locale/findlocale.c

   1 /* Copyright (C) 1996-2001, 2002, 2003, 2006 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.str
  84                         + _nl_category_name_idxs[category]);
  85       if (*name == NULL || (*name)[0] == '\0')
  86         *name = getenv ("LANG");
  87     }
  88
  89   if (*name == NULL || (*name)[0] == '\0'
  90       || (__builtin_expect (__libc_enable_secure, 0)
  91           && strchr (*name, '/') != NULL))
  92     *name = (char *) _nl_C_name;
  93
  94   if (__builtin_expect (strcmp (*name, _nl_C_name), 1) == 0
  95       || __builtin_expect (strcmp (*name, _nl_POSIX_name), 1) == 0)
  96     {
  97       /* We need not load anything.  The needed data is contained in
  98          the library itself.  */
  99       *name = (char *) _nl_C_name;
 100       return _nl_C[category];
 101     }
 102
 103   /* We really have to load some data.  First we try the archive,
 104      but only if there was no LOCPATH environment variable specified.  */
 105   if (__builtin_expect (locale_path == NULL, 1))
 106     {
 107       struct locale_data *data = _nl_load_locale_from_archive (category, name);
 108       if (__builtin_expect (data != NULL, 1))
 109         return data;
 110
 111       /* Nothing in the archive.  Set the default path to search below.  */
 112       locale_path = _nl_default_locale_path;
 113       locale_path_len = sizeof _nl_default_locale_path;
 114     }
 115
 116   /* We really have to load some data.  First see whether the name is
 117      an alias.  Please note that this makes it impossible to have "C"
 118      or "POSIX" as aliases.  */
 119   loc_name = (char *) _nl_expand_alias (*name);
 120   if (loc_name == NULL)
 121     /* It is no alias.  */
 122     loc_name = (char *) *name;
 123
 124   /* Make a writable copy of the locale name.  */
 125   loc_name = strdupa (loc_name);
 126
 127   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
 128
 129                 language[_territory[.codeset]][@modifier]
 130
 131      Beside the first all of them are allowed to be missing.  If the
 132      full specified locale is not found, the less specific one are
 133      looked for.  The various part will be stripped off according to
 134      the following order:
 135                 (1) codeset
 136                 (2) normalized codeset
 137                 (3) territory
 138                 (4) modifier
 139    */
 140   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 141                            &codeset, &normalized_codeset);
 142
 143   /* If exactly this locale was already asked for we have an entry with
 144      the complete name.  */
 145   locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 146                                     locale_path, locale_path_len, mask,
 147                                     language, territory, codeset,
 148                                     normalized_codeset, modifier,
 149                                     _nl_category_names.str
 150                                     + _nl_category_name_idxs[category], 0);
 151
 152   if (locale_file == NULL)
 153     {
 154       /* Find status record for addressed locale file.  We have to search
 155          through all directories in the locale path.  */
 156       locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 157                                         locale_path, locale_path_len, mask,
 158                                         language, territory, codeset,
 159                                         normalized_codeset, modifier,
 160                                         _nl_category_names.str
 161                                         + _nl_category_name_idxs[category], 1);
 162       if (locale_file == NULL)
 163         /* This means we are out of core.  */
 164         return NULL;
 165     }
 166
 167   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 168   if (mask & XPG_NORM_CODESET)
 169     free ((void *) normalized_codeset);
 170
 171   if (locale_file->decided == 0)
 172     _nl_load_locale (locale_file, category);
 173
 174   if (locale_file->data == NULL)
 175     {
 176       int cnt;
 177       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 178         {
 179           if (locale_file->successor[cnt]->decided == 0)
 180             _nl_load_locale (locale_file->successor[cnt], category);
 181           if (locale_file->successor[cnt]->data != NULL)
 182             break;
 183         }
 184       /* Move the entry we found (or NULL) to the first place of
 185          successors.  */
 186       locale_file->successor[0] = locale_file->successor[cnt];
 187       locale_file = locale_file->successor[cnt];
 188
 189       if (locale_file == NULL)
 190         return NULL;
 191     }
 192
 193   /* The LC_CTYPE category allows to check whether a locale is really
 194      usable.  If the locale name contains a charset name and the
 195      charset name used in the locale (present in the LC_CTYPE data) is
 196      not the same (after resolving aliases etc) we reject the locale
 197      since using it would irritate users expecting the charset named
 198      in the locale name.  */
 199   if (codeset != NULL)
 200     {
 201       /* Get the codeset information from the locale file.  */
 202       static const int codeset_idx[] =
 203         {
 204           [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
 205           [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
 206           [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
 207           [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
 208           [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
 209           [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
 210           [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
 211           [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
 212           [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
 213           [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
 214           [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
 215           [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
 216         };
 217       const struct locale_data *data;
 218       const char *locale_codeset;
 219       char *clocale_codeset;
 220       char *ccodeset;
 221
 222       data = (const struct locale_data *) locale_file->data;
 223       locale_codeset =
 224         (const char *) data->values[codeset_idx[category]].string;
 225       assert (locale_codeset != NULL);
 226       /* Note the length of the allocated memory: +3 for up to two slashes
 227          and the NUL byte.  */
 228       clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
 229       strip (clocale_codeset, locale_codeset);
 230
 231       ccodeset = (char *) alloca (strlen (codeset) + 3);
 232       strip (ccodeset, codeset);
 233
 234       if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
 235                                  upstr (clocale_codeset,
 236                                         clocale_codeset)) != 0)
 237         /* The codesets are not identical, don't use the locale.  */
 238         return NULL;
 239     }
 240
 241   /* Determine the locale name for which loading succeeded.  This
 242      information comes from the file name.  The form is
 243      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 244   if (((const struct locale_data *) locale_file->data)->name == NULL)
 245     {
 246       char *cp, *endp;
 247
 248       endp = strrchr (locale_file->filename, '/');
 249       cp = endp - 1;
 250       while (cp[-1] != '/')
 251         --cp;
 252       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 253                                                                     endp - cp);
 254     }
 255
 256   /* Determine whether the user wants transliteration or not.  */
 257   if (modifier != NULL && __strcasecmp (modifier, "TRANSLIT") == 0)
 258     ((struct locale_data *) locale_file->data)->use_translit = 1;
 259
 260   /* Increment the usage count.  */
 261   if (((const struct locale_data *) locale_file->data)->usage_count
 262       < MAX_USAGE_COUNT)
 263     ++((struct locale_data *) locale_file->data)->usage_count;
 264
 265   return (struct locale_data *) locale_file->data;
 266 }
 267
 268
 269 /* Calling this function assumes the lock for handling global locale data
 270    is acquired.  */
 271 void
 272 internal_function
 273 _nl_remove_locale (int locale, struct locale_data *data)
 274 {
 275   if (--data->usage_count == 0)
 276     {
 277       if (data->alloc != ld_archive)
 278         {
 279           /* First search the entry in the list of loaded files.  */
 280           struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
 281
 282           /* Search for the entry.  It must be in the list.  Otherwise it
 283              is a bug and we crash badly.  */
 284           while ((struct locale_data *) ptr->data != data)
 285             ptr = ptr->next;
 286
 287           /* Mark the data as not available anymore.  So when the data has
 288              to be used again it is reloaded.  */
 289           ptr->decided = 0;
 290           ptr->data = NULL;
 291         }
 292
 293       /* This does the real work.  */
 294       _nl_unload_locale (data);
 295     }
 296 }