apps/plugins/lua/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_checkboolean (lua_State *L, int narg) {
 204   int b = lua_toboolean(L, narg);
 205   if( b == 0 && !lua_isboolean(L, narg))
 206     tag_error(L, narg, LUA_TBOOLEAN);
 207   return b;
 208 }
 209
 210
 211 LUALIB_API int luaL_optboolean (lua_State *L, int narg, int def) {
 212   return luaL_opt(L, luaL_checkboolean, narg, def);
 213 }
 214
 215
 216 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
 217   if (!lua_getmetatable(L, obj))  /* no metatable? */
 218     return 0;
 219   lua_pushstring(L, event);
 220   lua_rawget(L, -2);
 221   if (lua_isnil(L, -1)) {
 222     lua_pop(L, 2);  /* remove metatable and metafield */
 223     return 0;
 224   }
 225   else {
 226     lua_remove(L, -2);  /* remove only metatable */
 227     return 1;
 228   }
 229 }
 230
 231
 232 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
 233   obj = abs_index(L, obj);
 234   if (!luaL_getmetafield(L, obj, event))  /* no metafield? */
 235     return 0;
 236   lua_pushvalue(L, obj);
 237   lua_call(L, 1, 1);
 238   return 1;
 239 }
 240
 241
 242 LUALIB_API void (luaL_register) (lua_State *L, const char *libname,
 243                                 const luaL_Reg *l) {
 244   luaI_openlib(L, libname, l, 0);
 245 }
 246
 247
 248 static int libsize (const luaL_Reg *l) {
 249   int size = 0;
 250   for (; l->name; l++) size++;
 251   return size;
 252 }
 253
 254
 255 LUALIB_API void luaI_openlib (lua_State *L, const char *libname,
 256                               const luaL_Reg *l, int nup) {
 257   if (libname) {
 258     int size = libsize(l);
 259     /* check whether lib already exists */
 260     luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);
 261     lua_getfield(L, -1, libname);  /* get _LOADED[libname] */
 262     if (!lua_istable(L, -1)) {  /* not found? */
 263       lua_pop(L, 1);  /* remove previous result */
 264       /* try global variable (and create one if it does not exist) */
 265       if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
 266         luaL_error(L, "name conflict for module " LUA_QS, libname);
 267       lua_pushvalue(L, -1);
 268       lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */
 269     }
 270     lua_remove(L, -2);  /* remove _LOADED table */
 271     lua_insert(L, -(nup+1));  /* move library table to below upvalues */
 272   }
 273   for (; l->name; l++) {
 274     int i;
 275     for (i=0; i<nup; i++)  /* copy upvalues to the top */
 276       lua_pushvalue(L, -nup);
 277     lua_pushcclosure(L, l->func, nup);
 278     lua_setfield(L, -(nup+2), l->name);
 279   }
 280   lua_pop(L, nup);  /* remove upvalues */
 281 }
 282
 283
 284
 285 /*
 286 ** {======================================================
 287 ** getn-setn: size for arrays
 288 ** =======================================================
 289 */
 290
 291 #if defined(LUA_COMPAT_GETN)
 292
 293 static int checkint (lua_State *L, int topop) {
 294   int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;
 295   lua_pop(L, topop);
 296   return n;
 297 }
 298
 299
 300 static void getsizes (lua_State *L) {
 301   lua_getfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");
 302   if (lua_isnil(L, -1)) {  /* no `size' table? */
 303     lua_pop(L, 1);  /* remove nil */
 304     lua_newtable(L);  /* create it */
 305     lua_pushvalue(L, -1);  /* `size' will be its own metatable */
 306     lua_setmetatable(L, -2);
 307     lua_pushliteral(L, "kv");
 308     lua_setfield(L, -2, "__mode");  /* metatable(N).__mode = "kv" */
 309     lua_pushvalue(L, -1);
 310     lua_setfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  /* store in register */
 311   }
 312 }
 313
 314
 315 LUALIB_API void luaL_setn (lua_State *L, int t, int n) {
 316   t = abs_index(L, t);
 317   lua_pushliteral(L, "n");
 318   lua_rawget(L, t);
 319   if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */
 320     lua_pushliteral(L, "n");  /* use it */
 321     lua_pushinteger(L, n);
 322     lua_rawset(L, t);
 323   }
 324   else {  /* use `sizes' */
 325     getsizes(L);
 326     lua_pushvalue(L, t);
 327     lua_pushinteger(L, n);
 328     lua_rawset(L, -3);  /* sizes[t] = n */
 329     lua_pop(L, 1);  /* remove `sizes' */
 330   }
 331 }
 332
 333
 334 LUALIB_API int luaL_getn (lua_State *L, int t) {
 335   int n;
 336   t = abs_index(L, t);
