monotone

monotone Mtn Source Tree

Root/lua/lvm.cc

1/*
2** $Id: lvm.c,v 2.63a 2006/06/05 15:58:59 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 MAXTAGLOOP100
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_MASKLINE) { /* instruction-hook set? */
65 if (L->hookcount == 0) {
66 resethookcount(L);
67 luaD_callhook(L, LUA_HOOKCOUNT, -1);
68 }
69 }
70 if (mask & LUA_MASKLINE) {
71 Proto *p = ci_func(L->ci)->l.p;
72 int npc = pcRel(pc, p);
73 int newline = getline(p, npc);
74 /* call linehook when enter a new function, when jump back (loop),
75 or when enter a new line */
76 if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p)))
77 luaD_callhook(L, LUA_HOOKLINE, newline);
78 }
79}
80
81
82static void callTMres (lua_State *L, StkId res, const TValue *f,
83 const TValue *p1, const TValue *p2) {
84 ptrdiff_t result = savestack(L, res);
85 setobj2s(L, L->top, f); /* push function */
86 setobj2s(L, L->top+1, p1); /* 1st argument */
87 setobj2s(L, L->top+2, p2); /* 2nd argument */
88 luaD_checkstack(L, 3);
89 L->top += 3;
90 luaD_call(L, L->top - 3, 1);
91 res = restorestack(L, result);
92 L->top--;
93 setobjs2s(L, res, L->top);
94}
95
96
97
98static void callTM (lua_State *L, const TValue *f, const TValue *p1,
99 const TValue *p2, const TValue *p3) {
100 setobj2s(L, L->top, f); /* push function */
101 setobj2s(L, L->top+1, p1); /* 1st argument */
102 setobj2s(L, L->top+2, p2); /* 2nd argument */
103 setobj2s(L, L->top+3, p3); /* 3th argument */
104 luaD_checkstack(L, 4);
105 L->top += 4;
106 luaD_call(L, L->top - 4, 0);
107}
108
109
110void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
111 int loop;
112 for (loop = 0; loop < MAXTAGLOOP; loop++) {
113 const TValue *tm;
114 if (ttistable(t)) { /* `t' is a table? */
115 Table *h = hvalue(t);
116 const TValue *res = luaH_get(h, key); /* do a primitive get */
117 if (!ttisnil(res) || /* result is no nil? */
118 (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
119 setobj2s(L, val, res);
120 return;
121 }
122 /* else will try the tag method */
123 }
124 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
125 luaG_typeerror(L, t, "index");
126 if (ttisfunction(tm)) {
127 callTMres(L, val, tm, t, key);
128 return;
129 }
130 t = tm; /* else repeat with `tm' */
131 }
132 luaG_runerror(L, "loop in gettable");
133}
134
135
136void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
137 int loop;
138 for (loop = 0; loop < MAXTAGLOOP; loop++) {
139 const TValue *tm;
140 if (ttistable(t)) { /* `t' is a table? */
141 Table *h = hvalue(t);
142 TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
143 if (!ttisnil(oldval) || /* result is no nil? */
144 (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
145 setobj2t(L, oldval, val);
146 luaC_barriert(L, h, val);
147 return;
148 }
149 /* else will try the tag method */
150 }
151 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
152 luaG_typeerror(L, t, "index");
153 if (ttisfunction(tm)) {
154 callTM(L, tm, t, key, val);
155 return;
156 }
157 t = tm; /* else repeat with `tm' */
158 }
159 luaG_runerror(L, "loop in settable");
160}
161
162
163static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
164 StkId res, TMS event) {
165 const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
166 if (ttisnil(tm))
167 tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
168 if (ttisnil(tm)) return 0;
169 callTMres(L, res, tm, p1, p2);
170 return 1;
171}
172
173
174static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
175 TMS event) {
176 const TValue *tm1 = fasttm(L, mt1, event);
177 const TValue *tm2;
178 if (tm1 == NULL) return NULL; /* no metamethod */
179 if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
180 tm2 = fasttm(L, mt2, event);
181 if (tm2 == NULL) return NULL; /* no metamethod */
182 if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
183 return tm1;
184 return NULL;
185}
186
187
188static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
189 TMS event) {
190 const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
191 const TValue *tm2;
192 if (ttisnil(tm1)) return -1; /* no metamethod? */
