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Root/lua/lauxlib.cc

1/*
2** $Id: lauxlib.c,v 1.159 2006/03/21 19:31:09 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_REF0/* 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) : \
33lua_gettop(L) + (i) + 1)
34
35
36/*
37** {======================================================
38** Error-report functions
39** =======================================================
40*/
41
42
43LUALIB_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
61LUALIB_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
68static void tag_error (lua_State *L, int narg, int tag) {
69 luaL_typerror(L, narg, lua_typename(L, tag));
70}
71
72
73LUALIB_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
86LUALIB_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
99LUALIB_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
112LUALIB_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
124LUALIB_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
140LUALIB_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
146LUALIB_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
152LUALIB_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
158LUALIB_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
165LUALIB_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
176LUALIB_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
184LUALIB_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
189LUALIB_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
197LUALIB_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
203LUALIB_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
219LUALIB_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
229LUALIB_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
235static int libsize (const luaL_Reg *l) {
236 int size = 0;
237 for (; l->name; l++) size++;
238 return size;
239}
240
241
242LUALIB_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", size);
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
280static 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
287static 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
302LUALIB_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
321LUALIB_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
340LUALIB_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
357LUALIB_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
398static 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
410static 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
429LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
430 if (emptybuffer(B))
431 adjuststack(B);
432 return B->buffer;
433}
434
435
436LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
437 while (l--)
438 luaL_addchar(B, *s++);
439}
440
441
442LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
443 luaL_addlstring(B, s, strlen(s));
444}
445
446
447LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
448 emptybuffer(B);
449 lua_concat(B->L, B->lvl);
450 B->lvl = 1;
451}
452
453
454LUALIB_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
472LUALIB_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
481LUALIB_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
504LUALIB_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
522typedef struct LoadF {
523 int extraline;
524 FILE *f;
525 char buff[LUAL_BUFFERSIZE];
526} LoadF;
527
528
529static 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, LUAL_BUFFERSIZE, lf->f);
539 return (*size > 0) ? lf->buff : NULL;
540}
541
542
543static 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
552LUALIB_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] && lf.f != stdin) { /* binary file? */
574 fclose(lf.f);
575 lf.f = fopen(filename, "rb"); /* reopen in binary mode */
576 if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
577 /* skip eventual `#!...' */
578 while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;
579 lf.extraline = 0;
580 }
581 ungetc(c, lf.f);
582 status = lua_load(L, getF, &lf, lua_tostring(L, -1));
583 readstatus = ferror(lf.f);
584 if (lf.f != stdin) fclose(lf.f); /* close file (even in case of errors) */
585 if (readstatus) {
586 lua_settop(L, fnameindex); /* ignore results from `lua_load' */
587 return errfile(L, "read", fnameindex);
588 }
589 lua_remove(L, fnameindex);
590 return status;
591}
592
593
594typedef struct LoadS {
595 const char *s;
596 size_t size;
597} LoadS;
598
599
600static const char *getS (lua_State *L, void *ud, size_t *size) {
601 LoadS *ls = (LoadS *)ud;
602 (void)L;
603 if (ls->size == 0) return NULL;
604 *size = ls->size;
605 ls->size = 0;
606 return ls->s;
607}
608
609
610LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,
611 const char *name) {
612 LoadS ls;
613 ls.s = buff;
614 ls.size = size;
615 return lua_load(L, getS, &ls, name);
616}
617
618
619LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {
620 return luaL_loadbuffer(L, s, strlen(s), s);
621}
622
623
624
625/* }====================================================== */
626
627
628static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
629 (void)ud;
630 (void)osize;
631 if (nsize == 0) {
632 free(ptr);
633 return NULL;
634 }
635 else
636 return realloc(ptr, nsize);
637}
638
639
640static int panic (lua_State *L) {
641 (void)L; /* to avoid warnings */
642 fprintf(stderr, "PANIC: unprotected error in call to Lua API (%s)\n",
643 lua_tostring(L, -1));
644 return 0;
645}
646
647
648LUALIB_API lua_State *luaL_newstate (void) {
649 lua_State *L = lua_newstate(l_alloc, NULL);
650 if (L) lua_atpanic(L, &panic);
651 return L;
652}
653

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