 337   lua_pushliteral(L, "n");  /* try t.n */
 338   lua_rawget(L, t);
 339   if ((n = checkint(L, 1)) >= 0) return n;
 340   getsizes(L);  /* else try sizes[t] */
 341   lua_pushvalue(L, t);
 342   lua_rawget(L, -2);
 343   if ((n = checkint(L, 2)) >= 0) return n;
 344   return (int)lua_objlen(L, t);
 345 }
 346
 347 #endif
 348
 349 /* }====================================================== */
 350
 351
 352
 353 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
 354                                                                const char *r) {
 355   const char *wild;
 356   size_t l = strlen(p);
 357   luaL_Buffer b;
 358   luaL_buffinit(L, &b);
 359   while ((wild = strstr(s, p)) != NULL) {
 360     luaL_addlstring(&b, s, wild - s);  /* push prefix */
 361     luaL_addstring(&b, r);  /* push replacement in place of pattern */
 362     s = wild + l;  /* continue after `p' */
 363   }
 364   luaL_addstring(&b, s);  /* push last suffix */
 365   luaL_pushresult(&b);
 366   return lua_tostring(L, -1);
 367 }
 368
 369
 370 LUALIB_API const char *luaL_findtable (lua_State *L, int idx,
 371                                        const char *fname, int szhint) {
 372   const char *e;
 373   lua_pushvalue(L, idx);
 374   do {
 375     e = strchr(fname, '.');
 376     if (e == NULL) e = fname + strlen(fname);
 377     lua_pushlstring(L, fname, e - fname);
 378     lua_rawget(L, -2);
 379     if (lua_isnil(L, -1)) {  /* no such field? */
 380       lua_pop(L, 1);  /* remove this nil */
 381       lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
 382       lua_pushlstring(L, fname, e - fname);
 383       lua_pushvalue(L, -2);
 384       lua_settable(L, -4);  /* set new table into field */
 385     }
 386     else if (!lua_istable(L, -1)) {  /* field has a non-table value? */
 387       lua_pop(L, 2);  /* remove table and value */
 388       return fname;  /* return problematic part of the name */
 389     }
 390     lua_remove(L, -2);  /* remove previous table */
 391     fname = e + 1;
 392   } while (*e == '.');
 393   return NULL;
 394 }
 395
 396
 397
 398 /*
 399 ** {======================================================
 400 ** Generic Buffer manipulation
 401 ** =======================================================
 402 */
 403
 404
 405 #define bufflen(B)      ((B)->p - (B)->buffer)
 406 #define bufffree(B)     ((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
 407
 408 #define LIMIT   (LUA_MINSTACK/2)
 409
 410
 411 static int emptybuffer (luaL_Buffer *B) {
 412   size_t l = bufflen(B);
 413   if (l == 0) return 0;  /* put nothing on stack */
 414   else {
 415     lua_pushlstring(B->L, B->buffer, l);
 416     B->p = B->buffer;
 417     B->lvl++;
 418     return 1;
 419   }
 420 }
 421
 422
 423 static void adjuststack (luaL_Buffer *B) {
 424   if (B->lvl > 1) {
 425     lua_State *L = B->L;
 426     int toget = 1;  /* number of levels to concat */
 427     size_t toplen = lua_strlen(L, -1);
 428     do {
 429       size_t l = lua_strlen(L, -(toget+1));
 430       if (B->lvl - toget + 1 >= LIMIT || toplen > l) {
 431         toplen += l;
 432         toget++;
 433       }
 434       else break;
 435     } while (toget < B->lvl);
 436     lua_concat(L, toget);
 437     B->lvl = B->lvl - toget + 1;
 438   }
 439 }
 440
 441
 442 LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
 443   if (emptybuffer(B))
 444     adjuststack(B);
 445   return B->buffer;
 446 }
 447
 448
 449 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
 450   while (l--)
 451     luaL_addchar(B, *s++);
 452 }
 453
 454
 455 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
 456   luaL_addlstring(B, s, strlen(s));
 457 }
 458
 459
 460 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
 461   emptybuffer(B);
 462   lua_concat(B->L, B->lvl);
 463   B->lvl = 1;
 464 }
 465
 466
 467 LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
 468   lua_State *L = B->L;
 469   size_t vl;
 470   const char *s = lua_tolstring(L, -1, &vl);
 471   if (vl <= bufffree(B)) {  /* fit into buffer? */
 472     memcpy(B->p, s, vl);  /* put it there */
 473     B->p += vl;
 474     lua_pop(L, 1);  /* remove from stack */
 475   }
 476   else {
 477     if (emptybuffer(B))
 478       lua_insert(L, -2);  /* put buffer before new value */
 479     B->lvl++;  /* add new value into B stack */
 480     adjuststack(B);
