blob: 94dea3ffbfa19576e2cd8bb59b56658465101b49 [file] [log] [blame]
Robert P. J. Day94f582f2007-10-16 23:26:11 -07001#ifndef __LINUX_COMPILER_H
2#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
3#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
Linus Torvaldsf9d14252009-01-02 09:29:43 -08005/* GCC 4.1.[01] miscompiles __weak */
H. Peter Anvin8cd2c292009-02-25 15:22:19 -08006#ifdef __KERNEL__
7# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
8# error Your version of gcc miscompiles the __weak directive
9# endif
Linus Torvaldsf9d14252009-01-02 09:29:43 -080010#endif
11
David Rientjes0d7ebbb2007-05-09 02:35:27 -070012#define __used __attribute__((__used__))
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#define __must_check __attribute__((warn_unused_result))
14#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
Ingo Molnar40fc55c2006-01-14 13:21:28 -080015#define __always_inline inline __attribute__((always_inline))
Borislav Petkov94909912007-05-06 14:49:17 -070016
17/*
18 * A trick to suppress uninitialized variable warning without generating any
19 * code
20 */
21#define uninitialized_var(x) x = x
Andi Kleena586df02007-07-21 17:10:00 +020022
Linus Torvaldsf153b822009-01-02 09:23:03 -080023#if __GNUC_MINOR__ >= 3
Andi Kleena586df02007-07-21 17:10:00 +020024/* Mark functions as cold. gcc will assume any path leading to a call
25 to them will be unlikely. This means a lot of manual unlikely()s
26 are unnecessary now for any paths leading to the usual suspects
27 like BUG(), printk(), panic() etc. [but let's keep them for now for
28 older compilers]
29
30 Early snapshots of gcc 4.3 don't support this and we can't detect this
31 in the preprocessor, but we can live with this because they're unreleased.
32 Maketime probing would be overkill here.
33
34 gcc also has a __attribute__((__hot__)) to move hot functions into
35 a special section, but I don't see any sense in this right now in
36 the kernel context */
37#define __cold __attribute__((__cold__))
38
David Daney38938c82009-12-04 17:44:50 -080039
40#if __GNUC_MINOR__ >= 5
41/*
42 * Mark a position in code as unreachable. This can be used to
43 * suppress control flow warnings after asm blocks that transfer
44 * control elsewhere.
45 *
46 * Early snapshots of gcc 4.5 don't support this and we can't detect
47 * this in the preprocessor, but we can live with this because they're
48 * unreleased. Really, we need to have autoconf for the kernel.
49 */
50#define unreachable() __builtin_unreachable()
51#endif
52
Andi Kleena586df02007-07-21 17:10:00 +020053#endif
Arjan van de Ven9f0cf4a2009-09-26 14:33:01 +020054
Andrew Morton7cff7ce2009-10-09 00:01:39 -070055#if __GNUC_MINOR__ > 0
Arjan van de Ven9f0cf4a2009-09-26 14:33:01 +020056#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
Andrew Morton7cff7ce2009-10-09 00:01:39 -070057#endif
Arjan van de Ven4a312762009-09-30 13:05:23 +020058#if __GNUC_MINOR__ >= 4
59#define __compiletime_warning(message) __attribute__((warning(message)))
Arjan van de Ven63312b62009-10-02 07:50:50 -070060#define __compiletime_error(message) __attribute__((error(message)))
Arjan van de Ven4a312762009-09-30 13:05:23 +020061#endif