src/lib_base.c

   1 /*
   2 ** Base and coroutine library.
   3 ** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
   4 **
   5 ** Major portions taken verbatim or adapted from the Lua interpreter.
   6 ** Copyright (C) 1994-2011 Lua.org, PUC-Rio. See Copyright Notice in lua.h
   7 */
   8
   9 #include <stdio.h>
  10
  11 #define lib_base_c
  12 #define LUA_LIB
  13
  14 #include "lua.h"
  15 #include "lauxlib.h"
  16 #include "lualib.h"
  17
  18 #include "lj_obj.h"
  19 #include "lj_gc.h"
  20 #include "lj_err.h"
  21 #include "lj_debug.h"
  22 #include "lj_buf.h"
  23 #include "lj_str.h"
  24 #include "lj_tab.h"
  25 #include "lj_meta.h"
  26 #include "lj_state.h"
  27 #include "lj_frame.h"
  28 #if LJ_HASFFI
  29 #include "lj_ctype.h"
  30 #include "lj_cconv.h"
  31 #endif
  32 #include "lj_bc.h"
  33 #include "lj_ff.h"
  34 #include "lj_dispatch.h"
  35 #include "lj_char.h"
  36 #include "lj_strscan.h"
  37 #include "lj_strfmt.h"
  38 #include "lj_lib.h"
  39
  40 /* -- Base library: checks ------------------------------------------------ */
  41
  42 #define LJLIB_MODULE_base
  43
  44 LJLIB_ASM(assert)               LJLIB_REC(.)
  45 {
  46   lj_lib_checkany(L, 1);
  47   if (L->top == L->base+1)
  48     lj_err_caller(L, LJ_ERR_ASSERT);
  49   else if (tvisstr(L->base+1) || tvisnumber(L->base+1))
  50     lj_err_callermsg(L, strdata(lj_lib_checkstr(L, 2)));
  51   else
  52     lj_err_run(L);
  53   return FFH_UNREACHABLE;
  54 }
  55
  56 /* ORDER LJ_T */
  57 LJLIB_PUSH("nil")
  58 LJLIB_PUSH("boolean")
  59 LJLIB_PUSH(top-1)  /* boolean */
  60 LJLIB_PUSH("userdata")
  61 LJLIB_PUSH("string")
  62 LJLIB_PUSH("upval")
  63 LJLIB_PUSH("thread")
  64 LJLIB_PUSH("proto")
  65 LJLIB_PUSH("function")
  66 LJLIB_PUSH("trace")
  67 LJLIB_PUSH("cdata")
  68 LJLIB_PUSH("table")
  69 LJLIB_PUSH(top-9)  /* userdata */
  70 LJLIB_PUSH("number")
  71 LJLIB_ASM_(type)                LJLIB_REC(.)
  72 /* Recycle the lj_lib_checkany(L, 1) from assert. */
  73
  74 /* -- Base library: iterators --------------------------------------------- */
  75
  76 /* This solves a circular dependency problem -- change FF_next_N as needed. */
  77 LJ_STATIC_ASSERT((int)FF_next == FF_next_N);
  78
  79 LJLIB_ASM(next)                 LJLIB_REC(.)
  80 {
  81   lj_lib_checktab(L, 1);
  82   lj_err_msg(L, LJ_ERR_NEXTIDX);
  83   return FFH_UNREACHABLE;
  84 }
  85
  86 #if LJ_52 || LJ_HASFFI
  87 static int ffh_pairs(lua_State *L, MMS mm)
  88 {
  89   TValue *o = lj_lib_checkany(L, 1);
  90   cTValue *mo = lj_meta_lookup(L, o, mm);
  91   if ((LJ_52 || tviscdata(o)) && !tvisnil(mo)) {
  92     L->top = o+1;  /* Only keep one argument. */
  93     copyTV(L, L->base-1-LJ_FR2, mo);  /* Replace callable. */
  94     return FFH_TAILCALL;
  95   } else {
  96     if (!tvistab(o)) lj_err_argt(L, 1, LUA_TTABLE);
  97     if (LJ_FR2) { copyTV(L, o-1, o); o--; }
  98     setfuncV(L, o-1, funcV(lj_lib_upvalue(L, 1)));
  99     if (mm == MM_pairs) setnilV(o+1); else setintV(o+1, 0);
 100     return FFH_RES(3);
 101   }
 102 }
 103 #else
 104 #define ffh_pairs(L, mm)        (lj_lib_checktab(L, 1), FFH_UNREACHABLE)
 105 #endif
 106
 107 LJLIB_PUSH(lastcl)
 108 LJLIB_ASM(pairs)                LJLIB_REC(xpairs 0)
 109 {
 110   return ffh_pairs(L, MM_pairs);
