2 ** $Id: lvm.c,v 2.63a 2006/06/05 15:58:59 roberto Exp $
4 ** See Copyright Notice in lua.h
31 /* limit for table tag-method chains (to avoid loops) */
32 #define MAXTAGLOOP 100
35 const TValue *luaV_tonumber (const TValue *obj, TValue *n) {
37 if (ttisnumber(obj)) return obj;
38 if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
47 int luaV_tostring (lua_State *L, StkId obj) {
51 char s[LUAI_MAXNUMBER2STR];
52 lua_Number n = nvalue(obj);
54 setsvalue2s(L, obj, luaS_new(L, s));
60 static void traceexec (lua_State *L, const Instruction *pc) {
61 lu_byte mask = L->hookmask;
62 const Instruction *oldpc = L->savedpc;
64 if (mask > LUA_MASKLINE) { /* instruction-hook set? */
65 if (L->hookcount == 0) {
67 luaD_callhook(L, LUA_HOOKCOUNT, -1);
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);
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);
90 luaD_call(L, L->top - 3, 1);
91 res = restorestack(L, result);
93 setobjs2s(L, res, L->top);
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);
106 luaD_call(L, L->top - 4, 0);
110 void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
112 for (loop = 0; loop < MAXTAGLOOP; loop++) {
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);
122 /* else will try the tag method */
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);
130 t = tm; /* else repeat with `tm' */
132 luaG_runerror(L, "loop in gettable");
136 void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
138 for (loop = 0; loop < MAXTAGLOOP; loop++) {
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);
149 /* else will try the tag method */
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);
157 t = tm; /* else repeat with `tm' */
159 luaG_runerror(L, "loop in settable");
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 */
167 tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
168 if (ttisnil(tm)) return 0;
169 callTMres(L, res, tm, p1, p2);
174 static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
176 const TValue *tm1 = fasttm(L, mt1, event);
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? */
188 static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
190 const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
192 if (ttisnil(tm1)) return -1; /* no metamethod? */
193 tm2 = luaT_gettmbyobj(L, p2, event);
194 if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
196 callTMres(L, L->top, tm1, p1, p2);
197 return !l_isfalse(L->top);
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;
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') */
217 l += len; ll -= len; r += len; lr -= len;
223 int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
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)
233 return luaG_ordererror(L, l, r);
237 static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
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' */
247 else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
249 return luaG_ordererror(L, l, r);
253 int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
255 lua_assert(ttype(t1) == ttype(t2));
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,
265 break; /* will try TM */
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 */
272 default: return gcvalue(t1) == gcvalue(t2);
274 if (tm == NULL) return 0; /* no TM? */
275 callTMres(L, L->top, tm, t1, t2); /* call TM */
276 return !l_isfalse(L->top);
280 void luaV_concat (lua_State *L, int total, int last) {
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) */
290 /* at least two string values; get as many as possible */
291 size_t tl = tsvalue(top-1)->len;
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");
300 buffer = luaZ_openspace(L, &G(L)->buff, tl);
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);
307 setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
309 total -= n-1; /* got `n' strings to create 1 new */
311 } while (total > 1); /* repeat until only 1 result left */
315 static void Arith (lua_State *L, StkId ra, const TValue *rb,
316 const TValue *rc, TMS op) {
319 if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
320 (c = luaV_tonumber(rc, &tempc)) != NULL) {
321 lua_Number nb = nvalue(b), nc = nvalue(c);
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;
333 else if (!call_binTM(L, rb, rc, ra, op))
334 luaG_aritherror(L, rb, rc);
340 ** some macros for common tasks in `luaV_execute'
343 #define runtime_check(L, c) { if (!(c)) break; }
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, \
350 ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
351 #define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
352 ISK(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))
