src/lj_api.c

   1 /*
   2 ** Public Lua/C API.
   3 ** Copyright (C) 2005-2011 Mike Pall. See Copyright Notice in luajit.h
   4 **
   5 ** Major portions taken verbatim or adapted from the Lua interpreter.
   6 ** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
   7 */
   8
   9 #define lj_api_c
  10 #define LUA_CORE
  11
  12 #include "lj_obj.h"
  13 #include "lj_gc.h"
  14 #include "lj_err.h"
  15 #include "lj_debug.h"
  16 #include "lj_str.h"
  17 #include "lj_tab.h"
  18 #include "lj_func.h"
  19 #include "lj_udata.h"
  20 #include "lj_meta.h"
  21 #include "lj_state.h"
  22 #include "lj_bc.h"
  23 #include "lj_frame.h"
  24 #include "lj_trace.h"
  25 #include "lj_vm.h"
  26 #include "lj_lex.h"
  27 #include "lj_bcdump.h"
  28 #include "lj_parse.h"
  29
  30 /* -- Common helper functions --------------------------------------------- */
  31
  32 #define api_checknelems(L, n)           api_check(L, (n) <= (L->top - L->base))
  33 #define api_checkvalidindex(L, i)       api_check(L, (i) != niltv(L))
  34
  35 static TValue *index2adr(lua_State *L, int idx)
  36 {
  37   if (idx > 0) {
  38     TValue *o = L->base + (idx - 1);
  39     return o < L->top ? o : niltv(L);
  40   } else if (idx > LUA_REGISTRYINDEX) {
  41     api_check(L, idx != 0 && -idx <= L->top - L->base);
  42     return L->top + idx;
  43   } else if (idx == LUA_GLOBALSINDEX) {
  44     TValue *o = &G(L)->tmptv;
  45     settabV(L, o, tabref(L->env));
  46     return o;
  47   } else if (idx == LUA_REGISTRYINDEX) {
  48     return registry(L);
  49   } else {
  50     GCfunc *fn = curr_func(L);
  51     api_check(L, fn->c.gct == ~LJ_TFUNC && !isluafunc(fn));
  52     if (idx == LUA_ENVIRONINDEX) {
  53       TValue *o = &G(L)->tmptv;
  54       settabV(L, o, tabref(fn->c.env));
  55       return o;
  56     } else {
  57       idx = LUA_GLOBALSINDEX - idx;
  58       return idx <= fn->c.nupvalues ? &fn->c.upvalue[idx-1] : niltv(L);
  59     }
  60   }
  61 }
  62
  63 static TValue *stkindex2adr(lua_State *L, int idx)
  64 {
  65   if (idx > 0) {
  66     TValue *o = L->base + (idx - 1);
  67     return o < L->top ? o : niltv(L);
  68   } else {
  69     api_check(L, idx != 0 && -idx <= L->top - L->base);
  70     return L->top + idx;
  71   }
  72 }
  73
  74 static GCtab *getcurrenv(lua_State *L)
  75 {
  76   GCfunc *fn = curr_func(L);
  77   return fn->c.gct == ~LJ_TFUNC ? tabref(fn->c.env) : tabref(L->env);
  78 }
  79
  80 /* -- Miscellaneous API functions ----------------------------------------- */
  81
  82 LUA_API int lua_status(lua_State *L)
  83 {
  84   return L->status;
  85 }
  86
  87 LUA_API int lua_checkstack(lua_State *L, int size)
  88 {
  89   if (size > LUAI_MAXCSTACK || (L->top - L->base + size) > LUAI_MAXCSTACK) {
  90     return 0;  /* Stack overflow. */
  91   } else if (size > 0) {
  92     lj_state_checkstack(L, (MSize)size);
  93   }
  94   return 1;
  95 }
  96
  97 LUALIB_API void luaL_checkstack(lua_State *L, int size, const char *msg)
  98 {
  99   if (!lua_checkstack(L, size))
 100     lj_err_callerv(L, LJ_ERR_STKOVM, msg);
 101 }
 102
 103 LUA_API void lua_xmove(lua_State *from, lua_State *to, int n)
 104 {
 105   TValue *f, *t;
 106   if (from == to) return;
 107   api_checknelems(from, n);
 108   api_check(from, G(from) == G(to));
 109   lj_state_checkstack(to, (MSize)n);
 110   f = from->top;
 111   t = to->top = to->top + n;
 112   while (--n >= 0) copyTV(to, --t, --f);
 113   from->top = f;
 114 }
 115
 116 /* -- Stack manipulation -------------------------------------------------- */
 117
 118 LUA_API int lua_gettop(lua_State *L)
 119 {
 120   return (int)(L->top - L->base);
 121 }
 122
 123 LUA_API void lua_settop(lua_State *L, int idx)
 124 {
 125   if (idx >= 0) {
 126     api_check(L, idx <= tvref(L->maxstack) - L->base);
 127     if (L->base + idx > L->top) {
 128       if (L->base + idx >= tvref(L->maxstack))
 129         lj_state_growstack(L, (MSize)idx - (MSize)(L->top - L->base));
 130       do { setnilV(L->top++); } while (L->top < L->base + idx);
 131     } else {
 132       L->top = L->base + idx;
 133     }
 134   } else {
 135     api_check(L, -(idx+1) <= (L->top - L->base));
 136     L->top += idx+1;  /* Shrinks top (idx < 0). */
 137   }
 138 }
 139
 140 LUA_API void lua_remove(lua_State *L, int idx)
 141 {
 142   TValue *p = stkindex2adr(L, idx);
 143   api_checkvalidindex(L, p);
 144   while (++p < L->top) copyTV(L, p-1, p);