 111 }
 112
 113 LJLIB_NOREGUV LJLIB_ASM(ipairs_aux)     LJLIB_REC(.)
 114 {
 115   lj_lib_checktab(L, 1);
 116   lj_lib_checkint(L, 2);
 117   return FFH_UNREACHABLE;
 118 }
 119
 120 LJLIB_PUSH(lastcl)
 121 LJLIB_ASM(ipairs)               LJLIB_REC(xpairs 1)
 122 {
 123   return ffh_pairs(L, MM_ipairs);
 124 }
 125
 126 /* -- Base library: getters and setters ----------------------------------- */
 127
 128 LJLIB_ASM_(getmetatable)        LJLIB_REC(.)
 129 /* Recycle the lj_lib_checkany(L, 1) from assert. */
 130
 131 LJLIB_ASM(setmetatable)         LJLIB_REC(.)
 132 {
 133   GCtab *t = lj_lib_checktab(L, 1);
 134   GCtab *mt = lj_lib_checktabornil(L, 2);
 135   if (!tvisnil(lj_meta_lookup(L, L->base, MM_metatable)))
 136     lj_err_caller(L, LJ_ERR_PROTMT);
 137   setgcref(t->metatable, obj2gco(mt));
 138   if (mt) { lj_gc_objbarriert(L, t, mt); }
 139   settabV(L, L->base-1-LJ_FR2, t);
 140   return FFH_RES(1);
 141 }
 142
 143 LJLIB_CF(getfenv)               LJLIB_REC(.)
 144 {
 145   GCfunc *fn;
 146   cTValue *o = L->base;
 147   if (!(o < L->top && tvisfunc(o))) {
 148     int level = lj_lib_optint(L, 1, 1);
 149     o = lj_debug_frame(L, level, &level);
 150     if (o == NULL)
 151       lj_err_arg(L, 1, LJ_ERR_INVLVL);
 152     if (LJ_FR2) o--;
 153   }
 154   fn = &gcval(o)->fn;
 155   settabV(L, L->top++, isluafunc(fn) ? tabref(fn->l.env) : tabref(L->env));
 156   return 1;
 157 }
 158
 159 LJLIB_CF(setfenv)
 160 {
 161   GCfunc *fn;
 162   GCtab *t = lj_lib_checktab(L, 2);
 163   cTValue *o = L->base;
 164   if (!(o < L->top && tvisfunc(o))) {
 165     int level = lj_lib_checkint(L, 1);
 166     if (level == 0) {
 167       /* NOBARRIER: A thread (i.e. L) is never black. */
 168       setgcref(L->env, obj2gco(t));
 169       return 0;
 170     }
 171     o = lj_debug_frame(L, level, &level);
 172     if (o == NULL)
 173       lj_err_arg(L, 1, LJ_ERR_INVLVL);
 174     if (LJ_FR2) o--;
 175   }
 176   fn = &gcval(o)->fn;
 177   if (!isluafunc(fn))
 178     lj_err_caller(L, LJ_ERR_SETFENV);
 179   setgcref(fn->l.env, obj2gco(t));
 180   lj_gc_objbarrier(L, obj2gco(fn), t);
 181   setfuncV(L, L->top++, fn);
 182   return 1;
 183 }
 184
 185 LJLIB_ASM(rawget)               LJLIB_REC(.)
 186 {
 187   lj_lib_checktab(L, 1);
 188   lj_lib_checkany(L, 2);
 189   return FFH_UNREACHABLE;
 190 }
 191
 192 LJLIB_CF(rawset)                LJLIB_REC(.)
 193 {
 194   lj_lib_checktab(L, 1);
 195   lj_lib_checkany(L, 2);
 196   L->top = 1+lj_lib_checkany(L, 3);
 197   lua_rawset(L, 1);
 198   return 1;
