src/lauxlib.c

   1 /*
   2 ** $Id: lauxlib.c,v 1.159.1.3 2008/01/21 13:20:51 roberto Exp $
   3 ** Auxiliary functions for building Lua libraries
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <ctype.h>
   9 #include <errno.h>
  10 #include <stdarg.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15
  16 /* This file uses only the official API of Lua.
  17 ** Any function declared here could be written as an application function.
  18 */
  19
  20 #define lauxlib_c
  21 #define LUA_LIB
  22
  23 #include "lua.h"
  24
  25 #include "lauxlib.h"
  26
  27
  28 #define FREELIST_REF    0       /* free list of references */
  29
  30
  31 /* convert a stack index to positive */
  32 #define abs_index(L, i)         ((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \
  33                                         lua_gettop(L) + (i) + 1)
  34
  35
  36 /*
  37 ** {======================================================
  38 ** Error-report functions
  39 ** =======================================================
  40 */
  41
  42
  43 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {
  44   lua_Debug ar;
  45   if (!lua_getstack(L, 0, &ar))  /* no stack frame? */
  46     return luaL_error(L, "bad argument #%d (%s)", narg, extramsg);
  47   lua_getinfo(L, "n", &ar);
  48   if (strcmp(ar.namewhat, "method") == 0) {
  49     narg--;  /* do not count `self' */
  50     if (narg == 0)  /* error is in the self argument itself? */
  51       return luaL_error(L, "calling " LUA_QS " on bad self (%s)",
  52                            ar.name, extramsg);
  53   }
  54   if (ar.name == NULL)
  55     ar.name = "?";
  56   return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)",
  57                         narg, ar.name, extramsg);
  58 }
  59
  60
  61 LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname) {
  62   const char *msg = lua_pushfstring(L, "%s expected, got %s",
  63                                     tname, luaL_typename(L, narg));
  64   return luaL_argerror(L, narg, msg);
  65 }
  66
  67
  68 static void tag_error (lua_State *L, int narg, int tag) {
  69   luaL_typerror(L, narg, lua_typename(L, tag));
  70 }
  71
  72
  73 LUALIB_API void luaL_where (lua_State *L, int level) {
  74   lua_Debug ar;
  75   if (lua_getstack(L, level, &ar)) {  /* check function at level */
  76     lua_getinfo(L, "Sl", &ar);  /* get info about it */
  77     if (ar.currentline > 0) {  /* is there info? */
  78       lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
  79       return;
  80     }
  81   }
  82   lua_pushliteral(L, "");  /* else, no information available... */
  83 }
  84
  85
  86 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
  87   va_list argp;
  88   va_start(argp, fmt);
  89   luaL_where(L, 1);
  90   lua_pushvfstring(L, fmt, argp);
  91   va_end(argp);
  92   lua_concat(L, 2);
  93   return lua_error(L);
  94 }
  95
  96 /* }====================================================== */
  97
  98
  99 LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def,
 100                                  const char *const lst[]) {
 101   const char *name = (def) ? luaL_optstring(L, narg, def) :
 102                              luaL_checkstring(L, narg);
 103   int i;
 104   for (i=0; lst[i]; i++)
 105     if (strcmp(lst[i], name) == 0)
 106       return i;
 107   return luaL_argerror(L, narg,
 108                        lua_pushfstring(L, "invalid option " LUA_QS, name));
 109 }
 110
 111
 112 LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
 113   lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get registry.name */
 114   if (!lua_isnil(L, -1))  /* name already in use? */
 115     return 0;  /* leave previous value on top, but return 0 */
 116   lua_pop(L, 1);
 117   lua_newtable(L);  /* create metatable */
 118   lua_pushvalue(L, -1);
 119   lua_setfield(L, LUA_REGISTRYINDEX, tname);  /* registry.name = metatable */
 120   return 1;
 121 }
 122
 123
 124 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
