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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 <config.h>
  27 #endif
  28
  29 #include <ctype.h>
  30 #include <stdio.h>
  31 #include <sys/types.h>
  32
  33 #ifdef __GNUC__
  34 # define alloca __builtin_alloca
  35 # define HAVE_ALLOCA 1
  36 #else
  37 # if defined HAVE_ALLOCA_H || defined _LIBC
  38 #  include <alloca.h>
  39 # else
  40 #  ifdef _AIX
  41  #pragma alloca
  42 #  else
  43 #   ifndef alloca
  44 char *alloca ();
  45 #   endif
  46 #  endif
  47 # endif
  48 #endif
  49
  50 #include <stdlib.h>
  51
  52 #include <string.h>
  53 #if !HAVE_STRCHR && !defined _LIBC
  54 # ifndef strchr
  55 #  define strchr index
  56 # endif
  57 #endif
  58
  59 #include "gettextP.h"
  60
  61 /* @@ end of prolog @@ */
  62
  63 #ifdef _LIBC
  64 /* Rename the non ANSI C functions.  This is required by the standard
  65    because some ANSI C functions will require linking with this object
  66    file and the name space must not be polluted.  */
  67 # define strcasecmp __strcasecmp
  68
  69 # ifndef mempcpy
  70 #  define mempcpy __mempcpy
  71 # endif
  72 # define HAVE_MEMPCPY   1
  73
  74 /* We need locking here since we can be called from different places.  */
  75 # include <bits/libc-lock.h>
  76
  77 __libc_lock_define_initialized (static, lock);
  78 #endif
  79
  80 #ifndef internal_function
  81 # define internal_function
  82 #endif
  83
  84 /* For those losing systems which don't have `alloca' we have to add
  85    some additional code emulating it.  */
  86 #ifdef HAVE_ALLOCA
  87 # define freea(p) /* nothing */
  88 #else
  89 # define alloca(n) malloc (n)
  90 # define freea(p) free (p)
  91 #endif
  92
  93 #if defined _LIBC_REENTRANT || defined HAVE_FGETS_UNLOCKED
  94 # undef fgets
  95 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
  96 #endif
  97 #if defined _LIBC_REENTRANT || defined HAVE_FEOF_UNLOCKED
  98 # undef feof
  99 # define feof(s) feof_unlocked (s)
 100 #endif
 101
 102
 103 struct alias_map
 104 {
 105   const char *alias;
 106   const char *value;
 107 };
 108
 109
 110 static char *string_space;
 111 static size_t string_space_act;
 112 static size_t string_space_max;
 113 static struct alias_map *map;
 114 static size_t nmap;
 115 static size_t maxmap;
 116
 117
 118 /* Prototypes for local functions.  */
 119 static size_t read_alias_file PARAMS ((const char *fname, int fname_len))
 120      internal_function;
 121 static int extend_alias_table PARAMS ((void));
 122 static int alias_compare PARAMS ((const struct alias_map *map1,
 123                                   const struct alias_map *map2));
 124
 125
 126 const char *
 127 _nl_expand_alias (name)
 128     const char *name;
 129 {
 130   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 131   struct alias_map *retval;
 132   const char *result = NULL;
 133   size_t added;
 134
 135 #ifdef _LIBC
 136   __libc_lock_lock (lock);
 137 #endif
 138
 139   do
 140     {
 141       struct alias_map item;
 142
 143       item.alias = name;
 144
 145       if (nmap > 0)
 146         retval = (struct alias_map *) bsearch (&item, map, nmap,
 147                                                sizeof (struct alias_map),
 148                                                (int (*) PARAMS ((const void *,
 149                                                                  const void *))
 150                                                 ) alias_compare);
 151       else
 152         retval = NULL;
 153
 154       /* We really found an alias.  Return the value.  */
 155       if (retval != NULL)
 156         {
 157           result = retval->value;
 158           break;
 159         }
 160
 161       /* Perhaps we can find another alias file.  */
 162       added = 0;
 163       while (added == 0 && locale_alias_path[0] != '\0')
 164         {
 165           const char *start;
 166
 167           while (locale_alias_path[0] == PATH_SEPARATOR)
 168             ++locale_alias_path;
 169           start = locale_alias_path;
 170
 171           while (locale_alias_path[0] != '\0'
 172                  && locale_alias_path[0] != PATH_SEPARATOR)
 173             ++locale_alias_path;
 174
 175           if (start < locale_alias_path)
 176             added = read_alias_file (start, locale_alias_path - start);
 177         }
 178     }
 179   while (added != 0);
 180
 181 #ifdef _LIBC
 182   __libc_lock_unlock (lock);
 183 #endif
 184
 185   return result;
 186 }
 187
 188
 189 static size_t
 190 internal_function
 191 read_alias_file (fname, fname_len)
 192      const char *fname;
 193      int fname_len;
 194 {
 195   FILE *fp;
 196   char *full_fname;
 197   size_t added;
 198   static const char aliasfile[] = "/locale.alias";
 199
 200   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 201 #ifdef HAVE_MEMPCPY
 202   mempcpy (mempcpy (full_fname, fname, fname_len),
 203            aliasfile, sizeof aliasfile);
 204 #else
 205   memcpy (full_fname, fname, fname_len);
 206   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 207 #endif
 208
 209   fp = fopen (full_fname, "r");
 210   freea (full_fname);
 211   if (fp == NULL)
 212     return 0;
 213
 214   added = 0;
 215   while (!feof (fp))
 216     {
 217       /* It is a reasonable approach to use a fix buffer here because
 218          a) we are only interested in the first two fields
 219          b) these fields must be usable as file names and so must not
 220             be that long
 221        */
 222       char buf[BUFSIZ];
 223       char *alias;
 224       char *value;
 225       char *cp;
 226
 227       if (fgets (buf, sizeof buf, fp) == NULL)
 228         /* EOF reached.  */
 229         break;
 230