 199 }
 200
 201 LJLIB_CF(rawequal)              LJLIB_REC(.)
 202 {
 203   cTValue *o1 = lj_lib_checkany(L, 1);
 204   cTValue *o2 = lj_lib_checkany(L, 2);
 205   setboolV(L->top-1, lj_obj_equal(o1, o2));
 206   return 1;
 207 }
 208
 209 #if LJ_52
 210 LJLIB_CF(rawlen)                LJLIB_REC(.)
 211 {
 212   cTValue *o = L->base;
 213   int32_t len;
 214   if (L->top > o && tvisstr(o))
 215     len = (int32_t)strV(o)->len;
 216   else
 217     len = (int32_t)lj_tab_len(lj_lib_checktab(L, 1));
 218   setintV(L->top-1, len);
 219   return 1;
 220 }
 221 #endif
 222
 223 LJLIB_CF(unpack)
 224 {
 225   GCtab *t = lj_lib_checktab(L, 1);
 226   int32_t n, i = lj_lib_optint(L, 2, 1);
 227   int32_t e = (L->base+3-1 < L->top && !tvisnil(L->base+3-1)) ?
 228               lj_lib_checkint(L, 3) : (int32_t)lj_tab_len(t);
 229   uint32_t nu;
 230   if (i > e) return 0;
 231   nu = (uint32_t)e - (uint32_t)i;
 232   n = (int32_t)(nu+1);
 233   if (nu >= LUAI_MAXCSTACK || !lua_checkstack(L, n))
 234     lj_err_caller(L, LJ_ERR_UNPACK);
 235   do {
 236     cTValue *tv = lj_tab_getint(t, i);
 237     if (tv) {
 238       copyTV(L, L->top++, tv);
 239     } else {
 240       setnilV(L->top++);
 241     }
 242   } while (i++ < e);
 243   return n;
 244 }
 245
 246 LJLIB_CF(select)                LJLIB_REC(.)
 247 {
 248   int32_t n = (int32_t)(L->top - L->base);
 249   if (n >= 1 && tvisstr(L->base) && *strVdata(L->base) == '#') {
 250     setintV(L->top-1, n-1);
 251     return 1;
 252   } else {
 253     int32_t i = lj_lib_checkint(L, 1);
 254     if (i < 0) i = n + i; else if (i > n) i = n;
 255     if (i < 1)
 256       lj_err_arg(L, 1, LJ_ERR_IDXRNG);
 257     return n - i;
 258   }
 259 }
 260
 261 /* -- Base library: conversions ------------------------------------------- */
 262
 263 LJLIB_ASM(tonumber)             LJLIB_REC(.)
 264 {
 265   int32_t base = lj_lib_optint(L, 2, 10);
 266   if (base == 10) {
 267     TValue *o = lj_lib_checkany(L, 1);
 268     if (lj_strscan_numberobj(o)) {
 269       copyTV(L, L->base-1-LJ_FR2, o);
 270       return FFH_RES(1);
 271     }
 272 #if LJ_HASFFI
 273     if (tviscdata(o)) {
 274       CTState *cts = ctype_cts(L);
 275       CType *ct = lj_ctype_rawref(cts, cdataV(o)->ctypeid);
 276       if (ctype_isenum(ct->info)) ct = ctype_child(cts, ct);
 277       if (ctype_isnum(ct->info) || ctype_iscomplex(ct->info)) {
 278         if (LJ_DUALNUM && ctype_isinteger_or_bool(ct->info) &&
 279             ct->size <= 4 && !(ct->size == 4 && (ct->info & CTF_UNSIGNED))) {
 280           int32_t i;
 281           lj_cconv_ct_tv(cts, ctype_get(cts, CTID_INT32), (uint8_t *)&i, o, 0);
 282           setintV(L->base-1-LJ_FR2, i);
 283           return FFH_RES(1);
 284         }
 285         lj_cconv_ct_tv(cts, ctype_get(cts, CTID_DOUBLE),
 286                        (uint8_t *)&(L->base-1-LJ_FR2)->n, o, 0);
 287         return FFH_RES(1);
 288       }
 289     }
 290 #endif
 291   } else {
 292     const char *p = strdata(lj_lib_checkstr(L, 1));
 293     char *ep;
 294     unsigned int neg = 0;
 295     unsigned long ul;
 296     if (base < 2 || base > 36)
 297       lj_err_arg(L, 2, LJ_ERR_BASERNG);
 298     while (lj_char_isspace((unsigned char)(*p))) p++;
 299     if (*p == '-') { p++; neg = 1; } else if (*p == '+') { p++; }
 300     if (lj_char_isalnum((unsigned char)(*p))) {
 301       ul = strtoul(p, &ep, base);
 302       if (p != ep) {
 303         while (lj_char_isspace((unsigned char)(*ep))) ep++;
 304         if (*ep == '\0') {
 305           if (LJ_DUALNUM && LJ_LIKELY(ul < 0x80000000u+neg)) {
 306             if (neg) ul = ~ul+1u;
 307             setintV(L->base-1-LJ_FR2, (int32_t)ul);
 308           } else {
 309             lua_Number n = (lua_Number)ul;
 310             if (neg) n = -n;
 311             setnumV(L->base-1-LJ_FR2, n);
 312           }
 313           return FFH_RES(1);
 314         }
 315       }
 316     }
 317   }
 318   setnilV(L->base-1-LJ_FR2);
 319   return FFH_RES(1);
