intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-2002, 2003, 2005 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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 /* Tell glibc's <string.h> to provide a prototype for mempcpy().
  21    This must come before <config.h> because <config.h> may include
  22    <features.h>, and once <features.h> has been included, it's too late.  */
  23 #ifndef _GNU_SOURCE
  24 # define _GNU_SOURCE    1
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include <config.h>
  29 #endif
  30
  31 #include <ctype.h>
  32 #include <stdio.h>
  33 #if defined _LIBC || defined HAVE___FSETLOCKING
  34 # include <stdio_ext.h>
  35 #endif
  36 #include <sys/types.h>
  37
  38 #ifdef __GNUC__
  39 # undef alloca
  40 # define alloca __builtin_alloca
  41 # define HAVE_ALLOCA 1
  42 #else
  43 # if defined HAVE_ALLOCA_H || defined _LIBC
  44 #  include <alloca.h>
  45 # else
  46 #  ifdef _AIX
  47  #pragma alloca
  48 #  else
  49 #   ifndef alloca
  50 char *alloca ();
  51 #   endif
  52 #  endif
  53 # endif
  54 #endif
  55
  56 #include <stdlib.h>
  57 #include <string.h>
  58
  59 #include "gettextP.h"
  60
  61 /* @@ end of prolog @@ */
  62
  63 #ifdef _LIBC
  64 /* Rename the non ANSI C functions.  This is required by the standard
  65    because some ANSI C functions will require linking with this object
  66    file and the name space must not be polluted.  */
  67 # define strcasecmp __strcasecmp
  68
  69 # ifndef mempcpy
  70 #  define mempcpy __mempcpy
  71 # endif
  72 # define HAVE_MEMPCPY   1
  73 # define HAVE___FSETLOCKING     1
  74
  75 /* We need locking here since we can be called from different places.  */
  76 # include <bits/libc-lock.h>
  77
  78 __libc_lock_define_initialized (static, lock);
  79 #endif
  80
  81 #ifndef internal_function
  82 # define internal_function
  83 #endif
  84
  85 /* Some optimizations for glibc.  */
  86 #ifdef _LIBC
  87 # define FEOF(fp)               feof_unlocked (fp)
  88 # define FGETS(buf, n, fp)      fgets_unlocked (buf, n, fp)
  89 #else
  90 # define FEOF(fp)               feof (fp)
  91 # define FGETS(buf, n, fp)      fgets (buf, n, fp)
  92 #endif
  93
  94 /* For those losing systems which don't have `alloca' we have to add
  95    some additional code emulating it.  */
  96 #ifdef HAVE_ALLOCA
  97 # define freea(p) /* nothing */
  98 #else
  99 # define alloca(n) malloc (n)
 100 # define freea(p) free (p)
 101 #endif
 102
 103 #if defined _LIBC_REENTRANT || defined HAVE_FGETS_UNLOCKED
 104 # undef fgets
 105 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 106 #endif
 107 #if defined _LIBC_REENTRANT || defined HAVE_FEOF_UNLOCKED
 108 # undef feof
 109 # define feof(s) feof_unlocked (s)
 110 #endif
 111
 112
 113 struct alias_map
 114 {
 115   const char *alias;
 116   const char *value;
 117 };
 118
 119
 120 #ifndef _LIBC
 121 # define libc_freeres_ptr(decl) decl
 122 #endif
 123
 124 libc_freeres_ptr (static char *string_space);
 125 static size_t string_space_act;
 126 static size_t string_space_max;
 127 libc_freeres_ptr (static struct alias_map *map);
 128 static size_t nmap;
 129 static size_t maxmap;
 130
 131
 132 /* Prototypes for local functions.  */
 133 static size_t read_alias_file PARAMS ((const char *fname, int fname_len))
 134      internal_function;
 135 static int extend_alias_table PARAMS ((void));
 136 static int alias_compare PARAMS ((const struct alias_map *map1,
 137                                   const struct alias_map *map2));
 138
 139
 140 const char *
 141 _nl_expand_alias (name)
 142     const char *name;
 143 {
 144   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 145   struct alias_map *retval;
 146   const char *result = NULL;
 147   size_t added;
 148
 149 #ifdef _LIBC
 150   __libc_lock_lock (lock);
 151 #endif
 152
 153   do
 154     {
 155       struct alias_map item;
 156
 157       item.alias = name;
 158
 159       if (nmap > 0)
 160         retval = (struct alias_map *) bsearch (&item, map, nmap,
 161                                                sizeof (struct alias_map),
 162                                                (int (*) PARAMS ((const void *,
