external/mit/lua/dist/src/lbaselib.c

   1 /*      $NetBSD: lbaselib.c,v 1.5 2015/10/08 13:21:00 mbalmer Exp $     */
   2
   3 /*
   4 ** Id: lbaselib.c,v 1.310 2015/03/28 19:14:47 roberto Exp
   5 ** Basic library
   6 ** See Copyright Notice in lua.h
   7 */
   8
   9 #define lbaselib_c
  10 #define LUA_LIB
  11
  12 #include "lprefix.h"
  13
  14
  15 #ifndef _KERNEL
  16 #include <ctype.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #endif
  21
  22 #include "lua.h"
  23
  24 #include "lauxlib.h"
  25 #include "lualib.h"
  26
  27
  28 static int luaB_print (lua_State *L) {
  29   int n = lua_gettop(L);  /* number of arguments */
  30   int i;
  31   lua_getglobal(L, "tostring");
  32   for (i=1; i<=n; i++) {
  33     const char *s;
  34     size_t l;
  35     lua_pushvalue(L, -1);  /* function to be called */
  36     lua_pushvalue(L, i);   /* value to print */
  37     lua_call(L, 1, 1);
  38     s = lua_tolstring(L, -1, &l);  /* get result */
  39     if (s == NULL)
  40       return luaL_error(L, "'tostring' must return a string to 'print'");
  41     if (i>1) lua_writestring("\t", 1);
  42     lua_writestring(s, l);
  43     lua_pop(L, 1);  /* pop result */
  44   }
  45   lua_writeline();
  46   return 0;
  47 }
  48
  49
  50 #define SPACECHARS      " \f\n\r\t\v"
  51
  52 static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
  53   lua_Unsigned n = 0;
  54   int neg = 0;
  55   s += strspn(s, SPACECHARS);  /* skip initial spaces */
  56   if (*s == '-') { s++; neg = 1; }  /* handle signal */
  57   else if (*s == '+') s++;
  58   if (!isalnum((unsigned char)*s))  /* no digit? */
  59     return NULL;
  60   do {
  61     int digit = (isdigit((unsigned char)*s)) ? *s - '0'
  62                    : (toupper((unsigned char)*s) - 'A') + 10;
  63     if (digit >= base) return NULL;  /* invalid numeral */
  64     n = n * base + digit;
  65     s++;
  66   } while (isalnum((unsigned char)*s));
  67   s += strspn(s, SPACECHARS);  /* skip trailing spaces */
  68   *pn = (lua_Integer)((neg) ? (0u - n) : n);
  69   return s;
  70 }
  71
  72
  73 static int luaB_tonumber (lua_State *L) {
  74   if (lua_isnoneornil(L, 2)) {  /* standard conversion? */
  75     luaL_checkany(L, 1);
  76     if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */
  77       lua_settop(L, 1);  /* yes; return it */
  78       return 1;
  79     }
  80     else {
  81       size_t l;
  82       const char *s = lua_tolstring(L, 1, &l);
  83       if (s != NULL && lua_stringtonumber(L, s) == l + 1)
  84         return 1;  /* successful conversion to number */
  85       /* else not a number */
  86     }
  87   }
  88   else {
  89     size_t l;
  90     const char *s;
  91     lua_Integer n = 0;  /* to avoid warnings */
  92     lua_Integer base = luaL_checkinteger(L, 2);
  93     luaL_checktype(L, 1, LUA_TSTRING);  /* before 'luaL_checklstring'! */
  94     s = luaL_checklstring(L, 1, &l);
  95     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
  96     if (b_str2int(s, (int)base, &n) == s + l) {
  97       lua_pushinteger(L, n);
  98       return 1;
  99     }  /* else not a number */