 320 }
 321
 322 LJLIB_ASM(tostring)             LJLIB_REC(.)
 323 {
 324   TValue *o = lj_lib_checkany(L, 1);
 325   cTValue *mo;
 326   L->top = o+1;  /* Only keep one argument. */
 327   if (!tvisnil(mo = lj_meta_lookup(L, o, MM_tostring))) {
 328     copyTV(L, L->base-1-LJ_FR2, mo);  /* Replace callable. */
 329     return FFH_TAILCALL;
 330   }
 331   lj_gc_check(L);
 332   setstrV(L, L->base-1-LJ_FR2, lj_strfmt_obj(L, L->base));
 333   return FFH_RES(1);
 334 }
 335
 336 /* -- Base library: throw and catch errors -------------------------------- */
 337
 338 LJLIB_CF(error)
 339 {
 340   int32_t level = lj_lib_optint(L, 2, 1);
 341   lua_settop(L, 1);
 342   if (lua_isstring(L, 1) && level > 0) {
 343     luaL_where(L, level);
 344     lua_pushvalue(L, 1);
 345     lua_concat(L, 2);
 346   }
 347   return lua_error(L);
 348 }
 349
 350 LJLIB_ASM(pcall)                LJLIB_REC(.)
 351 {
 352   lj_lib_checkany(L, 1);
 353   lj_lib_checkfunc(L, 2);  /* For xpcall only. */
 354   return FFH_UNREACHABLE;
 355 }
 356 LJLIB_ASM_(xpcall)              LJLIB_REC(.)
 357
 358 /* -- Base library: load Lua code ----------------------------------------- */
 359
 360 static int load_aux(lua_State *L, int status, int envarg)
 361 {
 362   if (status == LUA_OK) {
 363     /*
 364     ** Set environment table for top-level function.
 365     ** Don't do this for non-native bytecode, which returns a prototype.
 366     */
 367     if (tvistab(L->base+envarg-1) && tvisfunc(L->top-1)) {
 368       GCfunc *fn = funcV(L->top-1);
 369       GCtab *t = tabV(L->base+envarg-1);
 370       setgcref(fn->c.env, obj2gco(t));
 371       lj_gc_objbarrier(L, fn, t);
 372     }
 373     return 1;
 374   } else {
 375     setnilV(L->top-2);
 376     return 2;
 377   }
 378 }
 379
 380 LJLIB_CF(loadfile)
 381 {
 382   GCstr *fname = lj_lib_optstr(L, 1);
 383   GCstr *mode = lj_lib_optstr(L, 2);
 384   int status;
 385   lua_settop(L, 3);  /* Ensure env arg exists. */
 386   status = luaL_loadfilex(L, fname ? strdata(fname) : NULL,
 387                           mode ? strdata(mode) : NULL);
 388   return load_aux(L, status, 3);
 389 }
 390
 391 static const char *reader_func(lua_State *L, void *ud, size_t *size)
 392 {
 393   UNUSED(ud);
 394   luaL_checkstack(L, 2, "too many nested functions");
 395   copyTV(L, L->top++, L->base);
 396   lua_call(L, 0, 1);  /* Call user-supplied function. */
 397   L->top--;
 398   if (tvisnil(L->top)) {
 399     *size = 0;
 400     return NULL;
 401   } else if (tvisstr(L->top) || tvisnumber(L->top)) {
 402     copyTV(L, L->base+4, L->top);  /* Anchor string in reserved stack slot. */
 403     return lua_tolstring(L, 5, size);
 404   } else {
 405     lj_err_caller(L, LJ_ERR_RDRSTR);
 406     return NULL;
 407   }
 408 }
 409
 410 LJLIB_CF(load)
 411 {
 412   GCstr *name = lj_lib_optstr(L, 2);
 413   GCstr *mode = lj_lib_optstr(L, 3);
 414   int status;
 415   if (L->base < L->top &&
 416       (tvisstr(L->base) || tvisnumber(L->base) || tvisbuf(L->base))) {
