1/*
2** $Id: lvm.c,v 2.155 2013/03/16 21:10:18 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), tsvalue(obj)->len, &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    int l = lua_number2str(s, n);
54    setsvalue2s(L, obj, luaS_newlstr(L, s, l));
55    return 1;
56  }
57}
58
59
60static void traceexec (lua_State *L) {
61  CallInfo *ci = L->ci;
62  lu_byte mask = L->hookmask;
63  int counthook = ((mask & LUA_MASKCOUNT) && L->hookcount == 0);
64  if (counthook)
65    resethookcount(L);  /* reset count */
66  if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
67    ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
68    return;  /* do not call hook again (VM yielded, so it did not move) */
69  }
70  if (counthook)
71    luaD_hook(L, LUA_HOOKCOUNT, -1);  /* call count hook */
72  if (mask & LUA_MASKLINE) {
73    Proto *p = ci_func(ci)->p;
74    int npc = pcRel(ci->u.l.savedpc, p);
75    int newline = getfuncline(p, npc);
76    if (npc == 0 ||  /* call linehook when enter a new function, */
77        ci->u.l.savedpc <= L->oldpc ||  /* when jump back (loop), or when */
78        newline != getfuncline(p, pcRel(L->oldpc, p)))  /* enter a new line */
79      luaD_hook(L, LUA_HOOKLINE, newline);  /* call line hook */
80  }
81  L->oldpc = ci->u.l.savedpc;
82  if (L->status == LUA_YIELD) {  /* did hook yield? */
83    if (counthook)
84      L->hookcount = 1;  /* undo decrement to zero */
85    ci->u.l.savedpc--;  /* undo increment (resume will increment it again) */
86    ci->callstatus |= CIST_HOOKYIELD;  /* mark that it yielded */
87    ci->func = L->top - 1;  /* protect stack below results */
88    luaD_throw(L, LUA_YIELD);
89  }
90}
91
92
93static void callTM (lua_State *L, const TValue *f, const TValue *p1,
94                    const TValue *p2, TValue *p3, int hasres) {
95  ptrdiff_t result = savestack(L, p3);
96  setobj2s(L, L->top++, f);  /* push function */
97  setobj2s(L, L->top++, p1);  /* 1st argument */
98  setobj2s(L, L->top++, p2);  /* 2nd argument */
99  if (!hasres)  /* no result? 'p3' is third argument */
100    setobj2s(L, L->top++, p3);  /* 3rd argument */
101  /* metamethod may yield only when called from Lua code */
102  luaD_call(L, L->top - (4 - hasres), hasres, isLua(L->ci));
103  if (hasres) {  /* if has result, move it to its place */
104    p3 = restorestack(L, result);
105    setobjs2s(L, p3, --L->top);
106  }
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 not 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      callTM(L, tm, t, key, val, 1);
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 = cast(TValue *, luaH_get(h, key));
143      /* if previous value is not nil, there must be a previous entry
144         in the table; moreover, a metamethod has no relevance */
145      if (!ttisnil(oldval) ||
146         /* previous value is nil; must check the metamethod */
147         ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
148         /* no metamethod; is there a previous entry in the table? */
149         (oldval != luaO_nilobject ||
150         /* no previous entry; must create one. (The next test is
151            always true; we only need the assignment.) */
152         (oldval = luaH_newkey(L, h, key), 1)))) {
153        /* no metamethod and (now) there is an entry with given key */
154        setobj2t(L, oldval, val);  /* assign new value to that entry */
155        invalidateTMcache(h);
156        luaC_barrierback(L, obj2gco(h), val);
157        return;
158      }
159      /* else will try the metamethod */
160    }
161    else  /* not a table; check metamethod */
162      if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
163        luaG_typeerror(L, t, "index");
164    /* there is a metamethod */
165    if (ttisfunction(tm)) {
166      callTM(L, tm, t, key, val, 0);
167      return;
168    }
169    t = tm;  /* else repeat with 'tm' */
170  }
171  luaG_runerror(L, "loop in settable");
172}
173
174
175static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
176                       StkId res, TMS event) {
