lvm.c 23 KB

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  1. /*
  2. ** $Id: lvm.c,v 2.63.1.3 2007/12/28 15:32:23 roberto Exp $
  3. ** Lua virtual machine
  4. ** See Copyright Notice in lua.h
  5. */
  6. #if 0
  7. #include <stdio.h>
  8. #include <stdlib.h>
  9. #include <string.h>
  10. #endif
  11. #define lvm_c
  12. #define LUA_CORE
  13. #include "lua.h"
  14. #include "ldebug.h"
  15. #include "ldo.h"
  16. #include "lfunc.h"
  17. #include "lgc.h"
  18. #include "lobject.h"
  19. #include "lopcodes.h"
  20. #include "lstate.h"
  21. #include "lstring.h"
  22. #include "ltable.h"
  23. #include "ltm.h"
  24. #include "lvm.h"
  25. /* limit for table tag-method chains (to avoid loops) */
  26. #define MAXTAGLOOP 100
  27. const TValue *luaV_tonumber (const TValue *obj, TValue *n) {
  28. lua_Number num;
  29. if (ttisnumber(obj)) return obj;
  30. if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
  31. setnvalue(n, num);
  32. return n;
  33. }
  34. else
  35. return NULL;
  36. }
  37. int luaV_tostring (lua_State *L, StkId obj) {
  38. if (!ttisnumber(obj))
  39. return 0;
  40. else {
  41. char s[LUAI_MAXNUMBER2STR];
  42. lua_Number n = nvalue(obj);
  43. lua_number2str(s, n);
  44. setsvalue2s(L, obj, luaS_new(L, s));
  45. return 1;
  46. }
  47. }
  48. static void traceexec (lua_State *L, const Instruction *pc) {
  49. lu_byte mask = L->hookmask;
  50. const Instruction *oldpc = L->savedpc;
  51. L->savedpc = pc;
  52. if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
  53. resethookcount(L);
  54. luaD_callhook(L, LUA_HOOKCOUNT, -1);
  55. }
  56. if (mask & LUA_MASKLINE) {
  57. Proto *p = ci_func(L->ci)->l.p;
  58. int npc = pcRel(pc, p);
  59. int newline = getline(p, npc);
  60. /* call linehook when enter a new function, when jump back (loop),
  61. or when enter a new line */
  62. if (npc == 0 || pc <= oldpc || newline != getline(p, pcRel(oldpc, p)))
  63. luaD_callhook(L, LUA_HOOKLINE, newline);
  64. }
  65. }
  66. static void callTMres (lua_State *L, StkId res, const TValue *f,
  67. const TValue *p1, const TValue *p2) {
  68. ptrdiff_t result = savestack(L, res);
  69. setobj2s(L, L->top, f); /* push function */
  70. setobj2s(L, L->top+1, p1); /* 1st argument */
  71. setobj2s(L, L->top+2, p2); /* 2nd argument */
  72. luaD_checkstack(L, 3);
  73. L->top += 3;
  74. luaD_call(L, L->top - 3, 1);
  75. res = restorestack(L, result);
  76. L->top--;
  77. setobjs2s(L, res, L->top);
  78. }
  79. static void callTM (lua_State *L, const TValue *f, const TValue *p1,
  80. const TValue *p2, const TValue *p3) {
  81. setobj2s(L, L->top, f); /* push function */
  82. setobj2s(L, L->top+1, p1); /* 1st argument */
  83. setobj2s(L, L->top+2, p2); /* 2nd argument */
  84. setobj2s(L, L->top+3, p3); /* 3th argument */
  85. luaD_checkstack(L, 4);
  86. L->top += 4;
  87. luaD_call(L, L->top - 4, 0);
  88. }
  89. void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  90. int loop;
  91. for (loop = 0; loop < MAXTAGLOOP; loop++) {
  92. const TValue *tm;
  93. if (ttistable(t)) { /* `t' is a table? */
  94. Table *h = hvalue(t);
  95. const TValue *res = luaH_get(h, key); /* do a primitive get */
  96. if (!ttisnil(res) || /* result is no nil? */
  97. (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
  98. setobj2s(L, val, res);
  99. return;
  100. }
  101. /* else will try the tag method */
  102. }
  103. else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
  104. luaG_typeerror(L, t, "index");
  105. if (ttisfunction(tm)) {
  106. callTMres(L, val, tm, t, key);
  107. return;
  108. }
  109. t = tm; /* else repeat with `tm' */
  110. }
  111. luaG_runerror(L, "loop in gettable");
  112. }
  113. void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
  114. int loop;
  115. for (loop = 0; loop < MAXTAGLOOP; loop++) {
  116. const TValue *tm;
