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comparison lib/lua/lua-5.2.2/lauxlib.c @ 1866:41cc4dd3c122

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Lua 5.2.2 added.
author Nomad
date Wed, 16 Oct 2013 13:34:26 +0200
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1848:3b39b70e8e93 1866:41cc4dd3c122
1 /*
2 ** $Id: lauxlib.c,v 1.248 2013/03/21 13:54:57 roberto Exp $
3 ** Auxiliary functions for building Lua libraries
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #include <errno.h>
9 #include <stdarg.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13
14
15 /* This file uses only the official API of Lua.
16 ** Any function declared here could be written as an application function.
17 */
18
19 #define lauxlib_c
20 #define LUA_LIB
21
22 #include "lua.h"
23
24 #include "lauxlib.h"
25
26
27 /*
28 ** {======================================================
29 ** Traceback
30 ** =======================================================
31 */
32
33
34 #define LEVELS1 12 /* size of the first part of the stack */
35 #define LEVELS2 10 /* size of the second part of the stack */
36
37
38
39 /*
40 ** search for 'objidx' in table at index -1.
41 ** return 1 + string at top if find a good name.
42 */
43 static int findfield (lua_State *L, int objidx, int level) {
44 if (level == 0 || !lua_istable(L, -1))
45 return 0; /* not found */
46 lua_pushnil(L); /* start 'next' loop */
47 while (lua_next(L, -2)) { /* for each pair in table */
48 if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */
49 if (lua_rawequal(L, objidx, -1)) { /* found object? */
50 lua_pop(L, 1); /* remove value (but keep name) */
51 return 1;
52 }
53 else if (findfield(L, objidx, level - 1)) { /* try recursively */
54 lua_remove(L, -2); /* remove table (but keep name) */
55 lua_pushliteral(L, ".");
56 lua_insert(L, -2); /* place '.' between the two names */
57 lua_concat(L, 3);
58 return 1;
59 }
60 }
61 lua_pop(L, 1); /* remove value */
62 }
63 return 0; /* not found */
64 }
65
66
67 static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
68 int top = lua_gettop(L);
69 lua_getinfo(L, "f", ar); /* push function */
70 lua_pushglobaltable(L);
71 if (findfield(L, top + 1, 2)) {
72 lua_copy(L, -1, top + 1); /* move name to proper place */
73 lua_pop(L, 2); /* remove pushed values */
74 return 1;
75 }
76 else {
77 lua_settop(L, top); /* remove function and global table */
78 return 0;
79 }
80 }
81
82
83 static void pushfuncname (lua_State *L, lua_Debug *ar) {
84 if (*ar->namewhat != '\0') /* is there a name? */
85 lua_pushfstring(L, "function " LUA_QS, ar->name);
86 else if (*ar->what == 'm') /* main? */
87 lua_pushliteral(L, "main chunk");
88 else if (*ar->what == 'C') {
89 if (pushglobalfuncname(L, ar)) {
90 lua_pushfstring(L, "function " LUA_QS, lua_tostring(L, -1));
91 lua_remove(L, -2); /* remove name */
92 }
93 else
94 lua_pushliteral(L, "?");
95 }
96 else
97 lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
98 }
99
100
101 static int countlevels (lua_State *L) {
102 lua_Debug ar;
103 int li = 1, le = 1;
104 /* find an upper bound */
105 while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }
106 /* do a binary search */
107 while (li < le) {
108 int m = (li + le)/2;
109 if (lua_getstack(L, m, &ar)) li = m + 1;
110 else le = m;
111 }
112 return le - 1;
113 }
114
115
116 LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
117 const char *msg, int level) {
118 lua_Debug ar;
119 int top = lua_gettop(L);
120 int numlevels = countlevels(L1);
121 int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0;
122 if (msg) lua_pushfstring(L, "%s\n", msg);
123 lua_pushliteral(L, "stack traceback:");
124 while (lua_getstack(L1, level++, &ar)) {
125 if (level == mark) { /* too many levels? */
126 lua_pushliteral(L, "\n\t..."); /* add a '...' */
127 level = numlevels - LEVELS2; /* and skip to last ones */
128 }
129 else {
130 lua_getinfo(L1, "Slnt", &ar);
131 lua_pushfstring(L, "\n\t%s:", ar.short_src);
132 if (ar.currentline > 0)
133 lua_pushfstring(L, "%d:", ar.currentline);
134 lua_pushliteral(L, " in ");
135 pushfuncname(L, &ar);
136 if (ar.istailcall)
