libntfs/source/support.h

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/*
* support.h - Useful definitions and macros. Originated from the Linux-NTFS project.
*
* Copyright (c) 2000-2004 Anton Altaparmakov
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the NTFS-3G
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _NTFS_SUPPORT_H
#define _NTFS_SUPPORT_H
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
/*
* Our mailing list. Use this define to prevent typos in email address.
*/
#define NTFS_DEV_LIST "ntfs-3g-devel@lists.sf.net"
/*
* Generic macro to convert pointers to values for comparison purposes.
*/
#ifndef p2n
#define p2n(p) ((ptrdiff_t)((ptrdiff_t*)(p)))
#endif
/*
* The classic min and max macros.
*/
#ifndef min
#define min(a,b) ((a) <= (b) ? (a) : (b))
#endif
#ifndef max
#define max(a,b) ((a) >= (b) ? (a) : (b))
#endif
/*
* Useful macro for determining the offset of a struct member.
*/
#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif
/*
* Simple bit operation macros. NOTE: These are NOT atomic.
*/
#define test_bit(bit, var) ((var) & (1 << (bit)))
#define set_bit(bit, var) (var) |= 1 << (bit)
#define clear_bit(bit, var) (var) &= ~(1 << (bit))
#define test_and_set_bit(bit, var) \
({ \
const BOOL old_state = test_bit(bit, var); \
set_bit(bit, var); \
old_state; \
})
#define test_and_clear_bit(bit, var) \
({ \
const BOOL old_state = test_bit(bit, var); \
clear_bit(bit, var); \
old_state; \
})
#endif /* defined _NTFS_SUPPORT_H */