193 tm2 = luaT_gettmbyobj(L, p2, event);
194 if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
195 return -1;
196 callTMres(L, L->top, tm1, p1, p2);
197 return !l_isfalse(L->top);
198}
199
200
201static int l_strcmp (const TString *ls, const TString *rs) {
202 const char *l = getstr(ls);
203 size_t ll = ls->tsv.len;
204 const char *r = getstr(rs);
205 size_t lr = rs->tsv.len;
206 for (;;) {
207 int temp = strcoll(l, r);
208 if (temp != 0) return temp;
209 else { /* strings are equal up to a `\0' */
210 size_t len = strlen(l); /* index of first `\0' in both strings */
211 if (len == lr) /* r is finished? */
212 return (len == ll) ? 0 : 1;
213 else if (len == ll) /* l is finished? */
214 return -1; /* l is smaller than r (because r is not finished) */
215 /* both strings longer than `len'; go on comparing (after the `\0') */
216 len++;
217 l += len; ll -= len; r += len; lr -= len;
218 }
219 }
220}
221
222
223int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
224 int res;
225 if (ttype(l) != ttype(r))
226 return luaG_ordererror(L, l, r);
227 else if (ttisnumber(l))
228 return luai_numlt(nvalue(l), nvalue(r));
229 else if (ttisstring(l))
230 return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
231 else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
232 return res;
233 return luaG_ordererror(L, l, r);
234}
235
236
237static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
238 int res;
239 if (ttype(l) != ttype(r))
240 return luaG_ordererror(L, l, r);
241 else if (ttisnumber(l))
242 return luai_numle(nvalue(l), nvalue(r));
243 else if (ttisstring(l))
244 return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
245 else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
246 return res;
247 else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
248 return !res;
249 return luaG_ordererror(L, l, r);
250}
251
252
253int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
254 const TValue *tm;
255 lua_assert(ttype(t1) == ttype(t2));
256 switch (ttype(t1)) {
257 case LUA_TNIL: return 1;
258 case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
259 case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
260 case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
261 case LUA_TUSERDATA: {
262 if (uvalue(t1) == uvalue(t2)) return 1;
263 tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
264 TM_EQ);
265 break; /* will try TM */
266 }
267 case LUA_TTABLE: {
268 if (hvalue(t1) == hvalue(t2)) return 1;
269 tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
270 break; /* will try TM */
271 }
272 default: return gcvalue(t1) == gcvalue(t2);
273 }
274 if (tm == NULL) return 0; /* no TM? */
275 callTMres(L, L->top, tm, t1, t2); /* call TM */
276 return !l_isfalse(L->top);
277}
278
279
280void luaV_concat (lua_State *L, int total, int last) {
281 do {
282 StkId top = L->base + last + 1;
283 int n = 2; /* number of elements handled in this pass (at least 2) */
284 if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
285 if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
286 luaG_concaterror(L, top-2, top-1);
287 } else if (tsvalue(top-1)->len == 0) /* second op is empty? */
288 (void)tostring(L, top - 2); /* result is first op (as string) */
289 else {
290 /* at least two string values; get as many as possible */
291 size_t tl = tsvalue(top-1)->len;
292 char *buffer;
293 int i;
294 /* collect total length */
295 for (n = 1; n < total && tostring(L, top-n-1); n++) {
296 size_t l = tsvalue(top-n-1)->len;
297 if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
298 tl += l;
299 }
300 buffer = luaZ_openspace(L, &G(L)->buff, tl);
301 tl = 0;
302 for (i=n; i>0; i--) { /* concat all strings */
303 size_t l = tsvalue(top-i)->len;
304 memcpy(buffer+tl, svalue(top-i), l);
305 tl += l;
306 }
307 setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
308 }
309 total -= n-1; /* got `n' strings to create 1 new */
310 last -= n-1;
311 } while (total > 1); /* repeat until only 1 result left */
312}
313
314
315static void Arith (lua_State *L, StkId ra, const TValue *rb,
316 const TValue *rc, TMS op) {
