string/strerror_l.c

   1 /* Copyright (C) 2007 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <libintl.h>
  20 #include <locale.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/param.h>
  25
  26
  27 static __thread char *last_value;
  28
  29
  30 static const char *
  31 translate (const char *str, locale_t loc)
  32 {
  33   locale_t oldloc = __uselocale (loc);
  34   const char *res = _(str);
  35   __uselocale (oldloc);
  36   return res;
  37 }
  38
  39
  40 /* Return a string describing the errno code in ERRNUM.  */
  41 char *
  42 strerror_l (int errnum, locale_t loc)
  43 {
  44
  45
  46   if (__builtin_expect (errnum < 0 || errnum >= _sys_nerr_internal
  47                         || _sys_errlist_internal[errnum] == NULL, 0))
  48     {
  49       free (last_value);
  50       if (__asprintf (&last_value, "%s%d",
  51                       translate ("Unknown error ", loc), errnum) == -1)
  52         last_value = NULL;
  53
  54       return last_value;
  55     }
  56
  57   return (char *) translate (_sys_errlist_internal[errnum], loc);
  58 }
  59
  60
  61 #ifdef _LIBC
  62 # ifdef _LIBC_REENTRANT
  63 /* This is called when a thread is exiting to free the last_value string.  */
  64 static void __attribute__ ((section ("__libc_thread_freeres_fn")))
  65 strerror_thread_freeres (void)
  66 {
  67   free (last_value);
  68 }
  69 text_set_element (__libc_thread_subfreeres, strerror_thread_freeres);
  70 text_set_element (__libc_subfreeres, strerror_thread_freeres);
  71 # endif
  72 #endif