 100   }  /* else not a number */
 101   lua_pushnil(L);  /* not a number */
 102   return 1;
 103 }
 104
 105
 106 static int luaB_error (lua_State *L) {
 107   int level = (int)luaL_optinteger(L, 2, 1);
 108   lua_settop(L, 1);
 109   if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
 110     luaL_where(L, level);
 111     lua_pushvalue(L, 1);
 112     lua_concat(L, 2);
 113   }
 114   return lua_error(L);
 115 }
 116
 117
 118 static int luaB_getmetatable (lua_State *L) {
 119   luaL_checkany(L, 1);
 120   if (!lua_getmetatable(L, 1)) {
 121     lua_pushnil(L);
 122     return 1;  /* no metatable */
 123   }
 124   luaL_getmetafield(L, 1, "__metatable");
 125   return 1;  /* returns either __metatable field (if present) or metatable */
 126 }
 127
 128
 129 static int luaB_setmetatable (lua_State *L) {
 130   int t = lua_type(L, 2);
 131   luaL_checktype(L, 1, LUA_TTABLE);
 132   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
 133                     "nil or table expected");
 134   if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
 135     return luaL_error(L, "cannot change a protected metatable");
 136   lua_settop(L, 2);
 137   lua_setmetatable(L, 1);
 138   return 1;
 139 }
 140
 141
 142 static int luaB_rawequal (lua_State *L) {
 143   luaL_checkany(L, 1);
 144   luaL_checkany(L, 2);
 145   lua_pushboolean(L, lua_rawequal(L, 1, 2));
 146   return 1;
 147 }
 148
 149
 150 static int luaB_rawlen (lua_State *L) {
 151   int t = lua_type(L, 1);
 152   luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
 153                    "table or string expected");
 154   lua_pushinteger(L, lua_rawlen(L, 1));
 155   return 1;
 156 }
 157
 158
 159 static int luaB_rawget (lua_State *L) {
 160   luaL_checktype(L, 1, LUA_TTABLE);
 161   luaL_checkany(L, 2);
 162   lua_settop(L, 2);
 163   lua_rawget(L, 1);
 164   return 1;
 165 }
 166
 167 static int luaB_rawset (lua_State *L) {
 168   luaL_checktype(L, 1, LUA_TTABLE);
 169   luaL_checkany(L, 2);
 170   luaL_checkany(L, 3);
 171   lua_settop(L, 3);
 172   lua_rawset(L, 1);
 173   return 1;
 174 }
 175
 176
 177 static int luaB_collectgarbage (lua_State *L) {
 178   static const char *const opts[] = {"stop", "restart", "collect",
 179     "count", "step", "setpause", "setstepmul",
 180     "isrunning", NULL};
 181   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
 182     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
 183     LUA_GCISRUNNING};
 184   int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
 185   int ex = (int)luaL_optinteger(L, 2, 0);
 186   int res = lua_gc(L, o, ex);
 187   switch (o) {
 188     case LUA_GCCOUNT: {
 189       int b = lua_gc(L, LUA_GCCOUNTB, 0);
 190       lua_pushnumber(L, (lua_Number)res + ((lua_Number)b/1024));
 191       return 1;
 192     }
 193     case LUA_GCSTEP: case LUA_GCISRUNNING: {
 194       lua_pushboolean(L, res);
 195       return 1;
 196     }
 197     default: {
 198       lua_pushinteger(L, res);
 199       return 1;
 200     }
 201   }
 202 }
 203
 204
 205 /*
 206 ** This function has all type names as upvalues, to maximize performance.