 417     const char *s;
 418     MSize len;
 419     if (tvisbuf(L->base)) {
 420       SBufExt *sbx = bufV(L->base);
 421       s = sbx->r;
 422       len = sbufxlen(sbx);
 423       if (!name) name = &G(L)->strempty;  /* Buffers are not NUL-terminated. */
 424     } else {
 425       GCstr *str = lj_lib_checkstr(L, 1);
 426       s = strdata(str);
 427       len = str->len;
 428     }
 429     lua_settop(L, 4);  /* Ensure env arg exists. */
 430     status = luaL_loadbufferx(L, s, len, name ? strdata(name) : s,
 431                               mode ? strdata(mode) : NULL);
 432   } else {
 433     lj_lib_checkfunc(L, 1);
 434     lua_settop(L, 5);  /* Reserve a slot for the string from the reader. */
 435     status = lua_loadx(L, reader_func, NULL, name ? strdata(name) : "=(load)",
 436                        mode ? strdata(mode) : NULL);
 437   }
 438   return load_aux(L, status, 4);
 439 }
 440
 441 LJLIB_CF(loadstring)
 442 {
 443   return lj_cf_load(L);
 444 }
 445
 446 LJLIB_CF(dofile)
 447 {
 448   GCstr *fname = lj_lib_optstr(L, 1);
 449   setnilV(L->top);
 450   L->top = L->base+1;
 451   if (luaL_loadfile(L, fname ? strdata(fname) : NULL) != LUA_OK)
 452     lua_error(L);
 453   lua_call(L, 0, LUA_MULTRET);
 454   return (int)(L->top - L->base) - 1;
 455 }
 456
 457 /* -- Base library: GC control -------------------------------------------- */
 458
 459 LJLIB_CF(gcinfo)
 460 {
 461   setintV(L->top++, (int32_t)(G(L)->gc.total >> 10));
 462   return 1;
 463 }
 464
 465 LJLIB_CF(collectgarbage)
 466 {
 467   int opt = lj_lib_checkopt(L, 1, LUA_GCCOLLECT,  /* ORDER LUA_GC* */
 468     "\4stop\7restart\7collect\5count\1\377\4step\10setpause\12setstepmul\1\377\11isrunning");
 469   int32_t data = lj_lib_optint(L, 2, 0);
 470   if (opt == LUA_GCCOUNT) {
 471     setnumV(L->top, (lua_Number)G(L)->gc.total/1024.0);
 472   } else {
 473     int res = lua_gc(L, opt, data);
 474     if (opt == LUA_GCSTEP || opt == LUA_GCISRUNNING)
 475       setboolV(L->top, res);
 476     else
 477       setintV(L->top, res);
 478   }
 479   L->top++;
 480   return 1;
 481 }
 482
 483 /* -- Base library: miscellaneous functions ------------------------------- */
 484
 485 LJLIB_PUSH(top-2)  /* Upvalue holds weak table. */
 486 LJLIB_CF(newproxy)
 487 {
 488   lua_settop(L, 1);
 489   lua_newuserdata(L, 0);
 490   if (lua_toboolean(L, 1) == 0) {  /* newproxy(): without metatable. */
 491     return 1;
 492   } else if (lua_isboolean(L, 1)) {  /* newproxy(true): with metatable. */
 493     lua_newtable(L);
 494     lua_pushvalue(L, -1);
 495     lua_pushboolean(L, 1);
 496     lua_rawset(L, lua_upvalueindex(1));  /* Remember mt in weak table. */
 497   } else {  /* newproxy(proxy): inherit metatable. */
 498     int validproxy = 0;
 499     if (lua_getmetatable(L, 1)) {
 500       lua_rawget(L, lua_upvalueindex(1));
 501       validproxy = lua_toboolean(L, -1);
 502       lua_pop(L, 1);
 503     }
 504     if (!validproxy)
