src/lua/lbaselib.cpp

   1 /*
   2 ** $Id: lbaselib.c,v 1.191.1.6 2008/02/14 16:46:22 roberto Exp $
   3 ** Basic library
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8
   9 #include <ctype.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 /* stdio.h */
  14 #include "vfs/export.h"
  15
  16 #define lbaselib_c
  17 #define LUA_LIB
  18
  19 #include "lua.h"
  20
  21 #include "lauxlib.h"
  22 #include "lualib.h"
  23
  24
  25
  26
  27 /*
  28 ** If your system does not support `stdout', you can just remove this function.
  29 ** If you need, you can define your own `print' function, following this
  30 ** model but changing `fputs' to put the strings at a proper place
  31 ** (a console window or a log file, for instance).
  32 */
  33 static int luaB_print (lua_State *L) {
  34   int n = lua_gettop(L);  /* number of arguments */
  35   int i;
  36   lua_getglobal(L, "tostring");
  37   for (i=1; i<=n; i++) {
  38     const char *s;
  39     lua_pushvalue(L, -1);  /* function to be called */
  40     lua_pushvalue(L, i);   /* value to print */
  41     lua_call(L, 1, 1);
  42     s = lua_tostring(L, -1);  /* get result */
  43     if (s == NULL)
  44       return luaL_error(L, LUA_QL("tostring") " must return a string to "
  45                            LUA_QL("print"));
  46     if (i>1) vfs_fputs("\t", vfs_stdout);
  47     vfs_fputs(s, vfs_stdout);
  48     lua_pop(L, 1);  /* pop result */
  49   }
  50   vfs_fputs("\n", vfs_stdout);
  51   return 0;
  52 }
  53
  54
  55 static int luaB_tonumber (lua_State *L) {
  56   int base = luaL_optint(L, 2, 10);
  57   if (base == 10) {  /* standard conversion */
  58     luaL_checkany(L, 1);
  59     if (lua_isnumber(L, 1)) {
  60       lua_pushnumber(L, lua_tonumber(L, 1));
  61       return 1;
  62     }
  63   }
  64   else {
  65     const char *s1 = luaL_checkstring(L, 1);
  66     char *s2;
  67     unsigned long n;
  68     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
  69     n = strtoul(s1, &s2, base);
  70     if (s1 != s2) {  /* at least one valid digit? */
  71       while (isspace((unsigned char)(*s2))) s2++;  /* skip trailing spaces */
  72       if (*s2 == '\0') {  /* no invalid trailing characters? */
  73         lua_pushnumber(L, (lua_Number)n);
  74         return 1;
  75       }
  76     }
  77   }
  78   lua_pushnil(L);  /* else not a number */
  79   return 1;
  80 }
  81
  82
  83 static int luaB_error (lua_State *L) {
  84   int level = luaL_optint(L, 2, 1);
  85   lua_settop(L, 1);
  86   if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
  87     luaL_where(L, level);
  88     lua_pushvalue(L, 1);
  89     lua_concat(L, 2);
  90   }
  91   return lua_error(L);
  92 }
  93
  94
  95 static int luaB_getmetatable (lua_State *L) {
  96   luaL_checkany(L, 1);
  97   if (!lua_getmetatable(L, 1)) {
  98     lua_pushnil(L);
  99     return 1;  /* no metatable */
 100   }
 101   luaL_getmetafield(L, 1, "__metatable");
 102   return 1;  /* returns either __metatable field (if present) or metatable */
 103 }
 104
 105
 106 static int luaB_setmetatable (lua_State *L) {
 107   int t = lua_type(L, 2);
 108   luaL_checktype(L, 1, LUA_TTABLE);
 109   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
 110                     "nil or table expected");
 111   if (luaL_getmetafield(L, 1, "__metatable"))
