root/src/lua/src/lvm.c

Revision 22d1941d0ca5ba7027cdfa51ce34bd1d8fb1931e, 22.6 kB (checked in by Theo Schlossnagle <jesus@omniti.com>, 6 years ago)

take the version out... it is what it is

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1 /*
2 ** $Id: lvm.c,v 2.63.1.3 2007/12/28 15:32:23 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
35 const 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
47 int 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
60 static 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
80 static 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
96 static 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
108 void 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
134 void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
135   int loop;
136   for (loop = 0; loop < MAXTAGLOOP; loop++) {
137     const TValue *tm;
138     if (ttistable(t)) {  /* `t' is a table? */
139       Table *h = hvalue(t);
140       TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
141       if (!ttisnil(oldval) ||  /* result is no nil? */
142           (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
143         setobj2t(L, oldval, val);
144         luaC_barriert(L, h, val);
145         return;
146       }
147       /* else will try the tag method */
148     }
149     else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
150       luaG_typeerror(L, t, "index");
151     if (ttisfunction(tm)) {
152       callTM(L, tm, t, key, val);
153       return;
154     }
155     t = tm;  /* else repeat with `tm' */
156   }
157   luaG_runerror(L, "loop in settable");
158 }
159
160
161 static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
162                        StkId res, TMS event) {
163   const TValue *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
164   if (ttisnil(tm))
165     tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
166   if (ttisnil(tm)) return 0;
167   callTMres(L, res, tm, p1, p2);
168   return 1;
169 }
170
171
172 static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
173                                   TMS event) {
174   const TValue *tm1 = fasttm(L, mt1, event);
175   const TValue *tm2;
176   if (tm1 == NULL) return NULL;  /* no metamethod */
177   if (mt1 == mt2) return tm1;  /* same metatables => same metamethods */
178   tm2 = fasttm(L, mt2, event);
179   if (tm2 == NULL) return NULL;  /* no metamethod */
180   if (luaO_rawequalObj(tm1, tm2))  /* same metamethods? */
181     return tm1;
182   return NULL;
183 }
184
185
186 static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
187                          TMS event) {
188   const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
189   const TValue *tm2;
190   if (ttisnil(tm1)) return -1;  /* no metamethod? */
191   tm2 = luaT_gettmbyobj(L, p2, event);
192   if (!luaO_rawequalObj(tm1, tm2))  /* different metamethods? */
193     return -1;
194   callTMres(L, L->top, tm1, p1, p2);
195   return !l_isfalse(L->top);
196 }
197
198
199 static int l_strcmp (const TString *ls, const TString *rs) {
200   const char *l = getstr(ls);
201   size_t ll = ls->tsv.len;
202   const char *r = getstr(rs);
203   size_t lr = rs->tsv.len;
204   for (;;) {
205     int temp = strcoll(l, r);
206     if (temp != 0) return temp;
207     else {  /* strings are equal up to a `\0' */
208       size_t len = strlen(l);  /* index of first `\0' in both strings */
209       if (len == lr)  /* r is finished? */
210         return (len == ll) ? 0 : 1;
211       else if (len == ll)  /* l is finished? */
212         return -1;  /* l is smaller than r (because r is not finished) */
213       /* both strings longer than `len'; go on comparing (after the `\0') */
214       len++;
215       l += len; ll -= len; r += len; lr -= len;
216     }
217   }
218 }
219
220
221 int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
222   int res;
223   if (ttype(l) != ttype(r))
224     return luaG_ordererror(L, l, r);
225   else if (ttisnumber(l))
226     return luai_numlt(nvalue(l), nvalue(r));
227   else if (ttisstring(l))
228     return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
229   else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
230     return res;
231   return luaG_ordererror(L, l, r);
232 }
233
234
235 static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
236   int res;
237   if (ttype(l) != ttype(r))
238     return luaG_ordererror(L, l, r);
239   else if (ttisnumber(l))
240     return luai_numle(nvalue(l), nvalue(r));
241   else if (ttisstring(l))
242     return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
