locale/findlocale.c

   1 /* Copyright (C) 1996-2001, 2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <assert.h>
  21 #include <locale.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #ifdef _POSIX_MAPPED_FILES
  26 # include <sys/mman.h>
  27 #endif
  28
  29 #include "localeinfo.h"
  30 #include "../iconv/gconv_charset.h"
  31
  32
  33 #ifdef NL_CURRENT_INDIRECT
  34 # define DEFINE_CATEGORY(category, category_name, items, a) \
  35 extern struct locale_data _nl_C_##category; \
  36 weak_extern (_nl_C_##category)
  37 # include "categories.def"
  38 # undef DEFINE_CATEGORY
  39
  40 /* Array indexed by category of pointers to _nl_C_CATEGORY slots.
  41    Elements are zero for categories whose data is never used.  */
  42 struct locale_data *const _nl_C[] attribute_hidden =
  43   {
  44 # define DEFINE_CATEGORY(category, category_name, items, a) \
  45     [category] = &_nl_C_##category,
  46 # include "categories.def"
  47 # undef DEFINE_CATEGORY
  48   };
  49 #else
  50 # define _nl_C          (_nl_C_locobj.__locales)
  51 #endif
  52
  53
  54 /* For each category we keep a list of records for the locale files
  55    which are somehow addressed.  */
  56 struct loaded_l10nfile *_nl_locale_file_list[__LC_LAST];
  57
  58 const char _nl_default_locale_path[] attribute_hidden = LOCALEDIR;
  59
  60
  61 struct locale_data *
  62 internal_function
  63 _nl_find_locale (const char *locale_path, size_t locale_path_len,
  64                  int category, const char **name)
  65 {
  66   int mask;
  67   /* Name of the locale for this category.  */
  68   char *loc_name;
  69   const char *language;
  70   const char *modifier;
  71   const char *territory;
  72   const char *codeset;
  73   const char *normalized_codeset;
  74   struct loaded_l10nfile *locale_file;
  75
  76   if ((*name)[0] == '\0')
  77     {
  78       /* The user decides which locale to use by setting environment
  79          variables.  */
  80       *name = getenv ("LC_ALL");
  81       if (*name == NULL || (*name)[0] == '\0')
  82         *name = getenv (_nl_category_names[category]);
  83       if (*name == NULL || (*name)[0] == '\0')
  84         *name = getenv ("LANG");
  85     }
  86
  87   if (*name == NULL || (*name)[0] == '\0'
  88       || (__builtin_expect (__libc_enable_secure, 0)
  89           && strchr (*name, '/') != NULL))
  90     *name = (char *) _nl_C_name;
  91
  92   if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0
  93       || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0)
  94     {
  95       /* We need not load anything.  The needed data is contained in
  96          the library itself.  */
  97       *name = (char *) _nl_C_name;
  98       return _nl_C[category];
  99     }
 100
 101   /* We really have to load some data.  First we try the archive,
 102      but only if there was no LOCPATH environment variable specified.  */
 103   if (__builtin_expect (locale_path == NULL, 1))
 104     {
 105       struct locale_data *data = _nl_load_locale_from_archive (category, name);
 106       if (__builtin_expect (data != NULL, 1))
 107         return data;
 108
 109       /* Nothing in the archive.  Set the default path to search below.  */
 110       locale_path = _nl_default_locale_path;
 111       locale_path_len = sizeof _nl_default_locale_path;
 112     }
 113
 114   /* We really have to load some data.  First see whether the name is
 115      an alias.  Please note that this makes it impossible to have "C"
 116      or "POSIX" as aliases.  */
 117   loc_name = (char *) _nl_expand_alias (*name);
 118   if (loc_name == NULL)
 119     /* It is no alias.  */
 120     loc_name = (char *) *name;
 121
 122   /* Make a writable copy of the locale name.  */
 123   loc_name = strdupa (loc_name);
 124
 125   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
 126
 127                 language[_territory[.codeset]][@modifier]
 128
 129      Beside the first all of them are allowed to be missing.  If the
 130      full specified locale is not found, the less specific one are
 131      looked for.  The various part will be stripped off according to
 132      the following order:
 133                 (1) codeset
 134                 (2) normalized codeset
 135                 (3) territory
 136                 (4) modifier
 137    */
 138   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 139                            &codeset, &normalized_codeset);
 140
 141   /* If exactly this locale was already asked for we have an entry with
 142      the complete name.  */
 143   locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 144                                     locale_path, locale_path_len, mask,
 145                                     language, territory, codeset,
 146                                     normalized_codeset, modifier,
 147                                     _nl_category_names[category], 0);
 148
 149   if (locale_file == NULL)
 150     {
 151       /* Find status record for addressed locale file.  We have to search
 152          through all directories in the locale path.  */
 153       locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 154                                         locale_path, locale_path_len, mask,
 155                                         language, territory, codeset,
 156                                         normalized_codeset, modifier,
 157                                         _nl_category_names[category], 1);
 158       if (locale_file == NULL)
 159         /* This means we are out of core.  */