 125   void *p = lua_touserdata(L, ud);
 126   if (p != NULL) {  /* value is a userdata? */
 127     if (lua_getmetatable(L, ud)) {  /* does it have a metatable? */
 128       lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get correct metatable */
 129       if (lua_rawequal(L, -1, -2)) {  /* does it have the correct mt? */
 130         lua_pop(L, 2);  /* remove both metatables */
 131         return p;
 132       }
 133     }
 134   }
 135   luaL_typerror(L, ud, tname);  /* else error */
 136   return NULL;  /* to avoid warnings */
 137 }
 138
 139
 140 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) {
 141   if (!lua_checkstack(L, space))
 142     luaL_error(L, "stack overflow (%s)", mes);
 143 }
 144
 145
 146 LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) {
 147   if (lua_type(L, narg) != t)
 148     tag_error(L, narg, t);
 149 }
 150
 151
 152 LUALIB_API void luaL_checkany (lua_State *L, int narg) {
 153   if (lua_type(L, narg) == LUA_TNONE)
 154     luaL_argerror(L, narg, "value expected");
 155 }
 156
 157
 158 LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) {
 159   const char *s = lua_tolstring(L, narg, len);
 160   if (!s) tag_error(L, narg, LUA_TSTRING);
 161   return s;
 162 }
 163
 164
 165 LUALIB_API const char *luaL_optlstring (lua_State *L, int narg,
 166                                         const char *def, size_t *len) {
 167   if (lua_isnoneornil(L, narg)) {
 168     if (len)
 169       *len = (def ? strlen(def) : 0);
 170     return def;
 171   }
 172   else return luaL_checklstring(L, narg, len);
 173 }
 174
 175
 176 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) {
 177   lua_Number d = lua_tonumber(L, narg);
 178   if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
 179     tag_error(L, narg, LUA_TNUMBER);
 180   return d;
 181 }
 182
 183
 184 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {
 185   return luaL_opt(L, luaL_checknumber, narg, def);
 186 }
 187
 188
 189 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) {
 190   lua_Integer d = lua_tointeger(L, narg);
 191   if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
 192     tag_error(L, narg, LUA_TNUMBER);
 193   return d;
 194 }
 195
 196
 197 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,
 198                                                       lua_Integer def) {
 199   return luaL_opt(L, luaL_checkinteger, narg, def);
 200 }
 201
 202
 203 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
 204   if (!lua_getmetatable(L, obj))  /* no metatable? */
 205     return 0;
 206   lua_pushstring(L, event);
 207   lua_rawget(L, -2);
 208   if (lua_isnil(L, -1)) {
 209     lua_pop(L, 2);  /* remove metatable and metafield */
 210     return 0;
 211   }
 212   else {
 213     lua_remove(L, -2);  /* remove only metatable */
 214     return 1;
 215   }
 216 }
 217
 218
 219 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
 220   obj = abs_index(L, obj);
 221   if (!luaL_getmetafield(L, obj, event))  /* no metafield? */
 222     return 0;
 223   lua_pushvalue(L, obj);
 224   lua_call(L, 1, 1);
 225   return 1;
 226 }
 227
 228
 229 LUALIB_API void (luaL_register) (lua_State *L, const char *libname,
 230                                 const luaL_Reg *l) {
 231   luaI_openlib(L, libname, l, 0);
 232 }
 233
 234
 235 static int libsize (const luaL_Reg *l) {
 236   int size = 0;
 237   for (; l->name; l++) size++;
 238   return size;
 239 }
 240
 241
 242 LUALIB_API void luaI_openlib (lua_State *L, const char *libname,
 243                               const luaL_Reg *l, int nup) {
 244   if (libname) {
 245     int size = libsize(l);
 246     /* check whether lib already exists */
 247     luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);
 248     lua_getfield(L, -1, libname);  /* get _LOADED[libname] */
 249     if (!lua_istable(L, -1)) {  /* not found? */
 250       lua_pop(L, 1);  /* remove previous result */
 251       /* try global variable (and create one if it does not exist) */