 207 */
 208 static int luaB_type (lua_State *L) {
 209   luaL_checkany(L, 1);
 210   lua_pushvalue(L, lua_upvalueindex(lua_type(L, 1) + 1));
 211   return 1;
 212 }
 213
 214
 215 static int pairsmeta (lua_State *L, const char *method, int iszero,
 216                       lua_CFunction iter) {
 217   if (luaL_getmetafield(L, 1, method) == LUA_TNIL) {  /* no metamethod? */
 218     luaL_checktype(L, 1, LUA_TTABLE);  /* argument must be a table */
 219     lua_pushcfunction(L, iter);  /* will return generator, */
 220     lua_pushvalue(L, 1);  /* state, */
 221     if (iszero) lua_pushinteger(L, 0);  /* and initial value */
 222     else lua_pushnil(L);
 223   }
 224   else {
 225     lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
 226     lua_call(L, 1, 3);  /* get 3 values from metamethod */
 227   }
 228   return 3;
 229 }
 230
 231
 232 static int luaB_next (lua_State *L) {
 233   luaL_checktype(L, 1, LUA_TTABLE);
 234   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
 235   if (lua_next(L, 1))
 236     return 2;
 237   else {
 238     lua_pushnil(L);
 239     return 1;
 240   }
 241 }
 242
 243
 244 static int luaB_pairs (lua_State *L) {
 245   return pairsmeta(L, "__pairs", 0, luaB_next);
 246 }
 247
 248
 249 /*
 250 ** Traversal function for 'ipairs' for raw tables
 251 */
 252 static int ipairsaux_raw (lua_State *L) {
 253   lua_Integer i = luaL_checkinteger(L, 2) + 1;
 254   luaL_checktype(L, 1, LUA_TTABLE);
 255   lua_pushinteger(L, i);
 256   return (lua_rawgeti(L, 1, i) == LUA_TNIL) ? 1 : 2;
 257 }
 258
 259
 260 /*
 261 ** Traversal function for 'ipairs' for tables with metamethods
 262 */
 263 static int ipairsaux (lua_State *L) {
 264   lua_Integer i = luaL_checkinteger(L, 2) + 1;
 265   lua_pushinteger(L, i);
 266   return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
 267 }
 268
 269
 270 /*
 271 ** This function will use either 'ipairsaux' or 'ipairsaux_raw' to
 272 ** traverse a table, depending on whether the table has metamethods
 273 ** that can affect the traversal.
 274 */
 275 static int luaB_ipairs (lua_State *L) {
 276   lua_CFunction iter = (luaL_getmetafield(L, 1, "__index") != LUA_TNIL)
 277                        ? ipairsaux : ipairsaux_raw;
 278 #if defined(LUA_COMPAT_IPAIRS)
 279   return pairsmeta(L, "__ipairs", 1, iter);
 280 #else
 281   luaL_checkany(L, 1);
 282   lua_pushcfunction(L, iter);  /* iteration function */
 283   lua_pushvalue(L, 1);  /* state */
 284   lua_pushinteger(L, 0);  /* initial value */
 285   return 3;
 286 #endif
 287 }
 288
 289
 290 static int load_aux (lua_State *L, int status, int envidx) {
 291   if (status == LUA_OK) {
 292     if (envidx != 0) {  /* 'env' parameter? */
 293       lua_pushvalue(L, envidx);  /* environment for loaded function */
 294       if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
 295         lua_pop(L, 1);  /* remove 'env' if not used by previous call */
 296     }
 297     return 1;
 298   }
 299   else {  /* error (message is on top of the stack) */
 300     lua_pushnil(L);
 301     lua_insert(L, -2);  /* put before error message */
 302     return 2;  /* return nil plus error message */
 303   }
 304 }
 305
 306
 307 #ifndef _KERNEL
 308 static int luaB_loadfile (lua_State *L) {
 309   const char *fname = luaL_optstring(L, 1, NULL);
 310   const char *mode = luaL_optstring(L, 2, NULL);
 311   int env = (!lua_isnone(L, 3) ? 3 : 0);  /* 'env' index or 0 if no 'env' */
 312   int status = luaL_loadfilex(L, fname, mode);
 313   return load_aux(L, status, env);
 314 }
 315 #endif
 316
 317
 318 /*
 319 ** {======================================================
 320 ** Generic Read function
 321 ** =======================================================
 322 */
 323
 324
 325 /*
 326 ** reserved slot, above all arguments, to hold a copy of the returned
 327 ** string to avoid it being collected while parsed. 'load' has four
 328 ** optional arguments (chunk, source name, mode, and environment).
