compat/vasprintf.c

   1 /*****************************************************************************
   2  * vasprintf.c: GNU vasprintf() replacement
   3  *****************************************************************************
   4  * Copyright © 1998-2009 VLC authors and VideoLAN
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <stdint.h>
  28 #include <stdarg.h>
  29 #include <assert.h>
  30
  31 int vasprintf (char **strp, const char *fmt, va_list ap)
  32 {
  33     va_list args;
  34     int len;
  35
  36     va_copy (args, ap);
  37     len = vsnprintf (NULL, 0, fmt, args);
  38     va_end (args);
  39
  40     char *str = malloc (len + 1);
  41     if (str != NULL)
  42     {
  43         int len2;
  44
  45         va_copy (args, ap);
  46         len2 = vsprintf (str, fmt, args);
  47         assert (len2 == len);
  48         va_end (args);
  49     }
  50     else
  51     {
  52         len = -1;
  53 #ifndef NDEBUG
  54         str = (void *)(intptr_t)0x41414141; /* poison */
  55 #endif
  56     }
  57     *strp = str;
  58     return len;
  59 }