2 ** $Id: lvm.c,v 2.63.1.3 2007/12/28 15:32:23 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_MASKCOUNT) && L->hookcount == 0) {
66 luaD_callhook(L, LUA_HOOKCOUNT, -1);
68 if (mask & LUA_MASKLINE) {
69 Proto *p = ci_func(L->ci)->l.p;
70 int npc = pcRel(pc, p);
71 int newline = getline(p, npc);
72 /* call linehook when enter a new function, when jump back (loop),
73 or when enter a new line */
74 if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p)))
75 luaD_callhook(L, LUA_HOOKLINE, newline);
80 static void callTMres (lua_State *L, StkId res, const TValue *f,
81 const TValue *p1, const TValue *p2) {
82 ptrdiff_t result = savestack(L, res);
83 setobj2s(L, L->top, f); /* push function */
84 setobj2s(L, L->top+1, p1); /* 1st argument */
85 setobj2s(L, L->top+2, p2); /* 2nd argument */
86 luaD_checkstack(L, 3);
88 luaD_call(L, L->top - 3, 1);
89 res = restorestack(L, result);
91 setobjs2s(L, res, L->top);
96 static void callTM (lua_State *L, const TValue *f, const TValue *p1,
97 const TValue *p2, const TValue *p3) {
98 setobj2s(L, L->top, f); /* push function */
99 setobj2s(L, L->top+1, p1); /* 1st argument */
100 setobj2s(L, L->top+2, p2); /* 2nd argument */
101 setobj2s(L, L->top+3, p3); /* 3th argument */
102 luaD_checkstack(L, 4);
104 luaD_call(L, L->top - 4, 0);
108 void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
110 for (loop = 0; loop < MAXTAGLOOP; loop++) {
112 if (ttistable(t)) { /* `t' is a table? */
113 Table *h = hvalue(t);
114 const TValue *res = luaH_get(h, key); /* do a primitive get */
115 if (!ttisnil(res) || /* result is no nil? */
116 (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
117 setobj2s(L, val, res);
120 /* else will try the tag method */
122 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
123 luaG_typeerror(L, t, "index");
124 if (ttisfunction(tm)) {
125 callTMres(L, val, tm, t, key);
128 t = tm; /* else repeat with `tm' */
130 luaG_runerror(L, "loop in gettable");
134 void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
136 for (loop = 0; loop < MAXTAGLOOP; loop++) {
138 if (ttistable(t)) { /* `t' is a table? */
139 Table *h = hvalue(t);
140 TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
141 if (!ttisnil(oldval) || /* result is no nil? */
142 (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
143 setobj2t(L, oldval, val);
144 luaC_barriert(L, h, val);
147 /* else will try the tag method */
149 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
150 luaG_typeerror(L, t, "index");
151 if (ttisfunction(tm)) {
152 callTM(L, tm, t, key, val);
155 t = tm; /* else repeat with `tm' */
157 luaG_runerror(L, "loop in settable");
161 static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
162 StkId res, TMS event) {
163 const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
165 tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
166 if (ttisnil(tm)) return 0;
167 callTMres(L, res, tm, p1, p2);
172 static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
174 const TValue *tm1 = fasttm(L, mt1, event);
176 if (tm1 == NULL) return NULL; /* no metamethod */
177 if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
178 tm2 = fasttm(L, mt2, event);
179 if (tm2 == NULL) return NULL; /* no metamethod */
180 if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
186 static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
188 const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
190 if (ttisnil(tm1)) return -1; /* no metamethod? */
191 tm2 = luaT_gettmbyobj(L, p2, event);
192 if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
194 callTMres(L, L->top, tm1, p1, p2);
195 return !l_isfalse(L->top);
199 static int l_strcmp (const TString *ls, const TString *rs) {
200 const char *l = getstr(ls);
201 size_t ll = ls->tsv.len;
202 const char *r = getstr(rs);
203 size_t lr = rs->tsv.len;
205 int temp = strcoll(l, r);
206 if (temp != 0) return temp;
207 else { /* strings are equal up to a `\0' */
208 size_t len = strlen(l); /* index of first `\0' in both strings */
