locale/findlocale.c

   1 /* Copyright (C) 1996-2001, 2002, 2003 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 #include "../iconv/gconv_int.h"
  32
  33
  34 #ifdef NL_CURRENT_INDIRECT
  35 # define DEFINE_CATEGORY(category, category_name, items, a) \
  36 extern struct locale_data _nl_C_##category; \
  37 weak_extern (_nl_C_##category)
  38 # include "categories.def"
  39 # undef DEFINE_CATEGORY
  40
  41 /* Array indexed by category of pointers to _nl_C_CATEGORY slots.
  42    Elements are zero for categories whose data is never used.  */
  43 struct locale_data *const _nl_C[] attribute_hidden =
  44   {
  45 # define DEFINE_CATEGORY(category, category_name, items, a) \
  46     [category] = &_nl_C_##category,
  47 # include "categories.def"
  48 # undef DEFINE_CATEGORY
  49   };
  50 #else
  51 # define _nl_C          (_nl_C_locobj.__locales)
  52 #endif
  53
  54
  55 /* For each category we keep a list of records for the locale files
  56    which are somehow addressed.  */
  57 struct loaded_l10nfile *_nl_locale_file_list[__LC_LAST];
  58
  59 const char _nl_default_locale_path[] attribute_hidden = LOCALEDIR;
  60
  61
  62 struct locale_data *
  63 internal_function
  64 _nl_find_locale (const char *locale_path, size_t locale_path_len,
  65                  int category, const char **name)
  66 {
  67   int mask;
  68   /* Name of the locale for this category.  */
  69   char *loc_name;
  70   const char *language;
  71   const char *modifier;
  72   const char *territory;
  73   const char *codeset;
  74   const char *normalized_codeset;
  75   struct loaded_l10nfile *locale_file;
  76
  77   if ((*name)[0] == '\0')
  78     {
  79       /* The user decides which locale to use by setting environment
  80          variables.  */
  81       *name = getenv ("LC_ALL");
  82       if (*name == NULL || (*name)[0] == '\0')
  83         *name = getenv (_nl_category_names[category]);
  84       if (*name == NULL || (*name)[0] == '\0')
  85         *name = getenv ("LANG");
  86     }
  87
  88   if (*name == NULL || (*name)[0] == '\0'
  89       || (__builtin_expect (__libc_enable_secure, 0)
  90           && strchr (*name, '/') != NULL))
  91     *name = (char *) _nl_C_name;
  92
  93   if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0
  94       || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0)
  95     {
  96       /* We need not load anything.  The needed data is contained in
  97          the library itself.  */
  98       *name = (char *) _nl_C_name;
  99       return _nl_C[category];
 100     }
 101
 102   /* We really have to load some data.  First we try the archive,
 103      but only if there was no LOCPATH environment variable specified.  */
 104   if (__builtin_expect (locale_path == NULL, 1))
 105     {
 106       struct locale_data *data = _nl_load_locale_from_archive (category, name);
 107       if (__builtin_expect (data != NULL, 1))
 108         return data;
 109
 110       /* Nothing in the archive.  Set the default path to search below.  */
 111       locale_path = _nl_default_locale_path;
 112       locale_path_len = sizeof _nl_default_locale_path;
 113     }
 114
 115   /* We really have to load some data.  First see whether the name is
 116      an alias.  Please note that this makes it impossible to have "C"
 117      or "POSIX" as aliases.  */
 118   loc_name = (char *) _nl_expand_alias (*name);
 119   if (loc_name == NULL)
 120     /* It is no alias.  */
 121     loc_name = (char *) *name;
 122
 123   /* Make a writable copy of the locale name.  */
 124   loc_name = strdupa (loc_name);
 125
 126   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
 127
 128                 language[_territory[.codeset]][@modifier]
 129
 130      Beside the first all of them are allowed to be missing.  If the
 131      full specified locale is not found, the less specific one are
 132      looked for.  The various part will be stripped off according to
 133      the following order:
 134                 (1) codeset
 135                 (2) normalized codeset
 136                 (3) territory
 137                 (4) modifier
 138    */
 139   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 140                            &codeset, &normalized_codeset);
 141
 142   /* If exactly this locale was already asked for we have an entry with
 143      the complete name.  */
 144   locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 145                                     locale_path, locale_path_len, mask,
 146                                     language, territory, codeset,
 147                                     normalized_codeset, modifier,
 148                                     _nl_category_names[category], 0);
 149
 150   if (locale_file == NULL)
 151     {
 152       /* Find status record for addressed locale file.  We have to search
 153          through all directories in the locale path.  */
 154       locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 155                                         locale_path, locale_path_len, mask,
 156                                         language, territory, codeset,
 157                                         normalized_codeset, modifier,
 158                                         _nl_category_names[category], 1);
 159       if (locale_file == NULL)
 160         /* This means we are out of core.  */
 161         return NULL;
 162     }
 163
