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/script_binding/lua/lua/lauxlib.c

http://ftk.googlecode.com/
C | 652 lines | 485 code | 131 blank | 36 comment | 109 complexity | 036e167458cdea501bd65bac3b28bc1e MD5 | raw file
  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
 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", 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
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, sizeof(lf->buff), 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] && 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
593typedef struct LoadS {
594  const char *s;
595  size_t size;
596} LoadS;
597
598
599static 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
609LUALIB_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
618LUALIB_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
627static 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
639static 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
647LUALIB_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