 145   L->top--;
 146 }
 147
 148 LUA_API void lua_insert(lua_State *L, int idx)
 149 {
 150   TValue *q, *p = stkindex2adr(L, idx);
 151   api_checkvalidindex(L, p);
 152   for (q = L->top; q > p; q--) copyTV(L, q, q-1);
 153   copyTV(L, p, L->top);
 154 }
 155
 156 LUA_API void lua_replace(lua_State *L, int idx)
 157 {
 158   api_checknelems(L, 1);
 159   if (idx == LUA_GLOBALSINDEX) {
 160     api_check(L, tvistab(L->top-1));
 161     /* NOBARRIER: A thread (i.e. L) is never black. */
 162     setgcref(L->env, obj2gco(tabV(L->top-1)));
 163   } else if (idx == LUA_ENVIRONINDEX) {
 164     GCfunc *fn = curr_func(L);
 165     if (fn->c.gct != ~LJ_TFUNC)
 166       lj_err_msg(L, LJ_ERR_NOENV);
 167     api_check(L, tvistab(L->top-1));
 168     setgcref(fn->c.env, obj2gco(tabV(L->top-1)));
 169     lj_gc_barrier(L, fn, L->top-1);
 170   } else {
 171     TValue *o = index2adr(L, idx);
 172     api_checkvalidindex(L, o);
 173     copyTV(L, o, L->top-1);
 174     if (idx < LUA_GLOBALSINDEX)  /* Need a barrier for upvalues. */
 175       lj_gc_barrier(L, curr_func(L), L->top-1);
 176   }
 177   L->top--;
 178 }
 179
 180 LUA_API void lua_pushvalue(lua_State *L, int idx)
 181 {
 182   copyTV(L, L->top, index2adr(L, idx));
 183   incr_top(L);
 184 }
 185
 186 /* -- Stack getters ------------------------------------------------------- */
 187
 188 LUA_API int lua_type(lua_State *L, int idx)
 189 {
 190   cTValue *o = index2adr(L, idx);
 191   if (tvisnumber(o)) {
 192     return LUA_TNUMBER;
 193 #if LJ_64
 194   } else if (tvislightud(o)) {
 195     return LUA_TLIGHTUSERDATA;
 196 #endif
 197   } else if (o == niltv(L)) {
 198     return LUA_TNONE;
 199   } else {  /* Magic internal/external tag conversion. ORDER LJ_T */
 200     uint32_t t = ~itype(o);
 201 #if LJ_64
 202     int tt = (int)((U64x(75a06,98042110) >> 4*t) & 15u);
 203 #else
 204     int tt = (int)(((t < 8 ? 0x98042110u : 0x75a06u) >> 4*(t&7)) & 15u);
 205 #endif
 206     lua_assert(tt != LUA_TNIL || tvisnil(o));
 207     return tt;
 208   }
 209 }
 210
 211 LUALIB_API void luaL_checktype(lua_State *L, int idx, int tt)
 212 {
 213   if (lua_type(L, idx) != tt)
 214     lj_err_argt(L, idx, tt);
 215 }
 216
 217 LUALIB_API void luaL_checkany(lua_State *L, int idx)
 218 {
 219   if (index2adr(L, idx) == niltv(L))
 220     lj_err_arg(L, idx, LJ_ERR_NOVAL);
 221 }
 222
 223 LUA_API const char *lua_typename(lua_State *L, int t)
 224 {
 225   UNUSED(L);
 226   return lj_obj_typename[t+1];
 227 }
 228
 229 LUA_API int lua_iscfunction(lua_State *L, int idx)
 230 {
 231   cTValue *o = index2adr(L, idx);
 232   return tvisfunc(o) && !isluafunc(funcV(o));
 233 }
 234
 235 LUA_API int lua_isnumber(lua_State *L, int idx)
 236 {
 237   cTValue *o = index2adr(L, idx);
 238   TValue tmp;
 239   return (tvisnumber(o) || (tvisstr(o) && lj_str_tonumber(strV(o), &tmp)));
 240 }
 241
 242 LUA_API int lua_isstring(lua_State *L, int idx)
 243 {
 244   cTValue *o = index2adr(L, idx);
 245   return (tvisstr(o) || tvisnumber(o));
 246 }
 247
 248 LUA_API int lua_isuserdata(lua_State *L, int idx)
 249 {
 250   cTValue *o = index2adr(L, idx);
 251   return (tvisudata(o) || tvislightud(o));
 252 }
 253
 254 LUA_API int lua_rawequal(lua_State *L, int idx1, int idx2)
 255 {
 256   cTValue *o1 = index2adr(L, idx1);
 257   cTValue *o2 = index2adr(L, idx2);
 258   return (o1 == niltv(L) || o2 == niltv(L)) ? 0 : lj_obj_equal(o1, o2);
 259 }
 260
 261 LUA_API int lua_equal(lua_State *L, int idx1, int idx2)
 262 {
 263   cTValue *o1 = index2adr(L, idx1);
 264   cTValue *o2 = index2adr(L, idx2);
 265   if (tvisint(o1) && tvisint(o2)) {
 266     return intV(o1) == intV(o2);
 267   } else if (tvisnumber(o1) && tvisnumber(o2)) {
 268     return numberVnum(o1) == numberVnum(o2);
 269   } else if (itype(o1) != itype(o2)) {
 270     return 0;
 271   } else if (tvispri(o1)) {
 272     return o1 != niltv(L) && o2 != niltv(L);
 273 #if LJ_64
 274   } else if (tvislightud(o1)) {
 275     return o1->u64 == o2->u64;
 276 #endif
 277   } else if (gcrefeq(o1->gcr, o2->gcr)) {
 278     return 1;
 279   } else if (!tvistabud(o1)) {
 280     return 0;
 281   } else {
 282     TValue *base = lj_meta_equal(L, gcV(o1), gcV(o2), 0);
 283     if ((uintptr_t)base <= 1) {
 284       return (int)(uintptr_t)base;
 285     } else {
 286       L->top = base+2;
 287       lj_vm_call(L, base, 1+1);
 288       L->top -= 2;
 289       return tvistruecond(L->top+1);
