intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-2013 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, see
  17    <http://www.gnu.org/licenses/>.  */
  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 # if defined HAVE_ALLOCA_H || defined _LIBC
  43 #  include <alloca.h>
  44 # else
  45 #  ifdef _AIX
  46  #pragma alloca
  47 #  else
  48 #   ifndef alloca
  49 char *alloca ();
  50 #   endif
  51 #  endif
  52 # endif
  53 #endif
  54
  55 #include <stdlib.h>
  56 #include <string.h>
  57
  58 #include "gettextP.h"
  59
  60 /* @@ end of prolog @@ */
  61
  62 #ifdef _LIBC
  63 /* Rename the non ANSI C functions.  This is required by the standard
  64    because some ANSI C functions will require linking with this object
  65    file and the name space must not be polluted.  */
  66 # define strcasecmp(s1, s2) __strcasecmp_l (s1, s2, _nl_C_locobj_ptr)
  67
  68 # ifndef mempcpy
  69 #  define mempcpy __mempcpy
  70 # endif
  71 # define HAVE_MEMPCPY   1
  72 # define HAVE___FSETLOCKING     1
  73
  74 /* We need locking here since we can be called from different places.  */
  75 # include <bits/libc-lock.h>
  76
  77 __libc_lock_define_initialized (static, lock);
  78 #endif
  79
  80 #ifndef internal_function
  81 # define internal_function
  82 #endif
  83
  84 /* Some optimizations for glibc.  */
  85 #ifdef _LIBC
  86 # define FEOF(fp)               feof_unlocked (fp)
  87 # define FGETS(buf, n, fp)      fgets_unlocked (buf, n, fp)
  88 #else
  89 # define FEOF(fp)               feof (fp)
  90 # define FGETS(buf, n, fp)      fgets (buf, n, fp)
  91 #endif
  92
  93 /* For those losing systems which don't have `alloca' we have to add
  94    some additional code emulating it.  */
  95 #ifdef HAVE_ALLOCA
  96 # define freea(p) /* nothing */
  97 #else
  98 # define alloca(n) malloc (n)
  99 # define freea(p) free (p)
 100 #endif
 101
 102 #if defined _LIBC_REENTRANT || defined HAVE_FGETS_UNLOCKED
 103 # undef fgets
 104 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 105 #endif
 106 #if defined _LIBC_REENTRANT || defined HAVE_FEOF_UNLOCKED
 107 # undef feof
 108 # define feof(s) feof_unlocked (s)
 109 #endif
 110
 111
 112 struct alias_map
 113 {
 114   const char *alias;
 115   const char *value;
 116 };
 117
 118
 119 #ifndef _LIBC
 120 # define libc_freeres_ptr(decl) decl
 121 #endif
 122
 123 libc_freeres_ptr (static char *string_space);
 124 static size_t string_space_act;
 125 static size_t string_space_max;
 126 libc_freeres_ptr (static struct alias_map *map);
 127 static size_t nmap;
 128 static size_t maxmap;
 129
 130
 131 /* Prototypes for local functions.  */
 132 static size_t read_alias_file PARAMS ((const char *fname, int fname_len))
 133      internal_function;
 134 static int extend_alias_table PARAMS ((void));
 135 static int alias_compare PARAMS ((const struct alias_map *map1,
 136                                   const struct alias_map *map2));
 137
 138
 139 const char *
 140 _nl_expand_alias (name)
 141     const char *name;
 142 {
 143   static const char *locale_alias_path = LOCALE_ALIAS_PATH;
 144   struct alias_map *retval;
 145   const char *result = NULL;
 146   size_t added;
 147
 148 #ifdef _LIBC
 149   __libc_lock_lock (lock);
 150 #endif
 151
 152   do
 153     {
 154       struct alias_map item;
 155
 156       item.alias = name;
 157
 158       if (nmap > 0)
 159         retval = (struct alias_map *) bsearch (&item, map, nmap,
 160                                                sizeof (struct alias_map),
 161                                                (int (*) PARAMS ((const void *,
 162                                                                  const void *))
 163                                                 ) alias_compare);
 164       else
 165         retval = NULL;
 166
 167       /* We really found an alias.  Return the value.  */
 168       if (retval != NULL)
 169         {
 170           result = retval->value;
 171           break;
 172         }
