ba8b5c17 |
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 | |
35 | const 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 | |
47 | int 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 | |
60 | static 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 | |
93 | static 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 | |
110 | void 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 | |
136 | void 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 | |
175 | static 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 | |
186 | static 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 | |
200 | static 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 | |
209 | static 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 | |
231 | int 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 | |
243 | int 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 | */ |
260 | int 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 | |
293 | void 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 | |
335 | void 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 | |
360 | void 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 | */ |
379 | static 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 | */ |
401 | static 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 | */ |
423 | void 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 | |
534 | void 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 | |