root/src/lua-5.1.3/src/lauxlib.c

Revision 5c8778c4361d2ad3adc94ef98d804c6fa9e6ba7c, 17.0 kB (checked in by Theo Schlossnagle <jesus@omniti.com>, 10 years ago)

import lua... I'd like to write checkers in lua

  • Property mode set to 100644
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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
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