 173
 174       /* Perhaps we can find another alias file.  */
 175       added = 0;
 176       while (added == 0 && locale_alias_path[0] != '\0')
 177         {
 178           const char *start;
 179
 180           while (locale_alias_path[0] == ':')
 181             ++locale_alias_path;
 182           start = locale_alias_path;
 183
 184           while (locale_alias_path[0] != '\0' && locale_alias_path[0] != ':')
 185             ++locale_alias_path;
 186
 187           if (start < locale_alias_path)
 188             added = read_alias_file (start, locale_alias_path - start);
 189         }
 190     }
 191   while (added != 0);
 192
 193 #ifdef _LIBC
 194   __libc_lock_unlock (lock);
 195 #endif
 196
 197   return result;
 198 }
 199
 200
 201 static size_t
 202 internal_function
 203 read_alias_file (fname, fname_len)
 204      const char *fname;
 205      int fname_len;
 206 {
 207   FILE *fp;
 208   char *full_fname;
 209   size_t added;
 210   static const char aliasfile[] = "/locale.alias";
 211
 212   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 213 #ifdef HAVE_MEMPCPY
 214   mempcpy (mempcpy (full_fname, fname, fname_len),
 215            aliasfile, sizeof aliasfile);
 216 #else
 217   memcpy (full_fname, fname, fname_len);
 218   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 219 #endif
 220
 221   /* Note the file is opened with cancellation in the I/O functions
 222      disabled.  */
 223   fp = fopen (full_fname, "rce");
 224   freea (full_fname);
 225   if (fp == NULL)
 226     return 0;
 227
 228 #ifdef HAVE___FSETLOCKING
 229   /* No threads present.  */
 230   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 231 #endif
 232
 233   added = 0;
 234   while (!FEOF (fp))
 235     {
 236       /* It is a reasonable approach to use a fix buffer here because
 237          a) we are only interested in the first two fields
 238          b) these fields must be usable as file names and so must not
 239             be that long
 240          We avoid a multi-kilobyte buffer here since this would use up
 241          stack space which we might not have if the program ran out of
 242          memory.  */
 243       char buf[400];
 244       char *alias;
 245       char *value;
 246       char *cp;
 247       int complete_line;
 248
 249       if (FGETS (buf, sizeof buf, fp) == NULL)
 250         /* EOF reached.  */
 251         break;
 252
 253       /* Determine whether the line is complete.  */
 254       complete_line = strchr (buf, '\n') != NULL;
 255
 256       cp = buf;
 257       /* Ignore leading white space.  */
 258       while (isspace ((unsigned char) cp[0]))
 259         ++cp;
 260
 261       /* A leading '#' signals a comment line.  */
 262       if (cp[0] != '\0' && cp[0] != '#')
 263         {
 264           alias = cp++;
 265           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 266             ++cp;
 267           /* Terminate alias name.  */
 268           if (cp[0] != '\0')
 269             *cp++ = '\0';
 270
 271           /* Now look for the beginning of the value.  */
 272           while (isspace ((unsigned char) cp[0]))
 273             ++cp;
 274
 275           if (cp[0] != '\0')
 276             {
 277               size_t alias_len;
 278               size_t value_len;
 279
 280               value = cp++;
 281               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 282                 ++cp;
 283               /* Terminate value.  */
 284               if (cp[0] == '\n')
 285                 {
 286                   /* This has to be done to make the following test
 287                      for the end of line possible.  We are looking for
 288                      the terminating '\n' which do not overwrite here.  */
 289                   *cp++ = '\0';
 290                   *cp = '\n';
 291                 }
 292               else if (cp[0] != '\0')
 293                 *cp++ = '\0';
 294
 295               if (nmap >= maxmap)