317 TValue tempb, tempc;
318 const TValue *b, *c;
319 if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
320 (c = luaV_tonumber(rc, &tempc)) != NULL) {
321 lua_Number nb = nvalue(b), nc = nvalue(c);
322 switch (op) {
323 case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break;
324 case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break;
325 case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break;
326 case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break;
327 case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break;
328 case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break;
329 case TM_UNM: setnvalue(ra, luai_numunm(nb)); break;
330 default: lua_assert(0); break;
331 }
332 }
333 else if (!call_binTM(L, rb, rc, ra, op))
334 luaG_aritherror(L, rb, rc);
335}
336
337
338
339/*
340** some macros for common tasks in `luaV_execute'
341*/
342
343#define runtime_check(L, c){ if (!(c)) break; }
344
345#define RA(i)(base+GETARG_A(i))
346/* to be used after possible stack reallocation */
347#define RB(i)check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
348#define RC(i)check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
349#define RKB(i)check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
350ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
351#define RKC(i)check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
352ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
353#define KBx(i)check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
354
355
356#define dojump(L,pc,i){(pc) += (i); luai_threadyield(L);}
357
358
359#define Protect(x){ L->savedpc = pc; {x;}; base = L->base; }
360
361
362#define arith_op(op,tm) { \
363 TValue *rb = RKB(i); \
364 TValue *rc = RKC(i); \
365 if (ttisnumber(rb) && ttisnumber(rc)) { \
366 lua_Number nb = nvalue(rb), nc = nvalue(rc); \
367 setnvalue(ra, op(nb, nc)); \
368 } \
369 else \
370 Protect(Arith(L, ra, rb, rc, tm)); \
371 }
372
373
374
375void luaV_execute (lua_State *L, int nexeccalls) {
376 LClosure *cl;
377 StkId base;
378 TValue *k;
379 const Instruction *pc;
380 reentry: /* entry point */
381 lua_assert(isLua(L->ci));
382 pc = L->savedpc;
383 cl = &clvalue(L->ci->func)->l;
384 base = L->base;
385 k = cl->p->k;
386 /* main loop of interpreter */
387 for (;;) {
388 const Instruction i = *pc++;
389 StkId ra;
390 if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
391 (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
392 traceexec(L, pc);
393 if (L->status == LUA_YIELD) { /* did hook yield? */
394 L->savedpc = pc - 1;
395 return;
396 }
397 base = L->base;
398 }
399 /* warning!! several calls may realloc the stack and invalidate `ra' */
400 ra = RA(i);
401 lua_assert(base == L->base && L->base == L->ci->base);
402 lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
403 lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
404 switch (GET_OPCODE(i)) {
405 case OP_MOVE: {
406 setobjs2s(L, ra, RB(i));
407 continue;
408 }
409 case OP_LOADK: {
410 setobj2s(L, ra, KBx(i));
411 continue;
412 }
413 case OP_LOADBOOL: {
414 setbvalue(ra, GETARG_B(i));
415 if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
416 continue;
417 }
418 case OP_LOADNIL: {
419 TValue *rb = RB(i);
420 do {
421 setnilvalue(rb--);
422 } while (rb >= ra);
423 continue;
424 }
425 case OP_GETUPVAL: {
426 int b = GETARG_B(i);
427 setobj2s(L, ra, cl->upvals[b]->v);
428 continue;
429 }
430 case OP_GETGLOBAL: {
431 TValue g;
432 TValue *rb = KBx(i);
433 sethvalue(L, &g, cl->env);
434 lua_assert(ttisstring(rb));
435 Protect(luaV_gettable(L, &g, rb, ra));
436 continue;
437 }
438 case OP_GETTABLE: {
439 Protect(luaV_gettable(L, RB(i), RKC(i), ra));
440 continue;
441 }
442 case OP_SETGLOBAL: {
443 TValue g;
444 sethvalue(L, &g, cl->env);
445 lua_assert(ttisstring(KBx(i)));
446 Protect(luaV_settable(L, &g, KBx(i), ra));
447 continue;
448 }
449 case OP_SETUPVAL: {
450 UpVal *uv = cl->upvals[GETARG_B(i)];
451 setobj(L, uv->v, ra);
452 luaC_barrier(L, uv, ra);
453 continue;
454 }
455 case OP_SETTABLE: {
456 Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