243   else if ((res = call_orderTM(L, l, r, TM_LE)) != -1)  /* first try `le' */
244     return res;
245   else if ((res = call_orderTM(L, r, l, TM_LT)) != -1)  /* else try `lt' */
246     return !res;
247   return luaG_ordererror(L, l, r);
248 }
249
250
251 int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
252   const TValue *tm;
253   lua_assert(ttype(t1) == ttype(t2));
254   switch (ttype(t1)) {
255     case LUA_TNIL: return 1;
256     case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
257     case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
258     case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
259     case LUA_TUSERDATA: {
260       if (uvalue(t1) == uvalue(t2)) return 1;
261       tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
262                          TM_EQ);
263       break;  /* will try TM */
264     }
265     case LUA_TTABLE: {
266       if (hvalue(t1) == hvalue(t2)) return 1;
267       tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
268       break;  /* will try TM */
269     }
270     default: return gcvalue(t1) == gcvalue(t2);
271   }
272   if (tm == NULL) return 0;  /* no TM? */
273   callTMres(L, L->top, tm, t1, t2);  /* call TM */
274   return !l_isfalse(L->top);
275 }
276
277
278 void luaV_concat (lua_State *L, int total, int last) {
279   do {
280     StkId top = L->base + last + 1;
281     int n = 2;  /* number of elements handled in this pass (at least 2) */
282     if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
283       if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
284         luaG_concaterror(L, top-2, top-1);
285     } else if (tsvalue(top-1)->len == 0)  /* second op is empty? */
286       (void)tostring(L, top - 2);  /* result is first op (as string) */
287     else {
288       /* at least two string values; get as many as possible */
289       size_t tl = tsvalue(top-1)->len;
290       char *buffer;
291       int i;
292       /* collect total length */
293       for (n = 1; n < total && tostring(L, top-n-1); n++) {
294         size_t l = tsvalue(top-n-1)->len;
295         if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
296         tl += l;
297       }
298       buffer = luaZ_openspace(L, &G(L)->buff, tl);
299       tl = 0;
300       for (i=n; i>0; i--) {  /* concat all strings */
301         size_t l = tsvalue(top-i)->len;
302         memcpy(buffer+tl, svalue(top-i), l);
303         tl += l;
304       }
305       setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
306     }
307     total -= n-1;  /* got `n' strings to create 1 new */
308     last -= n-1;
309   } while (total > 1);  /* repeat until only 1 result left */
310 }
311
312
313 static void Arith (lua_State *L, StkId ra, const TValue *rb,
314                    const TValue *rc, TMS op) {
315   TValue tempb, tempc;
316   const TValue *b, *c;
317   if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
318       (c = luaV_tonumber(rc, &tempc)) != NULL) {
319     lua_Number nb = nvalue(b), nc = nvalue(c);
320     switch (op) {
321       case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break;
322       case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break;
323       case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break;
324       case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break;
325       case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break;
326       case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break;
327       case TM_UNM: setnvalue(ra, luai_numunm(nb)); break;
328       default: lua_assert(0); break;
329     }
330   }
331   else if (!call_binTM(L, rb, rc, ra, op))
332     luaG_aritherror(L, rb, rc);
333 }
334
335
336
337 /*
338 ** some macros for common tasks in `luaV_execute'
339 */
340
341 #define runtime_check(L, c)     { if (!(c)) break; }
342
343 #define RA(i)   (base+GETARG_A(i))
344 /* to be used after possible stack reallocation */
345 #define RB(i)   check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
346 #define RC(i)   check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
347 #define RKB(i)  check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
348         ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
349 #define RKC(i)  check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
350         ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
351 #define KBx(i)  check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
352
353
354 #define dojump(L,pc,i)  {(pc) += (i); luai_threadyield(L);}
355
356
