if (uvalue(t1) == uvalue(t2)) return 1;
267 tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
268 TM_EQ);
269 break; /* will try TM */
270 }
271 case LUA_TTABLE: {
272 if (hvalue(t1) == hvalue(t2)) return 1;
273 tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
274 break; /* will try TM */
275 }
276 default: return gcvalue(t1) == gcvalue(t2);
277 }
278 if (tm == NULL) return 0; /* no TM? */
279 callTMres(L, L->top, tm, t1, t2); /* call TM */
280 return !l_isfalse(L->top);
281}
282
283
284void luaV_concat (lua_State *L, int total, int last) {
285 do {
286 StkId top = L->base + last + 1;
287 int n = 2; /* number of elements handled in this pass (at least 2) */
288 if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
289 if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
290 luaG_concaterror(L, top-2, top-1);
291 } else if (tsvalue(top-1)->len == 0) /* second op is empty? */
292 (void)tostring(L, top - 2); /* result is first op (as string) */
293 else {
294 /* at least two string values; get as many as possible */
295 size_t tl = tsvalue(top-1)->len;
296 char *buffer;
297 int i;
298 /* collect total length */
299 for (n = 1; n < total && tostring(L, top-n-1); n++) {
300 size_t l = tsvalue(top-n-1)->len;
301 if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
302 tl += l;
303 }
304 buffer = luaZ_openspace(L, &G(L)->buff, tl);
305 tl = 0;
306 for (i=n; i>0; i--) { /* concat all strings */
307 size_t l = tsvalue(top-i)->len;
308 memcpy(buffer+tl, svalue(top-i), l);
309 tl += l;
310 }
311 setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
312 }
313 total -= n-1; /* got `n' strings to create 1 new */
314 last -= n-1;
315 } while (total > 1); /* repeat until only 1 result left */
316}
317
318
319static void Arith (lua_State *L, StkId ra, const TValue *rb,
320 const TValue *rc, TMS op) {
321 TValue tempb, tempc;
322 const TValue *b, *c;
323 if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
324 (c = luaV_tonumber(rc, &tempc)) != NULL) {
325 lua_Number nb = nvalue(b), nc = nvalue(c);
326 switch (op) {
327 case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break;
328 case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break;
329 case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break;
330 case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break;
331 case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break;
332 case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break;
333 case TM_UNM: setnvalue(ra, luai_numunm(nb)); break;
334 default: lua_assert(0); break;
335 }
336 }
337 else if (!call_binTM(L, rb, rc, ra, op))
338 luaG_aritherror(L, rb, rc);
339}
340
341
342
343/*
344** some macros for common tasks in `luaV_execute'
345*/
346
347#define runtime_check(L, c) { if (!(c)) break; }
348
349#define RA(i) (base+GETARG_A(i))
350/* to be used after possible stack reallocation */
351#define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
352#define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
353#define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
354 ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
355#define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
356 ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
357#define KBx(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
358
359
360#define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);}
361
362
363#define Protect(x) { L->savedpc = pc; {x;}; base = L->base; }
364
365