 290     }
 291   }
 292 }
 293
 294 LUA_API int lua_lessthan(lua_State *L, int idx1, int idx2)
 295 {
 296   cTValue *o1 = index2adr(L, idx1);
 297   cTValue *o2 = index2adr(L, idx2);
 298   if (o1 == niltv(L) || o2 == niltv(L)) {
 299     return 0;
 300   } else if (tvisint(o1) && tvisint(o2)) {
 301     return intV(o1) < intV(o2);
 302   } else if (tvisnumber(o1) && tvisnumber(o2)) {
 303     return numberVnum(o1) < numberVnum(o2);
 304   } else {
 305     TValue *base = lj_meta_comp(L, o1, o2, 0);
 306     if ((uintptr_t)base <= 1) {
 307       return (int)(uintptr_t)base;
 308     } else {
 309       L->top = base+2;
 310       lj_vm_call(L, base, 1+1);
 311       L->top -= 2;
 312       return tvistruecond(L->top+1);
 313     }
 314   }
 315 }
 316
 317 LUA_API lua_Number lua_tonumber(lua_State *L, int idx)
 318 {
 319   cTValue *o = index2adr(L, idx);
 320   TValue tmp;
 321   if (LJ_LIKELY(tvisnumber(o)))
 322     return numberVnum(o);
 323   else if (tvisstr(o) && lj_str_tonum(strV(o), &tmp))
 324     return numV(&tmp);
 325   else
 326     return 0;
 327 }
 328
 329 LUALIB_API lua_Number luaL_checknumber(lua_State *L, int idx)
 330 {
 331   cTValue *o = index2adr(L, idx);
 332   TValue tmp;
 333   if (LJ_LIKELY(tvisnumber(o)))
 334     return numberVnum(o);
 335   else if (!(tvisstr(o) && lj_str_tonum(strV(o), &tmp)))
 336     lj_err_argt(L, idx, LUA_TNUMBER);
 337   return numV(&tmp);
 338 }
 339
 340 LUALIB_API lua_Number luaL_optnumber(lua_State *L, int idx, lua_Number def)
 341 {
 342   cTValue *o = index2adr(L, idx);
 343   TValue tmp;
 344   if (LJ_LIKELY(tvisnumber(o)))
 345     return numberVnum(o);
 346   else if (tvisnil(o))
 347     return def;
 348   else if (!(tvisstr(o) && lj_str_tonum(strV(o), &tmp)))
 349     lj_err_argt(L, idx, LUA_TNUMBER);
 350   return numV(&tmp);
 351 }
 352
 353 LUA_API lua_Integer lua_tointeger(lua_State *L, int idx)
 354 {
 355   cTValue *o = index2adr(L, idx);
 356   TValue tmp;
 357   lua_Number n;
 358   if (LJ_LIKELY(tvisint(o))) {
 359     return intV(o);
 360   } else if (LJ_LIKELY(tvisnum(o))) {
 361     n = numV(o);
 362   } else {
 363     if (!(tvisstr(o) && lj_str_tonumber(strV(o), &tmp)))
 364       return 0;
 365     if (tvisint(&tmp))
 366       return (lua_Integer)intV(&tmp);
 367     n = numV(&tmp);
 368   }
 369 #if LJ_64
 370   return (lua_Integer)n;
 371 #else
 372   return lj_num2int(n);
 373 #endif
 374 }
 375
 376 LUALIB_API lua_Integer luaL_checkinteger(lua_State *L, int idx)
 377 {
 378   cTValue *o = index2adr(L, idx);
 379   TValue tmp;
 380   lua_Number n;
 381   if (LJ_LIKELY(tvisint(o))) {
 382     return intV(o);
 383   } else if (LJ_LIKELY(tvisnum(o))) {
 384     n = numV(o);
 385   } else {
 386     if (!(tvisstr(o) && lj_str_tonumber(strV(o), &tmp)))
 387       lj_err_argt(L, idx, LUA_TNUMBER);
 388     if (tvisint(&tmp))
 389       return (lua_Integer)intV(&tmp);
 390     n = numV(&tmp);
 391   }
 392 #if LJ_64
 393   return (lua_Integer)n;
 394 #else
 395   return lj_num2int(n);
 396 #endif
 397 }
 398
 399 LUALIB_API lua_Integer luaL_optinteger(lua_State *L, int idx, lua_Integer def)
 400 {
 401   cTValue *o = index2adr(L, idx);
 402   TValue tmp;
 403   lua_Number n;
 404   if (LJ_LIKELY(tvisint(o))) {
 405     return intV(o);
 406   } else if (LJ_LIKELY(tvisnum(o))) {
 407     n = numV(o);
 408   } else if (tvisnil(o)) {
 409     return def;
 410   } else {
 411     if (!(tvisstr(o) && lj_str_tonumber(strV(o), &tmp)))
 412       lj_err_argt(L, idx, LUA_TNUMBER);
 413     if (tvisint(&tmp))
 414       return (lua_Integer)intV(&tmp);
 415     n = numV(&tmp);
 416   }
 417 #if LJ_64
 418   return (lua_Integer)n;
 419 #else
 420   return lj_num2int(n);
 421 #endif
 422 }
 423
 424 LUA_API int lua_toboolean(lua_State *L, int idx)
 425 {
 426   cTValue *o = index2adr(L, idx);
 427   return tvistruecond(o);
 428 }
 429
 430 LUA_API const char *lua_tolstring(lua_State *L, int idx, size_t *len)
 431 {
 432   TValue *o = index2adr(L, idx);
 433   GCstr *s;
 434   if (LJ_LIKELY(tvisstr(o))) {
 435     s = strV(o);
 436   } else if (tvisnumber(o)) {
 437     lj_gc_check(L);
 438     o = index2adr(L, idx);  /* GC may move the stack. */
 439     s = lj_str_fromnumber(L, o);
 440   } else {
 441     if (len != NULL) *len = 0;
 442     return NULL;
 443   }
 444   if (len != NULL) *len = s->len;
 445   return strdata(s);
 446 }
 447
