compat/aligned_alloc.c

   1 /*****************************************************************************
   2  * aligned_alloc.c: C11 aligned_alloc() replacement
   3  *****************************************************************************
   4  * Copyright © 2012, 2017 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 <assert.h>
  26 #include <stdlib.h>
  27 #include <errno.h>
  28 #if !defined (HAVE_POSIX_MEMALIGN)
  29 # include <malloc.h>
  30 #endif
  31
  32 void *aligned_alloc(size_t align, size_t size)
  33 {
  34     /* align must be a power of 2 */
  35     /* size must be a multiple of align */
  36     if ((align & (align - 1)) || (size & (align - 1)))
  37     {
  38         errno = EINVAL;
  39         return NULL;
  40     }
  41
  42 #ifdef HAVE_POSIX_MEMALIGN
  43     if (align < sizeof (void *)) /* POSIX does not allow small alignment */
  44         align = sizeof (void *);
  45
  46     void *ptr;
  47     int err = posix_memalign(&ptr, align, size);
  48     if (err)
  49     {
  50         errno = err;
  51         ptr = NULL;
  52     }
  53     return ptr;
  54
  55 #elif defined(HAVE_MEMALIGN)
  56     return memalign(align, size);
  57 #elif defined (_WIN32) && defined(__MINGW32__)
  58     return __mingw_aligned_malloc(size, align);
  59 #elif defined (_WIN32) && defined(_MSC_VER)
  60     return _aligned_malloc(size, align);
  61 #else
  62 #warning unsupported aligned allocation!
  63     if (size > 0)
  64         errno = ENOMEM;
  65     return NULL;
  66 #endif
  67 }