356 #define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);}
359 #define Protect(x) { L->savedpc = pc; {x;}; base = L->base; }
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)); \
370 Protect(Arith(L, ra, rb, rc, tm)); \
375 void luaV_execute (lua_State *L, int nexeccalls) {
379 const Instruction *pc;
380 reentry: /* entry point */
381 lua_assert(isLua(L->ci));
383 cl = &clvalue(L->ci->func)->l;
386 /* main loop of interpreter */
388 const Instruction i = *pc++;
390 if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
391 (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
393 if (L->status == LUA_YIELD) { /* did hook yield? */
399 /* warning!! several calls may realloc the stack and invalidate `ra' */
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)) {
406 setobjs2s(L, ra, RB(i));
410 setobj2s(L, ra, KBx(i));
414 setbvalue(ra, GETARG_B(i));
415 if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
427 setobj2s(L, ra, cl->upvals[b]->v);
433 sethvalue(L, &g, cl->env);
434 lua_assert(ttisstring(rb));
435 Protect(luaV_gettable(L, &g, rb, ra));
439 Protect(luaV_gettable(L, RB(i), RKC(i), ra));
444 sethvalue(L, &g, cl->env);
445 lua_assert(ttisstring(KBx(i)));
446 Protect(luaV_settable(L, &g, KBx(i), ra));
450 UpVal *uv = cl->upvals[GETARG_B(i)];
451 setobj(L, uv->v, ra);
452 luaC_barrier(L, uv, ra);
456 Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
462 sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
463 Protect(luaC_checkGC(L));
468 setobjs2s(L, ra+1, rb);
469 Protect(luaV_gettable(L, rb, RKC(i), ra));
473 arith_op(luai_numadd, TM_ADD);
477 arith_op(luai_numsub, TM_SUB);
481 arith_op(luai_nummul, TM_MUL);
485 arith_op(luai_numdiv, TM_DIV);
489 arith_op(luai_nummod, TM_MOD);
493 arith_op(luai_numpow, TM_POW);
498 if (ttisnumber(rb)) {
499 lua_Number nb = nvalue(rb);
500 setnvalue(ra, luai_numunm(nb));
503 Protect(Arith(L, ra, rb, rb, TM_UNM));
508 int res = l_isfalse(RB(i)); /* next assignment may change this value */
513 const TValue *rb = RB(i);
516 setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
520 setnvalue(ra, cast_num(tsvalue(rb)->len));
523 default: { /* try metamethod */
525 if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
526 luaG_typeerror(L, rb, "get length of");
535 Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
536 setobjs2s(L, RA(i), base+b);
540 dojump(L, pc, GETARG_sBx(i));
547 if (equalobj(L, rb, rc) == GETARG_A(i))
548 dojump(L, pc, GETARG_sBx(*pc));
555 if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
556 dojump(L, pc, GETARG_sBx(*pc));
563 if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
564 dojump(L, pc, GETARG_sBx(*pc));
570 if (l_isfalse(ra) != GETARG_C(i))
571 dojump(L, pc, GETARG_sBx(*pc));
577 if (l_isfalse(rb) != GETARG_C(i)) {
578 setobjs2s(L, ra, rb);
579 dojump(L, pc, GETARG_sBx(*pc));
586 int nresults = GETARG_C(i) - 1;
587 if (b != 0) L->top = ra+b; /* else previous instruction set top */
589 switch (luaD_precall(L, ra, nresults)) {
592 goto reentry; /* restart luaV_execute over new Lua function */
595 /* it was a C function (`precall' called it); adjust results */
596 if (nresults >= 0) L->top = L->ci->top;
607 if (b != 0) L->top = ra+b; /* else previous instruction set top */
609 lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
610 switch (luaD_precall(L, ra, LUA_MULTRET)) {
612 /* tail call: put new frame in place of previous one */
613 CallInfo *ci = L->ci - 1; /* previous frame */
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 */
628 case PCRC: { /* it was a C function (`precall' called it) */
639 if (b != 0) L->top = ra+b-1;
640 if (L->openupval) luaF_close(L, base);
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);
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 */
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));
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)));
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 */
701 n = cast_int(L->top - ra) - 1;
704 if (c == 0) c = cast_int(*pc++);
705 runtime_check(L, ttistable(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 */
712 setobj2t(L, luaH_setnum(L, h, last--), val);
713 luaC_barriert(L, h, val);
725 p = cl->p->p[GETARG_Bx(i)];
727 ncl = luaF_newLclosure(L, nup, cl->env);
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)];
733 lua_assert(GET_OPCODE(*pc) == OP_MOVE);
734 ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
737 setclvalue(L, ra, ncl);
738 Protect(luaC_checkGC(L));
742 int b = GETARG_B(i) - 1;
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 */
752 for (j = 0; j < b; j++) {
754 setobjs2s(L, ra + j, ci->base - n + j);