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
16 /* This file uses only the official API of Lua.
17 ** Any function declared here could be written as an application function.
28 #define FREELIST_REF 0 /* free list of references */
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)
37 ** {======================================================
38 ** Error-report functions
39 ** =======================================================
43 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {
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)",
56 return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)",
57 narg, ar.name, extramsg);
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);
68 static void tag_error (lua_State *L, int narg, int tag) {
69 luaL_typerror(L, narg, lua_typename(L, tag));
73 LUALIB_API void luaL_where (lua_State *L, int level) {
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);
82 lua_pushliteral(L, ""); /* else, no information available... */
86 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
90 lua_pushvfstring(L, fmt, argp);
96 /* }====================================================== */
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);
104 for (i=0; lst[i]; i++)
105 if (strcmp(lst[i], name) == 0)
107 return luaL_argerror(L, narg,
108 lua_pushfstring(L, "invalid option " LUA_QS, name));
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 */
117 lua_newtable(L); /* create metatable */
118 lua_pushvalue(L, -1);
119 lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */
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 */
135 luaL_typerror(L, ud, tname); /* else error */
136 return NULL; /* to avoid warnings */
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);
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);
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");
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);
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)) {
169 *len = (def ? strlen(def) : 0);
172 else return luaL_checklstring(L, narg, len);
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);
184 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {
185 return luaL_opt(L, luaL_checknumber, narg, def);
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);
197 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,
199 return luaL_opt(L, luaL_checkinteger, narg, def);
203 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
204 if (!lua_getmetatable(L, obj)) /* no metatable? */
206 lua_pushstring(L, event);
208 if (lua_isnil(L, -1)) {
209 lua_pop(L, 2); /* remove metatable and metafield */
213 lua_remove(L, -2); /* remove only metatable */
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? */
223 lua_pushvalue(L, obj);
229 LUALIB_API void (luaL_register) (lua_State *L, const char *libname,
231 luaI_openlib(L, libname, l, 0);
235 static int libsize (const luaL_Reg *l) {
237 for (; l->name; l++) size++;
242 LUALIB_API void luaI_openlib (lua_State *L, const char *libname,
243 const luaL_Reg *l, int nup) {
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 */
257 lua_remove(L, -2); /* remove _LOADED table */
258 lua_insert(L, -(nup+1)); /* move library table to below upvalues */
260 for (; l->name; l++) {
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);
267 lua_pop(L, nup); /* remove upvalues */
273 ** {======================================================
274 ** getn-setn: size for arrays
275 ** =======================================================
278 #if defined(LUA_COMPAT_GETN)
280 static int checkint (lua_State *L, int topop) {
281 int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;
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 */
302 LUALIB_API void luaL_setn (lua_State *L, int t, int n) {
304 lua_pushliteral(L, "n");
306 if (checkint(L, 1) >= 0) { /* is there a numeric field `n'? */
307 lua_pushliteral(L, "n"); /* use it */
308 lua_pushinteger(L, n);
311 else { /* use `sizes' */
314 lua_pushinteger(L, n);
315 lua_rawset(L, -3); /* sizes[t] = n */
316 lua_pop(L, 1); /* remove `sizes' */
321 LUALIB_API int luaL_getn (lua_State *L, int t) {
324 lua_pushliteral(L, "n"); /* try t.n */
326 if ((n = checkint(L, 1)) >= 0) return n;
327 getsizes(L); /* else try sizes[t] */
330 if ((n = checkint(L, 2)) >= 0) return n;
331 return (int)lua_objlen(L, t);
336 /* }====================================================== */
340 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
343 size_t l = strlen(p);
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' */
351 luaL_addstring(&b, s); /* push last suffix */
353 return lua_tostring(L, -1);
357 LUALIB_API const char *luaL_findtable (lua_State *L, int idx,
358 const char *fname, int szhint) {
360 lua_pushvalue(L, idx);
362 e = strchr(fname, '.');
363 if (e == NULL) e = fname + strlen(fname);
364 lua_pushlstring(L, fname, e - fname);
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 */
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 */
377 lua_remove(L, -2); /* remove previous table */
386 ** {======================================================
387 ** Generic Buffer manipulation
388 ** =======================================================
392 #define bufflen(B) ((B)->p - (B)->buffer)
393 #define bufffree(B) ((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
395 #define LIMIT (LUA_MINSTACK/2)
398 static int emptybuffer (luaL_Buffer *B) {
399 size_t l = bufflen(B);
400 if (l == 0) return 0; /* put nothing on stack */
402 lua_pushlstring(B->L, B->buffer, l);
410 static void adjuststack (luaL_Buffer *B) {
413 int toget = 1; /* number of levels to concat */
414 size_t toplen = lua_strlen(L, -1);
416 size_t l = lua_strlen(L, -(toget+1));
417 if (B->lvl - toget + 1 >= LIMIT || toplen > l) {
422 } while (toget < B->lvl);
423 lua_concat(L, toget);
424 B->lvl = B->lvl - toget + 1;
429 LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
436 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
438 luaL_addchar(B, *s++);
442 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
443 luaL_addlstring(B, s, strlen(s));
447 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
449 lua_concat(B->L, B->lvl);
454 LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
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 */
461 lua_pop(L, 1); /* remove from stack */
465 lua_insert(L, -2); /* put buffer before new value */
466 B->lvl++; /* add new value into B stack */
472 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
478 /* }====================================================== */
481 LUALIB_API int luaL_ref (lua_State *L, int 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 */
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]) */
495 else { /* no free elements */
496 ref = (int)lua_objlen(L, t);
497 ref++; /* create new reference */
499 lua_rawseti(L, t, ref);
504 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
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 */
517 ** {======================================================
519 ** =======================================================
522 typedef struct LoadF {
525 char buff[LUAL_BUFFERSIZE];
529 static const char *getF (lua_State *L, void *ud, size_t *size) {
530 LoadF *lf = (LoadF *)ud;
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;
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);
552 LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
554 int status, readstatus;
556 int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */
558 if (filename == NULL) {
559 lua_pushliteral(L, "=stdin");
563 lua_pushfstring(L, "@%s", filename);
564 lf.f = fopen(filename, "r");
565 if (lf.f == NULL) return errfile(L, "open", fnameindex);
568 if (c == '#') { /* Unix exec. file? */
570 while ((c = getc(lf.f)) != EOF && c != '\n') ; /* skip first line */
571 if (c == '\n') c = getc(lf.f);
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]) ;
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) */
585 lua_settop(L, fnameindex); /* ignore results from `lua_load' */
586 return errfile(L, "read", fnameindex);
588 lua_remove(L, fnameindex);
593 typedef struct LoadS {
599 static const char *getS (lua_State *L, void *ud, size_t *size) {
600 LoadS *ls = (LoadS *)ud;
602 if (ls->size == 0) return NULL;
609 LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,
614 return lua_load(L, getS, &ls, name);
618 LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {
619 return luaL_loadbuffer(L, s, strlen(s), s);
624 /* }====================================================== */
627 static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
635 return realloc(ptr, nsize);
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));
647 LUALIB_API lua_State *luaL_newstate (void) {
648 lua_State *L = lua_newstate(l_alloc, NULL);
649 if (L) lua_atpanic(L, &panic);