2
** $Id: lvm.c,v 2.63.1.3 2007/12/28 15:32:23 roberto Exp $
4
** See Copyright Notice in lua.h
32
/* limit for table tag-method chains (to avoid loops) */
33
#define MAXTAGLOOP 100
36
const TValue *luaV_tonumber (const TValue *obj, TValue *n) {
38
if (ttisnumber(obj)) return obj;
39
if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
48
int luaV_tostring (lua_State *L, StkId obj) {
52
char s[LUAI_MAXNUMBER2STR];
53
lua_Number n = nvalue(obj);
55
setsvalue2s(L, obj, luaS_new(L, s));
61
static void traceexec (lua_State *L, const Instruction *pc) {
62
lu_byte mask = L->hookmask;
63
const Instruction *oldpc = L->savedpc;
65
if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
67
luaD_callhook(L, LUA_HOOKCOUNT, -1);
69
if (mask & LUA_MASKLINE) {
70
Proto *p = ci_func(L->ci)->l.p;
71
int npc = pcRel(pc, p);
72
int newline = getline(p, npc);
73
/* call linehook when enter a new function, when jump back (loop),
74
or when enter a new line */
75
if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p)))
76
luaD_callhook(L, LUA_HOOKLINE, newline);
81
static void callTMres (lua_State *L, StkId res, const TValue *f,
82
const TValue *p1, const TValue *p2) {
83
ptrdiff_t result = savestack(L, res);
84
setobj2s(L, L->top, f); /* push function */
85
setobj2s(L, L->top+1, p1); /* 1st argument */
86
setobj2s(L, L->top+2, p2); /* 2nd argument */
87
luaD_checkstack(L, 3);
89
luaD_call(L, L->top - 3, 1);
90
res = restorestack(L, result);
92
setobjs2s(L, res, L->top);
97
static void callTM (lua_State *L, const TValue *f, const TValue *p1,
98
const TValue *p2, const TValue *p3) {
99
setobj2s(L, L->top, f); /* push function */
100
setobj2s(L, L->top+1, p1); /* 1st argument */
101
setobj2s(L, L->top+2, p2); /* 2nd argument */
102
setobj2s(L, L->top+3, p3); /* 3th argument */
103
luaD_checkstack(L, 4);
105
luaD_call(L, L->top - 4, 0);
109
void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
111
for (loop = 0; loop < MAXTAGLOOP; loop++) {
113
if (ttistable(t)) { /* `t' is a table? */
114
Table *h = hvalue(t);
115
const TValue *res = luaH_get(h, key); /* do a primitive get */
116
if (!ttisnil(res) || /* result is no nil? */
117
(tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
118
setobj2s(L, val, res);
121
/* else will try the tag method */
123
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
124
luaG_typeerror(L, t, "index");
125
if (ttisfunction(tm)) {
126
callTMres(L, val, tm, t, key);
129
t = tm; /* else repeat with `tm' */
131
luaG_runerror(L, "loop in gettable");
135
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
137
for (loop = 0; loop < MAXTAGLOOP; loop++) {
139
if (ttistable(t)) { /* `t' is a table? */
140
Table *h = hvalue(t);
141
TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
142
if (!ttisnil(oldval) || /* result is no nil? */
143
(tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
144
setobj2t(L, oldval, val);
145
luaC_barriert(L, h, val);
148
/* else will try the tag method */
150
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
151
luaG_typeerror(L, t, "index");
152
if (ttisfunction(tm)) {
153
callTM(L, tm, t, key, val);
156
t = tm; /* else repeat with `tm' */
158
luaG_runerror(L, "loop in settable");
162
static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
163
StkId res, TMS event) {
164
const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
166
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
167
if (ttisnil(tm)) return 0;
168
callTMres(L, res, tm, p1, p2);
173
static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
175
const TValue *tm1 = fasttm(L, mt1, event);
177
if (tm1 == NULL) return NULL; /* no metamethod */
178
if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
179
tm2 = fasttm(L, mt2, event);
180
if (tm2 == NULL) return NULL; /* no metamethod */
181
if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
187
static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
189
const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
191
if (ttisnil(tm1)) return -1; /* no metamethod? */
192
