intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-1999, 2000, 2001 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Tell glibc's <string.h> to provide a prototype for mempcpy().
  19    This must come before <config.h> because <config.h> may include
  20    <features.h>, and once <features.h> has been included, it's too late.  */
  21 #ifndef _GNU_SOURCE
  22 # define _GNU_SOURCE    1
  23 #endif
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include <gnulib/config.h>
  27 # undef VERSION
  28 # undef PACKAGE_VERSION
  29 # undef PACKAGE_TARNAME
  30 # undef PACKAGE_STRING
  31 # include <config.h>
  32 #endif
  33
  34 #include <ctype.h>
  35 #include <stdio.h>
  36 #include <sys/types.h>
  37
  38 #ifdef __GNUC__
  39 # define alloca __builtin_alloca
  40 # define HAVE_ALLOCA 1
  41 #else
  42 # if defined HAVE_ALLOCA_H || defined _LIBC
  43 #  include <alloca.h>
  44 # else
  45 #  ifdef _AIX
  46  #pragma alloca
  47 #  else
  48 #   ifndef alloca
  49 char *alloca ();
  50 #   endif
  51 #  endif
  52 # endif
  53 #endif
  54
  55 #include <stdlib.h>
  56
  57 #include <string.h>
  58 #if !HAVE_STRCHR && !defined _LIBC
  59 # ifndef strchr
  60 #  define strchr index
  61 # endif
  62 #endif
  63
  64 #include "gettextP.h"
  65
  66 /* @@ end of prolog @@ */
  67
  68 #ifdef _LIBC
  69 /* Rename the non ANSI C functions.  This is required by the standard
  70    because some ANSI C functions will require linking with this object
  71    file and the name space must not be polluted.  */
  72 # define strcasecmp __strcasecmp
  73
  74 # ifndef mempcpy
  75 #  define mempcpy __mempcpy
  76 # endif
  77 # define HAVE_MEMPCPY   1
  78
  79 /* We need locking here since we can be called from different places.  */
  80 # include <bits/libc-lock.h>
  81
  82 __libc_lock_define_initialized (static, lock);
  83 #endif
  84
  85 #ifndef internal_function
  86 # define internal_function
  87 #endif
  88
  89 /* For those losing systems which don't have `alloca' we have to add
  90    some additional code emulating it.  */
  91 #ifdef HAVE_ALLOCA
  92 # define freea(p) /* nothing */
  93 #else
  94 # define alloca(n) malloc (n)
  95 # define freea(p) free (p)
  96 #endif
  97
  98 #if defined _LIBC_REENTRANT || defined HAVE_FGETS_UNLOCKED
  99 # undef fgets
 100 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 101 #endif
 102 #if defined _LIBC_REENTRANT || defined HAVE_FEOF_UNLOCKED
 103 # undef feof
 104 # define feof(s) feof_unlocked (s)
 105 #endif
 106
 107
 108 struct alias_map
 109 {
 110   const char *alias;
 111   const char *value;
 112 };
 113
 114
 115 static char *string_space;
 116 static size_t string_space_act;
 117 static size_t string_space_max;
 118 static struct alias_map *map;
 119 static size_t nmap;
 120 static size_t maxmap;
 121
 122
 123 /* Prototypes for local functions.  */
 124 static size_t read_alias_file PARAMS ((const char *fname, int fname_len))
 125      internal_function;
 126 static int extend_alias_table PARAMS ((void));
 127 static int alias_compare PARAMS ((const struct alias_map *map1,
 128                                   const struct alias_map *map2));
 129
 130
 131 const char *
 132 _nl_expand_alias (name)
 133     const char *name;
 134 {
 135   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 136   struct alias_map *retval;
 137   const char *result = NULL;
 138   size_t added;
 139
 140 #ifdef _LIBC
 141   __libc_lock_lock (lock);
 142 #endif
 143
 144   do
 145     {
 146       struct alias_map item;
 147
 148       item.alias = name;
 149
 150       if (nmap > 0)
 151         retval = (struct alias_map *) bsearch (&item, map, nmap,
 152                                                sizeof (struct alias_map),
 153                                                (int (*) PARAMS ((const void *,
 154                                                                  const void *))
 155                                                 ) alias_compare);
 156       else