137 lua_pushliteral(L, "\n\t(...tail calls...)");
138 lua_concat(L, lua_gettop(L) - top);
139 }
140 }
141 lua_concat(L, lua_gettop(L) - top);
142 }
143
144 /* }====================================================== */
145
146
147 /*
148 ** {======================================================
149 ** Error-report functions
150 ** =======================================================
151 */
152
153 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {
154 lua_Debug ar;
155 if (!lua_getstack(L, 0, &ar)) /* no stack frame? */
156 return luaL_error(L, "bad argument #%d (%s)", narg, extramsg);
157 lua_getinfo(L, "n", &ar);
158 if (strcmp(ar.namewhat, "method") == 0) {
159 narg--; /* do not count `self' */
160 if (narg == 0) /* error is in the self argument itself? */
161 return luaL_error(L, "calling " LUA_QS " on bad self (%s)",
162 ar.name, extramsg);
163 }
164 if (ar.name == NULL)
165 ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?";
166 return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)",
167 narg, ar.name, extramsg);
168 }
169
170
171 static int typeerror (lua_State *L, int narg, const char *tname) {
172 const char *msg = lua_pushfstring(L, "%s expected, got %s",
173 tname, luaL_typename(L, narg));
174 return luaL_argerror(L, narg, msg);
175 }
176
177
178 static void tag_error (lua_State *L, int narg, int tag) {
179 typeerror(L, narg, lua_typename(L, tag));
180 }
181
182
183 LUALIB_API void luaL_where (lua_State *L, int level) {
184 lua_Debug ar;
185 if (lua_getstack(L, level, &ar)) { /* check function at level */
186 lua_getinfo(L, "Sl", &ar); /* get info about it */
187 if (ar.currentline > 0) { /* is there info? */
188 lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
189 return;
190 }
191 }
192 lua_pushliteral(L, ""); /* else, no information available... */
193 }
194
195
196 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
197 va_list argp;
198 va_start(argp, fmt);
199 luaL_where(L, 1);
200 lua_pushvfstring(L, fmt, argp);
201 va_end(argp);
202 lua_concat(L, 2);
203 return lua_error(L);
204 }
205
206
207 LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
208 int en = errno; /* calls to Lua API may change this value */
209 if (stat) {
210 lua_pushboolean(L, 1);
211 return 1;
212 }
213 else {
214 lua_pushnil(L);
215 if (fname)
216 lua_pushfstring(L, "%s: %s", fname, strerror(en));
217 else
218 lua_pushstring(L, strerror(en));
219 lua_pushinteger(L, en);
220 return 3;
221 }
222 }
223
224
225 #if !defined(inspectstat) /* { */
226
227 #if defined(LUA_USE_POSIX)
228
229 #include <sys/wait.h>
230
231 /*
232 ** use appropriate macros to interpret 'pclose' return status
233 */
234 #define inspectstat(stat,what) \
235 if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \
236 else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }
237
238 #else
239
240 #define inspectstat(stat,what) /* no op */
241
242 #endif
243
244 #endif /* } */
245
246
247 LUALIB_API int luaL_execresult (lua_State *L, int stat) {
248 const char *what = "exit"; /* type of termination */
249 if (stat == -1) /* error? */
250 return luaL_fileresult(L, 0, NULL);
251 else {
252 inspectstat(stat, what); /* interpret result */
253 if (*what == 'e' && stat == 0) /* successful termination? */
254 lua_pushboolean(L, 1);
255 else
256 lua_pushnil(L);
257 lua_pushstring(L, what);
258 lua_pushinteger(L, stat);
259 return 3; /* return true/nil,what,code */
260 }
261 }
262
263 /* }====================================================== */
264
265
266 /*
267 ** {======================================================
268 ** Userdata's metatable manipulation
269 ** =======================================================
270 */
271
272 LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
273 luaL_getmetatable(L, tname); /* try to get metatable */
274 if (!lua_isnil(L, -1)) /* name already in use? */
275 return 0; /* leave previous value on top, but return 0 */
276 lua_pop(L, 1);
277 lua_newtable(L); /* create metatable */
278 lua_pushvalue(L, -1);
279 lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */
280 return 1;
281 }
282
283
284 LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) {