 448 LUALIB_API const char *luaL_checklstring(lua_State *L, int idx, size_t *len)
 449 {
 450   TValue *o = index2adr(L, idx);
 451   GCstr *s;
 452   if (LJ_LIKELY(tvisstr(o))) {
 453     s = strV(o);
 454   } else if (tvisnumber(o)) {
 455     lj_gc_check(L);
 456     o = index2adr(L, idx);  /* GC may move the stack. */
 457     s = lj_str_fromnumber(L, o);
 458   } else {
 459     lj_err_argt(L, idx, LUA_TSTRING);
 460   }
 461   if (len != NULL) *len = s->len;
 462   return strdata(s);
 463 }
 464
 465 LUALIB_API const char *luaL_optlstring(lua_State *L, int idx,
 466                                        const char *def, size_t *len)
 467 {
 468   TValue *o = index2adr(L, idx);
 469   GCstr *s;
 470   if (LJ_LIKELY(tvisstr(o))) {
 471     s = strV(o);
 472   } else if (tvisnil(o)) {
 473     if (len != NULL) *len = def ? strlen(def) : 0;
 474     return def;
 475   } else if (tvisnumber(o)) {
 476     lj_gc_check(L);
 477     o = index2adr(L, idx);  /* GC may move the stack. */
 478     s = lj_str_fromnumber(L, o);
 479   } else {
 480     lj_err_argt(L, idx, LUA_TSTRING);
 481   }
 482   if (len != NULL) *len = s->len;
 483   return strdata(s);
 484 }
 485
 486 LUALIB_API int luaL_checkoption(lua_State *L, int idx, const char *def,
 487                                 const char *const lst[])
 488 {
 489   ptrdiff_t i;
 490   const char *s = lua_tolstring(L, idx, NULL);
 491   if (s == NULL && (s = def) == NULL)
 492     lj_err_argt(L, idx, LUA_TSTRING);
 493   for (i = 0; lst[i]; i++)
 494     if (strcmp(lst[i], s) == 0)
 495       return (int)i;
 496   lj_err_argv(L, idx, LJ_ERR_INVOPTM, s);
 497 }
 498
 499 LUA_API size_t lua_objlen(lua_State *L, int idx)
 500 {
 501   TValue *o = index2adr(L, idx);
 502   if (tvisstr(o))
 503     return strV(o)->len;
 504   else if (tvistab(o))
 505     return (size_t)lj_tab_len(tabV(o));
 506   else if (tvisudata(o))
 507     return udataV(o)->len;
 508   else if (tvisnumber(o))
 509     return lj_str_fromnumber(L, o)->len;
 510   else
 511     return 0;
 512 }
 513
 514 LUA_API lua_CFunction lua_tocfunction(lua_State *L, int idx)
 515 {
 516   cTValue *o = index2adr(L, idx);
 517   if (tvisfunc(o)) {
 518     BCOp op = bc_op(*mref(funcV(o)->c.pc, BCIns));
 519     if (op == BC_FUNCC || op == BC_FUNCCW)
 520       return funcV(o)->c.f;
 521   }
 522   return NULL;
 523 }
 524
 525 LUA_API void *lua_touserdata(lua_State *L, int idx)
 526 {
 527   cTValue *o = index2adr(L, idx);
 528   if (tvisudata(o))
 529     return uddata(udataV(o));
 530   else if (tvislightud(o))
 531     return lightudV(o);
 532   else
 533     return NULL;
 534 }
 535
 536 LUA_API lua_State *lua_tothread(lua_State *L, int idx)
 537 {
 538   cTValue *o = index2adr(L, idx);
 539   return (!tvisthread(o)) ? NULL : threadV(o);
 540 }
 541
 542 LUA_API const void *lua_topointer(lua_State *L, int idx)
 543 {
 544   cTValue *o = index2adr(L, idx);
 545   if (tvisudata(o))
 546     return uddata(udataV(o));
 547   else if (tvislightud(o))
 548     return lightudV(o);
 549   else if (tviscdata(o))
 550     return cdataptr(cdataV(o));
 551   else if (tvisgcv(o))
 552     return gcV(o);
 553   else
 554     return NULL;
 555 }
 556
 557 /* -- Stack setters (object creation) ------------------------------------- */
 558
 559 LUA_API void lua_pushnil(lua_State *L)
 560 {
 561   setnilV(L->top);
 562   incr_top(L);
 563 }
 564
 565 LUA_API void lua_pushnumber(lua_State *L, lua_Number n)
 566 {
 567   setnumV(L->top, n);
 568   if (LJ_UNLIKELY(tvisnan(L->top)))
 569     setnanV(L->top);  /* Canonicalize injected NaNs. */
 570   incr_top(L);
 571 }
 572
 573 LUA_API void lua_pushinteger(lua_State *L, lua_Integer n)
 574 {
 575   setintptrV(L->top, n);
 576   incr_top(L);
 577 }
 578
 579 LUA_API void lua_pushlstring(lua_State *L, const char *str, size_t len)
 580 {
 581   GCstr *s;
 582   lj_gc_check(L);
 583   s = lj_str_new(L, str, len);
 584   setstrV(L, L->top, s);
 585   incr_top(L);
 586 }
 587
 588 LUA_API void lua_pushstring(lua_State *L, const char *str)
 589 {
 590   if (str == NULL) {
 591     setnilV(L->top);
 592   } else {
 593     GCstr *s;
 594     lj_gc_check(L);
 595     s = lj_str_newz(L, str);
 596     setstrV(L, L->top, s);
 597   }
 598   incr_top(L);
 599 }
 600
 601 LUA_API const char *lua_pushvfstring(lua_State *L, const char *fmt,
 602                                      va_list argp)
 603 {
 604   lj_gc_check(L);
 605   return lj_str_pushvf(L, fmt, argp);
