intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-1999, 2000-2001, 2003, 2005 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify it
   5    under the terms of the GNU Library General Public License as published
   6    by the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with this program; if not, write to the Free Software
  16    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  17    USA.  */
  18
  19 /* Tell glibc's <string.h> to provide a prototype for mempcpy().
  20    This must come before <config.h> because <config.h> may include
  21    <features.h>, and once <features.h> has been included, it's too late.  */
  22 #ifndef _GNU_SOURCE
  23 # define _GNU_SOURCE    1
  24 #endif
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include <config.h>
  28 #endif
  29
  30 #include <ctype.h>
  31 #include <stdio.h>
  32 #if defined _LIBC || defined HAVE___FSETLOCKING
  33 # include <stdio_ext.h>
  34 #endif
  35 #include <sys/types.h>
  36
  37 #ifdef __GNUC__
  38 # undef alloca
  39 # define alloca __builtin_alloca
  40 # define HAVE_ALLOCA 1
  41 #else
  42 # ifdef _MSC_VER
  43 #  include <malloc.h>
  44 #  define alloca _alloca
  45 # else
  46 #  if defined HAVE_ALLOCA_H || defined _LIBC
  47 #   include <alloca.h>
  48 #  else
  49 #   ifdef _AIX
  50  #pragma alloca
  51 #   else
  52 #    ifndef alloca
  53 char *alloca ();
  54 #    endif
  55 #   endif
  56 #  endif
  57 # endif
  58 #endif
  59
  60 #include <stdlib.h>
  61 #include <string.h>
  62
  63 #include "gettextP.h"
  64
  65 #if ENABLE_RELOCATABLE
  66 # include "relocatable.h"
  67 #else
  68 # define relocate(pathname) (pathname)
  69 #endif
  70
  71 /* @@ end of prolog @@ */
  72
  73 #ifdef _LIBC
  74 /* Rename the non ANSI C functions.  This is required by the standard
  75    because some ANSI C functions will require linking with this object
  76    file and the name space must not be polluted.  */
  77 # define strcasecmp __strcasecmp
  78
  79 # ifndef mempcpy
  80 #  define mempcpy __mempcpy
  81 # endif
  82 # define HAVE_MEMPCPY   1
  83 # define HAVE___FSETLOCKING     1
  84 #endif
  85
  86 /* Handle multi-threaded applications.  */
  87 #ifdef _LIBC
  88 # include <bits/libc-lock.h>
  89 #else
  90 # include "lock.h"
  91 #endif
  92
  93 #ifndef internal_function
  94 # define internal_function
  95 #endif
  96
  97 /* Some optimizations for glibc.  */
  98 #ifdef _LIBC
  99 # define FEOF(fp)               feof_unlocked (fp)
 100 # define FGETS(buf, n, fp)      fgets_unlocked (buf, n, fp)
 101 #else
 102 # define FEOF(fp)               feof (fp)
 103 # define FGETS(buf, n, fp)      fgets (buf, n, fp)
 104 #endif
 105
 106 /* For those losing systems which don't have `alloca' we have to add
 107    some additional code emulating it.  */
 108 #ifdef HAVE_ALLOCA
 109 # define freea(p) /* nothing */
 110 #else
 111 # define alloca(n) malloc (n)
 112 # define freea(p) free (p)
 113 #endif
 114
 115 #if defined _LIBC_REENTRANT || HAVE_DECL_FGETS_UNLOCKED
 116 # undef fgets
 117 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 118 #endif
 119 #if defined _LIBC_REENTRANT || HAVE_DECL_FEOF_UNLOCKED
 120 # undef feof
 121 # define feof(s) feof_unlocked (s)
 122 #endif
 123
 124
 125 __libc_lock_define_initialized (static, lock)
 126
 127
 128 struct alias_map
 129 {
 130   const char *alias;
 131   const char *value;
 132 };
 133
 134
 135 #ifndef _LIBC
 136 # define libc_freeres_ptr(decl) decl
 137 #endif
 138
 139 libc_freeres_ptr (static char *string_space);
 140 static size_t string_space_act;
 141 static size_t string_space_max;
 142 libc_freeres_ptr (static struct alias_map *map);
 143 static size_t nmap;
 144 static size_t maxmap;
 145
 146
 147 /* Prototypes for local functions.  */
 148 static size_t read_alias_file (const char *fname, int fname_len)
 149      internal_function;
 150 static int extend_alias_table (void);
 151 static int alias_compare (const struct alias_map *map1,
 152                           const struct alias_map *map2);
 153
 154
 155 const char *
 156 _nl_expand_alias (const char *name)
 157 {
 158   static const char *locale_alias_path;
 159   struct alias_map *retval;
 160   const char *result = NULL;
 161   size_t added;
 162
 163   __libc_lock_lock (lock);
 164
 165   if (locale_alias_path == NULL)
 166     locale_alias_path = LOCALE_ALIAS_PATH;
 167
 168   do
 169     {
 170       struct alias_map item;
 171
 172       item.alias = name;
 173
 174       if (nmap > 0)
 175         retval = (struct alias_map *) bsearch (&item, map, nmap,