 157         retval = NULL;
 158
 159       /* We really found an alias.  Return the value.  */
 160       if (retval != NULL)
 161         {
 162           result = retval->value;
 163           break;
 164         }
 165
 166       /* Perhaps we can find another alias file.  */
 167       added = 0;
 168       while (added == 0 && locale_alias_path[0] != '\0')
 169         {
 170           const char *start;
 171
 172           while (locale_alias_path[0] == PATH_SEPARATOR)
 173             ++locale_alias_path;
 174           start = locale_alias_path;
 175
 176           while (locale_alias_path[0] != '\0'
 177                  && locale_alias_path[0] != PATH_SEPARATOR)
 178             ++locale_alias_path;
 179
 180           if (start < locale_alias_path)
 181             added = read_alias_file (start, locale_alias_path - start);
 182         }
 183     }
 184   while (added != 0);
 185
 186 #ifdef _LIBC
 187   __libc_lock_unlock (lock);
 188 #endif
 189
 190   return result;
 191 }
 192
 193
 194 static size_t
 195 internal_function
 196 read_alias_file (fname, fname_len)
 197      const char *fname;
 198      int fname_len;
 199 {
 200   FILE *fp;
 201   char *full_fname;
 202   size_t added;
 203   static const char aliasfile[] = "/locale.alias";
 204
 205   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 206 #ifdef HAVE_MEMPCPY
 207   mempcpy (mempcpy (full_fname, fname, fname_len),
 208            aliasfile, sizeof aliasfile);
 209 #else
 210   memcpy (full_fname, fname, fname_len);
 211   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 212 #endif
 213
 214   fp = fopen (full_fname, "r");
 215   freea (full_fname);
 216   if (fp == NULL)
 217     return 0;
 218
 219   added = 0;
 220   while (!feof (fp))
 221     {
 222       /* It is a reasonable approach to use a fix buffer here because
 223          a) we are only interested in the first two fields
 224          b) these fields must be usable as file names and so must not
 225             be that long
 226        */
 227       char buf[BUFSIZ];
 228       char *alias;
 229       char *value;
 230       char *cp;
 231
 232       if (fgets (buf, sizeof buf, fp) == NULL)
 233         /* EOF reached.  */
 234         break;
 235
 236       /* Possibly not the whole line fits into the buffer.  Ignore
 237          the rest of the line.  */
 238       if (strchr (buf, '\n') == NULL)
 239         {
 240           char altbuf[BUFSIZ];
 241           do
 242             if (fgets (altbuf, sizeof altbuf, fp) == NULL)
 243               /* Make sure the inner loop will be left.  The outer loop
 244                  will exit at the `feof' test.  */
 245               break;
 246           while (strchr (altbuf, '\n') == NULL);
 247         }
 248
 249       cp = buf;
 250       /* Ignore leading white space.  */
 251       while (isspace (cp[0]))
 252         ++cp;
 253
 254       /* A leading '#' signals a comment line.  */
 255       if (cp[0] != '\0' && cp[0] != '#')
 256         {
 257           alias = cp++;
 258           while (cp[0] != '\0' && !isspace (cp[0]))
 259             ++cp;
 260           /* Terminate alias name.  */
 261           if (cp[0] != '\0')
 262             *cp++ = '\0';
 263
 264           /* Now look for the beginning of the value.  */
 265           while (isspace (cp[0]))
 266             ++cp;
 267
 268           if (cp[0] != '\0')
 269             {
 270               size_t alias_len;
 271               size_t value_len;
 272
 273               value = cp++;
 274               while (cp[0] != '\0' && !isspace (cp[0]))
 275                 ++cp;
 276               /* Terminate value.  */
 277               if (cp[0] == '\n')
 278                 {
 279                   /* This has to be done to make the following test
 280                      for the end of line possible.  We are looking for
 281                      the terminating '\n' which do not overwrite here.  */
 282                   *cp++ = '\0';
 283                   *cp = '\n';
