include/struct.h

   1 /*      $OpenBSD: struct.h,v 1.3 2003/06/02 19:34:12 millert Exp $      */
   2 /*      $NetBSD: struct.h,v 1.3 1994/10/26 00:56:32 cgd Exp $   */
   3
   4 /*-
   5  * Copyright (c) 1983 The Regents of the University of California.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  *      @(#)struct.h    5.2 (Berkeley) 4/3/91
  33  */
  34
  35 #ifndef _STRUCT_H_
  36 #define _STRUCT_H_
  37
  38 /* Offset of the field in the structure. */
  39 #define fldoff(name, field) \
  40         ((int)&(((struct name *)0)->field))
  41
  42 /* Size of the field in the structure. */
  43 #define fldsiz(name, field) \
  44         (sizeof(((struct name *)0)->field))
  45
  46 /* Address of the structure from a field. */
  47 #define strbase(name, addr, field) \
  48         ((struct name *)((char *)(addr) - fldoff(name, field)))
  49
  50 #endif /* !_STRUCT_H_ */