  117. if (ttistable(t)) { /* `t' is a table? */
  118. Table *h = hvalue(t);
  119. TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
  120. if (!ttisnil(oldval) || /* result is no nil? */
  121. (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
  122. setobj2t(L, oldval, val);
  123. luaC_barriert(L, h, val);
  124. return;
  125. }
  126. /* else will try the tag method */
  127. }
  128. else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
  129. luaG_typeerror(L, t, "index");
  130. if (ttisfunction(tm)) {
  131. callTM(L, tm, t, key, val);
  132. return;
  133. }
  134. t = tm; /* else repeat with `tm' */
  135. }
  136. luaG_runerror(L, "loop in settable");
  137. }
  138. static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
  139. StkId res, TMS event) {
  140. const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
  141. if (ttisnil(tm))
  142. tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
  143. if (ttisnil(tm)) return 0;
  144. callTMres(L, res, tm, p1, p2);
  145. return 1;
  146. }
  147. static const TValue *get_compTM (lua_State *L, Table *mt1, Table *mt2,
  148. TMS event) {
  149. const TValue *tm1 = fasttm(L, mt1, event);
  150. const TValue *tm2;
  151. if (tm1 == NULL) return NULL; /* no metamethod */
  152. if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
  153. tm2 = fasttm(L, mt2, event);
  154. if (tm2 == NULL) return NULL; /* no metamethod */
  155. if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
  156. return tm1;
  157. return NULL;
  158. }
  159. static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
  160. TMS event) {
  161. const TValue *tm1 = luaT_gettmbyobj(L, p1, event);
  162. const TValue *tm2;
  163. if (ttisnil(tm1)) return -1; /* no metamethod? */
  164. tm2 = luaT_gettmbyobj(L, p2, event);
  165. if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
  166. return -1;
  167. callTMres(L, L->top, tm1, p1, p2);
  168. return !l_isfalse(L->top);
  169. }
  170. static int l_strcmp (const TString *ls, const TString *rs) {
  171. const char *l = getstr(ls);
  172. size_t ll = ls->tsv.len;
  173. const char *r = getstr(rs);
  174. size_t lr = rs->tsv.len;
  175. for (;;) {
  176. int temp = strcoll(l, r);
  177. if (temp != 0) return temp;
  178. else { /* strings are equal up to a `\0' */
  179. size_t len = strlen(l); /* index of first `\0' in both strings */
  180. if (len == lr) /* r is finished? */
  181. return (len == ll) ? 0 : 1;
  182. else if (len == ll) /* l is finished? */
  183. return -1; /* l is smaller than r (because r is not finished) */
  184. /* both strings longer than `len'; go on comparing (after the `\0') */
  185. len++;
  186. l += len; ll -= len; r += len; lr -= len;
  187. }
  188. }
  189. }
  190. int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
  191. int res;
  192. if (ttype(l) != ttype(r))
  193. return luaG_ordererror(L, l, r);
  194. else if (ttisnumber(l))
  195. return luai_numlt(nvalue(l), nvalue(r));
  196. else if (ttisstring(l))
  197. return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
  198. else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
  199. return res;
  200. return luaG_ordererror(L, l, r);
  201. }
  202. static int lessequal (lua_State *L, const TValue *l, const TValue *r) {
  203. int res;
  204. if (ttype(l) != ttype(r))
  205. return luaG_ordererror(L, l, r);
  206. else if (ttisnumber(l))
  207. return luai_numle(nvalue(l), nvalue(r));
  208. else if (ttisstring(l))
  209. return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
  210. else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
  211. return res;
  212. else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
  213. return !res;
  214. return luaG_ordererror(L, l, r);
  215. }
  216. int luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2) {
  217. const TValue *tm;
  218. lua_assert(ttype(t1) == ttype(t2));
