Subversion Repositories WoWGM

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
3 tristanc 1
/*
2
** $Id: lvm.c,v 2.63 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 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_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
 
82
static 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
 
98
static 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
 
110
void 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
 
136
void 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
 
163
static 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 (!ttisfunction(tm)) return 0;
169
  callTMres(L, res, tm, p1, p2);
170
  return 1;
171
}
172
 
173
 
174
static 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
 
188
static 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
 
201
static 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
 
223
int 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
 
237
static 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
 
253
int 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
 
280
void 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 (!tostring(L, 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) {  /* if len=0, do nothing */
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