 296                 if (__builtin_expect (extend_alias_table (), 0))
 297                   goto out;
 298
 299               alias_len = strlen (alias) + 1;
 300               value_len = strlen (value) + 1;
 301
 302               if (string_space_act + alias_len + value_len > string_space_max)
 303                 {
 304                   /* Increase size of memory pool.  */
 305                   size_t new_size = (string_space_max
 306                                      + (alias_len + value_len > 1024
 307                                         ? alias_len + value_len : 1024));
 308                   char *new_pool = (char *) realloc (string_space, new_size);
 309                   if (new_pool == NULL)
 310                     goto out;
 311
 312                   if (__builtin_expect (string_space != new_pool, 0))
 313                     {
 314                       size_t i;
 315
 316                       for (i = 0; i < nmap; i++)
 317                         {
 318                           map[i].alias += new_pool - string_space;
 319                           map[i].value += new_pool - string_space;
 320                         }
 321                     }
 322
 323                   string_space = new_pool;
 324                   string_space_max = new_size;
 325                 }
 326
 327               map[nmap].alias = memcpy (&string_space[string_space_act],
 328                                         alias, alias_len);
 329               string_space_act += alias_len;
 330
 331               map[nmap].value = memcpy (&string_space[string_space_act],
 332                                         value, value_len);
 333               string_space_act += value_len;
 334
 335               ++nmap;
 336               ++added;
 337             }
 338         }
 339
 340       /* Possibly not the whole line fits into the buffer.  Ignore
 341          the rest of the line.  */
 342       if (! complete_line)
 343         do
 344           if (FGETS (buf, sizeof buf, fp) == NULL)
 345             /* Make sure the inner loop will be left.  The outer loop
 346                will exit at the `feof' test.  */
 347             break;
 348         while (strchr (buf, '\n') == NULL);
 349     }
 350
 351 out:
 352   /* Should we test for ferror()?  I think we have to silently ignore
 353      errors.  --drepper  */
 354   fclose (fp);
 355
 356   if (added > 0)
 357     qsort (map, nmap, sizeof (struct alias_map),
 358            (int (*) PARAMS ((const void *, const void *))) alias_compare);
 359
 360   return added;
 361 }
 362
 363
 364 static int
 365 extend_alias_table ()
 366 {
 367   size_t new_size;
 368   struct alias_map *new_map;
 369
 370   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 371   new_map = (struct alias_map *) realloc (map, (new_size
 372                                                 * sizeof (struct alias_map)));
 373   if (new_map == NULL)
 374     /* Simply don't extend: we don't have any more core.  */
 375     return -1;
 376
 377   map = new_map;
 378   maxmap = new_size;
 379   return 0;
 380 }
 381
 382
 383 static int
 384 alias_compare (map1, map2)
 385      const struct alias_map *map1;
 386      const struct alias_map *map2;
 387 {
 388 #if defined _LIBC || defined HAVE_STRCASECMP
 389   return strcasecmp (map1->alias, map2->alias);
 390 #else
 391   const unsigned char *p1 = (const unsigned char *) map1->alias;
 392   const unsigned char *p2 = (const unsigned char *) map2->alias;
 393   unsigned char c1, c2;
 394
 395   if (p1 == p2)
 396     return 0;
 397
 398   do
 399     {
 400       /* I know this seems to be odd but the tolower() function in
 401          some systems libc cannot handle nonalpha characters.  */
 402       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 403       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 404       if (c1 == '\0')
 405         break;
 406       ++p1;
 407       ++p2;
 408     }
 409   while (c1 == c2);
 410
 411   return c1 - c2;
 412 #endif
 413 }