 112     luaL_error(L, "cannot change a protected metatable");
 113   lua_settop(L, 2);
 114   lua_setmetatable(L, 1);
 115   return 1;
 116 }
 117
 118
 119 static void getfunc (lua_State *L, int opt) {
 120   if (lua_isfunction(L, 1)) lua_pushvalue(L, 1);
 121   else {
 122     lua_Debug ar;
 123     int level = opt ? luaL_optint(L, 1, 1) : luaL_checkint(L, 1);
 124     luaL_argcheck(L, level >= 0, 1, "level must be non-negative");
 125     if (lua_getstack(L, level, &ar) == 0)
 126       luaL_argerror(L, 1, "invalid level");
 127     lua_getinfo(L, "f", &ar);
 128     if (lua_isnil(L, -1))
 129       luaL_error(L, "no function environment for tail call at level %d",
 130                     level);
 131   }
 132 }
 133
 134
 135 static int luaB_getfenv (lua_State *L) {
 136   getfunc(L, 1);
 137   if (lua_iscfunction(L, -1))  /* is a C function? */
 138     lua_pushvalue(L, LUA_GLOBALSINDEX);  /* return the thread's global env. */
 139   else
 140     lua_getfenv(L, -1);
 141   return 1;
 142 }
 143
 144
 145 static int luaB_setfenv (lua_State *L) {
 146   luaL_checktype(L, 2, LUA_TTABLE);
 147   getfunc(L, 0);
 148   lua_pushvalue(L, 2);
 149   if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0) {
 150     /* change environment of current thread */
 151     lua_pushthread(L);
 152     lua_insert(L, -2);
 153     lua_setfenv(L, -2);
 154     return 0;
 155   }
 156   else if (lua_iscfunction(L, -2) || lua_setfenv(L, -2) == 0)
 157     luaL_error(L,
 158           LUA_QL("setfenv") " cannot change environment of given object");
 159   return 1;
 160 }
 161
 162
 163 static int luaB_rawequal (lua_State *L) {
 164   luaL_checkany(L, 1);
 165   luaL_checkany(L, 2);
 166   lua_pushboolean(L, lua_rawequal(L, 1, 2));
 167   return 1;
 168 }
 169
 170
 171 static int luaB_rawget (lua_State *L) {
 172   luaL_checktype(L, 1, LUA_TTABLE);
 173   luaL_checkany(L, 2);
 174   lua_settop(L, 2);
 175   lua_rawget(L, 1);
 176   return 1;
 177 }
 178
 179 static int luaB_rawset (lua_State *L) {
 180   luaL_checktype(L, 1, LUA_TTABLE);
 181   luaL_checkany(L, 2);
 182   luaL_checkany(L, 3);
 183   lua_settop(L, 3);
 184   lua_rawset(L, 1);
 185   return 1;
 186 }
 187
 188
 189 static int luaB_gcinfo (lua_State *L) {
 190   lua_pushinteger(L, lua_getgccount(L));
 191   return 1;
 192 }
 193
 194
 195 static int luaB_collectgarbage (lua_State *L) {
 196   static const char *const opts[] = {"stop", "restart", "collect",
 197     "count", "step", "setpause", "setstepmul", NULL};
 198   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
 199     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL};
 200   int o = luaL_checkoption(L, 1, "collect", opts);
 201   int ex = luaL_optint(L, 2, 0);
 202   int res = lua_gc(L, optsnum[o], ex);
 203   switch (optsnum[o]) {
 204     case LUA_GCCOUNT: {
 205       int b = lua_gc(L, LUA_GCCOUNTB, 0);
 206       lua_pushnumber(L, res + ((lua_Number)b/1024));
 207       return 1;
 208     }
 209     case LUA_GCSTEP: {
 210       lua_pushboolean(L, res);
 211       return 1;
 212     }
 213     default: {
 214       lua_pushnumber(L, res);
 215       return 1;
 216     }
 217   }
 218 }
 219
 220
 221 static int luaB_type (lua_State *L) {
 222   luaL_checkany(L, 1);
 223   lua_pushstring(L, luaL_typename(L, 1));
 224   return 1;
 225 }
 226
 227
 228 static int luaB_next (lua_State *L) {
