intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-1999, 2000, 2001 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  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 # define alloca __builtin_alloca
  39 # define HAVE_ALLOCA 1
  40 #else
  41 # if defined HAVE_ALLOCA_H || defined _LIBC
  42 #  include <alloca.h>
  43 # else
  44 #  ifdef _AIX
  45  #pragma alloca
  46 #  else
  47 #   ifndef alloca
  48 char *alloca ();
  49 #   endif
  50 #  endif
  51 # endif
  52 #endif
  53
  54 #include <stdlib.h>
  55 #include <string.h>
  56
  57 #include "gettextP.h"
  58
  59 /* @@ end of prolog @@ */
  60
  61 #ifdef _LIBC
  62 /* Rename the non ANSI C functions.  This is required by the standard
  63    because some ANSI C functions will require linking with this object
  64    file and the name space must not be polluted.  */
  65 # define strcasecmp __strcasecmp
  66
  67 # ifndef mempcpy
  68 #  define mempcpy __mempcpy
  69 # endif
  70 # define HAVE_MEMPCPY   1
  71 # define HAVE___FSETLOCKING     1
  72
  73 /* We need locking here since we can be called from different places.  */
  74 # include <bits/libc-lock.h>
  75
  76 __libc_lock_define_initialized (static, lock);
  77 #endif
  78
  79 #ifndef internal_function
  80 # define internal_function
  81 #endif
  82
  83 /* Some optimizations for glibc.  */
  84 #ifdef _LIBC
  85 # define FEOF(fp)               feof_unlocked (fp)
  86 # define FGETS(buf, n, fp)      fgets_unlocked (buf, n, fp)
  87 #else
  88 # define FEOF(fp)               feof (fp)
  89 # define FGETS(buf, n, fp)      fgets (buf, n, fp)
  90 #endif
  91
  92 /* For those losing systems which don't have `alloca' we have to add
  93    some additional code emulating it.  */
  94 #ifdef HAVE_ALLOCA
  95 # define freea(p) /* nothing */
  96 #else
  97 # define alloca(n) malloc (n)
  98 # define freea(p) free (p)
  99 #endif
 100
 101 #if defined _LIBC_REENTRANT || defined HAVE_FGETS_UNLOCKED
 102 # undef fgets
 103 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 104 #endif
 105 #if defined _LIBC_REENTRANT || defined HAVE_FEOF_UNLOCKED
 106 # undef feof
 107 # define feof(s) feof_unlocked (s)
 108 #endif
 109
 110
 111 struct alias_map
 112 {
 113   const char *alias;
 114   const char *value;
 115 };
 116
 117
 118 static char *string_space;
 119 static size_t string_space_act;
 120 static size_t string_space_max;
 121 static struct alias_map *map;
 122 static size_t nmap;
 123 static size_t maxmap;
 124
 125
 126 /* Prototypes for local functions.  */
 127 static size_t read_alias_file PARAMS ((const char *fname, int fname_len))
 128      internal_function;
 129 static int extend_alias_table PARAMS ((void));
 130 static int alias_compare PARAMS ((const struct alias_map *map1,
 131                                   const struct alias_map *map2));
 132
 133
 134 const char *
 135 _nl_expand_alias (name)
 136     const char *name;
 137 {
 138   static const char *locale_alias_path;
 139   struct alias_map *retval;
 140   const char *result = NULL;
 141   size_t added;
 142
 143 #ifdef _LIBC
 144   __libc_lock_lock (lock);
 145 #endif
 146
 147   if (locale_alias_path == NULL)
 148     locale_alias_path = LOCALE_ALIAS_PATH;
 149
 150   do
 151     {
 152       struct alias_map item;
 153
 154       item.alias = name;
 155
 156       if (nmap > 0)
 157         retval = (struct alias_map *) bsearch (&item, map, nmap,
 158                                                sizeof (struct alias_map),
 159                                                (int (*) PARAMS ((const void *,
 160                                                                  const void *))
 161                                                 ) alias_compare);
 162       else
 163         retval = NULL;
 164
 165       /* We really found an alias.  Return the value.  */
 166       if (retval != NULL)
 167         {
 168           result = retval->value;
 169           break;
 170         }
 171
 172       /* Perhaps we can find another alias file.  */
 173       added = 0;
 174       while (added == 0 && locale_alias_path[0] != '\0')
 175         {
 176           const char *start;
 177
 178           while (locale_alias_path[0] == PATH_SEPARATOR)
 179             ++locale_alias_path;
 180           start = locale_alias_path;
 181
 182           while (locale_alias_path[0] != '\0'
 183                  && locale_alias_path[0] != PATH_SEPARATOR)
 184             ++locale_alias_path;
 185
 186           if (start < locale_alias_path)
 187             added = read_alias_file (start, locale_alias_path - start);
 188         }
 189     }
 190   while (added != 0);
 191
 192 #ifdef _LIBC
 193   __libc_lock_unlock (lock);
 194 #endif
 195
 196   return result;
 197 }
 198
 199
 200 static size_t
 201 internal_function
 202 read_alias_file (fname, fname_len)
 203      const char *fname;
 204      int fname_len;
 205 {
 206   FILE *fp;
 207   char *full_fname;
 208   size_t added;
 209   static const char aliasfile[] = "/locale.alias";
 210
 211   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 212 #ifdef HAVE_MEMPCPY
 213   mempcpy (mempcpy (full_fname, fname, fname_len),
 214            aliasfile, sizeof aliasfile);
 215 #else
 216   memcpy (full_fname, fname, fname_len);
 217   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 218 #endif
 219
 220   fp = fopen (full_fname, "r");
 221   freea (full_fname);
 222   if (fp == NULL)
 223     return 0;
 224
 225 #ifdef HAVE___FSETLOCKING
 226   /* No threads present.  */
 227   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 228 #endif
 229
 230   added = 0;
 231   while (!FEOF (fp))
 232     {
 233       /* It is a reasonable approach to use a fix buffer here because
 234          a) we are only interested in the first two fields
 235          b) these fields must be usable as file names and so must not
 236             be that long
 237        */
 238       char buf[BUFSIZ];
 239       char *alias;
 240       char *value;