 231       /* Possibly not the whole line fits into the buffer.  Ignore
 232          the rest of the line.  */
 233       if (strchr (buf, '\n') == NULL)
 234         {
 235           char altbuf[BUFSIZ];
 236           do
 237             if (fgets (altbuf, sizeof altbuf, fp) == NULL)
 238               /* Make sure the inner loop will be left.  The outer loop
 239                  will exit at the `feof' test.  */
 240               break;
 241           while (strchr (altbuf, '\n') == NULL);
 242         }
 243
 244       cp = buf;
 245       /* Ignore leading white space.  */
 246       while (isspace (cp[0]))
 247         ++cp;
 248
 249       /* A leading '#' signals a comment line.  */
 250       if (cp[0] != '\0' && cp[0] != '#')
 251         {
 252           alias = cp++;
 253           while (cp[0] != '\0' && !isspace (cp[0]))
 254             ++cp;
 255           /* Terminate alias name.  */
 256           if (cp[0] != '\0')
 257             *cp++ = '\0';
 258
 259           /* Now look for the beginning of the value.  */
 260           while (isspace (cp[0]))
 261             ++cp;
 262
 263           if (cp[0] != '\0')
 264             {
 265               size_t alias_len;
 266               size_t value_len;
 267
 268               value = cp++;
 269               while (cp[0] != '\0' && !isspace (cp[0]))
 270                 ++cp;
 271               /* Terminate value.  */
 272               if (cp[0] == '\n')
 273                 {
 274                   /* This has to be done to make the following test
 275                      for the end of line possible.  We are looking for
 276                      the terminating '\n' which do not overwrite here.  */
 277                   *cp++ = '\0';
 278                   *cp = '\n';
 279                 }
 280               else if (cp[0] != '\0')
 281                 *cp++ = '\0';
 282
 283               if (nmap >= maxmap)
 284                 if (__builtin_expect (extend_alias_table (), 0))
 285                   return added;
 286
 287               alias_len = strlen (alias) + 1;
 288               value_len = strlen (value) + 1;
 289
 290               if (string_space_act + alias_len + value_len > string_space_max)
 291                 {
 292                   /* Increase size of memory pool.  */
 293                   size_t new_size = (string_space_max
 294                                      + (alias_len + value_len > 1024
 295                                         ? alias_len + value_len : 1024));
 296                   char *new_pool = (char *) realloc (string_space, new_size);
 297                   if (new_pool == NULL)
 298                     return added;
 299
 300                   if (__builtin_expect (string_space != new_pool, 0))
 301                     {
 302                       size_t i;
 303
 304                       for (i = 0; i < nmap; i++)
 305                         {
 306                           map[i].alias += new_pool - string_space;
 307                           map[i].value += new_pool - string_space;
 308                         }
 309                     }
 310
 311                   string_space = new_pool;
 312                   string_space_max = new_size;
 313                 }
 314
 315               map[nmap].alias = memcpy (&string_space[string_space_act],
 316                                         alias, alias_len);
 317               string_space_act += alias_len;
 318
 319               map[nmap].value = memcpy (&string_space[string_space_act],
 320                                         value, value_len);
 321               string_space_act += value_len;
 322
 323               ++nmap;
 324               ++added;
 325             }
 326         }
 327     }
 328
 329   /* Should we test for ferror()?  I think we have to silently ignore
 330      errors.  --drepper  */
 331   fclose (fp);
 332
 333   if (added > 0)
 334     qsort (map, nmap, sizeof (struct alias_map),
 335            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 336
 337   return added;
 338 }
 339
 340
 341 static int
 342 extend_alias_table ()
 343 {
 344   size_t new_size;
 345   struct alias_map *new_map;
 346
 347   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 348   new_map = (struct alias_map *) realloc (map, (new_size
 349                                                 * sizeof (struct alias_map)));
 350   if (new_map == NULL)
 351     /* Simply don't extend: we don't have any more core.  */
 352     return -1;
 353
 354   map = new_map;
 355   maxmap = new_size;
 356   return 0;
 357 }
 358
 359
 360 #ifdef _LIBC
 361 static void __attribute__ ((unused))
 362 free_mem (void)
 363 {
 364   if (string_space != NULL)
 365     free (string_space);
 366   if (map != NULL)
 367     free (map);
 368 }
 369 text_set_element (__libc_subfreeres, free_mem);
 370 #endif
 371
 372
 373 static int
 374 alias_compare (map1, map2)
 375      const struct alias_map *map1;
 376      const struct alias_map *map2;
 377 {
 378 #if defined _LIBC || defined HAVE_STRCASECMP
 379   return strcasecmp (map1->alias, map2->alias);
 380 #else
 381   const unsigned char *p1 = (const unsigned char *) map1->alias;
 382   const unsigned char *p2 = (const unsigned char *) map2->alias;
 383   unsigned char c1, c2;
 384
 385   if (p1 == p2)
 386     return 0;
 387
 388   do
 389     {
 390       /* I know this seems to be odd but the tolower() function in
 391          some systems libc cannot handle nonalpha characters.  */
 392       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 393       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 394       if (c1 == '\0')
 395         break;
 396       ++p1;
 397       ++p2;
 398     }
 399   while (c1 == c2);
 400
 401   return c1 - c2;
 402 #endif
 403 }