285 luaL_getmetatable(L, tname);
286 lua_setmetatable(L, -2);
287 }
288
289
290 LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) {
291 void *p = lua_touserdata(L, ud);
292 if (p != NULL) { /* value is a userdata? */
293 if (lua_getmetatable(L, ud)) { /* does it have a metatable? */
294 luaL_getmetatable(L, tname); /* get correct metatable */
295 if (!lua_rawequal(L, -1, -2)) /* not the same? */
296 p = NULL; /* value is a userdata with wrong metatable */
297 lua_pop(L, 2); /* remove both metatables */
298 return p;
299 }
300 }
301 return NULL; /* value is not a userdata with a metatable */
302 }
303
304
305 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
306 void *p = luaL_testudata(L, ud, tname);
307 if (p == NULL) typeerror(L, ud, tname);
308 return p;
309 }
310
311 /* }====================================================== */
312
313
314 /*
315 ** {======================================================
316 ** Argument check functions
317 ** =======================================================
318 */
319
320 LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def,
321 const char *const lst[]) {
322 const char *name = (def) ? luaL_optstring(L, narg, def) :
323 luaL_checkstring(L, narg);
324 int i;
325 for (i=0; lst[i]; i++)
326 if (strcmp(lst[i], name) == 0)
327 return i;
328 return luaL_argerror(L, narg,
329 lua_pushfstring(L, "invalid option " LUA_QS, name));
330 }
331
332
333 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
334 /* keep some extra space to run error routines, if needed */
335 const int extra = LUA_MINSTACK;
336 if (!lua_checkstack(L, space + extra)) {
337 if (msg)
338 luaL_error(L, "stack overflow (%s)", msg);
339 else
340 luaL_error(L, "stack overflow");
341 }
342 }
343
344
345 LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) {
346 if (lua_type(L, narg) != t)
347 tag_error(L, narg, t);
348 }
349
350
351 LUALIB_API void luaL_checkany (lua_State *L, int narg) {
352 if (lua_type(L, narg) == LUA_TNONE)
353 luaL_argerror(L, narg, "value expected");
354 }
355
356
357 LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) {
358 const char *s = lua_tolstring(L, narg, len);
359 if (!s) tag_error(L, narg, LUA_TSTRING);
360 return s;
361 }
362
363
364 LUALIB_API const char *luaL_optlstring (lua_State *L, int narg,
365 const char *def, size_t *len) {
366 if (lua_isnoneornil(L, narg)) {
367 if (len)
368 *len = (def ? strlen(def) : 0);
369 return def;
370 }
371 else return luaL_checklstring(L, narg, len);
372 }
373
374
375 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) {
376 int isnum;
377 lua_Number d = lua_tonumberx(L, narg, &isnum);
378 if (!isnum)
379 tag_error(L, narg, LUA_TNUMBER);
380 return d;
381 }
382
383
384 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {
385 return luaL_opt(L, luaL_checknumber, narg, def);
386 }
387
388
389 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) {
390 int isnum;
391 lua_Integer d = lua_tointegerx(L, narg, &isnum);
392 if (!isnum)
393 tag_error(L, narg, LUA_TNUMBER);
394 return d;
395 }
396
397
398 LUALIB_API lua_Unsigned luaL_checkunsigned (lua_State *L, int narg) {
399 int isnum;
400 lua_Unsigned d = lua_tounsignedx(L, narg, &isnum);
401 if (!isnum)
402 tag_error(L, narg, LUA_TNUMBER);
403 return d;
404 }
405
406
407 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,
408 lua_Integer def) {
409 return luaL_opt(L, luaL_checkinteger, narg, def);
410 }
411
412
413 LUALIB_API lua_Unsigned luaL_optunsigned (lua_State *L, int narg,
414 lua_Unsigned def) {
415 return luaL_opt(L, luaL_checkunsigned, narg, def);
416 }
417
418 /* }====================================================== */
419
420
421 /*
422 ** {======================================================
423 ** Generic Buffer manipulation
424 ** =======================================================
425 */
426
427 /*
428 ** check whether buffer is using a userdata on the stack as a temporary
429 ** buffer
430 */
431 #define buffonstack(B) ((B)->b != (B)->initb)
432
433
434 /*
435 ** returns a pointer to a free area with at least 'sz' bytes
436 */
437 LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
