intl/textdomain.c

   1 /* Implementation of the textdomain(3) function.
   2    Copyright (C) 1995-2017 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as published by
   6    the Free Software Foundation; either version 2.1 of the License, or
   7    (at your option) 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
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 #ifdef HAVE_CONFIG_H
  18 # include <config.h>
  19 #endif
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #include "gettextP.h"
  25 #ifdef _LIBC
  26 # include <libintl.h>
  27 #else
  28 # include "libgnuintl.h"
  29 #endif
  30
  31 /* Handle multi-threaded applications.  */
  32 #ifdef _LIBC
  33 # include <libc-lock.h>
  34 # define gl_rwlock_define __libc_rwlock_define
  35 # define gl_rwlock_wrlock __libc_rwlock_wrlock
  36 # define gl_rwlock_unlock __libc_rwlock_unlock
  37 #else
  38 # include "lock.h"
  39 #endif
  40
  41 /* @@ end of prolog @@ */
  42
  43
  44 /* Names for the libintl functions are a problem.  They must not clash
  45    with existing names and they should follow ANSI C.  But this source
  46    code is also used in GNU C Library where the names have a __
  47    prefix.  So we have to make a difference here.  */
  48 #ifdef _LIBC
  49 # define TEXTDOMAIN __textdomain
  50 # ifndef strdup
  51 #  define strdup(str) __strdup (str)
  52 # endif
  53 #else
  54 # define TEXTDOMAIN libintl_textdomain
  55 #endif
  56
  57 /* Lock variable to protect the global data in the gettext implementation.  */
  58 gl_rwlock_define (extern, _nl_state_lock attribute_hidden)
  59
  60 /* Set the current default message catalog to DOMAINNAME.
  61    If DOMAINNAME is null, return the current default.
  62    If DOMAINNAME is "", reset to the default of "messages".  */
  63 char *
  64 TEXTDOMAIN (const char *domainname)
  65 {
  66   char *new_domain;
  67   char *old_domain;
  68
  69   /* A NULL pointer requests the current setting.  */
  70   if (domainname == NULL)
  71     return (char *) _nl_current_default_domain;
  72
  73   gl_rwlock_wrlock (_nl_state_lock);
  74
  75   old_domain = (char *) _nl_current_default_domain;
  76
  77   /* If domain name is the null string set to default domain "messages".  */
  78   if (domainname[0] == '\0'
  79       || strcmp (domainname, _nl_default_default_domain) == 0)
  80     {
  81       _nl_current_default_domain = _nl_default_default_domain;
  82       new_domain = (char *) _nl_current_default_domain;
  83     }
  84   else if (strcmp (domainname, old_domain) == 0)
  85     /* This can happen and people will use it to signal that some
  86        environment variable changed.  */
  87     new_domain = old_domain;
  88   else
  89     {
  90       /* If the following malloc fails `_nl_current_default_domain'
  91          will be NULL.  This value will be returned and so signals we
  92          are out of core.  */
  93 #if defined _LIBC || defined HAVE_STRDUP
  94       new_domain = strdup (domainname);
  95 #else
  96       size_t len = strlen (domainname) + 1;
  97       new_domain = (char *) malloc (len);
  98       if (new_domain != NULL)
  99         memcpy (new_domain, domainname, len);
 100 #endif
 101
 102       if (new_domain != NULL)
 103         _nl_current_default_domain = new_domain;
 104     }
 105
 106   /* We use this possibility to signal a change of the loaded catalogs
 107      since this is most likely the case and there is no other easy we
 108      to do it.  Do it only when the call was successful.  */
 109   if (new_domain != NULL)
 110     {
 111       ++_nl_msg_cat_cntr;
 112
 113       if (old_domain != new_domain && old_domain != _nl_default_default_domain)
 114         free (old_domain);
 115     }
 116
 117   gl_rwlock_unlock (_nl_state_lock);
 118
 119   return new_domain;
 120 }
 121
 122 #ifdef _LIBC
 123 /* Alias for function name in GNU C Library.  */
 124 weak_alias (__textdomain, textdomain);
 125 #endif