  219. switch (ttype(t1)) {
  220. case LUA_TNIL: return 1;
  221. case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
  222. case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
  223. case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
  224. case LUA_TUSERDATA: {
  225. if (uvalue(t1) == uvalue(t2)) return 1;
  226. tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
  227. TM_EQ);
  228. break; /* will try TM */
  229. }
  230. case LUA_TTABLE: {
  231. if (hvalue(t1) == hvalue(t2)) return 1;
  232. tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
  233. break; /* will try TM */
  234. }
  235. default: return gcvalue(t1) == gcvalue(t2);
  236. }
  237. if (tm == NULL) return 0; /* no TM? */
  238. callTMres(L, L->top, tm, t1, t2); /* call TM */
  239. return !l_isfalse(L->top);
  240. }
  241. void luaV_concat (lua_State *L, int total, int last) {
  242. do {
  243. StkId top = L->base + last + 1;
  244. int n = 2; /* number of elements handled in this pass (at least 2) */
  245. if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
  246. if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
  247. luaG_concaterror(L, top-2, top-1);
  248. } else if (tsvalue(top-1)->len == 0) /* second op is empty? */
  249. (void)tostring(L, top - 2); /* result is first op (as string) */
  250. else {
  251. /* at least two string values; get as many as possible */
  252. size_t tl = tsvalue(top-1)->len;
  253. char *buffer;
  254. int i;
  255. /* collect total length */
  256. for (n = 1; n < total && tostring(L, top-n-1); n++) {
  257. size_t l = tsvalue(top-n-1)->len;
  258. if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
  259. tl += l;
  260. }
  261. buffer = luaZ_openspace(L, &G(L)->buff, tl);
  262. tl = 0;
  263. for (i=n; i>0; i--) { /* concat all strings */
  264. size_t l = tsvalue(top-i)->len;
  265. memcpy(buffer+tl, svalue(top-i), l);
  266. tl += l;
  267. }
  268. setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
  269. }
  270. total -= n-1; /* got `n' strings to create 1 new */
  271. last -= n-1;
  272. } while (total > 1); /* repeat until only 1 result left */
  273. }
  274. static void Arith (lua_State *L, StkId ra, const TValue *rb,
  275. const TValue *rc, TMS op) {
  276. TValue tempb, tempc;
  277. const TValue *b, *c;
  278. if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
  279. (c = luaV_tonumber(rc, &tempc)) != NULL) {
  280. lua_Number nb = nvalue(b), nc = nvalue(c);
  281. switch (op) {
  282. case TM_ADD: setnvalue(ra, luai_numadd(nb, nc)); break;
  283. case TM_SUB: setnvalue(ra, luai_numsub(nb, nc)); break;
  284. case TM_MUL: setnvalue(ra, luai_nummul(nb, nc)); break;
  285. case TM_DIV: setnvalue(ra, luai_numdiv(nb, nc)); break;
  286. case TM_MOD: setnvalue(ra, luai_nummod(nb, nc)); break;
  287. case TM_POW: setnvalue(ra, luai_numpow(nb, nc)); break;
  288. case TM_UNM: setnvalue(ra, luai_numunm(nb)); break;
  289. default: lua_assert(0); break;
  290. }
  291. }
  292. else if (!call_binTM(L, rb, rc, ra, op))
  293. luaG_aritherror(L, rb, rc);
  294. }
  295. /*
  296. ** some macros for common tasks in `luaV_execute'
  297. */
  298. #define runtime_check(L, c) { if (!(c)) break; }
  299. #define RA(i) (base+GETARG_A(i))
  300. /* to be used after possible stack reallocation */
  301. #define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
  302. #define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
  303. #define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
  304. ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
  305. #define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
  306. ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
  307. #define KBx(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, k+GETARG_Bx(i))
  308. #define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);}
