locale/findlocale.c

   1 /* Copyright (C) 1996-2003, 2006, 2010, 2011 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   if (mask == -1)
 144     /* Memory allocate problem.  */
 145     return NULL;
 146
 147   /* If exactly this locale was already asked for we have an entry with
 148      the complete name.  */
 149   locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 150                                     locale_path, locale_path_len, mask,
 151                                     language, territory, codeset,
 152                                     normalized_codeset, modifier,
 153                                     _nl_category_names.str
 154                                     + _nl_category_name_idxs[category], 0);
 155
 156   if (locale_file == NULL)
 157     {
 158       /* Find status record for addressed locale file.  We have to search
 159          through all directories in the locale path.  */
 160       locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
 161                                         locale_path, locale_path_len, mask,
 162                                         language, territory, codeset,
 163                                         normalized_codeset, modifier,
 164                                         _nl_category_names.str
 165                                         + _nl_category_name_idxs[category], 1);
 166       if (locale_file == NULL)
 167         /* This means we are out of core.  */
 168         return NULL;
 169     }
 170
 171   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 172   if (mask & XPG_NORM_CODESET)
 173     free ((void *) normalized_codeset);
 174
 175   if (locale_file->decided == 0)
 176     _nl_load_locale (locale_file, category);
 177
 178   if (locale_file->data == NULL)
 179     {
 180       int cnt;
 181       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 182         {
 183           if (locale_file->successor[cnt]->decided == 0)
 184             _nl_load_locale (locale_file->successor[cnt], category);
 185           if (locale_file->successor[cnt]->data != NULL)
 186             break;
 187         }
 188       /* Move the entry we found (or NULL) to the first place of
 189          successors.  */
 190       locale_file->successor[0] = locale_file->successor[cnt];
 191       locale_file = locale_file->successor[cnt];
 192
 193       if (locale_file == NULL)
 194         return NULL;
 195     }
 196
 197   /* The LC_CTYPE category allows to check whether a locale is really
 198      usable.  If the locale name contains a charset name and the
 199      charset name used in the locale (present in the LC_CTYPE data) is
 200      not the same (after resolving aliases etc) we reject the locale
 201      since using it would irritate users expecting the charset named
 202      in the locale name.  */
 203   if (codeset != NULL)
 204     {
 205       /* Get the codeset information from the locale file.  */
 206       static const int codeset_idx[] =
 207         {
 208           [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
 209           [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
 210           [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
 211           [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
 212           [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
 213           [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
 214           [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
 215           [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
 216           [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
 217           [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
 218           [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
 219           [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
 220         };
 221       const struct __locale_data *data;
 222       const char *locale_codeset;
 223       char *clocale_codeset;
 224       char *ccodeset;
 225
 226       data = (const struct __locale_data *) locale_file->data;
 227       locale_codeset =
 228         (const char *) data->values[codeset_idx[category]].string;
 229       assert (locale_codeset != NULL);
 230       /* Note the length of the allocated memory: +3 for up to two slashes
 231          and the NUL byte.  */
 232       clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
 233       strip (clocale_codeset, locale_codeset);
 234
 235       ccodeset = (char *) alloca (strlen (codeset) + 3);
 236       strip (ccodeset, codeset);
 237
 238       if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
 239                                  upstr (clocale_codeset,
 240                                         clocale_codeset)) != 0)
 241         /* The codesets are not identical, don't use the locale.  */
 242         return NULL;
 243     }
 244
 245   /* Determine the locale name for which loading succeeded.  This
 246      information comes from the file name.  The form is
 247      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 248   if (((const struct __locale_data *) locale_file->data)->name == NULL)
 249     {
 250       char *cp, *endp;
 251
 252       endp = strrchr (locale_file->filename, '/');
 253       cp = endp - 1;
 254       while (cp[-1] != '/')
 255         --cp;
 256       ((struct __locale_data *) locale_file->data)->name
 257         = __strndup (cp, endp - cp);
 258     }
 259
 260   /* Determine whether the user wants transliteration or not.  */
 261   if (modifier != NULL
 262       && __strcasecmp_l (modifier, "TRANSLIT", _nl_C_locobj_ptr) == 0)
 263     ((struct __locale_data *) locale_file->data)->use_translit = 1;
 264
 265   /* Increment the usage count.  */
 266   if (((const struct __locale_data *) locale_file->data)->usage_count
 267       < MAX_USAGE_COUNT)
 268     ++((struct __locale_data *) locale_file->data)->usage_count;
 269
 270   return (struct __locale_data *) locale_file->data;
 271 }
 272
 273
 274 /* Calling this function assumes the lock for handling global locale data
 275    is acquired.  */
 276 void
 277 internal_function
 278 _nl_remove_locale (int locale, struct __locale_data *data)
 279 {
 280   if (--data->usage_count == 0)
 281     {
 282       if (data->alloc != ld_archive)
 283         {
 284           /* First search the entry in the list of loaded files.  */
 285           struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
 286
 287           /* Search for the entry.  It must be in the list.  Otherwise it
 288              is a bug and we crash badly.  */
 289           while ((struct __locale_data *) ptr->data != data)
 290             ptr = ptr->next;
 291
 292           /* Mark the data as not available anymore.  So when the data has
 293              to be used again it is reloaded.  */
 294           ptr->decided = 0;
 295           ptr->data = NULL;
 296         }
 297
 298       /* This does the real work.  */
 299       _nl_unload_locale (data);
 300     }
 301 }