compat/posix_memalign.c

   1 /*****************************************************************************
   2  * posix_memalign.c: POSIX posix_memalign() replacement
   3  *****************************************************************************
   4  * Copyright © 2012 Rémi Denis-Courmont
   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 <stdlib.h>
  26 #include <errno.h>
  27
  28 static int check_align (size_t align)
  29 {
  30     for (size_t i = sizeof (void *); i != 0; i *= 2)
  31         if (align == i)
  32             return 0;
  33     return EINVAL;
  34 }
  35
  36 #if !defined (_WIN32) && !defined (__APPLE__)
  37 #include <malloc.h>
  38
  39 int posix_memalign (void **ptr, size_t align, size_t size)
  40 {
  41     if (check_align (align))
  42         return EINVAL;
  43
  44     int saved_errno = errno;
  45     void *p = memalign (align, size);
  46     if (p == NULL)
  47     {
  48         errno = saved_errno;
  49         return ENOMEM;
  50     }
  51
  52     *ptr = p;
  53     return 0;
  54 }
  55
  56 #else
  57
  58 int posix_memalign (void **ptr, size_t align, size_t size)
  59 {
  60     if (check_align (align))
  61         return EINVAL;
  62
  63     *ptr = NULL;
  64     return size ? ENOMEM : 0;
  65 }
  66
  67 #endif