 481   }
 482 }
 483
 484
 485 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
 486   B->L = L;
 487   B->p = B->buffer;
 488   B->lvl = 0;
 489 }
 490
 491 /* }====================================================== */
 492
 493
 494 LUALIB_API int luaL_ref (lua_State *L, int t) {
 495   int ref;
 496   t = abs_index(L, t);
 497   if (lua_isnil(L, -1)) {
 498     lua_pop(L, 1);  /* remove from stack */
 499     return LUA_REFNIL;  /* `nil' has a unique fixed reference */
 500   }
 501   lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */
 502   ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */
 503   lua_pop(L, 1);  /* remove it from stack */
 504   if (ref != 0) {  /* any free element? */
 505     lua_rawgeti(L, t, ref);  /* remove it from list */
 506     lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */
 507   }
 508   else {  /* no free elements */
 509     ref = (int)lua_objlen(L, t);
 510     ref++;  /* create new reference */
 511   }
 512   lua_rawseti(L, t, ref);
 513   return ref;
 514 }
 515
 516
 517 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
 518   if (ref >= 0) {
 519     t = abs_index(L, t);
 520     lua_rawgeti(L, t, FREELIST_REF);
 521     lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */
 522     lua_pushinteger(L, ref);
 523     lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */
 524   }
 525 }
 526
 527
 528
 529 /*
 530 ** {======================================================
 531 ** Load functions
 532 ** =======================================================
 533 */
 534
 535 typedef struct LoadF {
 536   int extraline;
 537   int f;
 538   char buff[LUAL_BUFFERSIZE];
 539 } LoadF;
 540
 541 static const char *getF(lua_State *L, void *ud, size_t *size) {
 542   LoadF *lf = (LoadF *)ud;
 543   (void)L;
 544   if (lf->extraline) {
 545     lf->extraline = 0;
 546     *size = 1;
 547     return "\n";
 548   }
 549   *size = rb->read(lf->f, lf->buff, LUAL_BUFFERSIZE);
 550   if (*size <= 0) return NULL;
 551   return (*size > 0) ? lf->buff : NULL;
 552 }
 553
 554
 555 static int errfile (lua_State *L, const char *what, int fnameindex) {
 556   const char *serr = strerror(errno);
 557   const char *filename = lua_tostring(L, fnameindex) + 1;
 558   lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
 559   lua_remove(L, fnameindex);
 560   return LUA_ERRFILE;
 561 }
 562
 563 LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
 564   LoadF lf;
 565   int status;
 566   int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */
 567   lf.extraline = 0;
 568   lf.f = rb->open(filename, O_RDONLY);
 569   lua_pushfstring(L, "@%s", filename);
 570   if (lf.f < 0) return errfile(L, "open", fnameindex);
 571   status = lua_load(L, getF, &lf, lua_tostring(L, -1));
 572   rb->close(lf.f);
 573   lua_remove(L, fnameindex);
 574   return status;
 575 }
 576
 577
 578 typedef struct LoadS {
 579   const char *s;
 580   size_t size;
 581 } LoadS;
 582
 583
 584 static const char *getS (lua_State *L, void *ud, size_t *size) {
 585   LoadS *ls = (LoadS *)ud;
 586   (void)L;
 587   if (ls->size == 0) return NULL;
 588   *size = ls->size;
 589   ls->size = 0;
 590   return ls->s;
 591 }
 592
 593
 594 LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,
 595                                 const char *name) {
 596   LoadS ls;
 597   ls.s = buff;
 598   ls.size = size;
 599   return lua_load(L, getS, &ls, name);
 600 }
 601
 602
 603 LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {
 604   return luaL_loadbuffer(L, s, strlen(s), s);
 605 }
 606
 607
 608
 609 /* }====================================================== */
 610
 611
 612 static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
 613   (void)ud;
 614   (void)osize;
 615   if (nsize == 0) {
 616     free(ptr);
 617     return NULL;
 618   }
 619   else
 620     return realloc(ptr, nsize);
 621 }
 622
 623
 624 static int panic (lua_State *L) {
 625     DEBUGF("PANIC: unprotected error in call to Lua API (%s)\n",
 626         lua_tostring(L, -1));
 627     rb->splashf(5 * HZ, "PANIC: unprotected error in call to Lua API (%s)",
 628         lua_tostring(L, -1));
 629
 630     return 0;
 631 }
 632
 633
 634 LUALIB_API lua_State *luaL_newstate (void) {
 635   lua_State *L = lua_newstate(l_alloc, NULL);
 636   if (L) lua_atpanic(L, &panic);
 637   return L;
 638 }
 639