tm2 = luaT_gettmbyobj(L, p2, event);
193
if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
195
callTMres(L, L->top, tm1, p1, p2);
196
return !l_isfalse(L->top);
200
static int l_strcmp (const TString *ls, const TString *rs) {
201
const char *l = getstr(ls);
202
size_t ll = ls->tsv.len;
203
const char *r = getstr(rs);
204
size_t lr = rs->tsv.len;
206
int temp = strcoll(l, r);
207
if (temp != 0) return temp;
208
else { /* strings are equal up to a `\0' */
209
size_t len = strlen(l); /* index of first `\0' in both strings */
210
if (len == lr) /* r is finished? */
211
return (len == ll) ? 0 : 1;
212
else if (len == ll) /* l is finished? */
213
return -1; /* l is smaller than r (because r is not finished) */
214
/* both strings longer than `len'; go on comparing (after the `\0') */
216
l += len; ll -= len; r += len; lr -= len;
222
int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
224
if (ttype(l) != ttype(r))
225
return luaG_ordererror(L, l, r);
226
else if (ttisnumber(l))
227
return luai_numlt(nvalue(l), nvalue(r));
228
else if (ttisstring(l))
229
return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
230
else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
232
return luaG_ordererror(L, l, r);
236
static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
238
if (ttype(l) != ttype(r))
239
return luaG_ordererror(L, l, r);
240
else if (ttisnumber(l))
241
return luai_numle(nvalue(l), nvalue(r));
242
else if (ttisstring(l))
243
return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
244
else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
246
else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
248
return luaG_ordererror(L, l, r);
252
int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
254
lua_assert(ttype(t1) == ttype(t2));
256
case LUA_TNIL: return 1;
257
case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
258
case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
259
case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
260
case LUA_TUSERDATA: {
261
if (uvalue(t1) == uvalue(t2)) return 1;
262
tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
264
break; /* will try TM */
267
if (hvalue(t1) == hvalue(t2)) return 1;
268
tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
269
break; /* will try TM */
271
default: return gcvalue(t1) == gcvalue(t2);
273
if (tm == NULL) return 0; /* no TM? */
274
callTMres(L, L->top, tm, t1, t2); /* call TM */
275
return !l_isfalse(L->top);
279
void luaV_concat (lua_State *L, int total, int last) {
281
StkId top = L->base + last + 1;
282
int n = 2; /* number of elements handled in this pass (at least 2) */
283
if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
284
if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
285
luaG_concaterror(L, top-2, top-1);
286
} else if (tsvalue(top-1)->len == 0) /* second op is empty? */
287
(void)tostring(L, top - 2); /* result is first op (as string) */
289
/* at least two string values; get as many as possible */
290
size_t tl = tsvalue(top-1)->len;
293
/* collect total length */
294
for (n = 1; n < total && tostring(L, top-n-1); n++) {
295
size_t l = tsvalue(top-n-1)->len;
296
if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
299
buffer = luaZ_openspace(L, &G(L)->buff, tl);
301
for (i=n; i>0; i--) { /* concat all strings */
302
size_t l = tsvalue(top-i)->len;
303
memcpy(buffer+tl, svalue(top-i), l);
306
setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
308
total -= n-1; /* got `n' strings to create 1 new */
310
} while (total > 1); /* repeat until only 1 result left */
314
static void Arith (lua_State *L, StkId ra, const TValue *rb,
315
const TValue *rc, TMS op) {
318
if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
319
(c = luaV_tonumber(rc, &tempc)) != NULL) {
320
lua_Number nb = nvalue(b), nc = nvalue(c);
322
case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break;
323
case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break;
324
case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break;
325