 229   luaL_checktype(L, 1, LUA_TTABLE);
 230   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
 231   if (lua_next(L, 1))
 232     return 2;
 233   else {
 234     lua_pushnil(L);
 235     return 1;
 236   }
 237 }
 238
 239
 240 static int luaB_pairs (lua_State *L) {
 241   luaL_checktype(L, 1, LUA_TTABLE);
 242   lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */
 243   lua_pushvalue(L, 1);  /* state, */
 244   lua_pushnil(L);  /* and initial value */
 245   return 3;
 246 }
 247
 248
 249 static int ipairsaux (lua_State *L) {
 250   int i = luaL_checkint(L, 2);
 251   luaL_checktype(L, 1, LUA_TTABLE);
 252   i++;  /* next value */
 253   lua_pushinteger(L, i);
 254   lua_rawgeti(L, 1, i);
 255   return (lua_isnil(L, -1)) ? 0 : 2;
 256 }
 257
 258
 259 static int luaB_ipairs (lua_State *L) {
 260   luaL_checktype(L, 1, LUA_TTABLE);
 261   lua_pushvalue(L, lua_upvalueindex(1));  /* return generator, */
 262   lua_pushvalue(L, 1);  /* state, */
 263   lua_pushinteger(L, 0);  /* and initial value */
 264   return 3;
 265 }
 266
 267
 268 static int load_aux (lua_State *L, int status) {
 269   if (status == 0)  /* OK? */
 270     return 1;
 271   else {
 272     lua_pushnil(L);
 273     lua_insert(L, -2);  /* put before error message */
 274     return 2;  /* return nil plus error message */
 275   }
 276 }
 277
 278
 279 static int luaB_loadstring (lua_State *L) {
 280   size_t l;
 281   const char *s = luaL_checklstring(L, 1, &l);
 282   const char *chunkname = luaL_optstring(L, 2, s);
 283   return load_aux(L, luaL_loadbuffer(L, s, l, chunkname));
 284 }
 285
 286
 287 static int luaB_loadfile (lua_State *L) {
 288   const char *fname = luaL_optstring(L, 1, NULL);
 289   return load_aux(L, luaL_loadfile(L, fname));
 290 }
 291
 292
 293 /*
 294 ** Reader for generic `load' function: `lua_load' uses the
 295 ** stack for internal stuff, so the reader cannot change the
 296 ** stack top. Instead, it keeps its resulting string in a
 297 ** reserved slot inside the stack.
 298 */
 299 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
 300   (void)ud;  /* to avoid warnings */
 301   luaL_checkstack(L, 2, "too many nested functions");
 302   lua_pushvalue(L, 1);  /* get function */
 303   lua_call(L, 0, 1);  /* call it */
 304   if (lua_isnil(L, -1)) {
 305     *size = 0;
 306     return NULL;
 307   }
 308   else if (lua_isstring(L, -1)) {
 309     lua_replace(L, 3);  /* save string in a reserved stack slot */
 310     return lua_tolstring(L, 3, size);
 311   }
 312   else luaL_error(L, "reader function must return a string");
 313   return NULL;  /* to avoid warnings */
 314 }
 315
 316
 317 static int luaB_load (lua_State *L) {
 318   int status;
 319   const char *cname = luaL_optstring(L, 2, "=(load)");
 320   luaL_checktype(L, 1, LUA_TFUNCTION);
 321   lua_settop(L, 3);  /* function, eventual name, plus one reserved slot */
 322   status = lua_load(L, generic_reader, NULL, cname);
 323   return load_aux(L, status);
 324 }
 325
 326
 327 static int luaB_dofile (lua_State *L) {
 328   const char *fname = luaL_optstring(L, 1, NULL);
 329   int n = lua_gettop(L);
 330   if (luaL_loadfile(L, fname) != 0) lua_error(L);
 331   lua_call(L, 0, LUA_MULTRET);
 332   return lua_gettop(L) - n;
 333 }
 334
 335
 336 static int luaB_assert (lua_State *L) {
 337   luaL_checkany(L, 1);
 338   if (!lua_toboolean(L, 1))