 252       if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
 253         luaL_error(L, "name conflict for module " LUA_QS, libname);
 254       lua_pushvalue(L, -1);
 255       lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */
 256     }
 257     lua_remove(L, -2);  /* remove _LOADED table */
 258     lua_insert(L, -(nup+1));  /* move library table to below upvalues */
 259   }
 260   for (; l->name; l++) {
 261     int i;
 262     for (i=0; i<nup; i++)  /* copy upvalues to the top */
 263       lua_pushvalue(L, -nup);
 264     lua_pushcclosure(L, l->func, nup);
 265     lua_setfield(L, -(nup+2), l->name);
 266   }
 267   lua_pop(L, nup);  /* remove upvalues */
 268 }
 269
 270
 271
 272 /*
 273 ** {======================================================
 274 ** getn-setn: size for arrays
 275 ** =======================================================
 276 */
 277
 278 #if defined(LUA_COMPAT_GETN)
 279
 280 static int checkint (lua_State *L, int topop) {
 281   int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;
 282   lua_pop(L, topop);
 283   return n;
 284 }
 285
 286
 287 static void getsizes (lua_State *L) {
 288   lua_getfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");
 289   if (lua_isnil(L, -1)) {  /* no `size' table? */
 290     lua_pop(L, 1);  /* remove nil */
 291     lua_newtable(L);  /* create it */
 292     lua_pushvalue(L, -1);  /* `size' will be its own metatable */
 293     lua_setmetatable(L, -2);
 294     lua_pushliteral(L, "kv");
 295     lua_setfield(L, -2, "__mode");  /* metatable(N).__mode = "kv" */
 296     lua_pushvalue(L, -1);
 297     lua_setfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  /* store in register */
 298   }
 299 }
 300
 301
 302 LUALIB_API void luaL_setn (lua_State *L, int t, int n) {
 303   t = abs_index(L, t);
 304   lua_pushliteral(L, "n");
 305   lua_rawget(L, t);
 306   if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */
 307     lua_pushliteral(L, "n");  /* use it */
 308     lua_pushinteger(L, n);
 309     lua_rawset(L, t);
 310   }
 311   else {  /* use `sizes' */
 312     getsizes(L);
 313     lua_pushvalue(L, t);
 314     lua_pushinteger(L, n);
 315     lua_rawset(L, -3);  /* sizes[t] = n */
 316     lua_pop(L, 1);  /* remove `sizes' */
 317   }
 318 }
 319
 320
 321 LUALIB_API int luaL_getn (lua_State *L, int t) {
 322   int n;
 323   t = abs_index(L, t);
 324   lua_pushliteral(L, "n");  /* try t.n */
 325   lua_rawget(L, t);
 326   if ((n = checkint(L, 1)) >= 0) return n;
 327   getsizes(L);  /* else try sizes[t] */
 328   lua_pushvalue(L, t);
 329   lua_rawget(L, -2);
 330   if ((n = checkint(L, 2)) >= 0) return n;
 331   return (int)lua_objlen(L, t);
 332 }
 333
 334 #endif
 335
 336 /* }====================================================== */
 337
 338
 339
 340 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
 341                                                                const char *r) {
 342   const char *wild;
 343   size_t l = strlen(p);
 344   luaL_Buffer b;
 345   luaL_buffinit(L, &b);
 346   while ((wild = strstr(s, p)) != NULL) {
 347     luaL_addlstring(&b, s, wild - s);  /* push prefix */
 348     luaL_addstring(&b, r);  /* push replacement in place of pattern */
 349     s = wild + l;  /* continue after `p' */
 350   }
 351   luaL_addstring(&b, s);  /* push last suffix */
 352   luaL_pushresult(&b);
 353   return lua_tostring(L, -1);
 354 }
 355
 356
 357 LUALIB_API const char *luaL_findtable (lua_State *L, int idx,
 358                                        const char *fname, int szhint) {
 359   const char *e;
 360   lua_pushvalue(L, idx);
 361   do {
 362     e = strchr(fname, '.');
 363     if (e == NULL) e = fname + strlen(fname);
 364     lua_pushlstring(L, fname, e - fname);
 365     lua_rawget(L, -2);
 366     if (lua_isnil(L, -1)) {  /* no such field? */
 367       lua_pop(L, 1);  /* remove this nil */
 368       lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
 369       lua_pushlstring(L, fname, e - fname);
 370       lua_pushvalue(L, -2);