case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break;
326
case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break;
327
case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break;
328
case TM_UNM: setnvalue(ra, luai_numunm(nb)); break;
329
default: lua_assert(0); break;
332
else if (!call_binTM(L, rb, rc, ra, op))
333
luaG_aritherror(L, rb, rc);
339
** some macros for common tasks in `luaV_execute'
342
#define runtime_check(L, c) { if (!(c)) break; }
344
#define RA(i) (base+GETARG_A(i))
345
/* to be used after possible stack reallocation */
346
#define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
347
#define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
348
#define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
349
ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
350
#define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
351
ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
352
#define KBx(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
355
#define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);}
358
#define Protect(x) { L->savedpc = pc; {x;}; base = L->base; }
361
#define arith_op(op,tm) { \
362
TValue *rb = RKB(i); \
363
TValue *rc = RKC(i); \
364
if (ttisnumber(rb) && ttisnumber(rc)) { \
365
lua_Number nb = nvalue(rb), nc = nvalue(rc); \
366
setnvalue(ra, op(nb, nc)); \
369
Protect(Arith(L, ra, rb, rc, tm)); \
374
void luaV_execute (lua_State *L, int nexeccalls) {
378
const Instruction *pc;
379
reentry: /* entry point */
380
lua_assert(isLua(L->ci));
382
cl = &clvalue(L->ci->func)->l;
385
/* main loop of interpreter */
387
const Instruction i = *pc++;
389
if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
390
(--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
392
if (L->status == LUA_YIELD) { /* did hook yield? */
398
/* warning!! several calls may realloc the stack and invalidate `ra' */
400
lua_assert(base == L->base && L->base == L->ci->base);
401
lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
402
lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
403
switch (GET_OPCODE(i)) {
405
setobjs2s(L, ra, RB(i));
409
setobj2s(L, ra, KBx(i));
413
setbvalue(ra, GETARG_B(i));
414
if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
426
setobj2s(L, ra, cl->upvals[b]->v);
432
sethvalue(L, &g, cl->env);
433
lua_assert(ttisstring(rb));
434
Protect(luaV_gettable(L, &g, rb, ra));
438
Protect(luaV_gettable(L, RB(i), RKC(i), ra));
443
sethvalue(L, &g, cl->env);
444
lua_assert(ttisstring(KBx(i)));
445
Protect(luaV_settable(L, &g, KBx(i), ra));
449
UpVal *uv = cl->upvals[GETARG_B(i)];
450
setobj(L, uv->v, ra);
451
luaC_barrier(L, uv, ra);
455
Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
461
sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
462
Protect(luaC_checkGC(L));
467
setobjs2s(L, ra+1, rb);
468
Protect(luaV_gettable(L, rb, RKC(i), ra));
472
arith_op(luai_numadd, TM_ADD);
476
arith_op(luai_numsub, TM_SUB);
480
arith_op(luai_nummul, TM_MUL);
484
arith_op(luai_numdiv, TM_DIV);
488
arith_op(luai_nummod, TM_MOD);
492
arith_op(luai_numpow, TM_POW);
497
if (ttisnumber(rb)) {
498
lua_Number nb = nvalue(rb);
499
setnvalue(ra, luai_numunm(nb));
502
Protect(Arith(L, ra, rb, rb, TM_UNM));
507
int res = l_isfalse(RB(i)); /* next assignment may change this value */
512
const TValue *rb = RB(i);
515
setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
519
setnvalue(ra, cast_num(tsvalue(rb)->len));
522
default: { /* try metamethod */
524
if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
525
luaG_typeerror(L, rb, "get length of");
534
Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
535
setobjs2s(L, RA(i), base+b);
539
dojump(L, pc, GETARG_sBx(i));
546
if (equalobj(L, rb, rc) == GETARG_A(i))
547
dojump(L, pc, GETARG_sBx(*pc));
554
if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
555
dojump(L, pc, GETARG_sBx(*pc));
562
if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
563
dojump(L, pc, GETARG_sBx(*pc));
569
if (l_isfalse(ra) != GETARG_C(i))
570
dojump(L, pc, GETARG_sBx(*pc));
576