366#define arith_op(op,tm) { \
367 TValue *rb = RKB(i); \
368 TValue *rc = RKC(i); \
369 if (ttisnumber(rb) && ttisnumber(rc)) { \
370 lua_Number nb = nvalue(rb), nc = nvalue(rc); \
371 setnvalue(ra, op(nb, nc)); \
372 } \
373 else \
374 Protect(Arith(L, ra, rb, rc, tm)); \
375 }
376
377
378
379void luaV_execute (lua_State *L, int nexeccalls) {
380 LClosure *cl;
381 StkId base;
382 TValue *k;
383 const Instruction *pc;
384 reentry: /* entry point */
385 lua_assert(isLua(L->ci));
386 pc = L->savedpc;
387 cl = &clvalue(L->ci->func)->l;
388 base = L->base;
389 k = cl->p->k;
390 /* main loop of interpreter */
391 for (;;) {
392 const Instruction i = *pc++;
393 StkId ra;
394 if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
395 (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
396 traceexec(L, pc);
397 if (L->status == LUA_YIELD) { /* did hook yield? */
398 L->savedpc = pc - 1;
399 return;
400 }
401 base = L->base;
402 }
403 /* warning!! several calls may realloc the stack and invalidate `ra' */
404 ra = RA(i);
405 lua_assert(base == L->base && L->base == L->ci->base);
406 lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
407 lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
408 switch (GET_OPCODE(i)) {
409 case OP_MOVE: {
410 setobjs2s(L, ra, RB(i));
411 continue;
412 }
413 case OP_LOADK: {
414 setobj2s(L, ra, KBx(i));
415 continue;
416 }
417 case OP_LOADBOOL: {
418 setbvalue(ra, GETARG_B(i));
419 if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
420 continue;
421 }
422 case OP_LOADNIL: {
423 TValue *rb = RB(i);
424 do {
425 setnilvalue(rb--);
426 } while (rb >= ra);
427 continue;
428 }
429 case OP_GETUPVAL: {
430 int b = GETARG_B(i);
431 setobj2s(L, ra, cl->upvals[b]->v);
432 continue;
433 }
434 case OP_GETGLOBAL: {
435 TValue g;
436 TValue *rb = KBx(i);
437 sethvalue(L, &g, cl->env);
438 lua_assert(ttisstring(rb));
439 Protect(luaV_gettable(L, &g, rb, ra));
440 continue;
441 }
442 case OP_GETTABLE: {
443 Protect(luaV_gettable(L, RB(i), RKC(i), ra));
444 continue;
445 }
446 case OP_SETGLOBAL: {
447 TValue g;
448 sethvalue(L, &g, cl->env);
449 lua_assert(ttisstring(KBx(i)));
450 Protect(luaV_settable(L, &g, KBx(i), ra));
451 continue;
452 }
453 case OP_SETUPVAL: {
454 UpVal *uv = cl->upvals[GETARG_B(i)];
455 setobj(L, uv->v, ra);
456 luaC_barrier(L, uv, ra);
457 continue;
458 }
459 case OP_SETTABLE: {
460 Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
461 continue;
462 }
463 case OP_NEWTABLE: {
464 int b = GETARG_B(i);
465 int c = GETARG_C(i);
466 sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
467 Protect(luaC_checkGC(L));
468 continue;
469 }
470 case OP_SELF: {
471 StkId rb = RB(i);
472 setobjs2s(L, ra+1, rb);
473 Protect(luaV_gettable(L, rb, RKC(i), ra));
474 continue;
475 }
476 case OP_ADD: {
477 arith_op(luai_numadd, TM_ADD);
478 continue;
479 }
480 case OP_SUB: {
481 arith_op(luai_numsub, TM_SUB);
482 continue;
483 }
484 case OP_MUL: {
485 arith_op(luai_nummul, TM_MUL);
486 continue;
487 }
488 case OP_DIV: {
489 arith_op(luai_numdiv, TM_DIV);
490 continue;
491 }
492 case OP_MOD: {
493 arith_op(luai_nummod, TM_MOD);
494 continue;
495 }
496 case OP_POW: {
497 arith_op(luai_numpow, TM_POW);
498 continue;
499 }
500 case OP_UNM: {
501 TValue *rb = RB(i);
502 if (ttisnumber(rb)) {
503 lua_Number nb = nvalue(rb);
504 setnvalue(ra, luai_numunm(nb));
505 }
506 else {
507 Protect(Arith(L, ra, rb, rb, TM_UNM));
508 }
509 continue;
510 }
511 case OP_NOT: {
512 int res = l_isfalse(RB(i)); /* next assignment may change this value */
513 setbvalue(ra, res);
514 continue;
515 }
516 case OP_LEN: {
517 const TValue *rb = RB(i);
518 switch (ttype(rb)) {
519 case LUA_TTABLE: {
520 setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
521 break;
522 }
523 case LUA_TSTRING: {
524 setnvalue(ra, cast_num(tsvalue(rb)->len));
525 break;
526 }
527 default: { /* try metamethod */
528 Protect(
529 if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
530 luaG_typeerror(L, rb, "get length of");
531 )
532 }
533 }
534 continue;
535 }
536 case OP_CONCAT: {
537 int b = GETARG_B(i);
538 int c = GETARG_C(i);
539 Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
540 setobjs2s(L, RA(i), base+b);
541 continue;
542 }
543 case OP_JMP: {
544 dojump(L, pc, GETARG_sBx(i));
545 continue;
546 }
547 case OP_EQ: {
548 TValue *rb = RKB(i);
549 TValue *rc = RKC(i);
550 Protect(
551 if (equalobj(L, rb, rc) == GETARG_A(i))
552 dojump(L, pc, GETARG_sBx(*pc));
553 )
554 pc++;
555 continue;
556 }
557 case OP_LT: {
558 Protect(
559 if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
560 dojump(L, pc, GETARG_sBx(*pc));
561 )
562 pc++;
563 continue;
564 }
565 case OP_LE: {
566 Protect(
567 if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
568 dojump(L, pc, GETARG_sBx(*pc));
569 )
570 pc++;
571 continue;
572 }
573 case OP_TEST: {
574 if (l_isfalse(ra) != GETARG_C(i))
575 dojump(L, pc, GETARG_sBx(*pc));
576 pc++;
577 continue;
578 }
579 case OP_TESTSET: {
580 TValue *rb = RB(i);
581 if (l_isfalse(rb) != GETARG_C(i)) {
582 setobjs2s(L, ra, rb);
583 dojump(L, pc, GETARG_sBx(*pc));
584 }
585 pc++;
586 continue;
587 }
588 case OP_CALL: {
589 int b = GETARG_B(i);
590 int nresults = GETARG_C(i) - 1;
591 if (b != 0) L->top = ra+b; /* else previous instruction set top */
592 L->savedpc = pc;
593 switch (luaD_precall(L, ra, nresults)) {
594 case PCRLUA: {
595 nexeccalls++;
596 goto reentry; /* restart luaV_execute over new Lua function */
597 }
598 case PCRC: {
599 /* it was a C function (`precall' called it); adjust results */
600 if (nresults >= 0) L->top = L->ci->top;
601 base = L->base;
602 continue;
603 }
604 default: {
605 return; /* yield */
606 }
607 }
608 }
609 case OP_TAILCALL: {
610 int b = GETARG_B(i);
611 if (b != 0) L->top = ra+b; /* else previous instruction set top */
612 L->savedpc = pc;
613 lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
614 switch (luaD_precall(L, ra, LUA_MULTRET)) {
615 case PCRLUA: {
616 /* tail call: put new frame in place of previous one */
617 CallInfo *ci = L->ci - 1; /* previous frame */
618 int aux;
619 StkId func = ci->func;
620 StkId pfunc = (ci+1)->func; /* previous function index */
621 if (L->openupval) luaF_close(L, ci->base);
622 L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
623 for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */
624 setobjs2s(L, func+aux, pfunc+aux);
625 ci->top = L->top = func+aux; /* correct top */
626 lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
627 ci->savedpc = L->savedpc;
628 ci->tailcalls++; /* one more call lost */
629 L->ci--; /* remove new frame */
630 goto reentry;
631 }
632 case PCRC: { /* it was a C function (`precall' called it) */
633 base = L->base;
634 continue;
635 }
636 default: {
637 return; /* yield */
638 }
639 }
640 }
641 case OP_RETURN: {
642 int b = GETARG_B(i);
643 if (b != 0) L->top = ra+b-1;
644 if (L->openupval) luaF_close(L, base);
645 L->savedpc = pc;
646 b = luaD_poscall(L, ra);