 606 }
 607
 608 LUA_API const char *lua_pushfstring(lua_State *L, const char *fmt, ...)
 609 {
 610   const char *ret;
 611   va_list argp;
 612   lj_gc_check(L);
 613   va_start(argp, fmt);
 614   ret = lj_str_pushvf(L, fmt, argp);
 615   va_end(argp);
 616   return ret;
 617 }
 618
 619 LUA_API void lua_pushcclosure(lua_State *L, lua_CFunction f, int n)
 620 {
 621   GCfunc *fn;
 622   lj_gc_check(L);
 623   api_checknelems(L, n);
 624   fn = lj_func_newC(L, (MSize)n, getcurrenv(L));
 625   fn->c.f = f;
 626   L->top -= n;
 627   while (n--)
 628     copyTV(L, &fn->c.upvalue[n], L->top+n);
 629   setfuncV(L, L->top, fn);
 630   lua_assert(iswhite(obj2gco(fn)));
 631   incr_top(L);
 632 }
 633
 634 LUA_API void lua_pushboolean(lua_State *L, int b)
 635 {
 636   setboolV(L->top, (b != 0));
 637   incr_top(L);
 638 }
 639
 640 LUA_API void lua_pushlightuserdata(lua_State *L, void *p)
 641 {
 642   setlightudV(L->top, checklightudptr(L, p));
 643   incr_top(L);
 644 }
 645
 646 LUA_API void lua_createtable(lua_State *L, int narray, int nrec)
 647 {
 648   GCtab *t;
 649   lj_gc_check(L);
 650   t = lj_tab_new(L, (uint32_t)(narray > 0 ? narray+1 : 0), hsize2hbits(nrec));
 651   settabV(L, L->top, t);
 652   incr_top(L);
 653 }
 654
 655 LUALIB_API int luaL_newmetatable(lua_State *L, const char *tname)
 656 {
 657   GCtab *regt = tabV(registry(L));
 658   TValue *tv = lj_tab_setstr(L, regt, lj_str_newz(L, tname));
 659   if (tvisnil(tv)) {
 660     GCtab *mt = lj_tab_new(L, 0, 1);
 661     settabV(L, tv, mt);
 662     settabV(L, L->top++, mt);
 663     lj_gc_anybarriert(L, regt);
 664     return 1;
 665   } else {
 666     copyTV(L, L->top++, tv);
 667     return 0;
 668   }
 669 }
 670
 671 LUA_API int lua_pushthread(lua_State *L)
 672 {
 673   setthreadV(L, L->top, L);
 674   incr_top(L);
 675   return (mainthread(G(L)) == L);
 676 }
 677
 678 LUA_API lua_State *lua_newthread(lua_State *L)
 679 {
 680   lua_State *L1;
 681   lj_gc_check(L);
 682   L1 = lj_state_new(L);
 683   setthreadV(L, L->top, L1);
 684   incr_top(L);
 685   return L1;
 686 }
 687
 688 LUA_API void *lua_newuserdata(lua_State *L, size_t size)
 689 {
 690   GCudata *ud;
 691   lj_gc_check(L);
 692   if (size > LJ_MAX_UDATA)
 693     lj_err_msg(L, LJ_ERR_UDATAOV);
 694   ud = lj_udata_new(L, (MSize)size, getcurrenv(L));
 695   setudataV(L, L->top, ud);
 696   incr_top(L);
 697   return uddata(ud);
 698 }
 699
 700 LUA_API void lua_concat(lua_State *L, int n)
 701 {
 702   api_checknelems(L, n);
 703   if (n >= 2) {
 704     n--;
 705     do {
 706       TValue *top = lj_meta_cat(L, L->top-1, n);
 707       if (top == NULL) {
 708         L->top -= n;
 709         break;
 710       }
 711       n -= (int)(L->top - top);
 712       L->top = top+2;
 713       lj_vm_call(L, top, 1+1);
 714       L->top--;
 715       copyTV(L, L->top-1, L->top);
 716     } while (--n > 0);
 717   } else if (n == 0) {  /* Push empty string. */
 718     setstrV(L, L->top, &G(L)->strempty);
 719     incr_top(L);
 720   }
 721   /* else n == 1: nothing to do. */
 722 }
 723
 724 /* -- Object getters ------------------------------------------------------ */
 725
 726 LUA_API void lua_gettable(lua_State *L, int idx)
 727 {
 728   cTValue *v, *t = index2adr(L, idx);
 729   api_checkvalidindex(L, t);
 730   v = lj_meta_tget(L, t, L->top-1);
 731   if (v == NULL) {
 732     L->top += 2;
 733     lj_vm_call(L, L->top-2, 1+1);
 734     L->top -= 2;
 735     v = L->top+1;
 736   }
 737   copyTV(L, L->top-1, v);
 738 }
 739
 740 LUA_API void lua_getfield(lua_State *L, int idx, const char *k)
 741 {
 742   cTValue *v, *t = index2adr(L, idx);
 743   TValue key;
 744   api_checkvalidindex(L, t);
 745   setstrV(L, &key, lj_str_newz(L, k));
 746   v = lj_meta_tget(L, t, &key);
 747   if (v == NULL) {
 748     L->top += 2;
 749     lj_vm_call(L, L->top-2, 1+1);
 750     L->top -= 2;
 751     v = L->top+1;
 752   }
 753   copyTV(L, L->top, v);
 754   incr_top(L);
 755 }
 756
 757 LUA_API void lua_rawget(lua_State *L, int idx)
 758 {
 759   cTValue *t = index2adr(L, idx);
 760   api_check(L, tvistab(t));
 761   copyTV(L, L->top-1, lj_tab_get(L, tabV(t), L->top-1));
 762 }
 763
 764 LUA_API void lua_rawgeti(lua_State *L, int idx, int n)
 765 {
 766   cTValue *v, *t = index2adr(L, idx);
 767   api_check(L, tvistab(t));
 768   v = lj_tab_getint(tabV(t), n);
 769   if (v) {
 770     copyTV(L, L->top, v);
