1/*	$NetBSD$	*/
2
3/*
4** Id: lauxlib.c,v 1.159.1.3 2008/01/21 13:20:51 roberto Exp
5** Auxiliary functions for building Lua libraries
6** See Copyright Notice in lua.h
7*/
8
9
10#include <ctype.h>
11#include <errno.h>
12#include <stdarg.h>
13#include <stdio.h>
14#include <stdlib.h>
15#include <string.h>
16
17
18/* This file uses only the official API of Lua.
19** Any function declared here could be written as an application function.
20*/
21
22#define lauxlib_c
23#define LUA_LIB
24
25#include "lua.h"
26
27#include "lauxlib.h"
28
29
30#define FREELIST_REF	0	/* free list of references */
31
32
33/* convert a stack index to positive */
34#define abs_index(L, i)		((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \
35					lua_gettop(L) + (i) + 1)
36
37
38/*
39** {======================================================
40** Error-report functions
41** =======================================================
42*/
43
44
45LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {
46  lua_Debug ar;
47  if (!lua_getstack(L, 0, &ar))  /* no stack frame? */
48    return luaL_error(L, "bad argument #%d (%s)", narg, extramsg);
49  lua_getinfo(L, "n", &ar);
50  if (strcmp(ar.namewhat, "method") == 0) {
51    narg--;  /* do not count `self' */
52    if (narg == 0)  /* error is in the self argument itself? */
53      return luaL_error(L, "calling " LUA_QS " on bad self (%s)",
54                           ar.name, extramsg);
55  }
56  if (ar.name == NULL)
57    ar.name = "?";
58  return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)",
59                        narg, ar.name, extramsg);
60}
61
62
63LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname) {
64  const char *msg = lua_pushfstring(L, "%s expected, got %s",
65                                    tname, luaL_typename(L, narg));
66  return luaL_argerror(L, narg, msg);
67}
68
69
70static void tag_error (lua_State *L, int narg, int tag) {
71  luaL_typerror(L, narg, lua_typename(L, tag));
72}
73
74
75LUALIB_API void luaL_where (lua_State *L, int level) {
76  lua_Debug ar;
77  if (lua_getstack(L, level, &ar)) {  /* check function at level */
78    lua_getinfo(L, "Sl", &ar);  /* get info about it */
79    if (ar.currentline > 0) {  /* is there info? */
80      lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
81      return;
82    }
83  }
84  lua_pushliteral(L, "");  /* else, no information available... */
85}
86
87
88LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
89  va_list argp;
90  va_start(argp, fmt);
91  luaL_where(L, 1);
92  lua_pushvfstring(L, fmt, argp);
93  va_end(argp);
94  lua_concat(L, 2);
95  return lua_error(L);
96}
97
98/* }====================================================== */
99
100
101LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def,
102                                 const char *const lst[]) {
103  const char *name = (def) ? luaL_optstring(L, narg, def) :
104                             luaL_checkstring(L, narg);
105  int i;
106  for (i=0; lst[i]; i++)
107    if (strcmp(lst[i], name) == 0)
108      return i;
109  return luaL_argerror(L, narg,
110                       lua_pushfstring(L, "invalid option " LUA_QS, name));
111}
112
113
114LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
115  lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get registry.name */
116  if (!lua_isnil(L, -1))  /* name already in use? */
117    return 0;  /* leave previous value on top, but return 0 */
118  lua_pop(L, 1);
119  lua_newtable(L);  /* create metatable */
120  lua_pushvalue(L, -1);
121  lua_setfield(L, LUA_REGISTRYINDEX, tname);  /* registry.name = metatable */
122  return 1;
123}
124
125
126LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
127  void *p = lua_touserdata(L, ud);
128  if (p != NULL) {  /* value is a userdata? */
129    if (lua_getmetatable(L, ud)) {  /* does it have a metatable? */
130      lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get correct metatable */
131      if (lua_rawequal(L, -1, -2)) {  /* does it have the correct mt? */
132        lua_pop(L, 2);  /* remove both metatables */
133        return p;
134      }
135    }
136  }
137  luaL_typerror(L, ud, tname);  /* else error */
138  return NULL;  /* to avoid warnings */
139}
140
141
142LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) {
143  if (!lua_checkstack(L, space))
144    luaL_error(L, "stack overflow (%s)", mes);
145}
146
147
148LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) {
149  if (lua_type(L, narg) != t)
150    tag_error(L, narg, t);
151}
152
153
154LUALIB_API void luaL_checkany (lua_State *L, int narg) {
155  if (lua_type(L, narg) == LUA_TNONE)
156    luaL_argerror(L, narg, "value expected");
157}
158
159
160LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) {
161  const char *s = lua_tolstring(L, narg, len);
162  if (!s) tag_error(L, narg, LUA_TSTRING);
163  return s;
164}
165
166
167LUALIB_API const char *luaL_optlstring (lua_State *L, int narg,
168                                        const char *def, size_t *len) {
169  if (lua_isnoneornil(L, narg)) {
170    if (len)
171      *len = (def ? strlen(def) : 0);
172    return def;
173  }
174  else return luaL_checklstring(L, narg, len);
175}
176
177
178LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) {
179  lua_Number d = lua_tonumber(L, narg);
180  if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
181    tag_error(L, narg, LUA_TNUMBER);
182  return d;
183}
184
185
186LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {
187  return luaL_opt(L, luaL_checknumber, narg, def);
188}
189
190
191LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) {
192  lua_Integer d = lua_tointeger(L, narg);
193  if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
194    tag_error(L, narg, LUA_TNUMBER);
195  return d;
196}
197
198
199LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,
200                                                      lua_Integer def) {
201  return luaL_opt(L, luaL_checkinteger, narg, def);
202}
203
204
205LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
206  if (!lua_getmetatable(L, obj))  /* no metatable? */
207    return 0;
208  lua_pushstring(L, event);
209  lua_rawget(L, -2);
210  if (lua_isnil(L, -1)) {
211    lua_pop(L, 2);  /* remove metatable and metafield */
212    return 0;
213  }
214  else {
215    lua_remove(L, -2);  /* remove only metatable */
216    return 1;
217  }
218}
219
220
221LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
222  obj = abs_index(L, obj);
223  if (!luaL_getmetafield(L, obj, event))  /* no metafield? */
224    return 0;
225  lua_pushvalue(L, obj);
226  lua_call(L, 1, 1);
227  return 1;
228}
229
230
231LUALIB_API void (luaL_register) (lua_State *L, const char *libname,
232                                const luaL_Reg *l) {
233  luaI_openlib(L, libname, l, 0);
234}
235
236
237static int libsize (const luaL_Reg *l) {
238  int size = 0;
239  for (; l->name; l++) size++;
240  return size;
241}
242
243
244LUALIB_API void luaI_openlib (lua_State *L, const char *libname,
245                              const luaL_Reg *l, int nup) {
246  if (libname) {
247    int size = libsize(l);
248    /* check whether lib already exists */
249    luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);
250    lua_getfield(L, -1, libname);  /* get _LOADED[libname] */
251    if (!lua_istable(L, -1)) {  /* not found? */
252      lua_pop(L, 1);  /* remove previous result */
253      /* try global variable (and create one if it does not exist) */
254      if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
255        luaL_error(L, "name conflict for module " LUA_QS, libname);
256      lua_pushvalue(L, -1);
257      lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */
258    }
259    lua_remove(L, -2);  /* remove _LOADED table */
260    lua_insert(L, -(nup+1));  /* move library table to below upvalues */
261  }
262  for (; l->name; l++) {
263    int i;
264    for (i=0; i<nup; i++)  /* copy upvalues to the top */
265      lua_pushvalue(L, -nup);
266    lua_pushcclosure(L, l->func, nup);
267    lua_setfield(L, -(nup+2), l->name);
268  }
269  lua_pop(L, nup);  /* remove upvalues */
270}
271
272
273
274/*
275** {======================================================
276** getn-setn: size for arrays
277** =======================================================
278*/
279
280#if defined(LUA_COMPAT_GETN)
281
282static int checkint (lua_State *L, int topop) {
283  int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;
284  lua_pop(L, topop);
285  return n;
286}
287
288
289static void getsizes (lua_State *L) {
290  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");
291  if (lua_isnil(L, -1)) {  /* no `size' table? */
292    lua_pop(L, 1);  /* remove nil */
293    lua_newtable(L);  /* create it */
294    lua_pushvalue(L, -1);  /* `size' will be its own metatable */
295    lua_setmetatable(L, -2);
296    lua_pushliteral(L, "kv");
297    lua_setfield(L, -2, "__mode");  /* metatable(N).__mode = "kv" */
298    lua_pushvalue(L, -1);
299    lua_setfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  /* store in register */
300  }
301}
302
303
304LUALIB_API void luaL_setn (lua_State *L, int t, int n) {
305  t = abs_index(L, t);
306  lua_pushliteral(L, "n");
307  lua_rawget(L, t);
308  if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */
309    lua_pushliteral(L, "n");  /* use it */
310    lua_pushinteger(L, n);
311    lua_rawset(L, t);