647 if (--nexeccalls == 0) /* was previous function running `here'? */
648 return; /* no: return */
649 else { /* yes: continue its execution */
650 if (b) L->top = L->ci->top;
651 lua_assert(isLua(L->ci));
652 lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
653 goto reentry;
654 }
655 }
656 case OP_FORLOOP: {
657 lua_Number step = nvalue(ra+2);
658 lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
659 lua_Number limit = nvalue(ra+1);
660 if (luai_numlt(0, step) ? luai_numle(idx, limit)
661 : luai_numle(limit, idx)) {
662 dojump(L, pc, GETARG_sBx(i)); /* jump back */
663 setnvalue(ra, idx); /* update internal index... */
664 setnvalue(ra+3, idx); /* ...and external index */
665 }
666 continue;
667 }
668 case OP_FORPREP: {
669 const TValue *init = ra;
670 const TValue *plimit = ra+1;
671 const TValue *pstep = ra+2;
672 L->savedpc = pc; /* next steps may throw errors */
673 if (!tonumber(init, ra))
674 luaG_runerror(L, LUA_QL("for") " initial value must be a number");
675 else if (!tonumber(plimit, ra+1))
676 luaG_runerror(L, LUA_QL("for") " limit must be a number");
677 else if (!tonumber(pstep, ra+2))
678 luaG_runerror(L, LUA_QL("for") " step must be a number");
679 setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
680 dojump(L, pc, GETARG_sBx(i));
681 continue;
682 }
683 case OP_TFORLOOP: {
684 StkId cb = ra + 3; /* call base */
685 setobjs2s(L, cb+2, ra+2);
686 setobjs2s(L, cb+1, ra+1);
687 setobjs2s(L, cb, ra);
688 L->top = cb+3; /* func. + 2 args (state and index) */
689 Protect(luaD_call(L, cb, GETARG_C(i)));
690 L->top = L->ci->top;
691 cb = RA(i) + 3; /* previous call may change the stack */
692 if (!ttisnil(cb)) { /* continue loop? */
693 setobjs2s(L, cb-1, cb); /* save control variable */
694 dojump(L, pc, GETARG_sBx(*pc)); /* jump back */
695 }
696 pc++;
697 continue;
698 }
699 case OP_SETLIST: {
700 int n = GETARG_B(i);
701 int c = GETARG_C(i);
702 int last;
703 Table *h;
704 if (n == 0) {
705 n = cast_int(L->top - ra) - 1;
706 L->top = L->ci->top;
707 }
708 if (c == 0) c = cast_int(*pc++);
709 runtime_check(L, ttistable(ra));
710 h = hvalue(ra);
711 last = ((c-1)*LFIELDS_PER_FLUSH) + n;
712 if (last > h->sizearray) /* needs more space? */
713 luaH_resizearray(L, h, last); /* pre-alloc it at once */
714 for (; n > 0; n--) {
715 TValue *val = ra+n;
716 setobj2t(L, luaH_setnum(L, h, last--), val);
717 luaC_barriert(L, h, val);
718 }
719 continue;
720 }
721 case OP_CLOSE: {
722 luaF_close(L, ra);
723 continue;
724 }
725 case OP_CLOSURE: {
726 Proto *p;
727 Closure *ncl;
728 int nup, j;
729 p = cl->p->p[GETARG_Bx(i)];
730 nup = p->nups;
731 ncl = luaF_newLclosure(L, nup, cl->env);
732 ncl->l.p = p;
733 for (j=0; j<nup; j++, pc++) {
734 if (GET_OPCODE(*pc) == OP_GETUPVAL)
735 ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
736 else {
737 lua_assert(GET_OPCODE(*pc) == OP_MOVE);
738 ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
739 }
740 }
741 setclvalue(L, ra, ncl);
742 Protect(luaC_checkGC(L));
743 continue;
744 }
745 case OP_VARARG: {
746 int b = GETARG_B(i) - 1;
747 int j;
748 CallInfo *ci = L->ci;
749 int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
750 if (b == LUA_MULTRET) {
751 Protect(luaD_checkstack(L, n));
752 ra = RA(i); /* previous call may change the stack */
753 b = n;
754 L->top = ra + n;
755 }
756 for (j = 0; j < b; j++) {
757 if (j < n) {
758 setobjs2s(L, ra + j, ci->base - n + j);
759 }
760 else {
761 setnilvalue(ra + j);
762 }
763 }
764 continue;
765 }
766 }
767 }
768}
769
770