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);