 771   } else {
 772     setnilV(L->top);
 773   }
 774   incr_top(L);
 775 }
 776
 777 LUA_API int lua_getmetatable(lua_State *L, int idx)
 778 {
 779   cTValue *o = index2adr(L, idx);
 780   GCtab *mt = NULL;
 781   if (tvistab(o))
 782     mt = tabref(tabV(o)->metatable);
 783   else if (tvisudata(o))
 784     mt = tabref(udataV(o)->metatable);
 785   else
 786     mt = tabref(basemt_obj(G(L), o));
 787   if (mt == NULL)
 788     return 0;
 789   settabV(L, L->top, mt);
 790   incr_top(L);
 791   return 1;
 792 }
 793
 794 LUALIB_API int luaL_getmetafield(lua_State *L, int idx, const char *field)
 795 {
 796   if (lua_getmetatable(L, idx)) {
 797     cTValue *tv = lj_tab_getstr(tabV(L->top-1), lj_str_newz(L, field));
 798     if (tv && !tvisnil(tv)) {
 799       copyTV(L, L->top-1, tv);
 800       return 1;
 801     }
 802     L->top--;
 803   }
 804   return 0;
 805 }
 806
 807 LUA_API void lua_getfenv(lua_State *L, int idx)
 808 {
 809   cTValue *o = index2adr(L, idx);
 810   api_checkvalidindex(L, o);
 811   if (tvisfunc(o)) {
 812     settabV(L, L->top, tabref(funcV(o)->c.env));
 813   } else if (tvisudata(o)) {
 814     settabV(L, L->top, tabref(udataV(o)->env));
 815   } else if (tvisthread(o)) {
 816     settabV(L, L->top, tabref(threadV(o)->env));
 817   } else {
 818     setnilV(L->top);
 819   }
 820   incr_top(L);
 821 }
 822
 823 LUA_API int lua_next(lua_State *L, int idx)
 824 {
 825   cTValue *t = index2adr(L, idx);
 826   int more;
 827   api_check(L, tvistab(t));
 828   more = lj_tab_next(L, tabV(t), L->top-1);
 829   if (more) {
 830     incr_top(L);  /* Return new key and value slot. */
 831   } else {  /* End of traversal. */
 832     L->top--;  /* Remove key slot. */
 833   }
 834   return more;
 835 }
 836
 837 LUA_API const char *lua_getupvalue(lua_State *L, int idx, int n)
 838 {
 839   TValue *val;
 840   const char *name = lj_debug_uvnamev(index2adr(L, idx), (uint32_t)(n-1), &val);
 841   if (name) {
 842     copyTV(L, L->top, val);
 843     incr_top(L);
 844   }
 845   return name;
 846 }
 847
 848 LUALIB_API void *luaL_checkudata(lua_State *L, int idx, const char *tname)
 849 {
 850   cTValue *o = index2adr(L, idx);
 851   if (tvisudata(o)) {
 852     GCudata *ud = udataV(o);
 853     cTValue *tv = lj_tab_getstr(tabV(registry(L)), lj_str_newz(L, tname));
 854     if (tv && tvistab(tv) && tabV(tv) == tabref(ud->metatable))
 855       return uddata(ud);
 856   }
 857   lj_err_argtype(L, idx, tname);
 858   return NULL;  /* unreachable */
 859 }
 860
 861 /* -- Object setters ------------------------------------------------------ */
 862
 863 LUA_API void lua_settable(lua_State *L, int idx)
 864 {
 865   TValue *o;
 866   cTValue *t = index2adr(L, idx);
 867   api_checknelems(L, 2);
 868   api_checkvalidindex(L, t);
 869   o = lj_meta_tset(L, t, L->top-2);
 870   if (o) {
 871     /* NOBARRIER: lj_meta_tset ensures the table is not black. */
 872     copyTV(L, o, L->top-1);
 873     L->top -= 2;
 874   } else {
 875     L->top += 3;
 876     copyTV(L, L->top-1, L->top-6);
 877     lj_vm_call(L, L->top-3, 0+1);
 878     L->top -= 3;
 879   }
 880 }
 881
 882 LUA_API void lua_setfield(lua_State *L, int idx, const char *k)
 883 {
 884   TValue *o;
 885   TValue key;
 886   cTValue *t = index2adr(L, idx);
 887   api_checknelems(L, 1);
 888   api_checkvalidindex(L, t);
 889   setstrV(L, &key, lj_str_newz(L, k));
 890   o = lj_meta_tset(L, t, &key);
 891   if (o) {
 892     L->top--;
 893     /* NOBARRIER: lj_meta_tset ensures the table is not black. */
 894     copyTV(L, o, L->top);
 895   } else {
 896     L->top += 3;
 897     copyTV(L, L->top-1, L->top-6);
 898     lj_vm_call(L, L->top-3, 0+1);
 899     L->top -= 2;
 900   }
 901 }
 902
 903 LUA_API void lua_rawset(lua_State *L, int idx)
 904 {
 905   GCtab *t = tabV(index2adr(L, idx));
 906   TValue *dst, *key;
 907   api_checknelems(L, 2);
 908   key = L->top-2;
 909   dst = lj_tab_set(L, t, key);
 910   copyTV(L, dst, key+1);
 911   lj_gc_anybarriert(L, t);
 912   L->top = key;
 913 }
 914
 915 LUA_API void lua_rawseti(lua_State *L, int idx, int n)
 916 {
 917   GCtab *t = tabV(index2adr(L, idx));
 918   TValue *dst, *src;
 919   api_checknelems(L, 1);
 920   dst = lj_tab_setint(L, t, n);
 921   src = L->top-1;
 922   copyTV(L, dst, src);
 923   lj_gc_barriert(L, t, dst);
 924   L->top = src;
 925 }
 926