if (l_isfalse(rb) != GETARG_C(i)) {
577
setobjs2s(L, ra, rb);
578
dojump(L, pc, GETARG_sBx(*pc));
585
int nresults = GETARG_C(i) - 1;
586
if (b != 0) L->top = ra+b; /* else previous instruction set top */
588
switch (luaD_precall(L, ra, nresults)) {
591
goto reentry; /* restart luaV_execute over new Lua function */
594
/* it was a C function (`precall' called it); adjust results */
595
if (nresults >= 0) L->top = L->ci->top;
606
if (b != 0) L->top = ra+b; /* else previous instruction set top */
608
lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
609
switch (luaD_precall(L, ra, LUA_MULTRET)) {
611
/* tail call: put new frame in place of previous one */
612
CallInfo *ci = L->ci - 1; /* previous frame */
614
StkId func = ci->func;
615
StkId pfunc = (ci+1)->func; /* previous function index */
616
if (L->openupval) luaF_close(L, ci->base);
617
L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
618
for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */
619
setobjs2s(L, func+aux, pfunc+aux);
620
ci->top = L->top = func+aux; /* correct top */
621
lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
622
ci->savedpc = L->savedpc;
623
ci->tailcalls++; /* one more call lost */
624
L->ci--; /* remove new frame */
627
case PCRC: { /* it was a C function (`precall' called it) */
638
if (b != 0) L->top = ra+b-1;
639
if (L->openupval) luaF_close(L, base);
641
b = luaD_poscall(L, ra);
642
if (--nexeccalls == 0) /* was previous function running `here'? */
643
return; /* no: return */
644
else { /* yes: continue its execution */
645
if (b) L->top = L->ci->top;
646
lua_assert(isLua(L->ci));
647
lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
652
lua_Number step = nvalue(ra+2);
653
lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
654
lua_Number limit = nvalue(ra+1);
655
if (luai_numlt(0, step) ? luai_numle(idx, limit)
656
: luai_numle(limit, idx)) {
657
dojump(L, pc, GETARG_sBx(i)); /* jump back */
658
setnvalue(ra, idx); /* update internal index... */
659
setnvalue(ra+3, idx); /* ...and external index */
664
const TValue *init = ra;
665
const TValue *plimit = ra+1;
666
const TValue *pstep = ra+2;
667
L->savedpc = pc; /* next steps may throw errors */
668
if (!tonumber(init, ra))
669
luaG_runerror(L, LUA_QL("for") " initial value must be a number");
670
else if (!tonumber(plimit, ra+1))
671
luaG_runerror(L, LUA_QL("for") " limit must be a number");
672
else if (!tonumber(pstep, ra+2))
673
luaG_runerror(L, LUA_QL("for") " step must be a number");
674
setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
675
dojump(L, pc, GETARG_sBx(i));
679
StkId cb = ra + 3; /* call base */
680
setobjs2s(L, cb+2, ra+2);
681
setobjs2s(L, cb+1, ra+1);
682
setobjs2s(L, cb, ra);
683
L->top = cb+3; /* func. + 2 args (state and index) */
684
Protect(luaD_call(L, cb, GETARG_C(i)));
686
cb = RA(i) + 3; /* previous call may change the stack */
687
if (!ttisnil(cb)) { /* continue loop? */
688
setobjs2s(L, cb-1, cb); /* save control variable */
689
dojump(L, pc, GETARG_sBx(*pc)); /* jump back */
700
n = cast_int(L->top - ra) - 1;
703
if (c == 0) c = cast_int(*pc++);
704
runtime_check(L, ttistable(ra));
706
last = ((c-1)*LFIELDS_PER_FLUSH) + n;
707
if (last > h->sizearray) /* needs more space? */
708
luaH_resizearray(L, h, last); /* pre-alloc it at once */
711
setobj2t(L, luaH_setnum(L, h, last--), val);
712
luaC_barriert(L, h, val);
724
p = cl->p->p[GETARG_Bx(i)];
726
ncl = luaF_newLclosure(L, nup, cl->env);
728
for (j=0; j<nup; j++, pc++) {
729
if (GET_OPCODE(*pc) == OP_GETUPVAL)
730
ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
732
lua_assert(GET_OPCODE(*pc) == OP_MOVE);
733
ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
736
setclvalue(L, ra, ncl);
737
Protect(luaC_checkGC(L));
741
int b = GETARG_B(i) - 1;
743
CallInfo *ci = L->ci;
744
int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
745
if (b == LUA_MULTRET) {
746
Protect(luaD_checkstack(L, n));
747
ra = RA(i); /* previous call may change the stack */
751
for (j = 0; j < b; j++) {
753
setobjs2s(L, ra + j, ci->base - n + j);