 371       lua_settable(L, -4);  /* set new table into field */
 372     }
 373     else if (!lua_istable(L, -1)) {  /* field has a non-table value? */
 374       lua_pop(L, 2);  /* remove table and value */
 375       return fname;  /* return problematic part of the name */
 376     }
 377     lua_remove(L, -2);  /* remove previous table */
 378     fname = e + 1;
 379   } while (*e == '.');
 380   return NULL;
 381 }
 382
 383
 384
 385 /*
 386 ** {======================================================
 387 ** Generic Buffer manipulation
 388 ** =======================================================
 389 */
 390
 391
 392 #define bufflen(B)      ((B)->p - (B)->buffer)
 393 #define bufffree(B)     ((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
 394
 395 #define LIMIT   (LUA_MINSTACK/2)
 396
 397
 398 static int emptybuffer (luaL_Buffer *B) {
 399   size_t l = bufflen(B);
 400   if (l == 0) return 0;  /* put nothing on stack */
 401   else {
 402     lua_pushlstring(B->L, B->buffer, l);
 403     B->p = B->buffer;
 404     B->lvl++;
 405     return 1;
 406   }
 407 }
 408
 409
 410 static void adjuststack (luaL_Buffer *B) {
 411   if (B->lvl > 1) {
 412     lua_State *L = B->L;
 413     int toget = 1;  /* number of levels to concat */
 414     size_t toplen = lua_strlen(L, -1);
 415     do {
 416       size_t l = lua_strlen(L, -(toget+1));
 417       if (B->lvl - toget + 1 >= LIMIT || toplen > l) {
 418         toplen += l;
 419         toget++;
 420       }
 421       else break;
 422     } while (toget < B->lvl);
 423     lua_concat(L, toget);
 424     B->lvl = B->lvl - toget + 1;
 425   }
 426 }
 427
 428
 429 LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
 430   if (emptybuffer(B))
 431     adjuststack(B);
 432   return B->buffer;
 433 }
 434
 435
 436 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
 437   while (l--)
 438     luaL_addchar(B, *s++);
 439 }
 440
 441
 442 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
 443   luaL_addlstring(B, s, strlen(s));
 444 }
 445
 446
 447 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
 448   emptybuffer(B);
 449   lua_concat(B->L, B->lvl);
 450   B->lvl = 1;
 451 }
 452
 453
 454 LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
 455   lua_State *L = B->L;
 456   size_t vl;
 457   const char *s = lua_tolstring(L, -1, &vl);
 458   if (vl <= bufffree(B)) {  /* fit into buffer? */
 459     memcpy(B->p, s, vl);  /* put it there */
 460     B->p += vl;
 461     lua_pop(L, 1);  /* remove from stack */
 462   }
 463   else {
 464     if (emptybuffer(B))
 465       lua_insert(L, -2);  /* put buffer before new value */
 466     B->lvl++;  /* add new value into B stack */
 467     adjuststack(B);
 468   }
 469 }
 470
 471
 472 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
 473   B->L = L;
 474   B->p = B->buffer;
 475   B->lvl = 0;
 476 }
 477
 478 /* }====================================================== */
 479
 480
 481 LUALIB_API int luaL_ref (lua_State *L, int t) {
 482   int ref;
 483   t = abs_index(L, t);
 484   if (lua_isnil(L, -1)) {
 485     lua_pop(L, 1);  /* remove from stack */
 486     return LUA_REFNIL;  /* `nil' has a unique fixed reference */
 487   }
 488   lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */
 489   ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */
 490   lua_pop(L, 1);  /* remove it from stack */
 491   if (ref != 0) {  /* any free element? */
 492     lua_rawgeti(L, t, ref);  /* remove it from list */
 493     lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */
 494   }
 495   else {  /* no free elements */
 496     ref = (int)lua_objlen(L, t);
 497     ref++;  /* create new reference */
 498   }
 499   lua_rawseti(L, t, ref);
 500   return ref;
 501 }
 502
 503
 504 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
 505   if (ref >= 0) {
 506     t = abs_index(L, t);
 507     lua_rawgeti(L, t, FREELIST_REF);
 508     lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */
 509     lua_pushinteger(L, ref);