 176                                                sizeof (struct alias_map),
 177                                                (int (*) (const void *,
 178                                                          const void *)
 179                                                 ) alias_compare);
 180       else
 181         retval = NULL;
 182
 183       /* We really found an alias.  Return the value.  */
 184       if (retval != NULL)
 185         {
 186           result = retval->value;
 187           break;
 188         }
 189
 190       /* Perhaps we can find another alias file.  */
 191       added = 0;
 192       while (added == 0 && locale_alias_path[0] != '\0')
 193         {
 194           const char *start;
 195
 196           while (locale_alias_path[0] == PATH_SEPARATOR)
 197             ++locale_alias_path;
 198           start = locale_alias_path;
 199
 200           while (locale_alias_path[0] != '\0'
 201                  && locale_alias_path[0] != PATH_SEPARATOR)
 202             ++locale_alias_path;
 203
 204           if (start < locale_alias_path)
 205             added = read_alias_file (start, locale_alias_path - start);
 206         }
 207     }
 208   while (added != 0);
 209
 210   __libc_lock_unlock (lock);
 211
 212   return result;
 213 }
 214
 215
 216 static size_t
 217 internal_function
 218 read_alias_file (const char *fname, int fname_len)
 219 {
 220   FILE *fp;
 221   char *full_fname;
 222   size_t added;
 223   static const char aliasfile[] = "/locale.alias";
 224
 225   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 226 #ifdef HAVE_MEMPCPY
 227   mempcpy (mempcpy (full_fname, fname, fname_len),
 228            aliasfile, sizeof aliasfile);
 229 #else
 230   memcpy (full_fname, fname, fname_len);
 231   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 232 #endif
 233
 234 #ifdef _LIBC
 235   /* Note the file is opened with cancellation in the I/O functions
 236      disabled.  */
 237   fp = fopen (relocate (full_fname), "rc");
 238 #else
 239   fp = fopen (relocate (full_fname), "r");
 240 #endif
 241   freea (full_fname);
 242   if (fp == NULL)
 243     return 0;
 244
 245 #ifdef HAVE___FSETLOCKING
 246   /* No threads present.  */
 247   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 248 #endif
 249
 250   added = 0;
 251   while (!FEOF (fp))
 252     {
 253       /* It is a reasonable approach to use a fix buffer here because
 254          a) we are only interested in the first two fields
 255          b) these fields must be usable as file names and so must not
 256             be that long
 257          We avoid a multi-kilobyte buffer here since this would use up
 258          stack space which we might not have if the program ran out of
 259          memory.  */
 260       char buf[400];
 261       char *alias;
 262       char *value;
 263       char *cp;
 264       int complete_line;
 265
 266       if (FGETS (buf, sizeof buf, fp) == NULL)
 267         /* EOF reached.  */
 268         break;
 269
 270       /* Determine whether the line is complete.  */
 271       complete_line = strchr (buf, '\n') != NULL;
 272
 273       cp = buf;
 274       /* Ignore leading white space.  */
 275       while (isspace ((unsigned char) cp[0]))
 276         ++cp;
 277
 278       /* A leading '#' signals a comment line.  */
 279       if (cp[0] != '\0' && cp[0] != '#')
 280         {
 281           alias = cp++;
 282           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 283             ++cp;
 284           /* Terminate alias name.  */
 285           if (cp[0] != '\0')
 286             *cp++ = '\0';
 287
 288           /* Now look for the beginning of the value.  */
 289           while (isspace ((unsigned char) cp[0]))
 290             ++cp;
 291
 292           if (cp[0] != '\0')
 293             {
 294               value = cp++;
 295               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 296                 ++cp;
 297               /* Terminate value.  */
 298               if (cp[0] == '\n')
 299                 {
 300                   /* This has to be done to make the following test
 301                      for the end of line possible.  We are looking for
 302                      the terminating '\n' which do not overwrite here.  */
 303                   *cp++ = '\0';
 304                   *cp = '\n';
 305                 }
 306               else if (cp[0] != '\0')
 307                 *cp++ = '\0';
 308
 309 #ifdef IN_LIBGLOCALE
 310               /* glibc's locale.alias contains entries for ja_JP and ko_KR