457 continue;
458 }
459 case OP_NEWTABLE: {
460 int b = GETARG_B(i);
461 int c = GETARG_C(i);
462 sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
463 Protect(luaC_checkGC(L));
464 continue;
465 }
466 case OP_SELF: {
467 StkId rb = RB(i);
468 setobjs2s(L, ra+1, rb);
469 Protect(luaV_gettable(L, rb, RKC(i), ra));
470 continue;
471 }
472 case OP_ADD: {
473 arith_op(luai_numadd, TM_ADD);
474 continue;
475 }
476 case OP_SUB: {
477 arith_op(luai_numsub, TM_SUB);
478 continue;
479 }
480 case OP_MUL: {
481 arith_op(luai_nummul, TM_MUL);
482 continue;
483 }
484 case OP_DIV: {
485 arith_op(luai_numdiv, TM_DIV);
486 continue;
487 }
488 case OP_MOD: {
489 arith_op(luai_nummod, TM_MOD);
490 continue;
491 }
492 case OP_POW: {
493 arith_op(luai_numpow, TM_POW);
494 continue;
495 }
496 case OP_UNM: {
497 TValue *rb = RB(i);
498 if (ttisnumber(rb)) {
499 lua_Number nb = nvalue(rb);
500 setnvalue(ra, luai_numunm(nb));
501 }
502 else {
503 Protect(Arith(L, ra, rb, rb, TM_UNM));
504 }
505 continue;
506 }
507 case OP_NOT: {
508 int res = l_isfalse(RB(i)); /* next assignment may change this value */
509 setbvalue(ra, res);
510 continue;
511 }
512 case OP_LEN: {
513 const TValue *rb = RB(i);
514 switch (ttype(rb)) {
515 case LUA_TTABLE: {
516 setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
517 break;
518 }
519 case LUA_TSTRING: {
520 setnvalue(ra, cast_num(tsvalue(rb)->len));
521 break;
522 }
523 default: { /* try metamethod */
524 Protect(
525 if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
526 luaG_typeerror(L, rb, "get length of");
527 )
528 }
529 }
530 continue;
531 }
532 case OP_CONCAT: {
533 int b = GETARG_B(i);
534 int c = GETARG_C(i);
535 Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
536 setobjs2s(L, RA(i), base+b);
537 continue;
538 }
539 case OP_JMP: {
540 dojump(L, pc, GETARG_sBx(i));
541 continue;
542 }
543 case OP_EQ: {
544 TValue *rb = RKB(i);
545 TValue *rc = RKC(i);
546 Protect(
547 if (equalobj(L, rb, rc) == GETARG_A(i))
548 dojump(L, pc, GETARG_sBx(*pc));
549 )
550 pc++;
551 continue;
552 }
553 case OP_LT: {
554 Protect(
555 if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
556 dojump(L, pc, GETARG_sBx(*pc));
557 )
558 pc++;
559 continue;
560 }
561 case OP_LE: {
562 Protect(
563 if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
564 dojump(L, pc, GETARG_sBx(*pc));
565 )
566 pc++;
567 continue;
568 }
569 case OP_TEST: {
570 if (l_isfalse(ra) != GETARG_C(i))
571 dojump(L, pc, GETARG_sBx(*pc));
572 pc++;
573 continue;
574 }
575 case OP_TESTSET: {
576 TValue *rb = RB(i);
577 if (l_isfalse(rb) != GETARG_C(i)) {
578 setobjs2s(L, ra, rb);
579 dojump(L, pc, GETARG_sBx(*pc));
580 }
581 pc++;
582 continue;
583 }
584 case OP_CALL: {
585 int b = GETARG_B(i);
586 int nresults = GETARG_C(i) - 1;
587 if (b != 0) L->top = ra+b; /* else previous instruction set top */
588 L->savedpc = pc;
589 switch (luaD_precall(L, ra, nresults)) {
590 case PCRLUA: {
591 nexeccalls++;
592 goto reentry; /* restart luaV_execute over new Lua function */
593 }
594 case PCRC: {
595 /* it was a C function (`precall' called it); adjust results */
596 if (nresults >= 0) L->top = L->ci->top;
597 base = L->base;
598 continue;
599 }
600 default: {
601 return; /* yield */
602 }
603 }
604 }
605 case OP_TAILCALL: {
606 int b = GETARG_B(i);
607 if (b != 0) L->top = ra+b; /* else previous instruction set top */
608 L->savedpc = pc;
609 lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
610 switch (luaD_precall(L, ra, LUA_MULTRET)) {
611 case PCRLUA: {
612 /* tail call: put new frame in place of previous one */
613 CallInfo *ci = L->ci - 1; /* previous frame */
614 int aux;
615 StkId func = ci->func;
616 StkId pfunc = (ci+1)->func; /* previous function index */
617 if (L->openupval) luaF_close(L, ci->base);
618 L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
619 for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */
620 setobjs2s(L, func+aux, pfunc+aux);
621 ci->top = L->top = func+aux; /* correct top */
622 lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
623 ci->savedpc = L->savedpc;