438 lua_State *L = B->L;
439 if (B->size - B->n < sz) { /* not enough space? */
440 char *newbuff;
441 size_t newsize = B->size * 2; /* double buffer size */
442 if (newsize - B->n < sz) /* not big enough? */
443 newsize = B->n + sz;
444 if (newsize < B->n || newsize - B->n < sz)
445 luaL_error(L, "buffer too large");
446 /* create larger buffer */
447 newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char));
448 /* move content to new buffer */
449 memcpy(newbuff, B->b, B->n * sizeof(char));
450 if (buffonstack(B))
451 lua_remove(L, -2); /* remove old buffer */
452 B->b = newbuff;
453 B->size = newsize;
454 }
455 return &B->b[B->n];
456 }
457
458
459 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
460 char *b = luaL_prepbuffsize(B, l);
461 memcpy(b, s, l * sizeof(char));
462 luaL_addsize(B, l);
463 }
464
465
466 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
467 luaL_addlstring(B, s, strlen(s));
468 }
469
470
471 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
472 lua_State *L = B->L;
473 lua_pushlstring(L, B->b, B->n);
474 if (buffonstack(B))
475 lua_remove(L, -2); /* remove old buffer */
476 }
477
478
479 LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
480 luaL_addsize(B, sz);
481 luaL_pushresult(B);
482 }
483
484
485 LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
486 lua_State *L = B->L;
487 size_t l;
488 const char *s = lua_tolstring(L, -1, &l);
489 if (buffonstack(B))
490 lua_insert(L, -2); /* put value below buffer */
491 luaL_addlstring(B, s, l);
492 lua_remove(L, (buffonstack(B)) ? -2 : -1); /* remove value */
493 }
494
495
496 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
497 B->L = L;
498 B->b = B->initb;
499 B->n = 0;
500 B->size = LUAL_BUFFERSIZE;
501 }
502
503
504 LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
505 luaL_buffinit(L, B);
506 return luaL_prepbuffsize(B, sz);
507 }
508
509 /* }====================================================== */
510
511
512 /*
513 ** {======================================================
514 ** Reference system
515 ** =======================================================
516 */
517
518 /* index of free-list header */
519 #define freelist 0
520
521
522 LUALIB_API int luaL_ref (lua_State *L, int t) {
523 int ref;
524 if (lua_isnil(L, -1)) {
525 lua_pop(L, 1); /* remove from stack */
526 return LUA_REFNIL; /* `nil' has a unique fixed reference */
527 }
528 t = lua_absindex(L, t);
529 lua_rawgeti(L, t, freelist); /* get first free element */
530 ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */
531 lua_pop(L, 1); /* remove it from stack */
532 if (ref != 0) { /* any free element? */
533 lua_rawgeti(L, t, ref); /* remove it from list */
534 lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */
535 }
536 else /* no free elements */
537 ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */
538 lua_rawseti(L, t, ref);
539 return ref;
540 }
541
542
543 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
544 if (ref >= 0) {
545 t = lua_absindex(L, t);
546 lua_rawgeti(L, t, freelist);
547 lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */
548 lua_pushinteger(L, ref);
549 lua_rawseti(L, t, freelist); /* t[freelist] = ref */
550 }
551 }
552
553 /* }====================================================== */
554
555
556 /*
557 ** {======================================================
558 ** Load functions
559 ** =======================================================
560 */
561
562 typedef struct LoadF {
563 int n; /* number of pre-read characters */
564 FILE *f; /* file being read */
565 char buff[LUAL_BUFFERSIZE]; /* area for reading file */
566 } LoadF;
567
568
569 static const char *getF (lua_State *L, void *ud, size_t *size) {
570 LoadF *lf = (LoadF *)ud;
571 (void)L; /* not used */
572 if (lf->n > 0) { /* are there pre-read characters to be read? */
573 *size = lf->n; /* return them (chars already in buffer) */
574 lf->n = 0; /* no more pre-read characters */
575 }
576 else { /* read a block from file */
577 /* 'fread' can return > 0 *and* set the EOF flag. If next call to
578 'getF' called 'fread', it might still wait for user input.
