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