357 #define Protect(x)      { L->savedpc = pc; {x;}; base = L->base; }
358
359
360 #define arith_op(op,tm) { \
361         TValue *rb = RKB(i); \
362         TValue *rc = RKC(i); \
363         if (ttisnumber(rb) && ttisnumber(rc)) { \
364           lua_Number nb = nvalue(rb), nc = nvalue(rc); \
365           setnvalue(ra, op(nb, nc)); \
366         } \
367         else \
368           Protect(Arith(L, ra, rb, rc, tm)); \
369       }
370
371
372
373 void luaV_execute (lua_State *L, int nexeccalls) {
374   LClosure *cl;
375   StkId base;
376   TValue *k;
377   const Instruction *pc;
378  reentry:  /* entry point */
379   lua_assert(isLua(L->ci));
380   pc = L->savedpc;
381   cl = &clvalue(L->ci->func)->l;
382   base = L->base;
383   k = cl->p->k;
384   /* main loop of interpreter */
385   for (;;) {
386     const Instruction i = *pc++;
387     StkId ra;
388     if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
389         (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
390       traceexec(L, pc);
391       if (L->status == LUA_YIELD) {  /* did hook yield? */
392         L->savedpc = pc - 1;
393         return;
394       }
395       base = L->base;
396     }
397     /* warning!! several calls may realloc the stack and invalidate `ra' */
398     ra = RA(i);
399     lua_assert(base == L->base && L->base == L->ci->base);
400     lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
401     lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
402     switch (GET_OPCODE(i)) {
403       case OP_MOVE: {
404         setobjs2s(L, ra, RB(i));
405         continue;
406       }
407       case OP_LOADK: {
408         setobj2s(L, ra, KBx(i));
409         continue;
410       }
411       case OP_LOADBOOL: {
412         setbvalue(ra, GETARG_B(i));
413         if (GETARG_C(i)) pc++;  /* skip next instruction (if C) */
414         continue;
415       }
416       case OP_LOADNIL: {
417         TValue *rb = RB(i);
418         do {
419           setnilvalue(rb--);
420         } while (rb >= ra);
421         continue;
422       }
423       case OP_GETUPVAL: {
424         int b = GETARG_B(i);
425         setobj2s(L, ra, cl->upvals[b]->v);
426         continue;
427       }
428       case OP_GETGLOBAL: {
429         TValue g;
430         TValue *rb = KBx(i);
431         sethvalue(L, &g, cl->env);
432         lua_assert(ttisstring(rb));
433         Protect(luaV_gettable(L, &g, rb, ra));
434         continue;
435       }
436       case OP_GETTABLE: {
437         Protect(luaV_gettable(L, RB(i), RKC(i), ra));
438         continue;
439       }
440       case OP_SETGLOBAL: {
441         TValue g;
442         sethvalue(L, &g, cl->env);
443         lua_assert(ttisstring(KBx(i)));
444         Protect(luaV_settable(L, &g, KBx(i), ra));
445         continue;
446       }
447       case OP_SETUPVAL: {
448         UpVal *uv = cl->upvals[GETARG_B(i)];
449         setobj(L, uv->v, ra);
450         luaC_barrier(L, uv, ra);
451         continue;
452       }
453       case OP_SETTABLE: {
454         Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
455         continue;
456       }
457       case OP_NEWTABLE: {
458         int b = GETARG_B(i);
459         int c = GETARG_C(i);
460         sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
461         Protect(luaC_checkGC(L));
462         continue;
463       }
464       case OP_SELF: {
465         StkId rb = RB(i);
466         setobjs2s(L, ra+1, rb);
467         Protect(luaV_gettable(L, rb, RKC(i), ra));
468         continue;
469       }
470       case OP_ADD: {
471         arith_op(luai_numadd, TM_ADD);
472         continue;
473       }
474       case OP_SUB: {
475         arith_op(luai_numsub, TM_SUB);
476         continue;
477       }
478       case OP_MUL: {
479         arith_op(luai_nummul, TM_MUL);
480         continue;
481       }
482       case OP_DIV: {
483         arith_op(luai_numdiv, TM_DIV);
484         continue;
485       }
486       case OP_MOD: {
487         arith_op(luai_nummod, TM_MOD);
488         continue;
489       }
490       case OP_POW: {
491         arith_op(luai_numpow, TM_POW);
492         continue;
493       }
494       case OP_UNM: {
495         TValue *rb = RB(i);
496         if (ttisnumber(rb)) {
497           lua_Number nb = nvalue(rb);
498           setnvalue(ra, luai_numunm(nb));
499         }
500         else {
501           Protect(Arith(L, ra, rb, rb, TM_UNM));
502         }
503         continue;
504       }
505       case OP_NOT: {
506         int res = l_isfalse(RB(i));  /* next assignment may change this value */
507         setbvalue(ra, res);
508         continue;
509       }
