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- /*
- * support.h - Useful definitions and macros. Part of 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 Linux-NTFS
- * 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
-
- #include <stddef.h>
-
- /*
- * 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 */
-
-