177  const TValue *tm = luaT_gettmbyobj(L, p1, event);  /* try first operand */
178  if (ttisnil(tm))
179    tm = luaT_gettmbyobj(L, p2, event);  /* try second operand */
180  if (ttisnil(tm)) return 0;
181  callTM(L, tm, p1, p2, res, 1);
182  return 1;
183}
184
185
186static const TValue *get_equalTM (lua_State *L, Table *mt1, Table *mt2,
187                                  TMS event) {
188  const TValue *tm1 = fasttm(L, mt1, event);
189  const TValue *tm2;
190  if (tm1 == NULL) return NULL;  /* no metamethod */
191  if (mt1 == mt2) return tm1;  /* same metatables => same metamethods */
192  tm2 = fasttm(L, mt2, event);
193  if (tm2 == NULL) return NULL;  /* no metamethod */
194  if (luaV_rawequalobj(tm1, tm2))  /* same metamethods? */
195    return tm1;
196  return NULL;
197}
198
199
200static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
201                         TMS event) {
202  if (!call_binTM(L, p1, p2, L->top, event))
203    return -1;  /* no metamethod */
204  else
205    return !l_isfalse(L->top);
206}
207
208
209static int l_strcmp (const TString *ls, const TString *rs) {
210  const char *l = getstr(ls);
211  size_t ll = ls->tsv.len;
212  const char *r = getstr(rs);
213  size_t lr = rs->tsv.len;
214  for (;;) {
215    int temp = strcoll(l, r);
216    if (temp != 0) return temp;
217    else {  /* strings are equal up to a `\0' */
218      size_t len = strlen(l);  /* index of first `\0' in both strings */
219      if (len == lr)  /* r is finished? */
220        return (len == ll) ? 0 : 1;
221      else if (len == ll)  /* l is finished? */
222        return -1;  /* l is smaller than r (because r is not finished) */
223      /* both strings longer than `len'; go on comparing (after the `\0') */
224      len++;
225      l += len; ll -= len; r += len; lr -= len;
226    }
227  }
228}
229
230
231int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
232  int res;
233  if (ttisnumber(l) && ttisnumber(r))
234    return luai_numlt(L, nvalue(l), nvalue(r));
235  else if (ttisstring(l) && ttisstring(r))
236    return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
237  else if ((res = call_orderTM(L, l, r, TM_LT)) < 0)
238    luaG_ordererror(L, l, r);
239  return res;
240}
241
242
243int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
244  int res;
245  if (ttisnumber(l) && ttisnumber(r))
246    return luai_numle(L, nvalue(l), nvalue(r));
247  else if (ttisstring(l) && ttisstring(r))
248    return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
249  else if ((res = call_orderTM(L, l, r, TM_LE)) >= 0)  /* first try `le' */
250    return res;
251  else if ((res = call_orderTM(L, r, l, TM_LT)) < 0)  /* else try `lt' */
252    luaG_ordererror(L, l, r);
253  return !res;
254}
255
256
257/*
258** equality of Lua values. L == NULL means raw equality (no metamethods)
259*/
260int luaV_equalobj_ (lua_State *L, const TValue *t1, const TValue *t2) {
261  const TValue *tm;
262  lua_assert(ttisequal(t1, t2));
263  switch (ttype(t1)) {
264    case LUA_TNIL: return 1;
265    case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
266    case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
267    case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
268    case LUA_TLCF: return fvalue(t1) == fvalue(t2);
269    case LUA_TSHRSTR: return eqshrstr(rawtsvalue(t1), rawtsvalue(t2));
270    case LUA_TLNGSTR: return luaS_eqlngstr(rawtsvalue(t1), rawtsvalue(t2));
271    case LUA_TUSERDATA: {
272      if (uvalue(t1) == uvalue(t2)) return 1;
273      else if (L == NULL) return 0;
274      tm = get_equalTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable, TM_EQ);
275      break;  /* will try TM */
276    }
277    case LUA_TTABLE: {
278      if (hvalue(t1) == hvalue(t2)) return 1;
279      else if (L == NULL) return 0;
280      tm = get_equalTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
281      break;  /* will try TM */
282    }
283    default:
284      lua_assert(iscollectable(t1));
285      return gcvalue(t1) == gcvalue(t2);
286  }
287  if (tm == NULL) return 0;  /* no TM? */