624 ci->tailcalls++; /* one more call lost */
625 L->ci--; /* remove new frame */
626 goto reentry;
627 }
628 case PCRC: { /* it was a C function (`precall' called it) */
629 base = L->base;
630 continue;
631 }
632 default: {
633 return; /* yield */
634 }
635 }
636 }
637 case OP_RETURN: {
638 int b = GETARG_B(i);
639 if (b != 0) L->top = ra+b-1;
640 if (L->openupval) luaF_close(L, base);
641 L->savedpc = pc;
642 b = luaD_poscall(L, ra);
643 if (--nexeccalls == 0) /* was previous function running `here'? */
644 return; /* no: return */
645 else { /* yes: continue its execution */
646 if (b) L->top = L->ci->top;
647 lua_assert(isLua(L->ci));
648 lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
649 goto reentry;
650 }
651 }
652 case OP_FORLOOP: {
653 lua_Number step = nvalue(ra+2);
654 lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
655 lua_Number limit = nvalue(ra+1);
656 if (luai_numlt(0, step) ? luai_numle(idx, limit)
657 : luai_numle(limit, idx)) {
658 dojump(L, pc, GETARG_sBx(i)); /* jump back */
659 setnvalue(ra, idx); /* update internal index... */
660 setnvalue(ra+3, idx); /* ...and external index */
661 }
662 continue;
663 }
664 case OP_FORPREP: {
665 const TValue *init = ra;
666 const TValue *plimit = ra+1;
667 const TValue *pstep = ra+2;
668 L->savedpc = pc; /* next steps may throw errors */
669 if (!tonumber(init, ra))
670 luaG_runerror(L, LUA_QL("for") " initial value must be a number");
671 else if (!tonumber(plimit, ra+1))
672 luaG_runerror(L, LUA_QL("for") " limit must be a number");
673 else if (!tonumber(pstep, ra+2))
674 luaG_runerror(L, LUA_QL("for") " step must be a number");
675 setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
676 dojump(L, pc, GETARG_sBx(i));
677 continue;
678 }
679 case OP_TFORLOOP: {
680 StkId cb = ra + 3; /* call base */
681 setobjs2s(L, cb+2, ra+2);
682 setobjs2s(L, cb+1, ra+1);
683 setobjs2s(L, cb, ra);
684 L->top = cb+3; /* func. + 2 args (state and index) */
685 Protect(luaD_call(L, cb, GETARG_C(i)));
686 L->top = L->ci->top;
687 cb = RA(i) + 3; /* previous call may change the stack */
688 if (!ttisnil(cb)) { /* continue loop? */
689 setobjs2s(L, cb-1, cb); /* save control variable */
690 dojump(L, pc, GETARG_sBx(*pc)); /* jump back */
691 }
692 pc++;
693 continue;
694 }
695 case OP_SETLIST: {
696 int n = GETARG_B(i);
697 int c = GETARG_C(i);
698 int last;
699 Table *h;
700 if (n == 0) {
701 n = cast_int(L->top - ra) - 1;
702 L->top = L->ci->top;
703 }
704 if (c == 0) c = cast_int(*pc++);
705 runtime_check(L, ttistable(ra));
706 h = hvalue(ra);
707 last = ((c-1)*LFIELDS_PER_FLUSH) + n;
708 if (last > h->sizearray) /* needs more space? */
709 luaH_resizearray(L, h, last); /* pre-alloc it at once */
710 for (; n > 0; n--) {
711 TValue *val = ra+n;
712 setobj2t(L, luaH_setnum(L, h, last--), val);
713 luaC_barriert(L, h, val);
714 }
715 continue;
716 }
717 case OP_CLOSE: {
718 luaF_close(L, ra);
719 continue;
720 }
721 case OP_CLOSURE: {
722 Proto *p;
723 Closure *ncl;
724 int nup, j;
725 p = cl->p->p[GETARG_Bx(i)];
726 nup = p->nups;
727 ncl = luaF_newLclosure(L, nup, cl->env);
728 ncl->l.p = p;
729 for (j=0; j<nup; j++, pc++) {
730 if (GET_OPCODE(*pc) == OP_GETUPVAL)
731 ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
732 else {
733 lua_assert(GET_OPCODE(*pc) == OP_MOVE);
734 ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
735 }
736 }
737 setclvalue(L, ra, ncl);
738 Protect(luaC_checkGC(L));
739 continue;
740 }
741 case OP_VARARG: {
742 int b = GETARG_B(i) - 1;
743 int j;
744 CallInfo *ci = L->ci;
745 int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
746 if (b == LUA_MULTRET) {
747 Protect(luaD_checkstack(L, n));
748 ra = RA(i); /* previous call may change the stack */
749 b = n;
750 L->top = ra + n;
751 }
752 for (j = 0; j < b; j++) {
753 if (j < n) {
754 setobjs2s(L, ra + j, ci->base - n + j);
755 }
756 else {
757 setnilvalue(ra + j);
758 }
759 }
760 continue;
761 }
762 }
763 }
764}
765

Archive Download this file

Branches

Tags

Quick Links:     www.monotone.ca    -     Downloads    -     Documentation    -     Wiki    -     Code Forge    -     Build Status