 505       lj_err_arg(L, 1, LJ_ERR_NOPROXY);
 506     lua_getmetatable(L, 1);
 507   }
 508   lua_setmetatable(L, 2);
 509   return 1;
 510 }
 511
 512 LJLIB_PUSH("tostring")
 513 LJLIB_CF(print)
 514 {
 515   ptrdiff_t i, nargs = L->top - L->base;
 516   cTValue *tv = lj_tab_getstr(tabref(L->env), strV(lj_lib_upvalue(L, 1)));
 517   int shortcut;
 518   if (tv && !tvisnil(tv)) {
 519     copyTV(L, L->top++, tv);
 520   } else {
 521     setstrV(L, L->top++, strV(lj_lib_upvalue(L, 1)));
 522     lua_gettable(L, LUA_GLOBALSINDEX);
 523     tv = L->top-1;
 524   }
 525   shortcut = (tvisfunc(tv) && funcV(tv)->c.ffid == FF_tostring) &&
 526              !gcrefu(basemt_it(G(L), LJ_TNUMX));
 527   for (i = 0; i < nargs; i++) {
 528     cTValue *o = &L->base[i];
 529     const char *str;
 530     size_t size;
 531     MSize len;
 532     if (shortcut && (str = lj_strfmt_wstrnum(L, o, &len)) != NULL) {
 533       size = len;
 534     } else {
 535       copyTV(L, L->top+1, o);
 536       copyTV(L, L->top, L->top-1);
 537       L->top += 2;
 538       lua_call(L, 1, 1);
 539       str = lua_tolstring(L, -1, &size);
 540       if (!str)
 541         lj_err_caller(L, LJ_ERR_PRTOSTR);
 542       L->top--;
 543     }
 544     if (i)
 545       putchar('\t');
 546     fwrite(str, 1, size, stdout);
 547   }
 548   putchar('\n');
 549   return 0;
 550 }
 551
 552 LJLIB_PUSH(top-3)
 553 LJLIB_SET(_VERSION)
 554
 555 #include "lj_libdef.h"
 556
 557 /* -- Coroutine library --------------------------------------------------- */
 558
 559 #define LJLIB_MODULE_coroutine
 560
 561 LJLIB_CF(coroutine_status)
 562 {
 563   const char *s;
 564   lua_State *co;
 565   if (!(L->top > L->base && tvisthread(L->base)))
 566     lj_err_arg(L, 1, LJ_ERR_NOCORO);
 567   co = threadV(L->base);
 568   if (co == L) s = "running";
 569   else if (co->status == LUA_YIELD) s = "suspended";
 570   else if (co->status != LUA_OK) s = "dead";
 571   else if (co->base > tvref(co->stack)+1+LJ_FR2) s = "normal";
 572   else if (co->top == co->base) s = "dead";
 573   else s = "suspended";
 574   lua_pushstring(L, s);
 575   return 1;
 576 }
 577
 578 LJLIB_CF(coroutine_running)
 579 {
 580 #if LJ_52
 581   int ismain = lua_pushthread(L);
 582   setboolV(L->top++, ismain);
 583   return 2;
 584 #else
 585   if (lua_pushthread(L))
 586     setnilV(L->top++);
 587   return 1;
 588 #endif
 589 }
 590
 591 LJLIB_CF(coroutine_isyieldable)
 592 {
 593   setboolV(L->top++, cframe_canyield(L->cframe));
 594   return 1;
 595 }
 596
 597 LJLIB_CF(coroutine_create)
 598 {
 599   lua_State *L1;
 600   if (!(L->base < L->top && tvisfunc(L->base)))
 601     lj_err_argt(L, 1, LUA_TFUNCTION);
 602   L1 = lua_newthread(L);
 603   setfuncV(L, L1->top++, funcV(L->base));
 604   return 1;
 605 }
 606
 607 LJLIB_ASM(coroutine_yield)
 608 {
 609   lj_err_caller(L, LJ_ERR_CYIELD);
 610   return FFH_UNREACHABLE;
 611 }
 612
 613 static int ffh_resume(lua_State *L, lua_State *co, int wrap)
 614 {