288  callTM(L, tm, t1, t2, L->top, 1);  /* call TM */
289  return !l_isfalse(L->top);
290}
291
292
293void luaV_concat (lua_State *L, int total) {
294  lua_assert(total >= 2);
295  do {
296    StkId top = L->top;
297    int n = 2;  /* number of elements handled in this pass (at least 2) */
298    if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
299      if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
300        luaG_concaterror(L, top-2, top-1);
301    }
302    else if (tsvalue(top-1)->len == 0)  /* second operand is empty? */
303      (void)tostring(L, top - 2);  /* result is first operand */
304    else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) {
305      setobjs2s(L, top - 2, top - 1);  /* result is second op. */
306    }
307    else {
308      /* at least two non-empty string values; get as many as possible */
309      size_t tl = tsvalue(top-1)->len;
310      char *buffer;
311      int i;
312      /* collect total length */
313      for (i = 1; i < total && tostring(L, top-i-1); i++) {
314        size_t l = tsvalue(top-i-1)->len;
315        if (l >= (MAX_SIZET/sizeof(char)) - tl)
316          luaG_runerror(L, "string length overflow");
317        tl += l;
318      }
319      buffer = luaZ_openspace(L, &G(L)->buff, tl);
320      tl = 0;
321      n = i;
322      do {  /* concat all strings */
323        size_t l = tsvalue(top-i)->len;
324        memcpy(buffer+tl, svalue(top-i), l * sizeof(char));
325        tl += l;
326      } while (--i > 0);
327      setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
328    }
329    total -= n-1;  /* got 'n' strings to create 1 new */
330    L->top -= n-1;  /* popped 'n' strings and pushed one */
331  } while (total > 1);  /* repeat until only 1 result left */
332}
333
334
335void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
336  const TValue *tm;
337  switch (ttypenv(rb)) {
338    case LUA_TTABLE: {
339      Table *h = hvalue(rb);
340      tm = fasttm(L, h->metatable, TM_LEN);
341      if (tm) break;  /* metamethod? break switch to call it */
342      setnvalue(ra, cast_num(luaH_getn(h)));  /* else primitive len */
343      return;
344    }
345    case LUA_TSTRING: {
346      setnvalue(ra, cast_num(tsvalue(rb)->len));
347      return;
348    }
349    default: {  /* try metamethod */
350      tm = luaT_gettmbyobj(L, rb, TM_LEN);
351      if (ttisnil(tm))  /* no metamethod? */
352        luaG_typeerror(L, rb, "get length of");
353      break;
354    }
355  }
356  callTM(L, tm, rb, rb, ra, 1);
357}
358
359
360void luaV_arith (lua_State *L, StkId ra, const TValue *rb,
361                 const TValue *rc, TMS op) {
362  TValue tempb, tempc;
363  const TValue *b, *c;
364  if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
365      (c = luaV_tonumber(rc, &tempc)) != NULL) {
366    lua_Number res = luaO_arith(op - TM_ADD + LUA_OPADD, nvalue(b), nvalue(c));
367    setnvalue(ra, res);
368  }
369  else if (!call_binTM(L, rb, rc, ra, op))
370    luaG_aritherror(L, rb, rc);
371}
372
373
374/*
375** check whether cached closure in prototype 'p' may be reused, that is,
376** whether there is a cached closure with the same upvalues needed by
377** new closure to be created.
378*/
379static Closure *getcached (Proto *p, UpVal **encup, StkId base) {
380  Closure *c = p->cache;
381  if (c != NULL) {  /* is there a cached closure? */
382    int nup = p->sizeupvalues;
383    Upvaldesc *uv = p->upvalues;
384    int i;
385    for (i = 0; i < nup; i++) {  /* check whether it has right upvalues */
386      TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v;
387      if (c->l.upvals[i]->v != v)
388        return NULL;  /* wrong upvalue; cannot reuse closure */
389    }
390  }
391  return c;  /* return cached closure (or NULL if no cached closure) */
392}
393
394
395/*
396** create a new Lua closure, push it in the stack, and initialize
397** its upvalues. Note that the call to 'luaC_barrierproto' must come
398** before the assignment to 'p->cache', as the function needs the
399** original value of that field.