 927 LUA_API int lua_setmetatable(lua_State *L, int idx)
 928 {
 929   global_State *g;
 930   GCtab *mt;
 931   cTValue *o = index2adr(L, idx);
 932   api_checknelems(L, 1);
 933   api_checkvalidindex(L, o);
 934   if (tvisnil(L->top-1)) {
 935     mt = NULL;
 936   } else {
 937     api_check(L, tvistab(L->top-1));
 938     mt = tabV(L->top-1);
 939   }
 940   g = G(L);
 941   if (tvistab(o)) {
 942     setgcref(tabV(o)->metatable, obj2gco(mt));
 943     if (mt)
 944       lj_gc_objbarriert(L, tabV(o), mt);
 945   } else if (tvisudata(o)) {
 946     setgcref(udataV(o)->metatable, obj2gco(mt));
 947     if (mt)
 948       lj_gc_objbarrier(L, udataV(o), mt);
 949   } else {
 950     /* Flush cache, since traces specialize to basemt. But not during __gc. */
 951     if (lj_trace_flushall(L))
 952       lj_err_caller(L, LJ_ERR_NOGCMM);
 953     if (tvisbool(o)) {
 954       /* NOBARRIER: basemt is a GC root. */
 955       setgcref(basemt_it(g, LJ_TTRUE), obj2gco(mt));
 956       setgcref(basemt_it(g, LJ_TFALSE), obj2gco(mt));
 957     } else {
 958       /* NOBARRIER: basemt is a GC root. */
 959       setgcref(basemt_obj(g, o), obj2gco(mt));
 960     }
 961   }
 962   L->top--;
 963   return 1;
 964 }
 965
 966 LUA_API int lua_setfenv(lua_State *L, int idx)
 967 {
 968   cTValue *o = index2adr(L, idx);
 969   GCtab *t;
 970   api_checknelems(L, 1);
 971   api_checkvalidindex(L, o);
 972   api_check(L, tvistab(L->top-1));
 973   t = tabV(L->top-1);
 974   if (tvisfunc(o)) {
 975     setgcref(funcV(o)->c.env, obj2gco(t));
 976   } else if (tvisudata(o)) {
 977     setgcref(udataV(o)->env, obj2gco(t));
 978   } else if (tvisthread(o)) {
 979     setgcref(threadV(o)->env, obj2gco(t));
 980   } else {
 981     L->top--;
 982     return 0;
 983   }
 984   lj_gc_objbarrier(L, gcV(o), t);
 985   L->top--;
 986   return 1;
 987 }
 988
 989 LUA_API const char *lua_setupvalue(lua_State *L, int idx, int n)
 990 {
 991   cTValue *f = index2adr(L, idx);
 992   TValue *val;
 993   const char *name;
 994   api_checknelems(L, 1);
 995   name = lj_debug_uvnamev(f, (uint32_t)(n-1), &val);
 996   if (name) {
 997     L->top--;
 998     copyTV(L, val, L->top);
 999     lj_gc_barrier(L, funcV(f), L->top);
1000   }
1001   return name;
1002 }
1003
1004 /* -- Calls --------------------------------------------------------------- */
1005
1006 LUA_API void lua_call(lua_State *L, int nargs, int nresults)
1007 {
1008   api_check(L, L->status == 0 || L->status == LUA_ERRERR);
1009   api_checknelems(L, nargs+1);
1010   lj_vm_call(L, L->top - nargs, nresults+1);
1011 }
1012
1013 LUA_API int lua_pcall(lua_State *L, int nargs, int nresults, int errfunc)
1014 {
1015   global_State *g = G(L);
1016   uint8_t oldh = hook_save(g);
1017   ptrdiff_t ef;
1018   int status;
1019   api_check(L, L->status == 0 || L->status == LUA_ERRERR);
1020   api_checknelems(L, nargs+1);
1021   if (errfunc == 0) {
1022     ef = 0;
1023   } else {
1024     cTValue *o = stkindex2adr(L, errfunc);
1025     api_checkvalidindex(L, o);
1026     ef = savestack(L, o);
1027   }
1028   status = lj_vm_pcall(L, L->top - nargs, nresults+1, ef);
1029   if (status) hook_restore(g, oldh);
1030   return status;
1031 }
1032
1033 static TValue *cpcall(lua_State *L, lua_CFunction func, void *ud)
1034 {
1035   GCfunc *fn = lj_func_newC(L, 0, getcurrenv(L));
1036   fn->c.f = func;
1037   setfuncV(L, L->top, fn);
1038   setlightudV(L->top+1, checklightudptr(L, ud));
1039   cframe_nres(L->cframe) = 1+0;  /* Zero results. */
1040   L->top += 2;
1041   return L->top-1;  /* Now call the newly allocated C function. */
1042 }
1043
1044 LUA_API int lua_cpcall(lua_State *L, lua_CFunction func, void *ud)
1045 {
1046   global_State *g = G(L);
1047   uint8_t oldh = hook_save(g);
1048   int status;
1049   api_check(L, L->status == 0 || L->status == LUA_ERRERR);
1050   status = lj_vm_cpcall(L, func, ud, cpcall);
1051   if (status) hook_restore(g, oldh);
1052   return status;
1053 }
1054
1055 LUALIB_API int luaL_callmeta(lua_State *L, int idx, const char *field)
1056 {
1057   if (luaL_getmetafield(L, idx, field)) {
1058     TValue *base = L->top--;
1059     copyTV(L, base, index2adr(L, idx));
1060     L->top = base+1;
1061     lj_vm_call(L, base, 1+1);
1062     return 1;
1063   }
1064   return 0;
1065 }
1066
1067 /* -- Coroutine yield and resume ------------------------------------------ */
1068
1069 LUA_API int lua_yield(lua_State *L, int nresults)