579 The next check avoids this problem. */
580 if (feof(lf->f)) return NULL;
581 *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */
582 }
583 return lf->buff;
584 }
585
586
587 static int errfile (lua_State *L, const char *what, int fnameindex) {
588 const char *serr = strerror(errno);
589 const char *filename = lua_tostring(L, fnameindex) + 1;
590 lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
591 lua_remove(L, fnameindex);
592 return LUA_ERRFILE;
593 }
594
595
596 static int skipBOM (LoadF *lf) {
597 const char *p = "\xEF\xBB\xBF"; /* Utf8 BOM mark */
598 int c;
599 lf->n = 0;
600 do {
601 c = getc(lf->f);
602 if (c == EOF || c != *(const unsigned char *)p++) return c;
603 lf->buff[lf->n++] = c; /* to be read by the parser */
604 } while (*p != '\0');
605 lf->n = 0; /* prefix matched; discard it */
606 return getc(lf->f); /* return next character */
607 }
608
609
610 /*
611 ** reads the first character of file 'f' and skips an optional BOM mark
612 ** in its beginning plus its first line if it starts with '#'. Returns
613 ** true if it skipped the first line. In any case, '*cp' has the
614 ** first "valid" character of the file (after the optional BOM and
615 ** a first-line comment).
616 */
617 static int skipcomment (LoadF *lf, int *cp) {
618 int c = *cp = skipBOM(lf);
619 if (c == '#') { /* first line is a comment (Unix exec. file)? */
620 do { /* skip first line */
621 c = getc(lf->f);
622 } while (c != EOF && c != '\n') ;
623 *cp = getc(lf->f); /* skip end-of-line, if present */
624 return 1; /* there was a comment */
625 }
626 else return 0; /* no comment */
627 }
628
629
630 LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
631 const char *mode) {
632 LoadF lf;
633 int status, readstatus;
634 int c;
635 int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */
636 if (filename == NULL) {
637 lua_pushliteral(L, "=stdin");
638 lf.f = stdin;
639 }
640 else {
641 lua_pushfstring(L, "@%s", filename);
642 lf.f = fopen(filename, "r");
643 if (lf.f == NULL) return errfile(L, "open", fnameindex);
644 }
645 if (skipcomment(&lf, &c)) /* read initial portion */
646 lf.buff[lf.n++] = '\n'; /* add line to correct line numbers */
647 if (c == LUA_SIGNATURE[0] && filename) { /* binary file? */
648 lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */
649 if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
650 skipcomment(&lf, &c); /* re-read initial portion */
651 }
652 if (c != EOF)
653 lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */
654 status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
655 readstatus = ferror(lf.f);
656 if (filename) fclose(lf.f); /* close file (even in case of errors) */
657 if (readstatus) {
658 lua_settop(L, fnameindex); /* ignore results from `lua_load' */
659 return errfile(L, "read", fnameindex);
660 }
661 lua_remove(L, fnameindex);
662 return status;
663 }
664
665
666 typedef struct LoadS {
667 const char *s;
668 size_t size;
669 } LoadS;
670
671
672 static const char *getS (lua_State *L, void *ud, size_t *size) {
673 LoadS *ls = (LoadS *)ud;
674 (void)L; /* not used */
675 if (ls->size == 0) return NULL;
676 *size = ls->size;
677 ls->size = 0;
678 return ls->s;
679 }
680
681
682 LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size,
683 const char *name, const char *mode) {
684 LoadS ls;
685 ls.s = buff;
686 ls.size = size;
687 return lua_load(L, getS, &ls, name, mode);
688 }
689
690
691 LUALIB_API int luaL_loadstring (lua_State *L, const char *s) {
692 return luaL_loadbuffer(L, s, strlen(s), s);
693 }
694
695 /* }====================================================== */
696
697
698
699 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
700 if (!lua_getmetatable(L, obj)) /* no metatable? */
701 return 0;
702 lua_pushstring(L, event);
703 lua_rawget(L, -2);
704 if (lua_isnil(L, -1)) {
705 lua_pop(L, 2); /* remove metatable and metafield */
706 return 0;
707 }
708 else {
709 lua_remove(L, -2); /* remove only metatable */
710 return 1;
711 }