400*/
401static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
402                         StkId ra) {
403  int nup = p->sizeupvalues;
404  Upvaldesc *uv = p->upvalues;
405  int i;
406  Closure *ncl = luaF_newLclosure(L, nup);
407  ncl->l.p = p;
408  setclLvalue(L, ra, ncl);  /* anchor new closure in stack */
409  for (i = 0; i < nup; i++) {  /* fill in its upvalues */
410    if (uv[i].instack)  /* upvalue refers to local variable? */
411      ncl->l.upvals[i] = luaF_findupval(L, base + uv[i].idx);
412    else  /* get upvalue from enclosing function */
413      ncl->l.upvals[i] = encup[uv[i].idx];
414  }
415  luaC_barrierproto(L, p, ncl);
416  p->cache = ncl;  /* save it on cache for reuse */
417}
418
419
420/*
421** finish execution of an opcode interrupted by an yield
422*/
423void luaV_finishOp (lua_State *L) {
424  CallInfo *ci = L->ci;
425  StkId base = ci->u.l.base;
426  Instruction inst = *(ci->u.l.savedpc - 1);  /* interrupted instruction */
427  OpCode op = GET_OPCODE(inst);
428  switch (op) {  /* finish its execution */
429    case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV:
430    case OP_MOD: case OP_POW: case OP_UNM: case OP_LEN:
431    case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: {
432      setobjs2s(L, base + GETARG_A(inst), --L->top);
433      break;
434    }
435    case OP_LE: case OP_LT: case OP_EQ: {
436      int res = !l_isfalse(L->top - 1);
437      L->top--;
438      /* metamethod should not be called when operand is K */
439      lua_assert(!ISK(GETARG_B(inst)));
440      if (op == OP_LE &&  /* "<=" using "<" instead? */
441          ttisnil(luaT_gettmbyobj(L, base + GETARG_B(inst), TM_LE)))
442        res = !res;  /* invert result */
443      lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
444      if (res != GETARG_A(inst))  /* condition failed? */
445        ci->u.l.savedpc++;  /* skip jump instruction */
446      break;
447    }
448    case OP_CONCAT: {
449      StkId top = L->top - 1;  /* top when 'call_binTM' was called */
450      int b = GETARG_B(inst);      /* first element to concatenate */
451      int total = cast_int(top - 1 - (base + b));  /* yet to concatenate */
452      setobj2s(L, top - 2, top);  /* put TM result in proper position */
453      if (total > 1) {  /* are there elements to concat? */
454        L->top = top - 1;  /* top is one after last element (at top-2) */
455        luaV_concat(L, total);  /* concat them (may yield again) */
456      }
457      /* move final result to final position */
458      setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1);
459      L->top = ci->top;  /* restore top */
460      break;
461    }
462    case OP_TFORCALL: {
463      lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP);
464      L->top = ci->top;  /* correct top */
465      break;
466    }
467    case OP_CALL: {
468      if (GETARG_C(inst) - 1 >= 0)  /* nresults >= 0? */
469        L->top = ci->top;  /* adjust results */
470      break;
471    }
472    case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE:
473      break;
474    default: lua_assert(0);
475  }
476}
477
478
479
480/*
481** some macros for common tasks in `luaV_execute'
482*/
483
484#if !defined luai_runtimecheck
485#define luai_runtimecheck(L, c)		/* void */
486#endif
487
488
489#define RA(i)	(base+GETARG_A(i))
490/* to be used after possible stack reallocation */
491#define RB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
492#define RC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
493#define RKB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
494	ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
495#define RKC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
496	ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
497#define KBx(i)  \
498  (k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++)))
499
500
501/* execute a jump instruction */
502#define dojump(ci,i,e) \
503  { int a = GETARG_A(i); \
504    if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \
505    ci->u.l.savedpc += GETARG_sBx(i) + e; }
506
507/* for test instructions, execute the jump instruction that follows it */
508#define donextjump(ci)	{ i = *ci->u.l.savedpc; dojump(ci, i, 1); }
509
510
511#define Protect(x)	{ {x;}; base = ci->u.l.base; }
512
513#define checkGC(L,c)  \
