@@@ fltfmt mess

[mLib] / utils / align.h

/* -*-c-*-
 *
 * Pointer alignment hack
 *
 * (c) 2003 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * mLib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

#ifndef MLIB_ALIGN_H
#define MLIB_ALIGN_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#include <stddef.h>

/*----- Data structures ---------------------------------------------------*/

union align {
  int i;
  long l;
  double d;
  long double ld;
  void *p;
  void (*f)(void *);
  struct notexist *s;
#if __STDC_VERSION__ >= 201112
  max_align_t m;
#endif
};

/*----- Macros provided ---------------------------------------------------*/

#if __STDC_VERSION__ >= 201112
#  define ALIGNOF(ty) _Alignof(ty)
#else
#  define ALIGNOF(ty) (offsetof(struct { unsigned char _x; ty _y; }, _y))
#endif

#define ALIGN(sz) do {							\
  (sz) += ALIGNOF(union align) - 1;					\
  (sz) -= (sz)%ALIGNOF(union align);					\
} while (0)

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif