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