514  Protect( luaC_condGC(L,{L->top = (c);  /* limit of live values */ \
515                          luaC_step(L); \
516                          L->top = ci->top;})  /* restore top */ \
517           luai_threadyield(L); )
518
519
520#define arith_op(op,tm) { \
521        TValue *rb = RKB(i); \
522        TValue *rc = RKC(i); \
523        if (ttisnumber(rb) && ttisnumber(rc)) { \
524          lua_Number nb = nvalue(rb), nc = nvalue(rc); \
525          setnvalue(ra, op(L, nb, nc)); \
526        } \
527        else { Protect(luaV_arith(L, ra, rb, rc, tm)); } }
528
529
530#define vmdispatch(o)	switch(o)
531#define vmcase(l,b)	case l: {b}  break;
532#define vmcasenb(l,b)	case l: {b}		/* nb = no break */
533
534void luaV_execute (lua_State *L) {
535  CallInfo *ci = L->ci;
536  LClosure *cl;
537  TValue *k;
538  StkId base;
539 newframe:  /* reentry point when frame changes (call/return) */
540  lua_assert(ci == L->ci);
541  cl = clLvalue(ci->func);
542  k = cl->p->k;
543  base = ci->u.l.base;
544  /* main loop of interpreter */
545  for (;;) {
546    Instruction i = *(ci->u.l.savedpc++);
547    StkId ra;
548    if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
549        (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
550      Protect(traceexec(L));
551    }
552    /* WARNING: several calls may realloc the stack and invalidate `ra' */
553    ra = RA(i);
554    lua_assert(base == ci->u.l.base);
555    lua_assert(base <= L->top && L->top < L->stack + L->stacksize);
556    vmdispatch (GET_OPCODE(i)) {
557      vmcase(OP_MOVE,
558        setobjs2s(L, ra, RB(i));
559      )
560      vmcase(OP_LOADK,
561        TValue *rb = k + GETARG_Bx(i);
562        setobj2s(L, ra, rb);
563      )
564      vmcase(OP_LOADKX,
565        TValue *rb;
566        lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
567        rb = k + GETARG_Ax(*ci->u.l.savedpc++);
568        setobj2s(L, ra, rb);
569      )
570      vmcase(OP_LOADBOOL,
571        setbvalue(ra, GETARG_B(i));
572        if (GETARG_C(i)) ci->u.l.savedpc++;  /* skip next instruction (if C) */
573      )
574      vmcase(OP_LOADNIL,
575        int b = GETARG_B(i);
576        do {
577          setnilvalue(ra++);
578        } while (b--);
579      )
580      vmcase(OP_GETUPVAL,
581        int b = GETARG_B(i);
582        setobj2s(L, ra, cl->upvals[b]->v);
583      )
584      vmcase(OP_GETTABUP,
585        int b = GETARG_B(i);
586        Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra));
587      )
588      vmcase(OP_GETTABLE,
589        Protect(luaV_gettable(L, RB(i), RKC(i), ra));
590      )
591      vmcase(OP_SETTABUP,
592        int a = GETARG_A(i);
593        Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i)));
594      )
595      vmcase(OP_SETUPVAL,
596        UpVal *uv = cl->upvals[GETARG_B(i)];
597        setobj(L, uv->v, ra);
598        luaC_barrier(L, uv, ra);
599      )
600      vmcase(OP_SETTABLE,
601        Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
602      )
603      vmcase(OP_NEWTABLE,
604        int b = GETARG_B(i);
605        int c = GETARG_C(i);
606        Table *t = luaH_new(L);
607        sethvalue(L, ra, t);
608        if (b != 0 || c != 0)
609          luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c));
610        checkGC(L, ra + 1);
611      )
612      vmcase(OP_SELF,
613        StkId rb = RB(i);
614        setobjs2s(L, ra+1, rb);
615        Protect(luaV_gettable(L, rb, RKC(i), ra));
616      )
617      vmcase(OP_ADD,
618        arith_op(luai_numadd, TM_ADD);
619      )
620      vmcase(OP_SUB,
621        arith_op(luai_numsub, TM_SUB);
622      )
623      vmcase(OP_MUL,
624        arith_op(luai_nummul, TM_MUL);
625      )
626      vmcase(OP_DIV,
627        arith_op(luai_numdiv, TM_DIV);
628      )
629      vmcase(OP_MOD,
630        arith_op(luai_nummod, TM_MOD);
631      )
632      vmcase(OP_POW,
633        arith_op(luai_numpow, TM_POW);
634      )
635      vmcase(OP_UNM,
636        TValue *rb = RB(i);
637        if (ttisnumber(rb)) {
638          lua_Number nb = nvalue(rb);
639          setnvalue(ra, luai_numunm(L, nb));
640        }
641        else {
642          Protect(luaV_arith(L, ra, rb, rb, TM_UNM));
643        }
644      )
645      vmcase(OP_NOT,
646        TValue *rb = RB(i);
647        int res = l_isfalse(rb);  /* next assignment may change this value */
