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 <stdalign.h>
  27 #include <stddef.h>
  28 #include <stdlib.h>
  29 #include <errno.h>
  30 #if !defined (HAVE_POSIX_MEMALIGN)
  31 # include <malloc.h>
  32 #endif
  33
  34 void *aligned_alloc(size_t align, size_t size)
  35 {
  36     /* align must be a power of 2 */
  37     /* size must be a multiple of align */
  38     if ((align & (align - 1)) || (size & (align - 1)))
  39     {
  40         errno = EINVAL;
  41         return NULL;
  42     }
  43
  44 #ifdef HAVE_POSIX_MEMALIGN
  45     if (align < sizeof (void *)) /* POSIX does not allow small alignment */
  46         align = sizeof (void *);
  47
  48     void *ptr;
  49     int err = posix_memalign(&ptr, align, size);
  50     if (err)
  51     {
  52         errno = err;
  53         ptr = NULL;
  54     }
  55     return ptr;
  56
  57 #elif defined(HAVE_MEMALIGN)
  58     return memalign(align, size);
  59 #elif defined (_WIN32) && defined(__MINGW32__)
  60     return __mingw_aligned_malloc(size, align);
  61 #elif defined (_WIN32) && defined(_MSC_VER)
  62     return _aligned_malloc(size, align);
  63 #else
  64     /* align must be valid/supported */
  65     assert(align <= alignof (max_align_t));
  66     return malloc(((void) align, size));
  67 #endif
  68 }