 615   if (co->cframe != NULL || co->status > LUA_YIELD ||
 616       (co->status == LUA_OK && co->top == co->base)) {
 617     ErrMsg em = co->cframe ? LJ_ERR_CORUN : LJ_ERR_CODEAD;
 618     if (wrap) lj_err_caller(L, em);
 619     setboolV(L->base-1-LJ_FR2, 0);
 620     setstrV(L, L->base-LJ_FR2, lj_err_str(L, em));
 621     return FFH_RES(2);
 622   }
 623   if (lj_state_cpgrowstack(co, (MSize)(L->top - L->base)) != LUA_OK) {
 624     cTValue *msg = --co->top;
 625     lj_err_callermsg(L, strVdata(msg));
 626   }
 627   return FFH_RETRY;
 628 }
 629
 630 LJLIB_ASM(coroutine_resume)
 631 {
 632   if (!(L->top > L->base && tvisthread(L->base)))
 633     lj_err_arg(L, 1, LJ_ERR_NOCORO);
 634   return ffh_resume(L, threadV(L->base), 0);
 635 }
 636
 637 LJLIB_NOREG LJLIB_ASM(coroutine_wrap_aux)
 638 {
 639   return ffh_resume(L, threadV(lj_lib_upvalue(L, 1)), 1);
 640 }
 641
 642 /* Inline declarations. */
 643 LJ_ASMF void lj_ff_coroutine_wrap_aux(void);
 644 #if !(LJ_TARGET_MIPS && defined(ljamalg_c))
 645 LJ_FUNCA_NORET void LJ_FASTCALL lj_ffh_coroutine_wrap_err(lua_State *L,
 646                                                           lua_State *co);
 647 #endif
 648
 649 /* Error handler, called from assembler VM. */
 650 void LJ_FASTCALL lj_ffh_coroutine_wrap_err(lua_State *L, lua_State *co)
 651 {
 652   co->top--; copyTV(L, L->top, co->top); L->top++;
 653   if (tvisstr(L->top-1))
 654     lj_err_callermsg(L, strVdata(L->top-1));
 655   else
 656     lj_err_run(L);
 657 }
 658
 659 /* Forward declaration. */
 660 static void setpc_wrap_aux(lua_State *L, GCfunc *fn);
 661
 662 LJLIB_CF(coroutine_wrap)
 663 {
 664   GCfunc *fn;
 665   lj_cf_coroutine_create(L);
 666   fn = lj_lib_pushcc(L, lj_ffh_coroutine_wrap_aux, FF_coroutine_wrap_aux, 1);
 667   setpc_wrap_aux(L, fn);
 668   return 1;
 669 }
 670
 671 #include "lj_libdef.h"
 672
 673 /* Fix the PC of wrap_aux. Really ugly workaround. */
 674 static void setpc_wrap_aux(lua_State *L, GCfunc *fn)
 675 {
 676   setmref(fn->c.pc, &L2GG(L)->bcff[lj_lib_init_coroutine[1]+2]);
 677 }
 678
 679 /* ------------------------------------------------------------------------ */
 680
 681 static void newproxy_weaktable(lua_State *L)
 682 {
 683   /* NOBARRIER: The table is new (marked white). */
 684   GCtab *t = lj_tab_new(L, 0, 1);
 685   settabV(L, L->top++, t);
 686   setgcref(t->metatable, obj2gco(t));
 687   setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "__mode")),
 688             lj_str_newlit(L, "kv"));
 689   t->nomm = (uint8_t)(~(1u<<MM_mode));
 690 }
 691
 692 LUALIB_API int luaopen_base(lua_State *L)
 693 {
 694   /* NOBARRIER: Table and value are the same. */
 695   GCtab *env = tabref(L->env);
 696   settabV(L, lj_tab_setstr(L, env, lj_str_newlit(L, "_G")), env);
 697   lua_pushliteral(L, LUA_VERSION);  /* top-3. */
 698   newproxy_weaktable(L);  /* top-2. */
 699   LJ_LIB_REG(L, "_G", base);
 700   LJ_LIB_REG(L, LUA_COLIBNAME, coroutine);
 701   return 2;
 702 }
 703