712 }
713
714
715 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
716 obj = lua_absindex(L, obj);
717 if (!luaL_getmetafield(L, obj, event)) /* no metafield? */
718 return 0;
719 lua_pushvalue(L, obj);
720 lua_call(L, 1, 1);
721 return 1;
722 }
723
724
725 LUALIB_API int luaL_len (lua_State *L, int idx) {
726 int l;
727 int isnum;
728 lua_len(L, idx);
729 l = (int)lua_tointegerx(L, -1, &isnum);
730 if (!isnum)
731 luaL_error(L, "object length is not a number");
732 lua_pop(L, 1); /* remove object */
733 return l;
734 }
735
736
737 LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
738 if (!luaL_callmeta(L, idx, "__tostring")) { /* no metafield? */
739 switch (lua_type(L, idx)) {
740 case LUA_TNUMBER:
741 case LUA_TSTRING:
742 lua_pushvalue(L, idx);
743 break;
744 case LUA_TBOOLEAN:
745 lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false"));
746 break;
747 case LUA_TNIL:
748 lua_pushliteral(L, "nil");
749 break;
750 default:
751 lua_pushfstring(L, "%s: %p", luaL_typename(L, idx),
752 lua_topointer(L, idx));
753 break;
754 }
755 }
756 return lua_tolstring(L, -1, len);
757 }
758
759
760 /*
761 ** {======================================================
762 ** Compatibility with 5.1 module functions
763 ** =======================================================
764 */
765 #if defined(LUA_COMPAT_MODULE)
766
767 static const char *luaL_findtable (lua_State *L, int idx,
768 const char *fname, int szhint) {
769 const char *e;
770 if (idx) lua_pushvalue(L, idx);
771 do {
772 e = strchr(fname, '.');
773 if (e == NULL) e = fname + strlen(fname);
774 lua_pushlstring(L, fname, e - fname);
775 lua_rawget(L, -2);
776 if (lua_isnil(L, -1)) { /* no such field? */
777 lua_pop(L, 1); /* remove this nil */
778 lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
779 lua_pushlstring(L, fname, e - fname);
780 lua_pushvalue(L, -2);
781 lua_settable(L, -4); /* set new table into field */
782 }
783 else if (!lua_istable(L, -1)) { /* field has a non-table value? */
784 lua_pop(L, 2); /* remove table and value */
785 return fname; /* return problematic part of the name */
786 }
787 lua_remove(L, -2); /* remove previous table */
788 fname = e + 1;
789 } while (*e == '.');
790 return NULL;
791 }
792
793
794 /*
795 ** Count number of elements in a luaL_Reg list.
796 */
797 static int libsize (const luaL_Reg *l) {
798 int size = 0;
799 for (; l && l->name; l++) size++;
800 return size;
801 }
802
803
804 /*
805 ** Find or create a module table with a given name. The function
806 ** first looks at the _LOADED table and, if that fails, try a
807 ** global variable with that name. In any case, leaves on the stack
808 ** the module table.
809 */
810 LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname,
811 int sizehint) {
812 luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */
813 lua_getfield(L, -1, modname); /* get _LOADED[modname] */
814 if (!lua_istable(L, -1)) { /* not found? */
815 lua_pop(L, 1); /* remove previous result */
816 /* try global variable (and create one if it does not exist) */
817 lua_pushglobaltable(L);
818 if (luaL_findtable(L, 0, modname, sizehint) != NULL)
819 luaL_error(L, "name conflict for module " LUA_QS, modname);
820 lua_pushvalue(L, -1);
821 lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */
822 }
823 lua_remove(L, -2); /* remove _LOADED table */
824 }
825
826
827 LUALIB_API void luaL_openlib (lua_State *L, const char *libname,
828 const luaL_Reg *l, int nup) {
829 luaL_checkversion(L);
830 if (libname) {
831 luaL_pushmodule(L, libname, libsize(l)); /* get/create library table */
832 lua_insert(L, -(nup + 1)); /* move library table to below upvalues */
833 }
834 if (l)
835 luaL_setfuncs(L, l, nup);
836 else
837 lua_pop(L, nup); /* remove upvalues */
838 }
839
840 #endif
841 /* }====================================================== */
842
843 /*
844 ** set functions from list 'l' into table at top - 'nup'; each
845 ** function gets the 'nup' elements at the top as upvalues.
