intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-2002, 2003 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   fp = fopen (full_fname, "r");
 223   freea (full_fname);
 224   if (fp == NULL)
 225     return 0;
 226
 227 #ifdef HAVE___FSETLOCKING
 228   /* No threads present.  */
 229   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 230 #endif
 231
 232   added = 0;
 233   while (!FEOF (fp))
 234     {
 235       /* It is a reasonable approach to use a fix buffer here because
 236          a) we are only interested in the first two fields
 237          b) these fields must be usable as file names and so must not
 238             be that long
 239          We avoid a multi-kilobyte buffer here since this would use up
 240          stack space which we might not have if the program ran out of
 241          memory.  */
 242       char buf[400];
 243       char *alias;
 244       char *value;
 245       char *cp;
 246       int complete_line;
 247
 248       if (FGETS (buf, sizeof buf, fp) == NULL)
 249         /* EOF reached.  */
 250         break;
 251
 252       /* Determine whether the line is complete.  */
 253       complete_line = strchr (buf, '\n') != NULL;
 254
 255       cp = buf;
 256       /* Ignore leading white space.  */
 257       while (isspace ((unsigned char) cp[0]))
 258         ++cp;
 259
 260       /* A leading '#' signals a comment line.  */
 261       if (cp[0] != '\0' && cp[0] != '#')
 262         {
 263           alias = cp++;
 264           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 265             ++cp;
 266           /* Terminate alias name.  */
 267           if (cp[0] != '\0')
 268             *cp++ = '\0';
 269
 270           /* Now look for the beginning of the value.  */
 271           while (isspace ((unsigned char) cp[0]))
 272             ++cp;
 273
 274           if (cp[0] != '\0')
 275             {
 276               size_t alias_len;
 277               size_t value_len;
 278
 279               value = cp++;
 280               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 281                 ++cp;
 282               /* Terminate value.  */
 283               if (cp[0] == '\n')
 284                 {
 285                   /* This has to be done to make the following test
 286                      for the end of line possible.  We are looking for
 287                      the terminating '\n' which do not overwrite here.  */
 288                   *cp++ = '\0';
 289                   *cp = '\n';
 290                 }
 291               else if (cp[0] != '\0')
 292                 *cp++ = '\0';
 293
 294               if (nmap >= maxmap)
 295                 if (__builtin_expect (extend_alias_table (), 0))
 296                   return added;
 297
 298               alias_len = strlen (alias) + 1;
 299               value_len = strlen (value) + 1;
 300
 301               if (string_space_act + alias_len + value_len > string_space_max)
 302                 {
 303                   /* Increase size of memory pool.  */
 304                   size_t new_size = (string_space_max
 305                                      + (alias_len + value_len > 1024
 306                                         ? alias_len + value_len : 1024));
 307                   char *new_pool = (char *) realloc (string_space, new_size);
 308                   if (new_pool == NULL)
 309                     return added;
 310
 311                   if (__builtin_expect (string_space != new_pool, 0))
 312                     {
 313                       size_t i;
 314
 315                       for (i = 0; i < nmap; i++)
 316                         {
 317                           map[i].alias += new_pool - string_space;
 318                           map[i].value += new_pool - string_space;
 319                         }
 320                     }
 321
 322                   string_space = new_pool;
 323                   string_space_max = new_size;
 324                 }
 325
 326               map[nmap].alias = memcpy (&string_space[string_space_act],
 327                                         alias, alias_len);
 328               string_space_act += alias_len;
 329
 330               map[nmap].value = memcpy (&string_space[string_space_act],
 331                                         value, value_len);
 332               string_space_act += value_len;
 333
 334               ++nmap;
 335               ++added;
 336             }
 337         }
 338
 339       /* Possibly not the whole line fits into the buffer.  Ignore
 340          the rest of the line.  */
 341       if (! complete_line)
 342         do
 343           if (FGETS (buf, sizeof buf, fp) == NULL)
 344             /* Make sure the inner loop will be left.  The outer loop
 345                will exit at the `feof' test.  */
 346             break;
 347         while (strchr (buf, '\n') == NULL);
 348     }
 349
 350   /* Should we test for ferror()?  I think we have to silently ignore
 351      errors.  --drepper  */
 352   fclose (fp);
 353
 354   if (added > 0)
 355     qsort (map, nmap, sizeof (struct alias_map),
 356            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 357
 358   return added;
 359 }
 360
 361
 362 static int
 363 extend_alias_table ()
 364 {
 365   size_t new_size;
 366   struct alias_map *new_map;
 367
 368   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 369   new_map = (struct alias_map *) realloc (map, (new_size
 370                                                 * sizeof (struct alias_map)));
 371   if (new_map == NULL)
 372     /* Simply don't extend: we don't have any more core.  */
 373     return -1;
 374
 375   map = new_map;
 376   maxmap = new_size;
 377   return 0;
 378 }
 379
 380
 381 static int
 382 alias_compare (map1, map2)
 383      const struct alias_map *map1;
 384      const struct alias_map *map2;
 385 {
 386 #if defined _LIBC || defined HAVE_STRCASECMP
 387   return strcasecmp (map1->alias, map2->alias);
 388 #else
 389   const unsigned char *p1 = (const unsigned char *) map1->alias;
 390   const unsigned char *p2 = (const unsigned char *) map2->alias;
 391   unsigned char c1, c2;
 392
 393   if (p1 == p2)
 394     return 0;
 395
 396   do
 397     {
 398       /* I know this seems to be odd but the tolower() function in
 399          some systems libc cannot handle nonalpha characters.  */
 400       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 401       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 402       if (c1 == '\0')
 403         break;
 404       ++p1;
 405       ++p2;
 406     }
 407   while (c1 == c2);
 408
 409   return c1 - c2;
 410 #endif
 411 }