xref: /f-stack/freebsd/sys/_null.h (revision 22ce4aff)
1a9643ea8Slogwang /*-
2*22ce4affSfengbojiang  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3*22ce4affSfengbojiang  *
4a9643ea8Slogwang  * Copyright (c) 2003 Marcel Moolenaar
5a9643ea8Slogwang  * All rights reserved.
6a9643ea8Slogwang  *
7a9643ea8Slogwang  * Redistribution and use in source and binary forms, with or without
8a9643ea8Slogwang  * modification, are permitted provided that the following conditions
9a9643ea8Slogwang  * are met:
10a9643ea8Slogwang  *
11a9643ea8Slogwang  * 1. Redistributions of source code must retain the above copyright
12a9643ea8Slogwang  *    notice, this list of conditions and the following disclaimer.
13a9643ea8Slogwang  * 2. Redistributions in binary form must reproduce the above copyright
14a9643ea8Slogwang  *    notice, this list of conditions and the following disclaimer in the
15a9643ea8Slogwang  *    documentation and/or other materials provided with the distribution.
16a9643ea8Slogwang  *
17a9643ea8Slogwang  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18a9643ea8Slogwang  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19a9643ea8Slogwang  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20a9643ea8Slogwang  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21a9643ea8Slogwang  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22a9643ea8Slogwang  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23a9643ea8Slogwang  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24a9643ea8Slogwang  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25a9643ea8Slogwang  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26a9643ea8Slogwang  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27a9643ea8Slogwang  *
28a9643ea8Slogwang  * $FreeBSD$
29a9643ea8Slogwang  */
30a9643ea8Slogwang 
31a9643ea8Slogwang #ifndef NULL
32a9643ea8Slogwang 
33a9643ea8Slogwang #if !defined(__cplusplus)
34a9643ea8Slogwang #define	NULL	((void *)0)
35a9643ea8Slogwang #else
36a9643ea8Slogwang #if __cplusplus >= 201103L
37a9643ea8Slogwang #define	NULL	nullptr
38a9643ea8Slogwang #elif defined(__GNUG__) && defined(__GNUC__) && __GNUC__ >= 4
39a9643ea8Slogwang #define	NULL	__null
40a9643ea8Slogwang #else
41a9643ea8Slogwang #if defined(__LP64__)
42a9643ea8Slogwang #define	NULL	(0L)
43a9643ea8Slogwang #else
44a9643ea8Slogwang #define	NULL	0
45a9643ea8Slogwang #endif	/* __LP64__ */
46a9643ea8Slogwang #endif	/* __GNUG__ */
47a9643ea8Slogwang #endif	/* !__cplusplus */
48a9643ea8Slogwang 
49a9643ea8Slogwang #endif
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