 329 */
 330 #define RESERVEDSLOT    5
 331
 332
 333 /*
 334 ** Reader for generic 'load' function: 'lua_load' uses the
 335 ** stack for internal stuff, so the reader cannot change the
 336 ** stack top. Instead, it keeps its resulting string in a
 337 ** reserved slot inside the stack.
 338 */
 339 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
 340   (void)(ud);  /* not used */
 341   luaL_checkstack(L, 2, "too many nested functions");
 342   lua_pushvalue(L, 1);  /* get function */
 343   lua_call(L, 0, 1);  /* call it */
 344   if (lua_isnil(L, -1)) {
 345     lua_pop(L, 1);  /* pop result */
 346     *size = 0;
 347     return NULL;
 348   }
 349   else if (!lua_isstring(L, -1))
 350     luaL_error(L, "reader function must return a string");
 351   lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
 352   return lua_tolstring(L, RESERVEDSLOT, size);
 353 }
 354
 355
 356 static int luaB_load (lua_State *L) {
 357   int status;
 358   size_t l;
 359   const char *s = lua_tolstring(L, 1, &l);
 360   const char *mode = luaL_optstring(L, 3, "bt");
 361   int env = (!lua_isnone(L, 4) ? 4 : 0);  /* 'env' index or 0 if no 'env' */
 362   if (s != NULL) {  /* loading a string? */
 363     const char *chunkname = luaL_optstring(L, 2, s);
 364     status = luaL_loadbufferx(L, s, l, chunkname, mode);
 365   }
 366   else {  /* loading from a reader function */
 367     const char *chunkname = luaL_optstring(L, 2, "=(load)");
 368     luaL_checktype(L, 1, LUA_TFUNCTION);
 369     lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
 370     status = lua_load(L, generic_reader, NULL, chunkname, mode);
 371   }
 372   return load_aux(L, status, env);
 373 }
 374
 375 /* }====================================================== */
 376
 377
 378 #ifndef _KERNEL
 379 static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
 380   (void)d1;  (void)d2;  /* only to match 'lua_Kfunction' prototype */
 381   return lua_gettop(L) - 1;
 382 }
 383
 384
 385 static int luaB_dofile (lua_State *L) {
 386   const char *fname = luaL_optstring(L, 1, NULL);
 387   lua_settop(L, 1);
 388   if (luaL_loadfile(L, fname) != LUA_OK)
 389     return lua_error(L);
 390   lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
 391   return dofilecont(L, 0, 0);
 392 }
 393 #endif
 394
 395
 396 static int luaB_assert (lua_State *L) {
 397   if (lua_toboolean(L, 1))  /* condition is true? */
 398     return lua_gettop(L);  /* return all arguments */
 399   else {  /* error */
 400     luaL_checkany(L, 1);  /* there must be a condition */
 401     lua_remove(L, 1);  /* remove it */
 402     lua_pushliteral(L, "assertion failed!");  /* default message */
 403     lua_settop(L, 1);  /* leave only message (default if no other one) */
 404     return luaB_error(L);  /* call 'error' */
 405   }
 406 }
 407
 408
 409 static int luaB_select (lua_State *L) {
 410   int n = lua_gettop(L);
 411   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
 412     lua_pushinteger(L, n-1);
 413     return 1;
 414   }
 415   else {
 416     lua_Integer i = luaL_checkinteger(L, 1);
 417     if (i < 0) i = n + i;
 418     else if (i > n) i = n;
 419     luaL_argcheck(L, 1 <= i, 1, "index out of range");
 420     return n - (int)i;
 421   }
 422 }
 423
 424
 425 /*
 426 ** Continuation function for 'pcall' and 'xpcall'. Both functions
 427 ** already pushed a 'true' before doing the call, so in case of success
 428 ** 'finishpcall' only has to return everything in the stack minus
 429 ** 'extra' values (where 'extra' is exactly the number of items to be
 430 ** ignored).