648        setbvalue(ra, res);
649      )
650      vmcase(OP_LEN,
651        Protect(luaV_objlen(L, ra, RB(i)));
652      )
653      vmcase(OP_CONCAT,
654        int b = GETARG_B(i);
655        int c = GETARG_C(i);
656        StkId rb;
657        L->top = base + c + 1;  /* mark the end of concat operands */
658        Protect(luaV_concat(L, c - b + 1));
659        ra = RA(i);  /* 'luav_concat' may invoke TMs and move the stack */
660        rb = b + base;
661        setobjs2s(L, ra, rb);
662        checkGC(L, (ra >= rb ? ra + 1 : rb));
663        L->top = ci->top;  /* restore top */
664      )
665      vmcase(OP_JMP,
666        dojump(ci, i, 0);
667      )
668      vmcase(OP_EQ,
669        TValue *rb = RKB(i);
670        TValue *rc = RKC(i);
671        Protect(
672          if (cast_int(equalobj(L, rb, rc)) != GETARG_A(i))
673            ci->u.l.savedpc++;
674          else
675            donextjump(ci);
676        )
677      )
678      vmcase(OP_LT,
679        Protect(
680          if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i))
681            ci->u.l.savedpc++;
682          else
683            donextjump(ci);
684        )
685      )
686      vmcase(OP_LE,
687        Protect(
688          if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i))
689            ci->u.l.savedpc++;
690          else
691            donextjump(ci);
692        )
693      )
694      vmcase(OP_TEST,
695        if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra))
696            ci->u.l.savedpc++;
697          else
698          donextjump(ci);
699      )
700      vmcase(OP_TESTSET,
701        TValue *rb = RB(i);
702        if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb))
703          ci->u.l.savedpc++;
704        else {
705          setobjs2s(L, ra, rb);
706          donextjump(ci);
707        }
708      )
709      vmcase(OP_CALL,
710        int b = GETARG_B(i);
711        int nresults = GETARG_C(i) - 1;
712        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
713        if (luaD_precall(L, ra, nresults)) {  /* C function? */
714          if (nresults >= 0) L->top = ci->top;  /* adjust results */
715          base = ci->u.l.base;
716        }
717        else {  /* Lua function */
718          ci = L->ci;
719          ci->callstatus |= CIST_REENTRY;
720          goto newframe;  /* restart luaV_execute over new Lua function */
721        }
722      )
723      vmcase(OP_TAILCALL,
724        int b = GETARG_B(i);
725        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
726        lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
727        if (luaD_precall(L, ra, LUA_MULTRET))  /* C function? */
728          base = ci->u.l.base;
729        else {
730          /* tail call: put called frame (n) in place of caller one (o) */
731          CallInfo *nci = L->ci;  /* called frame */
732          CallInfo *oci = nci->previous;  /* caller frame */
733          StkId nfunc = nci->func;  /* called function */
734          StkId ofunc = oci->func;  /* caller function */
735          /* last stack slot filled by 'precall' */
736          StkId lim = nci->u.l.base + getproto(nfunc)->numparams;
737          int aux;
738          /* close all upvalues from previous call */
739          if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base);
740          /* move new frame into old one */
741          for (aux = 0; nfunc + aux < lim; aux++)
742            setobjs2s(L, ofunc + aux, nfunc + aux);
743          oci->u.l.base = ofunc + (nci->u.l.base - nfunc);  /* correct base */
744          oci->top = L->top = ofunc + (L->top - nfunc);  /* correct top */
745          oci->u.l.savedpc = nci->u.l.savedpc;
746          oci->callstatus |= CIST_TAIL;  /* function was tail called */
747          ci = L->ci = oci;  /* remove new frame */
748          lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize);
749          goto newframe;  /* restart luaV_execute over new Lua function */
750        }
751      )
752      vmcasenb(OP_RETURN,
753        int b = GETARG_B(i);
754        if (b != 0) L->top = ra+b-1;
755        if (cl->p->sizep > 0) luaF_close(L, base);
756        b = luaD_poscall(L, ra);
757        if (!(ci->callstatus & CIST_REENTRY))  /* 'ci' still the called one */