510       case OP_LEN: {
511         const TValue *rb = RB(i);
512         switch (ttype(rb)) {
513           case LUA_TTABLE: {
514             setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
515             break;
516           }
517           case LUA_TSTRING: {
518             setnvalue(ra, cast_num(tsvalue(rb)->len));
519             break;
520           }
521           default: {  /* try metamethod */
522             Protect(
523               if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
524                 luaG_typeerror(L, rb, "get length of");
525             )
526           }
527         }
528         continue;
529       }
530       case OP_CONCAT: {
531         int b = GETARG_B(i);
532         int c = GETARG_C(i);
533         Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
534         setobjs2s(L, RA(i), base+b);
535         continue;
536       }
537       case OP_JMP: {
538         dojump(L, pc, GETARG_sBx(i));
539         continue;
540       }
541       case OP_EQ: {
542         TValue *rb = RKB(i);
543         TValue *rc = RKC(i);
544         Protect(
545           if (equalobj(L, rb, rc) == GETARG_A(i))
546             dojump(L, pc, GETARG_sBx(*pc));
547         )
548         pc++;
549         continue;
550       }
551       case OP_LT: {
552         Protect(
553           if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
554             dojump(L, pc, GETARG_sBx(*pc));
555         )
556         pc++;
557         continue;
558       }
559       case OP_LE: {
560         Protect(
561           if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
562             dojump(L, pc, GETARG_sBx(*pc));
563         )
564         pc++;
565         continue;
566       }
567       case OP_TEST: {
568         if (l_isfalse(ra) != GETARG_C(i))
569           dojump(L, pc, GETARG_sBx(*pc));
570         pc++;
571         continue;
572       }
573       case OP_TESTSET: {
574         TValue *rb = RB(i);
575         if (l_isfalse(rb) != GETARG_C(i)) {
576           setobjs2s(L, ra, rb);
577           dojump(L, pc, GETARG_sBx(*pc));
578         }
579         pc++;
580         continue;
581       }
582       case OP_CALL: {
583         int b = GETARG_B(i);
584         int nresults = GETARG_C(i) - 1;
585         if (b != 0) L->top = ra+b;  /* else previous instruction set top */
586         L->savedpc = pc;
587         switch (luaD_precall(L, ra, nresults)) {
588           case PCRLUA: {
589             nexeccalls++;
590             goto reentry;  /* restart luaV_execute over new Lua function */
591           }
592           case PCRC: {
593             /* it was a C function (`precall' called it); adjust results */
594             if (nresults >= 0) L->top = L->ci->top;
595             base = L->base;
596             continue;
597           }
598           default: {
599             return;  /* yield */
600           }
601         }
602       }
603       case OP_TAILCALL: {
604         int b = GETARG_B(i);
605         if (b != 0) L->top = ra+b;  /* else previous instruction set top */
606         L->savedpc = pc;
607         lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
608         switch (luaD_precall(L, ra, LUA_MULTRET)) {
609           case PCRLUA: {
610             /* tail call: put new frame in place of previous one */
611             CallInfo *ci = L->ci - 1;  /* previous frame */
612             int aux;
613             StkId func = ci->func;
614             StkId pfunc = (ci+1)->func;  /* previous function index */
615             if (L->openupval) luaF_close(L, ci->base);
616             L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
617             for (aux = 0; pfunc+aux < L->top; aux++)  /* move frame down */
618               setobjs2s(L, func+aux, pfunc+aux);
619             ci->top = L->top = func+aux;  /* correct top */
620             lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
621             ci->savedpc = L->savedpc;
622             ci->tailcalls++;  /* one more call lost */
623             L->ci--;  /* remove new frame */
624             goto reentry;
625           }
626           case PCRC: {  /* it was a C function (`precall' called it) */
627             base = L->base;
628             continue;
629           }
630           default: {
631             return;  /* yield */
632           }
633         }
634       }
635       case OP_RETURN: {
636         int b = GETARG_B(i);
637         if (b != 0) L->top = ra+b-1;
638         if (L->openupval) luaF_close(L, base);
639         L->savedpc = pc;
640         b = luaD_poscall(L, ra);