 241       char *cp;
 242
 243       if (FGETS (buf, sizeof buf, fp) == NULL)
 244         /* EOF reached.  */
 245         break;
 246
 247       /* Possibly not the whole line fits into the buffer.  Ignore
 248          the rest of the line.  */
 249       if (strchr (buf, '\n') == NULL)
 250         {
 251           char altbuf[BUFSIZ];
 252           do
 253             if (FGETS (altbuf, sizeof altbuf, fp) == NULL)
 254               /* Make sure the inner loop will be left.  The outer loop
 255                  will exit at the `feof' test.  */
 256               break;
 257           while (strchr (altbuf, '\n') == NULL);
 258         }
 259
 260       cp = buf;
 261       /* Ignore leading white space.  */
 262       while (isspace ((unsigned char) cp[0]))
 263         ++cp;
 264
 265       /* A leading '#' signals a comment line.  */
 266       if (cp[0] != '\0' && cp[0] != '#')
 267         {
 268           alias = cp++;
 269           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 270             ++cp;
 271           /* Terminate alias name.  */
 272           if (cp[0] != '\0')
 273             *cp++ = '\0';
 274
 275           /* Now look for the beginning of the value.  */
 276           while (isspace ((unsigned char) cp[0]))
 277             ++cp;
 278
 279           if (cp[0] != '\0')
 280             {
 281               size_t alias_len;
 282               size_t value_len;
 283
 284               value = cp++;
 285               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 286                 ++cp;
 287               /* Terminate value.  */
 288               if (cp[0] == '\n')
 289                 {
 290                   /* This has to be done to make the following test
 291                      for the end of line possible.  We are looking for
 292                      the terminating '\n' which do not overwrite here.  */
 293                   *cp++ = '\0';
 294                   *cp = '\n';
 295                 }
 296               else if (cp[0] != '\0')
 297                 *cp++ = '\0';
 298
 299               if (nmap >= maxmap)
 300                 if (__builtin_expect (extend_alias_table (), 0))
 301                   return added;
 302
 303               alias_len = strlen (alias) + 1;
 304               value_len = strlen (value) + 1;
 305
 306               if (string_space_act + alias_len + value_len > string_space_max)
 307                 {
 308                   /* Increase size of memory pool.  */
 309                   size_t new_size = (string_space_max
 310                                      + (alias_len + value_len > 1024
 311                                         ? alias_len + value_len : 1024));
 312                   char *new_pool = (char *) realloc (string_space, new_size);
 313                   if (new_pool == NULL)
 314                     return added;
 315
 316                   if (__builtin_expect (string_space != new_pool, 0))
 317                     {
 318                       size_t i;
 319
 320                       for (i = 0; i < nmap; i++)
 321                         {
 322                           map[i].alias += new_pool - string_space;
 323                           map[i].value += new_pool - string_space;
 324                         }
 325                     }
 326
 327                   string_space = new_pool;
 328                   string_space_max = new_size;
 329                 }
 330
 331               map[nmap].alias = memcpy (&string_space[string_space_act],
 332                                         alias, alias_len);
 333               string_space_act += alias_len;
 334
 335               map[nmap].value = memcpy (&string_space[string_space_act],
 336                                         value, value_len);
 337               string_space_act += value_len;
 338
 339               ++nmap;
 340               ++added;
 341             }
 342         }
 343     }
 344
 345   /* Should we test for ferror()?  I think we have to silently ignore
 346      errors.  --drepper  */
 347   fclose (fp);
 348
 349   if (added > 0)
 350     qsort (map, nmap, sizeof (struct alias_map),
 351            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 352
 353   return added;
 354 }
 355
 356
 357 static int
 358 extend_alias_table ()
 359 {
 360   size_t new_size;
 361   struct alias_map *new_map;
 362
 363   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 364   new_map = (struct alias_map *) realloc (map, (new_size
 365                                                 * sizeof (struct alias_map)));
 366   if (new_map == NULL)
 367     /* Simply don't extend: we don't have any more core.  */
 368     return -1;
 369
 370   map = new_map;
 371   maxmap = new_size;
 372   return 0;
 373 }
 374
 375
 376 #ifdef _LIBC
 377 static void __attribute__ ((unused))
 378 free_mem (void)
 379 {
 380   if (string_space != NULL)
 381     free (string_space);
 382   if (map != NULL)
 383     free (map);
 384 }
 385 text_set_element (__libc_subfreeres, free_mem);
 386 #endif
 387
 388
 389 static int
 390 alias_compare (map1, map2)
 391      const struct alias_map *map1;
 392      const struct alias_map *map2;
 393 {
 394 #if defined _LIBC || defined HAVE_STRCASECMP
 395   return strcasecmp (map1->alias, map2->alias);
 396 #else
 397   const unsigned char *p1 = (const unsigned char *) map1->alias;
 398   const unsigned char *p2 = (const unsigned char *) map2->alias;
 399   unsigned char c1, c2;
 400
 401   if (p1 == p2)
 402     return 0;
 403
 404   do
 405     {
 406       /* I know this seems to be odd but the tolower() function in
 407          some systems libc cannot handle nonalpha characters.  */
 408       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 409       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 410       if (c1 == '\0')
 411         break;
 412       ++p1;
 413       ++p2;
 414     }
 415   while (c1 == c2);
 416
 417   return c1 - c2;
 418 #endif
 419 }