209 if (len == lr) /* r is finished? */
210 return (len == ll) ? 0 : 1;
211 else if (len == ll) /* l is finished? */
212 return -1; /* l is smaller than r (because r is not finished) */
213 /* both strings longer than `len'; go on comparing (after the `\0') */
215 l += len; ll -= len; r += len; lr -= len;
221 int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
223 if (ttype(l) != ttype(r))
224 return luaG_ordererror(L, l, r);
225 else if (ttisnumber(l))
226 return luai_numlt(nvalue(l), nvalue(r));
227 else if (ttisstring(l))
228 return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
229 else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
231 return luaG_ordererror(L, l, r);
235 static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
237 if (ttype(l) != ttype(r))
238 return luaG_ordererror(L, l, r);
239 else if (ttisnumber(l))
240 return luai_numle(nvalue(l), nvalue(r));
241 else if (ttisstring(l))
242 return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
243 else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
245 else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
247 return luaG_ordererror(L, l, r);
251 int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
253 lua_assert(ttype(t1) == ttype(t2));
255 case LUA_TNIL: return 1;
256 case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
257 case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
258 case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
259 case LUA_TUSERDATA: {
260 if (uvalue(t1) == uvalue(t2)) return 1;
261 tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
263 break; /* will try TM */
266 if (hvalue(t1) == hvalue(t2)) return 1;
267 tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
268 break; /* will try TM */
270 default: return gcvalue(t1) == gcvalue(t2);
272 if (tm == NULL) return 0; /* no TM? */
273 callTMres(L, L->top, tm, t1, t2); /* call TM */
274 return !l_isfalse(L->top);
278 void luaV_concat (lua_State *L, int total, int last) {
280 StkId top = L->base + last + 1;
281 int n = 2; /* number of elements handled in this pass (at least 2) */
282 if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
283 if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
284 luaG_concaterror(L, top-2, top-1);
285 } else if (tsvalue(top-1)->len == 0) /* second op is empty? */
286 (void)tostring(L, top - 2); /* result is first op (as string) */
288 /* at least two string values; get as many as possible */
289 size_t tl = tsvalue(top-1)->len;
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");
298 buffer = luaZ_openspace(L, &G(L)->buff, tl);
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);
305 setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
307 total -= n-1; /* got `n' strings to create 1 new */
309 } while (total > 1); /* repeat until only 1 result left */
313 static void Arith (lua_State *L, StkId ra, const TValue *rb,
314 const TValue *rc, TMS op) {
317 if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
318 (c = luaV_tonumber(rc, &tempc)) != NULL) {
319 lua_Number nb = nvalue(b), nc = nvalue(c);
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;
331 else if (!call_binTM(L, rb, rc, ra, op))
332 luaG_aritherror(L, rb, rc);
338 ** some macros for common tasks in `luaV_execute'
341 #define runtime_check(L, c) { if (!(c)) break; }
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))
354 #define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);}
357 #define Protect(x) { L->savedpc = pc; {x;}; base = L->base; }
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)); \
368 Protect(Arith(L, ra, rb, rc, tm)); \
373 void luaV_execute (lua_State *L, int nexeccalls) {
377 const Instruction *pc;
378 reentry: /* entry point */
379 lua_assert(isLua(L->ci));
381 cl = &clvalue(L->ci->func)->l;
384 /* main loop of interpreter */
386 const Instruction i = *pc++;
388 if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
389 (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