312  }
313  else {  /* use `sizes' */
314    getsizes(L);
315    lua_pushvalue(L, t);
316    lua_pushinteger(L, n);
317    lua_rawset(L, -3);  /* sizes[t] = n */
318    lua_pop(L, 1);  /* remove `sizes' */
319  }
320}
321
322
323LUALIB_API int luaL_getn (lua_State *L, int t) {
324  int n;
325  t = abs_index(L, t);
326  lua_pushliteral(L, "n");  /* try t.n */
327  lua_rawget(L, t);
328  if ((n = checkint(L, 1)) >= 0) return n;
329  getsizes(L);  /* else try sizes[t] */
330  lua_pushvalue(L, t);
331  lua_rawget(L, -2);
332  if ((n = checkint(L, 2)) >= 0) return n;
333  return (int)lua_objlen(L, t);
334}
335
336#endif
337
338/* }====================================================== */
339
340
341
342LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,
343                                                               const char *r) {
344  const char *wild;
345  size_t l = strlen(p);
346  luaL_Buffer b;
347  luaL_buffinit(L, &b);
348  while ((wild = strstr(s, p)) != NULL) {
349    luaL_addlstring(&b, s, wild - s);  /* push prefix */
350    luaL_addstring(&b, r);  /* push replacement in place of pattern */
351    s = wild + l;  /* continue after `p' */
352  }
353  luaL_addstring(&b, s);  /* push last suffix */
354  luaL_pushresult(&b);
355  return lua_tostring(L, -1);
356}
357
358
359LUALIB_API const char *luaL_findtable (lua_State *L, int idx,
360                                       const char *fname, int szhint) {
361  const char *e;
362  lua_pushvalue(L, idx);
363  do {
364    e = strchr(fname, '.');
365    if (e == NULL) e = fname + strlen(fname);
366    lua_pushlstring(L, fname, e - fname);
367    lua_rawget(L, -2);
368    if (lua_isnil(L, -1)) {  /* no such field? */
369      lua_pop(L, 1);  /* remove this nil */
370      lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
371      lua_pushlstring(L, fname, e - fname);
372      lua_pushvalue(L, -2);
373      lua_settable(L, -4);  /* set new table into field */
374    }
375    else if (!lua_istable(L, -1)) {  /* field has a non-table value? */
376      lua_pop(L, 2);  /* remove table and value */
377      return fname;  /* return problematic part of the name */
378    }
379    lua_remove(L, -2);  /* remove previous table */
380    fname = e + 1;
381  } while (*e == '.');
382  return NULL;
383}
384
385
386
387/*
388** {======================================================
389** Generic Buffer manipulation
390** =======================================================
391*/
392
393
394#define bufflen(B)	((B)->p - (B)->buffer)
395#define bufffree(B)	((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
396
397#define LIMIT	(LUA_MINSTACK/2)
398
399
400static int emptybuffer (luaL_Buffer *B) {
401  size_t l = bufflen(B);
402  if (l == 0) return 0;  /* put nothing on stack */
403  else {
404    lua_pushlstring(B->L, B->buffer, l);
405    B->p = B->buffer;
406    B->lvl++;
407    return 1;
408  }
409}
410
411
412static void adjuststack (luaL_Buffer *B) {
413  if (B->lvl > 1) {
414    lua_State *L = B->L;
415    int toget = 1;  /* number of levels to concat */
416    size_t toplen = lua_strlen(L, -1);
417    do {
418      size_t l = lua_strlen(L, -(toget+1));
419      if (B->lvl - toget + 1 >= LIMIT || toplen > l) {
420        toplen += l;
421        toget++;
422      }
423      else break;
424    } while (toget < B->lvl);
425    lua_concat(L, toget);
426    B->lvl = B->lvl - toget + 1;
427  }
428}
429
430
431LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {
432  if (emptybuffer(B))
433    adjuststack(B);
434  return B->buffer;
435}
436
437
438LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
439  while (l--)
440    luaL_addchar(B, *s++);
441}
442
443
444LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
445  luaL_addlstring(B, s, strlen(s));
446}
447
448
449LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
450  emptybuffer(B);
451  lua_concat(B->L, B->lvl);
452  B->lvl = 1;
453}
454
455
456LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
457  lua_State *L = B->L;
458  size_t vl;
459  const char *s = lua_tolstring(L, -1, &vl);
460  if (vl <= bufffree(B)) {  /* fit into buffer? */
461    memcpy(B->p, s, vl);  /* put it there */
462    B->p += vl;
463    lua_pop(L, 1);  /* remove from stack */
464  }
465  else {
466    if (emptybuffer(B))
467      lua_insert(L, -2);  /* put buffer before new value */
468    B->lvl++;  /* add new value into B stack */
469    adjuststack(B);
470  }
471}
472
473
474LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
475  B->L = L;
476  B->p = B->buffer;
477  B->lvl = 0;
478}
479
480/* }====================================================== */
481
482
483LUALIB_API int luaL_ref (lua_State *L, int t) {
484  int ref;