641         if (--nexeccalls == 0)  /* was previous function running `here'? */
642           return;  /* no: return */
643         else {  /* yes: continue its execution */
644           if (b) L->top = L->ci->top;
645           lua_assert(isLua(L->ci));
646           lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
647           goto reentry;
648         }
649       }
650       case OP_FORLOOP: {
651         lua_Number step = nvalue(ra+2);
652         lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
653         lua_Number limit = nvalue(ra+1);
654         if (luai_numlt(0, step) ? luai_numle(idx, limit)
655                                 : luai_numle(limit, idx)) {
656           dojump(L, pc, GETARG_sBx(i));  /* jump back */
657           setnvalue(ra, idx);  /* update internal index... */
658           setnvalue(ra+3, idx);  /* ...and external index */
659         }
660         continue;
661       }
662       case OP_FORPREP: {
663         const TValue *init = ra;
664         const TValue *plimit = ra+1;
665         const TValue *pstep = ra+2;
666         L->savedpc = pc;  /* next steps may throw errors */
667         if (!tonumber(init, ra))
668           luaG_runerror(L, LUA_QL("for") " initial value must be a number");
669         else if (!tonumber(plimit, ra+1))
670           luaG_runerror(L, LUA_QL("for") " limit must be a number");
671         else if (!tonumber(pstep, ra+2))
672           luaG_runerror(L, LUA_QL("for") " step must be a number");
673         setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
674         dojump(L, pc, GETARG_sBx(i));
675         continue;
676       }
677       case OP_TFORLOOP: {
678         StkId cb = ra + 3;  /* call base */
679         setobjs2s(L, cb+2, ra+2);
680         setobjs2s(L, cb+1, ra+1);
681         setobjs2s(L, cb, ra);
682         L->top = cb+3;  /* func. + 2 args (state and index) */
683         Protect(luaD_call(L, cb, GETARG_C(i)));
684         L->top = L->ci->top;
685         cb = RA(i) + 3;  /* previous call may change the stack */
686         if (!ttisnil(cb)) {  /* continue loop? */
687           setobjs2s(L, cb-1, cb);  /* save control variable */
688           dojump(L, pc, GETARG_sBx(*pc));  /* jump back */
689         }
690         pc++;
691         continue;
692       }
693       case OP_SETLIST: {
694         int n = GETARG_B(i);
695         int c = GETARG_C(i);
696         int last;
697         Table *h;
698         if (n == 0) {
699           n = cast_int(L->top - ra) - 1;
700           L->top = L->ci->top;
701         }
702         if (c == 0) c = cast_int(*pc++);
703         runtime_check(L, ttistable(ra));
704         h = hvalue(ra);
705         last = ((c-1)*LFIELDS_PER_FLUSH) + n;
706         if (last > h->sizearray)  /* needs more space? */
707           luaH_resizearray(L, h, last);  /* pre-alloc it at once */
708         for (; n > 0; n--) {
709           TValue *val = ra+n;
710           setobj2t(L, luaH_setnum(L, h, last--), val);
711           luaC_barriert(L, h, val);
712         }
713         continue;
714       }
715       case OP_CLOSE: {
716         luaF_close(L, ra);
717         continue;
718       }
719       case OP_CLOSURE: {
720         Proto *p;
721         Closure *ncl;
722         int nup, j;
723         p = cl->p->p[GETARG_Bx(i)];
724         nup = p->nups;
725         ncl = luaF_newLclosure(L, nup, cl->env);
726         ncl->l.p = p;
727         for (j=0; j<nup; j++, pc++) {
728           if (GET_OPCODE(*pc) == OP_GETUPVAL)
729             ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
730           else {
731             lua_assert(GET_OPCODE(*pc) == OP_MOVE);
732             ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
733           }
734         }
735         setclvalue(L, ra, ncl);
736         Protect(luaC_checkGC(L));
737         continue;
738       }
739       case OP_VARARG: {
740         int b = GETARG_B(i) - 1;
741         int j;
742         CallInfo *ci = L->ci;
743         int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
744         if (b == LUA_MULTRET) {
745           Protect(luaD_checkstack(L, n));
746           ra = RA(i);  /* previous call may change the stack */
747           b = n;
748           L->top = ra + n;
749         }
750         for (j = 0; j < b; j++) {
751           if (j < n) {
752             setobjs2s(L, ra + j, ci->base - n + j);
753           }
754           else {
755             setnilvalue(ra + j);
756           }
757         }
758         continue;
759       }
760     }
761   }
762 }
763
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