  309. #define Protect(x) { L->savedpc = pc; {x;}; base = L->base; }
  310. #define arith_op(op,tm) { \
  311. TValue *rb = RKB(i); \
  312. TValue *rc = RKC(i); \
  313. if (ttisnumber(rb) && ttisnumber(rc)) { \
  314. lua_Number nb = nvalue(rb), nc = nvalue(rc); \
  315. setnvalue(ra, op(nb, nc)); \
  316. } \
  317. else \
  318. Protect(Arith(L, ra, rb, rc, tm)); \
  319. }
  320. void luaV_execute (lua_State *L, int nexeccalls) {
  321. LClosure *cl;
  322. StkId base;
  323. TValue *k;
  324. const Instruction *pc;
  325. reentry: /* entry point */
  326. lua_assert(isLua(L->ci));
  327. pc = L->savedpc;
  328. cl = &clvalue(L->ci->func)->l;
  329. base = L->base;
  330. k = cl->p->k;
  331. /* main loop of interpreter */
  332. for (;;) {
  333. const Instruction i = *pc++;
  334. StkId ra;
  335. if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
  336. (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
  337. traceexec(L, pc);
  338. if (L->status == LUA_YIELD) { /* did hook yield? */
  339. L->savedpc = pc - 1;
  340. return;
  341. }
  342. base = L->base;
  343. }
  344. /* warning!! several calls may realloc the stack and invalidate `ra' */
  345. ra = RA(i);
  346. lua_assert(base == L->base && L->base == L->ci->base);
  347. lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
  348. lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
  349. switch (GET_OPCODE(i)) {
  350. case OP_MOVE: {
  351. setobjs2s(L, ra, RB(i));
  352. continue;
  353. }
  354. case OP_LOADK: {
  355. setobj2s(L, ra, KBx(i));
  356. continue;
  357. }
  358. case OP_LOADBOOL: {
  359. setbvalue(ra, GETARG_B(i));
  360. if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
  361. continue;
  362. }
  363. case OP_LOADNIL: {
  364. TValue *rb = RB(i);
  365. do {
  366. setnilvalue(rb--);
  367. } while (rb >= ra);
  368. continue;
  369. }
  370. case OP_GETUPVAL: {
  371. int b = GETARG_B(i);
  372. setobj2s(L, ra, cl->upvals[b]->v);
  373. continue;
  374. }
  375. case OP_GETGLOBAL: {
  376. TValue g;
  377. TValue *rb = KBx(i);
  378. sethvalue(L, &g, cl->env);
  379. lua_assert(ttisstring(rb));
  380. Protect(luaV_gettable(L, &g, rb, ra));
  381. continue;
  382. }
  383. case OP_GETTABLE: {
  384. Protect(luaV_gettable(L, RB(i), RKC(i), ra));
  385. continue;
  386. }
  387. case OP_SETGLOBAL: {
  388. TValue g;
  389. sethvalue(L, &g, cl->env);
  390. lua_assert(ttisstring(KBx(i)));
  391. Protect(luaV_settable(L, &g, KBx(i), ra));
  392. continue;
  393. }
  394. case OP_SETUPVAL: {
  395. UpVal *uv = cl->upvals[GETARG_B(i)];
  396. setobj(L, uv->v, ra);
  397. luaC_barrier(L, uv, ra);
  398. continue;
  399. }
  400. case OP_SETTABLE: {
  401. Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
  402. continue;
  403. }
  404. case OP_NEWTABLE: {
  405. int b = GETARG_B(i);
  406. int c = GETARG_C(i);
  407. sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
  408. Protect(luaC_checkGC(L));
  409. continue;
  410. }
  411. case OP_SELF: {
  412. StkId rb = RB(i);
  413. setobjs2s(L, ra+1, rb);
  414. Protect(luaV_gettable(L, rb, RKC(i), ra));
  415. continue;
  416. }
  417. case OP_ADD: {
  418. arith_op(luai_numadd, TM_ADD);
  419. continue;
  420. }
  421. case OP_SUB: {
  422. arith_op(luai_numsub, TM_SUB);
  423. continue;
  424. }
  425. case OP_MUL: {
  426. arith_op(luai_nummul, TM_MUL);
  427. continue;
  428. }
  429. case OP_DIV: {
  430. arith_op(luai_numdiv, TM_DIV);
  431. continue;
  432. }
  433. case OP_MOD: {
  434. arith_op(luai_nummod, TM_MOD);
  435. continue;
  436. }
  437. case OP_POW: {
  438. arith_op(luai_numpow, TM_POW);
  439. continue;
  440. }
  441. case OP_UNM: {
  442. TValue *rb = RB(i);
  443. if (ttisnumber(rb)) {
  444. lua_Number nb = nvalue(rb);
  445. setnvalue(ra, luai_numunm(nb));
  446. }
  447. else {
  448. Protect(Arith(L, ra, rb, rb, TM_UNM));
  449. }
  450. continue;