485  t = abs_index(L, t);
486  if (lua_isnil(L, -1)) {
487    lua_pop(L, 1);  /* remove from stack */
488    return LUA_REFNIL;  /* `nil' has a unique fixed reference */
489  }
490  lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */
491  ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */
492  lua_pop(L, 1);  /* remove it from stack */
493  if (ref != 0) {  /* any free element? */
494    lua_rawgeti(L, t, ref);  /* remove it from list */
495    lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */
496  }
497  else {  /* no free elements */
498    ref = (int)lua_objlen(L, t);
499    ref++;  /* create new reference */
500  }
501  lua_rawseti(L, t, ref);
502  return ref;
503}
504
505
506LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
507  if (ref >= 0) {
508    t = abs_index(L, t);
509    lua_rawgeti(L, t, FREELIST_REF);
510    lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */
511    lua_pushinteger(L, ref);
512    lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */
513  }
514}
515
516
517
518/*
519** {======================================================
520** Load functions
521** =======================================================
522*/
523
524typedef struct LoadF {
525  int extraline;
526  FILE *f;
527  char buff[LUAL_BUFFERSIZE];
528} LoadF;
529
530
531static const char *getF (lua_State *L, void *ud, size_t *size) {
532  LoadF *lf = (LoadF *)ud;
533  (void)L;
534  if (lf->extraline) {
535    lf->extraline = 0;
536    *size = 1;
537    return "\n";
538  }
539  if (feof(lf->f)) return NULL;
540  *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);
541  return (*size > 0) ? lf->buff : NULL;
542}
543
544
545static int errfile (lua_State *L, const char *what, int fnameindex) {
546  const char *serr = strerror(errno);
547  const char *filename = lua_tostring(L, fnameindex) + 1;
548  lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
549  lua_remove(L, fnameindex);
550  return LUA_ERRFILE;
551}
552
553
554LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
555  LoadF lf;
556  int status, readstatus;
557  int c;
558  int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */
559  lf.extraline = 0;
560  if (filename == NULL) {
561    lua_pushliteral(L, "=stdin");
562    lf.f = stdin;
563  }
564  else {
565    lua_pushfstring(L, "@%s", filename);
566    lf.f = fopen(filename, "r");
567    if (lf.f == NULL) return errfile(L, "open", fnameindex);
568  }
569  c = getc(lf.f);
570  if (c == '#') {  /* Unix exec. file? */
571    lf.extraline = 1;
572    while ((c = getc(lf.f)) != EOF && c != '\n') ;  /* skip first line */
573    if (c == '\n') c = getc(lf.f);
574  }
575  if (c == LUA_SIGNATURE[0] && filename) {  /* binary file? */
576    lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */
577    if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
578    /* skip eventual `#!...' */
579   while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;
580    lf.extraline = 0;
581  }
582  ungetc(c, lf.f);
583  status = lua_load(L, getF, &lf, lua_tostring(L, -1));
584  readstatus = ferror(lf.f);
585  if (filename) fclose(lf.f);  /* close file (even in case of errors) */
586  if (readstatus) {
587    lua_settop(L, fnameindex);  /* ignore results from `lua_load' */
588    return errfile(L, "read", fnameindex);
589  }
590  lua_remove(L, fnameindex);
591  return status;
592}
593
594
595typedef struct LoadS {
596  const char *s;
597  size_t size;
598} LoadS;
599
600
601static const char *getS (lua_State *L, void *ud, size_t *size) {
602  LoadS *ls = (LoadS *)ud;
603  (void)L;
604  if (ls->size == 0) return NULL;
605  *size = ls->size;
606  ls->size = 0;
607  return ls->s;
608}
609
610
611LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,
612                                const char *name) {
613  LoadS ls;
614  ls.s = buff;
615  ls.size = size;
616  return lua_load(L, getS, &ls, name);
617}
618
619
620LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {
621  return luaL_loadbuffer(L, s, strlen(s), s);
622}
623
624
625
626/* }====================================================== */
627
628
629static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
630  (void)ud;
631  (void)osize;
632  if (nsize == 0) {
633    free(ptr);
634    return NULL;
635  }
636  else
637    return realloc(ptr, nsize);
638}
639
640
641static int panic (lua_State *L) {
642  (void)L;  /* to avoid warnings */
643  fprintf(stderr, "PANIC: unprotected error in call to Lua API (%s)\n",
644                   lua_tostring(L, -1));
645  return 0;
646}
647
648
649LUALIB_API lua_State *luaL_newstate (void) {
650  lua_State *L = lua_newstate(l_alloc, NULL);
651  if (L) lua_atpanic(L, &panic);
652  return L;
653}
654
655