locale/findlocale.c

   1 /* Copyright (C) 1996-2001, 2002, 2003, 2006, 2010 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
 108         = _nl_load_locale_from_archive (category, name);
 109       if (__builtin_expect (data != NULL, 1))
 110         return data;
 111
 112       /* Nothing in the archive.  Set the default path to search below.  */
 113       locale_path = _nl_default_locale_path;
 114       locale_path_len = sizeof _nl_default_locale_path;
 115     }
 116
 117   /* We really have to load some data.  First see whether the name is
 118      an alias.  Please note that this makes it impossible to have "C"
 119      or "POSIX" as aliases.  */
 120   loc_name = (char *) _nl_expand_alias (*name);
 121   if (loc_name == NULL)
 122     /* It is no alias.  */
 123     loc_name = (char *) *name;
 124
 125   /* Make a writable copy of the locale name.  */
 126   loc_name = strdupa (loc_name);
 127
 128   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
 129
 130                 language[_territory[.codeset]][@modifier]
 131
 132      Beside the first all of them are allowed to be missing.  If the
 133      full specified locale is not found, the less specific one are
 134      looked for.  The various part will be stripped off according to
 135      the following order:
 136                 (1) codeset
 137                 (2) normalized codeset
 138                 (3) territory
 139                 (4) modifier
 140    */
 141   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 142                            &codeset, &normalized_codeset);
 143
 144   /* If exactly this locale was already asked for we have an entry with
 145      the complete name.  */
 146   locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 147                                     locale_path, locale_path_len, mask,
 148                                     language, territory, codeset,
 149                                     normalized_codeset, modifier,
 150                                     _nl_category_names.str
 151                                     + _nl_category_name_idxs[category], 0);
 152
 153   if (locale_file == NULL)
 154     {
 155       /* Find status record for addressed locale file.  We have to search
 156          through all directories in the locale path.  */
 157       locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 158                                         locale_path, locale_path_len, mask,
 159                                         language, territory, codeset,
 160                                         normalized_codeset, modifier,
 161                                         _nl_category_names.str
 162                                         + _nl_category_name_idxs[category], 1);
 163       if (locale_file == NULL)
 164         /* This means we are out of core.  */
 165         return NULL;
 166     }
 167
 168   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 169   if (mask & XPG_NORM_CODESET)
 170     free ((void *) normalized_codeset);
 171
 172   if (locale_file->decided == 0)
 173     _nl_load_locale (locale_file, category);
 174
 175   if (locale_file->data == NULL)
 176     {
 177       int cnt;
 178       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 179         {
 180           if (locale_file->successor[cnt]->decided == 0)
 181             _nl_load_locale (locale_file->successor[cnt], category);
 182           if (locale_file->successor[cnt]->data != NULL)
 183             break;
 184         }
 185       /* Move the entry we found (or NULL) to the first place of
 186          successors.  */
 187       locale_file->successor[0] = locale_file->successor[cnt];
 188       locale_file = locale_file->successor[cnt];
 189
 190       if (locale_file == NULL)
 191         return NULL;
 192     }
 193
 194   /* The LC_CTYPE category allows to check whether a locale is really
 195      usable.  If the locale name contains a charset name and the
 196      charset name used in the locale (present in the LC_CTYPE data) is
 197      not the same (after resolving aliases etc) we reject the locale
 198      since using it would irritate users expecting the charset named
 199      in the locale name.  */
 200   if (codeset != NULL)
 201     {
 202       /* Get the codeset information from the locale file.  */
 203       static const int codeset_idx[] =
 204         {
 205           [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
 206           [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
 207           [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
 208           [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
 209           [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
 210           [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
 211           [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
 212           [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
 213           [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
 214           [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
 215           [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
 216           [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
 217         };
 218       const struct __locale_data *data;
 219       const char *locale_codeset;
 220       char *clocale_codeset;
 221       char *ccodeset;
 222
 223       data = (const struct __locale_data *) locale_file->data;
 224       locale_codeset =
 225         (const char *) data->values[codeset_idx[category]].string;
 226       assert (locale_codeset != NULL);
 227       /* Note the length of the allocated memory: +3 for up to two slashes
 228          and the NUL byte.  */
 229       clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
 230       strip (clocale_codeset, locale_codeset);
 231
 232       ccodeset = (char *) alloca (strlen (codeset) + 3);
 233       strip (ccodeset, codeset);
 234
 235       if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
 236                                  upstr (clocale_codeset,
 237                                         clocale_codeset)) != 0)
 238         /* The codesets are not identical, don't use the locale.  */
 239         return NULL;
 240     }
 241
 242   /* Determine the locale name for which loading succeeded.  This
 243      information comes from the file name.  The form is
 244      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 245   if (((const struct __locale_data *) locale_file->data)->name == NULL)
 246     {
 247       char *cp, *endp;
 248
 249       endp = strrchr (locale_file->filename, '/');
 250       cp = endp - 1;
 251       while (cp[-1] != '/')
 252         --cp;
 253       ((struct __locale_data *) locale_file->data)->name
 254         = __strndup (cp, endp - cp);
 255     }
 256
 257   /* Determine whether the user wants transliteration or not.  */
 258   if (modifier != NULL && __strcasecmp (modifier, "TRANSLIT") == 0)
 259     ((struct __locale_data *) locale_file->data)->use_translit = 1;
 260
 261   /* Increment the usage count.  */
 262   if (((const struct __locale_data *) locale_file->data)->usage_count
 263       < MAX_USAGE_COUNT)
 264     ++((struct __locale_data *) locale_file->data)->usage_count;
 265
 266   return (struct __locale_data *) locale_file->data;
 267 }
 268
 269
 270 /* Calling this function assumes the lock for handling global locale data
 271    is acquired.  */
 272 void
 273 internal_function
 274 _nl_remove_locale (int locale, struct __locale_data *data)
 275 {
 276   if (--data->usage_count == 0)
 277     {
 278       if (data->alloc != ld_archive)
 279         {
 280           /* First search the entry in the list of loaded files.  */
 281           struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
 282
 283           /* Search for the entry.  It must be in the list.  Otherwise it
 284              is a bug and we crash badly.  */
 285           while ((struct __locale_data *) ptr->data != data)
 286             ptr = ptr->next;
 287
 288           /* Mark the data as not available anymore.  So when the data has
 289              to be used again it is reloaded.  */
 290           ptr->decided = 0;
 291           ptr->data = NULL;
 292         }
 293
 294       /* This does the real work.  */
 295       _nl_unload_locale (data);
 296     }
 297 }