 163                                                                  const void *))
 164                                                 ) alias_compare);
 165       else
 166         retval = NULL;
 167
 168       /* We really found an alias.  Return the value.  */
 169       if (retval != NULL)
 170         {
 171           result = retval->value;
 172           break;
 173         }
 174
 175       /* Perhaps we can find another alias file.  */
 176       added = 0;
 177       while (added == 0 && locale_alias_path[0] != '\0')
 178         {
 179           const char *start;
 180
 181           while (locale_alias_path[0] == ':')
 182             ++locale_alias_path;
 183           start = locale_alias_path;
 184
 185           while (locale_alias_path[0] != '\0' && locale_alias_path[0] != ':')
 186             ++locale_alias_path;
 187
 188           if (start < locale_alias_path)
 189             added = read_alias_file (start, locale_alias_path - start);
 190         }
 191     }
 192   while (added != 0);
 193
 194 #ifdef _LIBC
 195   __libc_lock_unlock (lock);
 196 #endif
 197
 198   return result;
 199 }
 200
 201
 202 static size_t
 203 internal_function
 204 read_alias_file (fname, fname_len)
 205      const char *fname;
 206      int fname_len;
 207 {
 208   FILE *fp;
 209   char *full_fname;
 210   size_t added;
 211   static const char aliasfile[] = "/locale.alias";
 212
 213   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 214 #ifdef HAVE_MEMPCPY
 215   mempcpy (mempcpy (full_fname, fname, fname_len),
 216            aliasfile, sizeof aliasfile);
 217 #else
 218   memcpy (full_fname, fname, fname_len);
 219   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 220 #endif
 221
 222   /* Note the file is opened with cancellation in the I/O functions
 223      disabled.  */
 224   fp = fopen (full_fname, "rc");
 225   freea (full_fname);
 226   if (fp == NULL)
 227     return 0;
 228
 229 #ifdef HAVE___FSETLOCKING
 230   /* No threads present.  */
 231   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 232 #endif
 233
 234   added = 0;
 235   while (!FEOF (fp))
 236     {
 237       /* It is a reasonable approach to use a fix buffer here because
 238          a) we are only interested in the first two fields
 239          b) these fields must be usable as file names and so must not
 240             be that long
 241          We avoid a multi-kilobyte buffer here since this would use up
 242          stack space which we might not have if the program ran out of
 243          memory.  */
 244       char buf[400];
 245       char *alias;
 246       char *value;
 247       char *cp;
 248       int complete_line;
 249
 250       if (FGETS (buf, sizeof buf, fp) == NULL)
 251         /* EOF reached.  */
 252         break;
 253
 254       /* Determine whether the line is complete.  */
 255       complete_line = strchr (buf, '\n') != NULL;
 256
 257       cp = buf;
 258       /* Ignore leading white space.  */
 259       while (isspace ((unsigned char) cp[0]))
 260         ++cp;
 261
 262       /* A leading '#' signals a comment line.  */
 263       if (cp[0] != '\0' && cp[0] != '#')
 264         {
 265           alias = cp++;
 266           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 267             ++cp;
 268           /* Terminate alias name.  */
 269           if (cp[0] != '\0')
 270             *cp++ = '\0';
 271
 272           /* Now look for the beginning of the value.  */
 273           while (isspace ((unsigned char) cp[0]))
 274             ++cp;
 275
 276           if (cp[0] != '\0')
 277             {
 278               size_t alias_len;
 279               size_t value_len;
 280
 281               value = cp++;
 282               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 283                 ++cp;
 284               /* Terminate value.  */
 285               if (cp[0] == '\n')
 286                 {
 287                   /* This has to be done to make the following test
 288                      for the end of line possible.  We are looking for
 289                      the terminating '\n' which do not overwrite here.  */
 290                   *cp++ = '\0';