391 if (L->status == LUA_YIELD) { /* did hook yield? */
397 /* warning!! several calls may realloc the stack and invalidate `ra' */
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)) {
404 setobjs2s(L, ra, RB(i));
408 setobj2s(L, ra, KBx(i));
412 setbvalue(ra, GETARG_B(i));
413 if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
425 setobj2s(L, ra, cl->upvals[b]->v);
431 sethvalue(L, &g, cl->env);
432 lua_assert(ttisstring(rb));
433 Protect(luaV_gettable(L, &g, rb, ra));
437 Protect(luaV_gettable(L, RB(i), RKC(i), ra));
442 sethvalue(L, &g, cl->env);
443 lua_assert(ttisstring(KBx(i)));
444 Protect(luaV_settable(L, &g, KBx(i), ra));
448 UpVal *uv = cl->upvals[GETARG_B(i)];
449 setobj(L, uv->v, ra);
450 luaC_barrier(L, uv, ra);
454 Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
460 sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
461 Protect(luaC_checkGC(L));
466 setobjs2s(L, ra+1, rb);
467 Protect(luaV_gettable(L, rb, RKC(i), ra));
471 arith_op(luai_numadd, TM_ADD);
475 arith_op(luai_numsub, TM_SUB);
479 arith_op(luai_nummul, TM_MUL);
483 arith_op(luai_numdiv, TM_DIV);
487 arith_op(luai_nummod, TM_MOD);
491 arith_op(luai_numpow, TM_POW);
496 if (ttisnumber(rb)) {
497 lua_Number nb = nvalue(rb);
498 setnvalue(ra, luai_numunm(nb));
501 Protect(Arith(L, ra, rb, rb, TM_UNM));
506 int res = l_isfalse(RB(i)); /* next assignment may change this value */
511 const TValue *rb = RB(i);
514 setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
518 setnvalue(ra, cast_num(tsvalue(rb)->len));
521 default: { /* try metamethod */
523 if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
524 luaG_typeerror(L, rb, "get length of");
533 Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
534 setobjs2s(L, RA(i), base+b);
538 dojump(L, pc, GETARG_sBx(i));
545 if (equalobj(L, rb, rc) == GETARG_A(i))
546 dojump(L, pc, GETARG_sBx(*pc));
553 if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
554 dojump(L, pc, GETARG_sBx(*pc));
561 if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
562 dojump(L, pc, GETARG_sBx(*pc));
568 if (l_isfalse(ra) != GETARG_C(i))
569 dojump(L, pc, GETARG_sBx(*pc));
575 if (l_isfalse(rb) != GETARG_C(i)) {
576 setobjs2s(L, ra, rb);
577 dojump(L, pc, GETARG_sBx(*pc));
584 int nresults = GETARG_C(i) - 1;
585 if (b != 0) L->top = ra+b; /* else previous instruction set top */
587 switch (luaD_precall(L, ra, nresults)) {
590 goto reentry; /* restart luaV_execute over new Lua function */
593 /* it was a C function (`precall' called it); adjust results */
594 if (nresults >= 0) L->top = L->ci->top;
605 if (b != 0) L->top = ra+b; /* else previous instruction set top */
607 lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
608 switch (luaD_precall(L, ra, LUA_MULTRET)) {
610 /* tail call: put new frame in place of previous one */
611 CallInfo *ci = L->ci - 1; /* previous frame */
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 */
626 case PCRC: { /* it was a C function (`precall' called it) */
637 if (b != 0) L->top = ra+b-1;
638 if (L->openupval) luaF_close(L, base);
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);
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 */
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));
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)));
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 */
699 n = cast_int(L->top - ra) - 1;
702 if (c == 0) c = cast_int(*pc++);
703 runtime_check(L, ttistable(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 */
710 setobj2t(L, luaH_setnum(L, h, last--), val);
711 luaC_barriert(L, h, val);
723 p = cl->p->p[GETARG_Bx(i)];
725 ncl = luaF_newLclosure(L, nup, cl->env);
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)];
731 lua_assert(GET_OPCODE(*pc) == OP_MOVE);
732 ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
735 setclvalue(L, ra, ncl);
736 Protect(luaC_checkGC(L));
740 int b = GETARG_B(i) - 1;
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 */
750 for (j = 0; j < b; j++) {
752 setobjs2s(L, ra + j, ci->base - n + j);