 339     return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
 340   return lua_gettop(L);
 341 }
 342
 343
 344 static int luaB_unpack (lua_State *L) {
 345   int i, e, n;
 346   luaL_checktype(L, 1, LUA_TTABLE);
 347   i = luaL_optint(L, 2, 1);
 348   e = luaL_opt(L, luaL_checkint, 3, luaL_getn(L, 1));
 349   if (i > e) return 0;  /* empty range */
 350   n = e - i + 1;  /* number of elements */
 351   if (n <= 0 || !lua_checkstack(L, n))  /* n <= 0 means arith. overflow */
 352     return luaL_error(L, "too many results to unpack");
 353   lua_rawgeti(L, 1, i);  /* push arg[i] (avoiding overflow problems) */
 354   while (i++ < e)  /* push arg[i + 1...e] */
 355     lua_rawgeti(L, 1, i);
 356   return n;
 357 }
 358
 359
 360 static int luaB_select (lua_State *L) {
 361   int n = lua_gettop(L);
 362   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
 363     lua_pushinteger(L, n-1);
 364     return 1;
 365   }
 366   else {
 367     int i = luaL_checkint(L, 1);
 368     if (i < 0) i = n + i;
 369     else if (i > n) i = n;
 370     luaL_argcheck(L, 1 <= i, 1, "index out of range");
 371     return n - i;
 372   }
 373 }
 374
 375
 376 static int luaB_pcall (lua_State *L) {
 377   int status;
 378   luaL_checkany(L, 1);
 379   status = lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0);
 380   lua_pushboolean(L, (status == 0));
 381   lua_insert(L, 1);
 382   return lua_gettop(L);  /* return status + all results */
 383 }
 384
 385
 386 static int luaB_xpcall (lua_State *L) {
 387   int status;
 388   luaL_checkany(L, 2);
 389   lua_settop(L, 2);
 390   lua_insert(L, 1);  /* put error function under function to be called */
 391   status = lua_pcall(L, 0, LUA_MULTRET, 1);
 392   lua_pushboolean(L, (status == 0));
 393   lua_replace(L, 1);
 394   return lua_gettop(L);  /* return status + all results */
 395 }
 396
 397
 398 static int luaB_tostring (lua_State *L) {
 399   luaL_checkany(L, 1);
 400   if (luaL_callmeta(L, 1, "__tostring"))  /* is there a metafield? */
 401     return 1;  /* use its value */
 402   switch (lua_type(L, 1)) {
 403     case LUA_TNUMBER:
 404       lua_pushstring(L, lua_tostring(L, 1));
 405       break;
 406     case LUA_TSTRING:
 407       lua_pushvalue(L, 1);
 408       break;
 409     case LUA_TBOOLEAN:
 410       lua_pushstring(L, (lua_toboolean(L, 1) ? "true" : "false"));
 411       break;
 412     case LUA_TNIL:
 413       lua_pushliteral(L, "nil");
 414       break;
 415     default:
 416       lua_pushfstring(L, "%s: %p", luaL_typename(L, 1), lua_topointer(L, 1));
 417       break;
 418   }
 419   return 1;
 420 }
 421
 422
 423 static int luaB_newproxy (lua_State *L) {
 424   lua_settop(L, 1);
 425   lua_newuserdata(L, 0);  /* create proxy */
 426   if (lua_toboolean(L, 1) == 0)
 427     return 1;  /* no metatable */
 428   else if (lua_isboolean(L, 1)) {
 429     lua_newtable(L);  /* create a new metatable `m' ... */
 430     lua_pushvalue(L, -1);  /* ... and mark `m' as a valid metatable */
 431     lua_pushboolean(L, 1);
 432     lua_rawset(L, lua_upvalueindex(1));  /* weaktable[m] = true */
 433   }
 434   else {
 435     int validproxy = 0;  /* to check if weaktable[metatable(u)] == true */
 436     if (lua_getmetatable(L, 1)) {
 437       lua_rawget(L, lua_upvalueindex(1));
 438       validproxy = lua_toboolean(L, -1);