 284                 }
 285               else if (cp[0] != '\0')
 286                 *cp++ = '\0';
 287
 288               if (nmap >= maxmap)
 289                 if (__builtin_expect (extend_alias_table (), 0))
 290                   return added;
 291
 292               alias_len = strlen (alias) + 1;
 293               value_len = strlen (value) + 1;
 294
 295               if (string_space_act + alias_len + value_len > string_space_max)
 296                 {
 297                   /* Increase size of memory pool.  */
 298                   size_t new_size = (string_space_max
 299                                      + (alias_len + value_len > 1024
 300                                         ? alias_len + value_len : 1024));
 301                   char *new_pool = (char *) realloc (string_space, new_size);
 302                   if (new_pool == NULL)
 303                     return added;
 304
 305                   if (__builtin_expect (string_space != new_pool, 0))
 306                     {
 307                       size_t i;
 308
 309                       for (i = 0; i < nmap; i++)
 310                         {
 311                           map[i].alias += new_pool - string_space;
 312                           map[i].value += new_pool - string_space;
 313                         }
 314                     }
 315
 316                   string_space = new_pool;
 317                   string_space_max = new_size;
 318                 }
 319
 320               map[nmap].alias = memcpy (&string_space[string_space_act],
 321                                         alias, alias_len);
 322               string_space_act += alias_len;
 323
 324               map[nmap].value = memcpy (&string_space[string_space_act],
 325                                         value, value_len);
 326               string_space_act += value_len;
 327
 328               ++nmap;
 329               ++added;
 330             }
 331         }
 332     }
 333
 334   /* Should we test for ferror()?  I think we have to silently ignore
 335      errors.  --drepper  */
 336   fclose (fp);
 337
 338   if (added > 0)
 339     qsort (map, nmap, sizeof (struct alias_map),
 340            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 341
 342   return added;
 343 }
 344
 345
 346 static int
 347 extend_alias_table ()
 348 {
 349   size_t new_size;
 350   struct alias_map *new_map;
 351
 352   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 353   new_map = (struct alias_map *) realloc (map, (new_size
 354                                                 * sizeof (struct alias_map)));
 355   if (new_map == NULL)
 356     /* Simply don't extend: we don't have any more core.  */
 357     return -1;
 358
 359   map = new_map;
 360   maxmap = new_size;
 361   return 0;
 362 }
 363
 364
 365 #ifdef _LIBC
 366 static void __attribute__ ((unused))
 367 free_mem (void)
 368 {
 369   if (string_space != NULL)
 370     free (string_space);
 371   if (map != NULL)
 372     free (map);
 373 }
 374 text_set_element (__libc_subfreeres, free_mem);
 375 #endif
 376
 377
 378 static int
 379 alias_compare (map1, map2)
 380      const struct alias_map *map1;
 381      const struct alias_map *map2;
 382 {
 383 #if defined _LIBC || defined HAVE_STRCASECMP
 384   return strcasecmp (map1->alias, map2->alias);
 385 #else
 386   const unsigned char *p1 = (const unsigned char *) map1->alias;
 387   const unsigned char *p2 = (const unsigned char *) map2->alias;
 388   unsigned char c1, c2;
 389
 390   if (p1 == p2)
 391     return 0;
 392
 393   do
 394     {
 395       /* I know this seems to be odd but the tolower() function in
 396          some systems libc cannot handle nonalpha characters.  */
 397       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 398       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 399       if (c1 == '\0')
 400         break;
 401       ++p1;
 402       ++p2;
 403     }
 404   while (c1 == c2);
 405
 406   return c1 - c2;
 407 #endif
 408 }