758          return;  /* external invocation: return */
759        else {  /* invocation via reentry: continue execution */
760          ci = L->ci;
761          if (b) L->top = ci->top;
762          lua_assert(isLua(ci));
763          lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL);
764          goto newframe;  /* restart luaV_execute over new Lua function */
765        }
766      )
767      vmcase(OP_FORLOOP,
768        lua_Number step = nvalue(ra+2);
769        lua_Number idx = luai_numadd(L, nvalue(ra), step); /* increment index */
770        lua_Number limit = nvalue(ra+1);
771        if (luai_numlt(L, 0, step) ? luai_numle(L, idx, limit)
772                                   : luai_numle(L, limit, idx)) {
773          ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
774          setnvalue(ra, idx);  /* update internal index... */
775          setnvalue(ra+3, idx);  /* ...and external index */
776        }
777      )
778      vmcase(OP_FORPREP,
779        const TValue *init = ra;
780        const TValue *plimit = ra+1;
781        const TValue *pstep = ra+2;
782        if (!tonumber(init, ra))
783          luaG_runerror(L, LUA_QL("for") " initial value must be a number");
784        else if (!tonumber(plimit, ra+1))
785          luaG_runerror(L, LUA_QL("for") " limit must be a number");
786        else if (!tonumber(pstep, ra+2))
787          luaG_runerror(L, LUA_QL("for") " step must be a number");
788        setnvalue(ra, luai_numsub(L, nvalue(ra), nvalue(pstep)));
789        ci->u.l.savedpc += GETARG_sBx(i);
790      )
791      vmcasenb(OP_TFORCALL,
792        StkId cb = ra + 3;  /* call base */
793        setobjs2s(L, cb+2, ra+2);
794        setobjs2s(L, cb+1, ra+1);
795        setobjs2s(L, cb, ra);
796        L->top = cb + 3;  /* func. + 2 args (state and index) */
797        Protect(luaD_call(L, cb, GETARG_C(i), 1));
798        L->top = ci->top;
799        i = *(ci->u.l.savedpc++);  /* go to next instruction */
800        ra = RA(i);
801        lua_assert(GET_OPCODE(i) == OP_TFORLOOP);
802        goto l_tforloop;
803      )
804      vmcase(OP_TFORLOOP,
805        l_tforloop:
806        if (!ttisnil(ra + 1)) {  /* continue loop? */
807          setobjs2s(L, ra, ra + 1);  /* save control variable */
808           ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
809        }
810      )
811      vmcase(OP_SETLIST,
812        int n = GETARG_B(i);
813        int c = GETARG_C(i);
814        int last;
815        Table *h;
816        if (n == 0) n = cast_int(L->top - ra) - 1;
817        if (c == 0) {
818          lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
819          c = GETARG_Ax(*ci->u.l.savedpc++);
820        }
821        luai_runtimecheck(L, ttistable(ra));
822        h = hvalue(ra);
823        last = ((c-1)*LFIELDS_PER_FLUSH) + n;
824        if (last > h->sizearray)  /* needs more space? */
825          luaH_resizearray(L, h, last);  /* pre-allocate it at once */
826        for (; n > 0; n--) {
827          TValue *val = ra+n;
828          luaH_setint(L, h, last--, val);
829          luaC_barrierback(L, obj2gco(h), val);
830        }
831        L->top = ci->top;  /* correct top (in case of previous open call) */
832      )
833      vmcase(OP_CLOSURE,
834        Proto *p = cl->p->p[GETARG_Bx(i)];
835        Closure *ncl = getcached(p, cl->upvals, base);  /* cached closure */
836        if (ncl == NULL)  /* no match? */
837          pushclosure(L, p, cl->upvals, base, ra);  /* create a new one */
838        else
839          setclLvalue(L, ra, ncl);  /* push cashed closure */
840        checkGC(L, ra + 1);
841      )
842      vmcase(OP_VARARG,
843        int b = GETARG_B(i) - 1;
844        int j;
845        int n = cast_int(base - ci->func) - cl->p->numparams - 1;
846        if (b < 0) {  /* B == 0? */
847          b = n;  /* get all var. arguments */
848          Protect(luaD_checkstack(L, n));
849          ra = RA(i);  /* previous call may change the stack */
850          L->top = ra + n;
851        }
852        for (j = 0; j < b; j++) {
853          if (j < n) {
854            setobjs2s(L, ra + j, base - n + j);
855          }
856          else {
857            setnilvalue(ra + j);
858          }
859        }
860      )
861      vmcase(OP_EXTRAARG,
862        lua_assert(0);
863      )
864    }
865  }
866}
867
868