 160         return NULL;
 161     }
 162
 163   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 164   if (mask & XPG_NORM_CODESET)
 165     free ((void *) normalized_codeset);
 166
 167   if (locale_file->decided == 0)
 168     _nl_load_locale (locale_file, category);
 169
 170   if (locale_file->data == NULL)
 171     {
 172       int cnt;
 173       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 174         {
 175           if (locale_file->successor[cnt]->decided == 0)
 176             _nl_load_locale (locale_file->successor[cnt], category);
 177           if (locale_file->successor[cnt]->data != NULL)
 178             break;
 179         }
 180       /* Move the entry we found (or NULL) to the first place of
 181          successors.  */
 182       locale_file->successor[0] = locale_file->successor[cnt];
 183       locale_file = locale_file->successor[cnt];
 184
 185       if (locale_file == NULL)
 186         return NULL;
 187     }
 188
 189   /* The LC_CTYPE category allows to check whether a locale is really
 190      usable.  If the locale name contains a charset name and the
 191      charset name used in the locale (present in the LC_CTYPE data) is
 192      not the same (after resolving aliases etc) we reject the locale
 193      since using it would irritate users expecting the charset named
 194      in the locale name.  */
 195   if (codeset != NULL)
 196     {
 197       /* Get the codeset information from the locale file.  */
 198       static const int codeset_idx[] =
 199         {
 200           [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
 201           [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
 202           [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
 203           [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
 204           [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
 205           [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
 206           [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
 207           [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
 208           [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
 209           [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
 210           [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
 211           [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
 212         };
 213       const struct locale_data *data;
 214       const char *locale_codeset;
 215       char *clocale_codeset;
 216       char *ccodeset;
 217
 218       data = (const struct locale_data *) locale_file->data;
 219       locale_codeset =
 220         (const char *) data->values[codeset_idx[category]].string;
 221       assert (locale_codeset != NULL);
 222       /* Note the length of the allocated memory: +3 for up to two slashes
 223          and the NUL byte.  */
 224       clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
 225       strip (clocale_codeset, locale_codeset);
 226
 227       ccodeset = (char *) alloca (strlen (codeset) + 3);
 228       strip (ccodeset, codeset);
 229
 230       if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
 231                                  upstr (clocale_codeset,
 232                                         clocale_codeset)) != 0)
 233         /* The codesets are not identical, don't use the locale.  */
 234         return NULL;
 235     }
 236
 237   /* Determine the locale name for which loading succeeded.  This
 238      information comes from the file name.  The form is
 239      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 240   if (((const struct locale_data *) locale_file->data)->name == NULL)
 241     {
 242       char *cp, *endp;
 243
 244       endp = strrchr (locale_file->filename, '/');
 245       cp = endp - 1;
 246       while (cp[-1] != '/')
 247         --cp;
 248       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 249                                                                     endp - cp);
 250     }
 251
 252   /* Determine whether the user wants transliteration or not.  */
 253   if (modifier != NULL && __strcasecmp (modifier, "TRANSLIT") == 0)
 254     ((struct locale_data *) locale_file->data)->use_translit = 1;
 255
 256   /* Increment the usage count.  */
 257   if (((const struct locale_data *) locale_file->data)->usage_count
 258       < MAX_USAGE_COUNT)
 259     ++((struct locale_data *) locale_file->data)->usage_count;
 260
 261   return (struct locale_data *) locale_file->data;
 262 }
 263
 264
 265 /* Calling this function assumes the lock for handling global locale data
 266    is acquired.  */
 267 void
 268 internal_function
 269 _nl_remove_locale (int locale, struct locale_data *data)
 270 {
 271   if (--data->usage_count == 0)
 272     {
 273       if (data->alloc != ld_archive)
 274         {
 275           /* First search the entry in the list of loaded files.  */
 276           struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
 277
 278           /* Search for the entry.  It must be in the list.  Otherwise it
 279              is a bug and we crash badly.  */
 280           while ((struct locale_data *) ptr->data != data)
 281             ptr = ptr->next;
 282
 283           /* Mark the data as not available anymore.  So when the data has
 284              to be used again it is reloaded.  */
 285           ptr->decided = 0;
 286           ptr->data = NULL;
 287         }
 288
 289       /* This does the real work.  */
 290       _nl_unload_locale (data);
 291     }
 292 }