846 ** Returns with only the table at the stack.
847 */
848 LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
849 luaL_checkversion(L);
850 luaL_checkstack(L, nup, "too many upvalues");
851 for (; l->name != NULL; l++) { /* fill the table with given functions */
852 int i;
853 for (i = 0; i < nup; i++) /* copy upvalues to the top */
854 lua_pushvalue(L, -nup);
855 lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */
856 lua_setfield(L, -(nup + 2), l->name);
857 }
858 lua_pop(L, nup); /* remove upvalues */
859 }
860
861
862 /*
863 ** ensure that stack[idx][fname] has a table and push that table
864 ** into the stack
865 */
866 LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
867 lua_getfield(L, idx, fname);
868 if (lua_istable(L, -1)) return 1; /* table already there */
869 else {
870 lua_pop(L, 1); /* remove previous result */
871 idx = lua_absindex(L, idx);
872 lua_newtable(L);
873 lua_pushvalue(L, -1); /* copy to be left at top */
874 lua_setfield(L, idx, fname); /* assign new table to field */
875 return 0; /* false, because did not find table there */
876 }
877 }
878
879
880 /*
881 ** stripped-down 'require'. Calls 'openf' to open a module,
882 ** registers the result in 'package.loaded' table and, if 'glb'
883 ** is true, also registers the result in the global table.
884 ** Leaves resulting module on the top.
885 */
886 LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
887 lua_CFunction openf, int glb) {
888 lua_pushcfunction(L, openf);
889 lua_pushstring(L, modname); /* argument to open function */
890 lua_call(L, 1, 1); /* open module */
891 luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
892 lua_pushvalue(L, -2); /* make copy of module (call result) */
893 lua_setfield(L, -2, modname); /* _LOADED[modname] = module */
894 lua_pop(L, 1); /* remove _LOADED table */
895 if (glb) {
896 lua_pushvalue(L, -1); /* copy of 'mod' */
897 lua_setglobal(L, modname); /* _G[modname] = module */
898 }
899 }
900
901
902 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
903 const char *r) {
904 const char *wild;
905 size_t l = strlen(p);
906 luaL_Buffer b;
907 luaL_buffinit(L, &b);
908 while ((wild = strstr(s, p)) != NULL) {
909 luaL_addlstring(&b, s, wild - s); /* push prefix */
910 luaL_addstring(&b, r); /* push replacement in place of pattern */
911 s = wild + l; /* continue after `p' */
912 }
913 luaL_addstring(&b, s); /* push last suffix */
914 luaL_pushresult(&b);
915 return lua_tostring(L, -1);
916 }
917
918
919 static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
920 (void)ud; (void)osize; /* not used */
921 if (nsize == 0) {
922 free(ptr);
923 return NULL;
924 }
925 else
926 return realloc(ptr, nsize);
927 }
928
929
930 static int panic (lua_State *L) {
931 luai_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
932 lua_tostring(L, -1));
933 return 0; /* return to Lua to abort */
934 }
935
936
937 LUALIB_API lua_State *luaL_newstate (void) {
938 lua_State *L = lua_newstate(l_alloc, NULL);
939 if (L) lua_atpanic(L, &panic);
940 return L;
941 }
942
943
944 LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver) {
945 const lua_Number *v = lua_version(L);
946 if (v != lua_version(NULL))
947 luaL_error(L, "multiple Lua VMs detected");
948 else if (*v != ver)
949 luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
950 ver, *v);
951 /* check conversions number -> integer types */
952 lua_pushnumber(L, -(lua_Number)0x1234);
953 if (lua_tointeger(L, -1) != -0x1234 ||
954 lua_tounsigned(L, -1) != (lua_Unsigned)-0x1234)
955 luaL_error(L, "bad conversion number->int;"
956 " must recompile Lua with proper settings");
957 lua_pop(L, 1);
958 }
959