  451. }
  452. case OP_NOT: {
  453. int res = l_isfalse(RB(i)); /* next assignment may change this value */
  454. setbvalue(ra, res);
  455. continue;
  456. }
  457. case OP_LEN: {
  458. const TValue *rb = RB(i);
  459. switch (ttype(rb)) {
  460. case LUA_TTABLE: {
  461. setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
  462. break;
  463. }
  464. case LUA_TSTRING: {
  465. setnvalue(ra, cast_num(tsvalue(rb)->len));
  466. break;
  467. }
  468. default: { /* try metamethod */
  469. Protect(
  470. if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
  471. luaG_typeerror(L, rb, "get length of");
  472. )
  473. }
  474. }
  475. continue;
  476. }
  477. case OP_CONCAT: {
  478. int b = GETARG_B(i);
  479. int c = GETARG_C(i);
  480. Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
  481. setobjs2s(L, RA(i), base+b);
  482. continue;
  483. }
  484. case OP_JMP: {
  485. dojump(L, pc, GETARG_sBx(i));
  486. continue;
  487. }
  488. case OP_EQ: {
  489. TValue *rb = RKB(i);
  490. TValue *rc = RKC(i);
  491. Protect(
  492. if (equalobj(L, rb, rc) == GETARG_A(i))
  493. dojump(L, pc, GETARG_sBx(*pc));
  494. )
  495. pc++;
  496. continue;
  497. }
  498. case OP_LT: {
  499. Protect(
  500. if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
  501. dojump(L, pc, GETARG_sBx(*pc));
  502. )
  503. pc++;
  504. continue;
  505. }
  506. case OP_LE: {
  507. Protect(
  508. if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
  509. dojump(L, pc, GETARG_sBx(*pc));
  510. )
  511. pc++;
  512. continue;
  513. }
  514. case OP_TEST: {
  515. if (l_isfalse(ra) != GETARG_C(i))
  516. dojump(L, pc, GETARG_sBx(*pc));
  517. pc++;
  518. continue;
  519. }
  520. case OP_TESTSET: {
  521. TValue *rb = RB(i);
  522. if (l_isfalse(rb) != GETARG_C(i)) {
  523. setobjs2s(L, ra, rb);
  524. dojump(L, pc, GETARG_sBx(*pc));
  525. }
  526. pc++;
  527. continue;
  528. }
  529. case OP_CALL: {
  530. int b = GETARG_B(i);
  531. int nresults = GETARG_C(i) - 1;
  532. if (b != 0) L->top = ra+b; /* else previous instruction set top */
  533. L->savedpc = pc;
  534. switch (luaD_precall(L, ra, nresults)) {
  535. case PCRLUA: {
  536. nexeccalls++;
  537. goto reentry; /* restart luaV_execute over new Lua function */
  538. }
  539. case PCRC: {
  540. /* it was a C function (`precall' called it); adjust results */
  541. if (nresults >= 0) L->top = L->ci->top;
  542. base = L->base;
  543. continue;
  544. }
  545. default: {
  546. return; /* yield */
  547. }
  548. }
  549. }
  550. case OP_TAILCALL: {
  551. int b = GETARG_B(i);
  552. if (b != 0) L->top = ra+b; /* else previous instruction set top */
  553. L->savedpc = pc;
  554. lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
  555. switch (luaD_precall(L, ra, LUA_MULTRET)) {
  556. case PCRLUA: {
  557. /* tail call: put new frame in place of previous one */
  558. CallInfo *ci = L->ci - 1; /* previous frame */
  559. int aux;
  560. StkId func = ci->func;
  561. StkId pfunc = (ci+1)->func; /* previous function index */
  562. if (L->openupval) luaF_close(L, ci->base);
  563. L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
  564. for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */
  565. setobjs2s(L, func+aux, pfunc+aux);
  566. ci->top = L->top = func+aux; /* correct top */
  567. lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
  568. ci->savedpc = L->savedpc;
  569. ci->tailcalls++; /* one more call lost */
  570. L->ci--; /* remove new frame */
  571. goto reentry;
  572. }
  573. case PCRC: { /* it was a C function (`precall' called it) */
  574. base = L->base;
  575. continue;
  576. }
  577. default: {
  578. return; /* yield */
  579. }
  580. }
  581. }
  582. case OP_RETURN: {
  583. int b = GETARG_B(i);
  584. if (b != 0) L->top = ra+b-1;
  585. if (L->openupval) luaF_close(L, base);
  586. L->savedpc = pc;