 164   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 165   if (mask & XPG_NORM_CODESET)
 166     free ((void *) normalized_codeset);
 167
 168   if (locale_file->decided == 0)
 169     _nl_load_locale (locale_file, category);
 170
 171   if (locale_file->data == NULL)
 172     {
 173       int cnt;
 174       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 175         {
 176           if (locale_file->successor[cnt]->decided == 0)
 177             _nl_load_locale (locale_file->successor[cnt], category);
 178           if (locale_file->successor[cnt]->data != NULL)
 179             break;
 180         }
 181       /* Move the entry we found (or NULL) to the first place of
 182          successors.  */
 183       locale_file->successor[0] = locale_file->successor[cnt];
 184       locale_file = locale_file->successor[cnt];
 185
 186       if (locale_file == NULL)
 187         return NULL;
 188     }
 189
 190   /* The LC_CTYPE category allows to check whether a locale is really
 191      usable.  If the locale name contains a charset name and the
 192      charset name used in the locale (present in the LC_CTYPE data) is
 193      not the same (after resolving aliases etc) we reject the locale
 194      since using it would irritate users expecting the charset named
 195      in the locale name.  */
 196   if (codeset != NULL)
 197     {
 198       /* Get the codeset information from the locale file.  */
 199       static const int codeset_idx[] =
 200         {
 201           [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
 202           [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
 203           [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
 204           [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
 205           [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
 206           [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
 207           [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
 208           [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
 209           [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
 210           [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
 211           [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
 212           [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
 213         };
 214       const struct locale_data *data;
 215       const char *locale_codeset;
 216       char *clocale_codeset;
 217       char *ccodeset;
 218
 219       data = (const struct locale_data *) locale_file->data;
 220       locale_codeset =
 221         (const char *) data->values[codeset_idx[category]].string;
 222       assert (locale_codeset != NULL);
 223       /* Note the length of the allocated memory: +3 for up to two slashes
 224          and the NUL byte.  */
 225       clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
 226       strip (clocale_codeset, locale_codeset);
 227
 228       ccodeset = (char *) alloca (strlen (codeset) + 3);
 229       strip (ccodeset, codeset);
 230
 231       if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
 232                                  upstr (clocale_codeset,
 233                                         clocale_codeset)) != 0)
 234         /* The codesets are not identical, don't use the locale.  */
 235         return NULL;
 236     }
 237
 238   /* Determine the locale name for which loading succeeded.  This
 239      information comes from the file name.  The form is
 240      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 241   if (((const struct locale_data *) locale_file->data)->name == NULL)
 242     {
 243       char *cp, *endp;
 244
 245       endp = strrchr (locale_file->filename, '/');
 246       cp = endp - 1;
 247       while (cp[-1] != '/')
 248         --cp;
 249       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 250                                                                     endp - cp);
 251     }
 252
 253   /* Determine whether the user wants transliteration or not.  */
 254   if (modifier != NULL && __strcasecmp (modifier, "TRANSLIT") == 0)
 255     ((struct locale_data *) locale_file->data)->use_translit = 1;
 256
 257   /* Increment the usage count.  */
 258   if (((const struct locale_data *) locale_file->data)->usage_count
 259       < MAX_USAGE_COUNT)
 260     ++((struct locale_data *) locale_file->data)->usage_count;
 261
 262   return (struct locale_data *) locale_file->data;
 263 }
 264
 265
 266 /* Calling this function assumes the lock for handling global locale data
 267    is acquired.  */
 268 void
 269 internal_function
 270 _nl_remove_locale (int locale, struct locale_data *data)
 271 {
 272   if (--data->usage_count == 0)
 273     {
 274       if (data->alloc != ld_archive)
 275         {
 276           /* First search the entry in the list of loaded files.  */
 277           struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
 278
 279           /* Search for the entry.  It must be in the list.  Otherwise it
 280              is a bug and we crash badly.  */
 281           while ((struct locale_data *) ptr->data != data)
 282             ptr = ptr->next;
 283
 284           /* Mark the data as not available anymore.  So when the data has
 285              to be used again it is reloaded.  */
 286           ptr->decided = 0;
 287           ptr->data = NULL;
 288         }
 289
 290       /* This does the real work.  */
 291       _nl_unload_locale (data);
 292     }
 293 }