 439       lua_pop(L, 1);  /* remove value */
 440     }
 441     luaL_argcheck(L, validproxy, 1, "boolean or proxy expected");
 442     lua_getmetatable(L, 1);  /* metatable is valid; get it */
 443   }
 444   lua_setmetatable(L, 2);
 445   return 1;
 446 }
 447
 448
 449 static const luaL_Reg base_funcs[] = {
 450   {"assert", luaB_assert},
 451   {"collectgarbage", luaB_collectgarbage},
 452   {"dofile", luaB_dofile},
 453   {"error", luaB_error},
 454   {"gcinfo", luaB_gcinfo},
 455   {"getfenv", luaB_getfenv},
 456   {"getmetatable", luaB_getmetatable},
 457   {"loadfile", luaB_loadfile},
 458   {"load", luaB_load},
 459   {"loadstring", luaB_loadstring},
 460   {"next", luaB_next},
 461   {"pcall", luaB_pcall},
 462   {"print", luaB_print},
 463   {"rawequal", luaB_rawequal},
 464   {"rawget", luaB_rawget},
 465   {"rawset", luaB_rawset},
 466   {"select", luaB_select},
 467   {"setfenv", luaB_setfenv},
 468   {"setmetatable", luaB_setmetatable},
 469   {"tonumber", luaB_tonumber},
 470   {"tostring", luaB_tostring},
 471   {"type", luaB_type},
 472   {"unpack", luaB_unpack},
 473   {"xpcall", luaB_xpcall},
 474   {NULL, NULL}
 475 };
 476
 477
 478 /*
 479 ** {======================================================
 480 ** Coroutine library
 481 ** =======================================================
 482 */
 483
 484 #define CO_RUN  0       /* running */
 485 #define CO_SUS  1       /* suspended */
 486 #define CO_NOR  2       /* 'normal' (it resumed another coroutine) */
 487 #define CO_DEAD 3
 488
 489 static const char *const statnames[] =
 490     {"running", "suspended", "normal", "dead"};
 491
 492 static int costatus (lua_State *L, lua_State *co) {
 493   if (L == co) return CO_RUN;
 494   switch (lua_status(co)) {
 495     case LUA_YIELD:
 496       return CO_SUS;
 497     case 0: {
 498       lua_Debug ar;
 499       if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
 500         return CO_NOR;  /* it is running */
 501       else if (lua_gettop(co) == 0)
 502           return CO_DEAD;
 503       else
 504         return CO_SUS;  /* initial state */
 505     }
 506     default:  /* some error occured */
 507       return CO_DEAD;
 508   }
 509 }
 510
 511
 512 static int luaB_costatus (lua_State *L) {
 513   lua_State *co = lua_tothread(L, 1);
 514   luaL_argcheck(L, co, 1, "coroutine expected");
 515   lua_pushstring(L, statnames[costatus(L, co)]);
 516   return 1;
 517 }
 518
 519
 520 static int auxresume (lua_State *L, lua_State *co, int narg) {
 521   int status = costatus(L, co);
 522   if (!lua_checkstack(co, narg))
 523     luaL_error(L, "too many arguments to resume");
 524   if (status != CO_SUS) {
 525     lua_pushfstring(L, "cannot resume %s coroutine", statnames[status]);
 526     return -1;  /* error flag */
 527   }
 528   lua_xmove(L, co, narg);
 529   lua_setlevel(L, co);
 530   status = lua_resume(co, narg);
 531   if (status == 0 || status == LUA_YIELD) {
 532     int nres = lua_gettop(co);
 533     if (!lua_checkstack(L, nres + 1))
 534       luaL_error(L, "too many results to resume");
 535     lua_xmove(co, L, nres);  /* move yielded values */
 536     return nres;
 537   }
 538   else {
 539     lua_xmove(co, L, 1);  /* move error message */
 540     return -1;  /* error flag */
 541   }
 542 }
 543
 544
 545 static int luaB_coresume (lua_State *L) {