 291                   *cp = '\n';
 292                 }
 293               else if (cp[0] != '\0')
 294                 *cp++ = '\0';
 295
 296               if (nmap >= maxmap)
 297                 if (__builtin_expect (extend_alias_table (), 0))
 298                   goto out;
 299
 300               alias_len = strlen (alias) + 1;
 301               value_len = strlen (value) + 1;
 302
 303               if (string_space_act + alias_len + value_len > string_space_max)
 304                 {
 305                   /* Increase size of memory pool.  */
 306                   size_t new_size = (string_space_max
 307                                      + (alias_len + value_len > 1024
 308                                         ? alias_len + value_len : 1024));
 309                   char *new_pool = (char *) realloc (string_space, new_size);
 310                   if (new_pool == NULL)
 311                     goto out;
 312
 313                   if (__builtin_expect (string_space != new_pool, 0))
 314                     {
 315                       size_t i;
 316
 317                       for (i = 0; i < nmap; i++)
 318                         {
 319                           map[i].alias += new_pool - string_space;
 320                           map[i].value += new_pool - string_space;
 321                         }
 322                     }
 323
 324                   string_space = new_pool;
 325                   string_space_max = new_size;
 326                 }
 327
 328               map[nmap].alias = memcpy (&string_space[string_space_act],
 329                                         alias, alias_len);
 330               string_space_act += alias_len;
 331
 332               map[nmap].value = memcpy (&string_space[string_space_act],
 333                                         value, value_len);
 334               string_space_act += value_len;
 335
 336               ++nmap;
 337               ++added;
 338             }
 339         }
 340
 341       /* Possibly not the whole line fits into the buffer.  Ignore
 342          the rest of the line.  */
 343       if (! complete_line)
 344         do
 345           if (FGETS (buf, sizeof buf, fp) == NULL)
 346             /* Make sure the inner loop will be left.  The outer loop
 347                will exit at the `feof' test.  */
 348             break;
 349         while (strchr (buf, '\n') == NULL);
 350     }
 351
 352 out:
 353   /* Should we test for ferror()?  I think we have to silently ignore
 354      errors.  --drepper  */
 355   fclose (fp);
 356
 357   if (added > 0)
 358     qsort (map, nmap, sizeof (struct alias_map),
 359            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 360
 361   return added;
 362 }
 363
 364
 365 static int
 366 extend_alias_table ()
 367 {
 368   size_t new_size;
 369   struct alias_map *new_map;
 370
 371   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 372   new_map = (struct alias_map *) realloc (map, (new_size
 373                                                 * sizeof (struct alias_map)));
 374   if (new_map == NULL)
 375     /* Simply don't extend: we don't have any more core.  */
 376     return -1;
 377
 378   map = new_map;
 379   maxmap = new_size;
 380   return 0;
 381 }
 382
 383
 384 static int
 385 alias_compare (map1, map2)
 386      const struct alias_map *map1;
 387      const struct alias_map *map2;
 388 {
 389 #if defined _LIBC || defined HAVE_STRCASECMP
 390   return strcasecmp (map1->alias, map2->alias);
 391 #else
 392   const unsigned char *p1 = (const unsigned char *) map1->alias;
 393   const unsigned char *p2 = (const unsigned char *) map2->alias;
 394   unsigned char c1, c2;
 395
 396   if (p1 == p2)
 397     return 0;
 398
 399   do
 400     {
 401       /* I know this seems to be odd but the tolower() function in
 402          some systems libc cannot handle nonalpha characters.  */
 403       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 404       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 405       if (c1 == '\0')
 406         break;
 407       ++p1;
 408       ++p2;
 409     }
 410   while (c1 == c2);
 411
 412   return c1 - c2;
 413 #endif
 414 }