 431 */
 432 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
 433   if (status != LUA_OK && status != LUA_YIELD) {  /* error? */
 434     lua_pushboolean(L, 0);  /* first result (false) */
 435     lua_pushvalue(L, -2);  /* error message */
 436     return 2;  /* return false, msg */
 437   }
 438   else
 439     return lua_gettop(L) - (int)extra;  /* return all results */
 440 }
 441
 442
 443 static int luaB_pcall (lua_State *L) {
 444   int status;
 445   luaL_checkany(L, 1);
 446   lua_pushboolean(L, 1);  /* first result if no errors */
 447   lua_insert(L, 1);  /* put it in place */
 448   status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
 449   return finishpcall(L, status, 0);
 450 }
 451
 452
 453 /*
 454 ** Do a protected call with error handling. After 'lua_rotate', the
 455 ** stack will have <f, err, true, f, [args...]>; so, the function passes
 456 ** 2 to 'finishpcall' to skip the 2 first values when returning results.
 457 */
 458 static int luaB_xpcall (lua_State *L) {
 459   int status;
 460   int n = lua_gettop(L);
 461   luaL_checktype(L, 2, LUA_TFUNCTION);  /* check error function */
 462   lua_pushboolean(L, 1);  /* first result */
 463   lua_pushvalue(L, 1);  /* function */
 464   lua_rotate(L, 3, 2);  /* move them below function's arguments */
 465   status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
 466   return finishpcall(L, status, 2);
 467 }
 468
 469
 470 static int luaB_tostring (lua_State *L) {
 471   luaL_checkany(L, 1);
 472   luaL_tolstring(L, 1, NULL);
 473   return 1;
 474 }
 475
 476
 477 static const luaL_Reg base_funcs[] = {
 478   {"assert", luaB_assert},
 479   {"collectgarbage", luaB_collectgarbage},
 480 #ifndef _KERNEL
 481   {"dofile", luaB_dofile},
 482 #endif
 483   {"error", luaB_error},
 484   {"getmetatable", luaB_getmetatable},
 485   {"ipairs", luaB_ipairs},
 486 #ifndef _KERNEL
 487   {"loadfile", luaB_loadfile},
 488 #endif
 489   {"load", luaB_load},
 490 #if defined(LUA_COMPAT_LOADSTRING)
 491   {"loadstring", luaB_load},
 492 #endif
 493   {"next", luaB_next},
 494   {"pairs", luaB_pairs},
 495   {"pcall", luaB_pcall},
 496   {"print", luaB_print},
 497   {"rawequal", luaB_rawequal},
 498   {"rawlen", luaB_rawlen},
 499   {"rawget", luaB_rawget},
 500   {"rawset", luaB_rawset},
 501   {"select", luaB_select},
 502   {"setmetatable", luaB_setmetatable},
 503   {"tonumber", luaB_tonumber},
 504   {"tostring", luaB_tostring},
 505   {"xpcall", luaB_xpcall},
 506   /* placeholders */
 507   {"type", NULL},
 508   {"_G", NULL},
 509   {"_VERSION", NULL},
 510   {NULL, NULL}
 511 };
 512
 513
 514 LUAMOD_API int luaopen_base (lua_State *L) {
 515   int i;
 516   /* open lib into global table */
 517   lua_pushglobaltable(L);
 518   luaL_setfuncs(L, base_funcs, 0);
 519   /* set global _G */
 520   lua_pushvalue(L, -1);
 521   lua_setfield(L, -2, "_G");
 522   /* set global _VERSION */
 523   lua_pushliteral(L, LUA_VERSION);
 524   lua_setfield(L, -2, "_VERSION");
 525   /* set function 'type' with proper upvalues */
 526   for (i = 0; i < LUA_NUMTAGS; i++)  /* push all type names as upvalues */
 527     lua_pushstring(L, lua_typename(L, i));
 528   lua_pushcclosure(L, luaB_type, LUA_NUMTAGS);
 529   lua_setfield(L, -2, "type");
 530   return 1;
 531 }
 532