 546   lua_State *co = lua_tothread(L, 1);
 547   int r;
 548   luaL_argcheck(L, co, 1, "coroutine expected");
 549   r = auxresume(L, co, lua_gettop(L) - 1);
 550   if (r < 0) {
 551     lua_pushboolean(L, 0);
 552     lua_insert(L, -2);
 553     return 2;  /* return false + error message */
 554   }
 555   else {
 556     lua_pushboolean(L, 1);
 557     lua_insert(L, -(r + 1));
 558     return r + 1;  /* return true + `resume' returns */
 559   }
 560 }
 561
 562
 563 static int luaB_auxwrap (lua_State *L) {
 564   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
 565   int r = auxresume(L, co, lua_gettop(L));
 566   if (r < 0) {
 567     if (lua_isstring(L, -1)) {  /* error object is a string? */
 568       luaL_where(L, 1);  /* add extra info */
 569       lua_insert(L, -2);
 570       lua_concat(L, 2);
 571     }
 572     lua_error(L);  /* propagate error */
 573   }
 574   return r;
 575 }
 576
 577
 578 static int luaB_cocreate (lua_State *L) {
 579   lua_State *NL = lua_newthread(L);
 580   luaL_argcheck(L, lua_isfunction(L, 1) && !lua_iscfunction(L, 1), 1,
 581     "Lua function expected");
 582   lua_pushvalue(L, 1);  /* move function to top */
 583   lua_xmove(L, NL, 1);  /* move function from L to NL */
 584   return 1;
 585 }
 586
 587
 588 static int luaB_cowrap (lua_State *L) {
 589   luaB_cocreate(L);
 590   lua_pushcclosure(L, luaB_auxwrap, 1);
 591   return 1;
 592 }
 593
 594
 595 static int luaB_yield (lua_State *L) {
 596   return lua_yield(L, lua_gettop(L));
 597 }
 598
 599
 600 static int luaB_corunning (lua_State *L) {
 601   if (lua_pushthread(L))
 602     lua_pushnil(L);  /* main thread is not a coroutine */
 603   return 1;
 604 }
 605
 606
 607 static const luaL_Reg co_funcs[] = {
 608   {"create", luaB_cocreate},
 609   {"resume", luaB_coresume},
 610   {"running", luaB_corunning},
 611   {"status", luaB_costatus},
 612   {"wrap", luaB_cowrap},
 613   {"yield", luaB_yield},
 614   {NULL, NULL}
 615 };
 616
 617 /* }====================================================== */
 618
 619
 620 static void auxopen (lua_State *L, const char *name,
 621                      lua_CFunction f, lua_CFunction u) {
 622   lua_pushcfunction(L, u);
 623   lua_pushcclosure(L, f, 1);
 624   lua_setfield(L, -2, name);
 625 }
 626
 627
 628 static void base_open (lua_State *L) {
 629   /* set global _G */
 630   lua_pushvalue(L, LUA_GLOBALSINDEX);
 631   lua_setglobal(L, "_G");
 632   /* open lib into global table */
 633   luaL_register(L, "_G", base_funcs);
 634   lua_pushliteral(L, LUA_VERSION);
 635   lua_setglobal(L, "_VERSION");  /* set global _VERSION */
 636   /* `ipairs' and `pairs' need auxliliary functions as upvalues */
 637   auxopen(L, "ipairs", luaB_ipairs, ipairsaux);
 638   auxopen(L, "pairs", luaB_pairs, luaB_next);
 639   /* `newproxy' needs a weaktable as upvalue */
 640   lua_createtable(L, 0, 1);  /* new table `w' */
 641   lua_pushvalue(L, -1);  /* `w' will be its own metatable */
 642   lua_setmetatable(L, -2);
 643   lua_pushliteral(L, "kv");
 644   lua_setfield(L, -2, "__mode");  /* metatable(w).__mode = "kv" */
 645   lua_pushcclosure(L, luaB_newproxy, 1);
 646   lua_setglobal(L, "newproxy");  /* set global `newproxy' */
 647 }
 648
 649
 650 LUALIB_API int luaopen_base (lua_State *L) {
 651   base_open(L);
 652   luaL_register(L, LUA_COLIBNAME, co_funcs);
 653   return 2;
 654 }
 655