1070 {
1071   void *cf = L->cframe;
1072   global_State *g = G(L);
1073   if (cframe_canyield(cf)) {
1074     cf = cframe_raw(cf);
1075     if (!hook_active(g)) {  /* Regular yield: move results down if needed. */
1076       cTValue *f = L->top - nresults;
1077       if (f > L->base) {
1078         TValue *t = L->base;
1079         while (--nresults >= 0) copyTV(L, t++, f++);
1080         L->top = t;
1081       }
1082     } else {  /* Yield from hook: add a pseudo-frame. */
1083       TValue *top = L->top;
1084       hook_leave(g);
1085       top->u64 = cframe_multres(cf);
1086       setcont(top+1, lj_cont_hook);
1087       setframe_pc(top+1, cframe_pc(cf)-1);
1088       setframe_gc(top+2, obj2gco(L));
1089       setframe_ftsz(top+2, (int)((char *)(top+3)-(char *)L->base)+FRAME_CONT);
1090       L->top = L->base = top+3;
1091     }
1092 #if LJ_TARGET_X64
1093     lj_err_throw(L, LUA_YIELD);
1094 #else
1095     L->cframe = NULL;
1096     L->status = LUA_YIELD;
1097     lj_vm_unwind_c(cf, LUA_YIELD);
1098 #endif
1099   }
1100   lj_err_msg(L, LJ_ERR_CYIELD);
1101   return 0;  /* unreachable */
1102 }
1103
1104 LUA_API int lua_resume(lua_State *L, int nargs)
1105 {
1106   if (L->cframe == NULL && L->status <= LUA_YIELD)
1107     return lj_vm_resume(L, L->top - nargs, 0, 0);
1108   L->top = L->base;
1109   setstrV(L, L->top, lj_err_str(L, LJ_ERR_COSUSP));
1110   incr_top(L);
1111   return LUA_ERRRUN;
1112 }
1113
1114 /* -- Load and dump Lua code ---------------------------------------------- */
1115
1116 static TValue *cpparser(lua_State *L, lua_CFunction dummy, void *ud)
1117 {
1118   LexState *ls = (LexState *)ud;
1119   GCproto *pt;
1120   GCfunc *fn;
1121   UNUSED(dummy);
1122   cframe_errfunc(L->cframe) = -1;  /* Inherit error function. */
1123   pt = lj_lex_setup(L, ls) ? lj_bcread(ls) : lj_parse(ls);
1124   fn = lj_func_newL_empty(L, pt, tabref(L->env));
1125   /* Don't combine above/below into one statement. */
1126   setfuncV(L, L->top++, fn);
1127   return NULL;
1128 }
1129
1130 LUA_API int lua_load(lua_State *L, lua_Reader reader, void *data,
1131                      const char *chunkname)
1132 {
1133   LexState ls;
1134   int status;
1135   ls.rfunc = reader;
1136   ls.rdata = data;
1137   ls.chunkarg = chunkname ? chunkname : "?";
1138   lj_str_initbuf(&ls.sb);
1139   status = lj_vm_cpcall(L, NULL, &ls, cpparser);
1140   lj_lex_cleanup(L, &ls);
1141   lj_gc_check(L);
1142   return status;
1143 }
1144
1145 LUA_API int lua_dump(lua_State *L, lua_Writer writer, void *data)
1146 {
1147   cTValue *o = L->top-1;
1148   api_checknelems(L, 1);
1149   if (tvisfunc(o) && isluafunc(funcV(o)))
1150     return lj_bcwrite(L, funcproto(funcV(o)), writer, data, 0);
1151   else
1152     return 1;
1153 }
1154
1155 /* -- GC and memory management -------------------------------------------- */
1156
1157 LUA_API int lua_gc(lua_State *L, int what, int data)
1158 {
1159   global_State *g = G(L);
1160   int res = 0;
1161   switch (what) {
1162   case LUA_GCSTOP:
1163     g->gc.threshold = LJ_MAX_MEM;
1164     break;
1165   case LUA_GCRESTART:
1166     g->gc.threshold = data == -1 ? (g->gc.total/100)*g->gc.pause : g->gc.total;
1167     break;
1168   case LUA_GCCOLLECT:
1169     lj_gc_fullgc(L);
1170     break;
1171   case LUA_GCCOUNT:
1172     res = (int)(g->gc.total >> 10);
1173     break;
1174   case LUA_GCCOUNTB:
1175     res = (int)(g->gc.total & 0x3ff);
1176     break;
1177   case LUA_GCSTEP: {
1178     MSize a = (MSize)data << 10;
1179     g->gc.threshold = (a <= g->gc.total) ? (g->gc.total - a) : 0;
1180     while (g->gc.total >= g->gc.threshold)
1181       if (lj_gc_step(L)) {
1182         res = 1;
1183         break;
1184       }
1185     break;
1186   }
1187   case LUA_GCSETPAUSE:
1188     res = (int)(g->gc.pause);
1189     g->gc.pause = (MSize)data;
1190     break;
1191   case LUA_GCSETSTEPMUL:
1192     res = (int)(g->gc.stepmul);
1193     g->gc.stepmul = (MSize)data;
1194     break;
1195   default:
1196     res = -1;  /* Invalid option. */
1197   }
1198   return res;
1199 }
1200
1201 LUA_API lua_Alloc lua_getallocf(lua_State *L, void **ud)
1202 {
1203   global_State *g = G(L);
1204   if (ud) *ud = g->allocd;
1205   return g->allocf;
1206 }
1207
1208 LUA_API void lua_setallocf(lua_State *L, lua_Alloc f, void *ud)
1209 {
1210   global_State *g = G(L);
1211   g->allocd = ud;
1212   g->allocf = f;
1213 }
1214