 510     lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */
 511   }
 512 }
 513
 514
 515
 516 /*
 517 ** {======================================================
 518 ** Load functions
 519 ** =======================================================
 520 */
 521
 522 typedef struct LoadF {
 523   int extraline;
 524   FILE *f;
 525   char buff[LUAL_BUFFERSIZE];
 526 } LoadF;
 527
 528
 529 static const char *getF (lua_State *L, void *ud, size_t *size) {
 530   LoadF *lf = (LoadF *)ud;
 531   (void)L;
 532   if (lf->extraline) {
 533     lf->extraline = 0;
 534     *size = 1;
 535     return "\n";
 536   }
 537   if (feof(lf->f)) return NULL;
 538   *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);
 539   return (*size > 0) ? lf->buff : NULL;
 540 }
 541
 542
 543 static int errfile (lua_State *L, const char *what, int fnameindex) {
 544   const char *serr = strerror(errno);
 545   const char *filename = lua_tostring(L, fnameindex) + 1;
 546   lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
 547   lua_remove(L, fnameindex);
 548   return LUA_ERRFILE;
 549 }
 550
 551
 552 LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
 553   LoadF lf;
 554   int status, readstatus;
 555   int c;
 556   int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */
 557   lf.extraline = 0;
 558   if (filename == NULL) {
 559     lua_pushliteral(L, "=stdin");
 560     lf.f = stdin;
 561   }
 562   else {
 563     lua_pushfstring(L, "@%s", filename);
 564     lf.f = fopen(filename, "r");
 565     if (lf.f == NULL) return errfile(L, "open", fnameindex);
 566   }
 567   c = getc(lf.f);
 568   if (c == '#') {  /* Unix exec. file? */
 569     lf.extraline = 1;
 570     while ((c = getc(lf.f)) != EOF && c != '\n') ;  /* skip first line */
 571     if (c == '\n') c = getc(lf.f);
 572   }
 573   if (c == LUA_SIGNATURE[0] && filename) {  /* binary file? */
 574     lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */
 575     if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
 576     /* skip eventual `#!...' */
 577    while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;
 578     lf.extraline = 0;
 579   }
 580   ungetc(c, lf.f);
 581   status = lua_load(L, getF, &lf, lua_tostring(L, -1));
 582   readstatus = ferror(lf.f);
 583   if (filename) fclose(lf.f);  /* close file (even in case of errors) */
 584   if (readstatus) {
 585     lua_settop(L, fnameindex);  /* ignore results from `lua_load' */
 586     return errfile(L, "read", fnameindex);
 587   }
 588   lua_remove(L, fnameindex);
 589   return status;
 590 }
 591
 592
 593 typedef struct LoadS {
 594   const char *s;
 595   size_t size;
 596 } LoadS;
 597
 598
 599 static const char *getS (lua_State *L, void *ud, size_t *size) {
 600   LoadS *ls = (LoadS *)ud;
 601   (void)L;
 602   if (ls->size == 0) return NULL;
 603   *size = ls->size;
 604   ls->size = 0;
 605   return ls->s;
 606 }
 607
 608
 609 LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,
 610                                 const char *name) {
 611   LoadS ls;
 612   ls.s = buff;
 613   ls.size = size;
 614   return lua_load(L, getS, &ls, name);
 615 }
 616
 617
 618 LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {
 619   return luaL_loadbuffer(L, s, strlen(s), s);
 620 }
 621
 622
 623
 624 /* }====================================================== */
 625
 626
 627 static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
 628   (void)ud;
 629   (void)osize;
 630   if (nsize == 0) {
 631     free(ptr);
 632     return NULL;
 633   }
 634   else
 635     return realloc(ptr, nsize);
 636 }
 637
 638
 639 static int panic (lua_State *L) {
 640   (void)L;  /* to avoid warnings */
 641   fprintf(stderr, "PANIC: unprotected error in call to Lua API (%s)\n",
 642                    lua_tostring(L, -1));
 643   return 0;
 644 }
 645
 646
 647 LUALIB_API lua_State *luaL_newstate (void) {
 648   lua_State *L = lua_newstate(l_alloc, NULL);
 649   if (L) lua_atpanic(L, &panic);
 650   return L;
 651 }
 652