 311                  that make it impossible to use a Japanese or Korean UTF-8
 312                  locale under the name "ja_JP" or "ko_KR".  Ignore these
 313                  entries.  */
 314               if (strchr (alias, '_') == NULL)
 315 #endif
 316                 {
 317                   size_t alias_len;
 318                   size_t value_len;
 319
 320                   if (nmap >= maxmap)
 321                     if (__builtin_expect (extend_alias_table (), 0))
 322                       goto out;
 323
 324                   alias_len = strlen (alias) + 1;
 325                   value_len = strlen (value) + 1;
 326
 327                   if (string_space_act + alias_len + value_len > string_space_max)
 328                     {
 329                       /* Increase size of memory pool.  */
 330                       size_t new_size = (string_space_max
 331                                          + (alias_len + value_len > 1024
 332                                             ? alias_len + value_len : 1024));
 333                       char *new_pool = (char *) realloc (string_space, new_size);
 334                       if (new_pool == NULL)
 335                         goto out;
 336
 337                       if (__builtin_expect (string_space != new_pool, 0))
 338                         {
 339                           size_t i;
 340
 341                           for (i = 0; i < nmap; i++)
 342                             {
 343                               map[i].alias += new_pool - string_space;
 344                               map[i].value += new_pool - string_space;
 345                             }
 346                         }
 347
 348                       string_space = new_pool;
 349                       string_space_max = new_size;
 350                     }
 351
 352                   map[nmap].alias = memcpy (&string_space[string_space_act],
 353                                             alias, alias_len);
 354                   string_space_act += alias_len;
 355
 356                   map[nmap].value = memcpy (&string_space[string_space_act],
 357                                             value, value_len);
 358                   string_space_act += value_len;
 359
 360                   ++nmap;
 361                   ++added;
 362                 }
 363             }
 364         }
 365
 366       /* Possibly not the whole line fits into the buffer.  Ignore
 367          the rest of the line.  */
 368       if (! complete_line)
 369         do
 370           if (FGETS (buf, sizeof buf, fp) == NULL)
 371             /* Make sure the inner loop will be left.  The outer loop
 372                will exit at the `feof' test.  */
 373             break;
 374         while (strchr (buf, '\n') == NULL);
 375     }
 376
 377  out:
 378   /* Should we test for ferror()?  I think we have to silently ignore
 379      errors.  --drepper  */
 380   fclose (fp);
 381
 382   if (added > 0)
 383     qsort (map, nmap, sizeof (struct alias_map),
 384            (int (*) (const void *, const void *)) alias_compare);
 385
 386   return added;
 387 }
 388
 389
 390 static int
 391 extend_alias_table ()
 392 {
 393   size_t new_size;
 394   struct alias_map *new_map;
 395
 396   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 397   new_map = (struct alias_map *) realloc (map, (new_size
 398                                                 * sizeof (struct alias_map)));
 399   if (new_map == NULL)
 400     /* Simply don't extend: we don't have any more core.  */
 401     return -1;
 402
 403   map = new_map;
 404   maxmap = new_size;
 405   return 0;
 406 }
 407
 408
 409 static int
 410 alias_compare (const struct alias_map *map1, const struct alias_map *map2)
 411 {
 412 #if defined _LIBC || defined HAVE_STRCASECMP
 413   return strcasecmp (map1->alias, map2->alias);
 414 #else
 415   const unsigned char *p1 = (const unsigned char *) map1->alias;
 416   const unsigned char *p2 = (const unsigned char *) map2->alias;
 417   unsigned char c1, c2;
 418
 419   if (p1 == p2)
 420     return 0;
 421
 422   do
 423     {
 424       /* I know this seems to be odd but the tolower() function in
 425          some systems libc cannot handle nonalpha characters.  */
 426       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 427       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 428       if (c1 == '\0')
 429         break;
 430       ++p1;
 431       ++p2;
 432     }
 433   while (c1 == c2);
 434
 435   return c1 - c2;
 436 #endif
 437 }