  587. b = luaD_poscall(L, ra);
  588. if (--nexeccalls == 0) /* was previous function running `here'? */
  589. return; /* no: return */
  590. else { /* yes: continue its execution */
  591. if (b) L->top = L->ci->top;
  592. lua_assert(isLua(L->ci));
  593. lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
  594. goto reentry;
  595. }
  596. }
  597. case OP_FORLOOP: {
  598. lua_Number step = nvalue(ra+2);
  599. lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
  600. lua_Number limit = nvalue(ra+1);
  601. if (luai_numlt(0, step) ? luai_numle(idx, limit)
  602. : luai_numle(limit, idx)) {
  603. dojump(L, pc, GETARG_sBx(i)); /* jump back */
  604. setnvalue(ra, idx); /* update internal index... */
  605. setnvalue(ra+3, idx); /* ...and external index */
  606. }
  607. continue;
  608. }
  609. case OP_FORPREP: {
  610. const TValue *init = ra;
  611. const TValue *plimit = ra+1;
  612. const TValue *pstep = ra+2;
  613. L->savedpc = pc; /* next steps may throw errors */
  614. if (!tonumber(init, ra))
  615. luaG_runerror(L, LUA_QL("for") " initial value must be a number");
  616. else if (!tonumber(plimit, ra+1))
  617. luaG_runerror(L, LUA_QL("for") " limit must be a number");
  618. else if (!tonumber(pstep, ra+2))
  619. luaG_runerror(L, LUA_QL("for") " step must be a number");
  620. setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
  621. dojump(L, pc, GETARG_sBx(i));
  622. continue;
  623. }
  624. case OP_TFORLOOP: {
  625. StkId cb = ra + 3; /* call base */
  626. setobjs2s(L, cb+2, ra+2);
  627. setobjs2s(L, cb+1, ra+1);
  628. setobjs2s(L, cb, ra);
  629. L->top = cb+3; /* func. + 2 args (state and index) */
  630. Protect(luaD_call(L, cb, GETARG_C(i)));
  631. L->top = L->ci->top;
  632. cb = RA(i) + 3; /* previous call may change the stack */
  633. if (!ttisnil(cb)) { /* continue loop? */
  634. setobjs2s(L, cb-1, cb); /* save control variable */
  635. dojump(L, pc, GETARG_sBx(*pc)); /* jump back */
  636. }
  637. pc++;
  638. continue;
  639. }
  640. case OP_SETLIST: {
  641. int n = GETARG_B(i);
  642. int c = GETARG_C(i);
  643. int last;
  644. Table *h;
  645. if (n == 0) {
  646. n = cast_int(L->top - ra) - 1;
  647. L->top = L->ci->top;
  648. }
  649. if (c == 0) c = cast_int(*pc++);
  650. runtime_check(L, ttistable(ra));
  651. h = hvalue(ra);
  652. last = ((c-1)*LFIELDS_PER_FLUSH) + n;
  653. if (last > h->sizearray) /* needs more space? */
  654. luaH_resizearray(L, h, last); /* pre-alloc it at once */
  655. for (; n > 0; n--) {
  656. TValue *val = ra+n;
  657. setobj2t(L, luaH_setnum(L, h, last--), val);
  658. luaC_barriert(L, h, val);
  659. }
  660. continue;
  661. }
  662. case OP_CLOSE: {
  663. luaF_close(L, ra);
  664. continue;
  665. }
  666. case OP_CLOSURE: {
  667. Proto *p;
  668. Closure *ncl;
  669. int nup, j;
  670. p = cl->p->p[GETARG_Bx(i)];
  671. nup = p->nups;
  672. ncl = luaF_newLclosure(L, nup, cl->env);
  673. ncl->l.p = p;
  674. for (j=0; j<nup; j++, pc++) {
  675. if (GET_OPCODE(*pc) == OP_GETUPVAL)
  676. ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
  677. else {
  678. lua_assert(GET_OPCODE(*pc) == OP_MOVE);
  679. ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
  680. }
  681. }
  682. setclvalue(L, ra, ncl);
  683. Protect(luaC_checkGC(L));
  684. continue;
  685. }
  686. case OP_VARARG: {
  687. int b = GETARG_B(i) - 1;
  688. int j;
  689. CallInfo *ci = L->ci;
  690. int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
  691. if (b == LUA_MULTRET) {
  692. Protect(luaD_checkstack(L, n));
  693. ra = RA(i); /* previous call may change the stack */
  694. b = n;
  695. L->top = ra + n;
  696. }
  697. for (j = 0; j < b; j++) {
  698. if (j < n) {
  699. setobjs2s(L, ra + j, ci->base - n + j);
  700. }
  701. else {
  702. setnilvalue(ra + j);
  703. }
  704. }
  705. continue;
  706. }
  707. }
  708. }
  709. }