Robert P. J. Day | 94f582f | 2007-10-16 23:26:11 -0700 | [diff] [blame] | 1 | #ifndef __LINUX_COMPILER_H |
| 2 | #error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead." |
| 3 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | |
Linus Torvalds | f9d1425 | 2009-01-02 09:29:43 -0800 | [diff] [blame] | 5 | /* GCC 4.1.[01] miscompiles __weak */ |
H. Peter Anvin | 8cd2c29 | 2009-02-25 15:22:19 -0800 | [diff] [blame] | 6 | #ifdef __KERNEL__ |
| 7 | # if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1 |
| 8 | # error Your version of gcc miscompiles the __weak directive |
| 9 | # endif |
Linus Torvalds | f9d1425 | 2009-01-02 09:29:43 -0800 | [diff] [blame] | 10 | #endif |
| 11 | |
David Rientjes | 0d7ebbb | 2007-05-09 02:35:27 -0700 | [diff] [blame] | 12 | #define __used __attribute__((__used__)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #define __must_check __attribute__((warn_unused_result)) |
| 14 | #define __compiler_offsetof(a,b) __builtin_offsetof(a,b) |
Andi Kleen | a586df0 | 2007-07-21 17:10:00 +0200 | [diff] [blame] | 15 | |
Linus Torvalds | f153b82 | 2009-01-02 09:23:03 -0800 | [diff] [blame] | 16 | #if __GNUC_MINOR__ >= 3 |
Andi Kleen | a586df0 | 2007-07-21 17:10:00 +0200 | [diff] [blame] | 17 | /* Mark functions as cold. gcc will assume any path leading to a call |
| 18 | to them will be unlikely. This means a lot of manual unlikely()s |
| 19 | are unnecessary now for any paths leading to the usual suspects |
| 20 | like BUG(), printk(), panic() etc. [but let's keep them for now for |
| 21 | older compilers] |
| 22 | |
| 23 | Early snapshots of gcc 4.3 don't support this and we can't detect this |
| 24 | in the preprocessor, but we can live with this because they're unreleased. |
| 25 | Maketime probing would be overkill here. |
| 26 | |
| 27 | gcc also has a __attribute__((__hot__)) to move hot functions into |
| 28 | a special section, but I don't see any sense in this right now in |
| 29 | the kernel context */ |
| 30 | #define __cold __attribute__((__cold__)) |
| 31 | |
David Daney | 38938c8 | 2009-12-04 17:44:50 -0800 | [diff] [blame] | 32 | |
| 33 | #if __GNUC_MINOR__ >= 5 |
| 34 | /* |
| 35 | * Mark a position in code as unreachable. This can be used to |
| 36 | * suppress control flow warnings after asm blocks that transfer |
| 37 | * control elsewhere. |
| 38 | * |
| 39 | * Early snapshots of gcc 4.5 don't support this and we can't detect |
| 40 | * this in the preprocessor, but we can live with this because they're |
| 41 | * unreleased. Really, we need to have autoconf for the kernel. |
| 42 | */ |
| 43 | #define unreachable() __builtin_unreachable() |
Mikael Pettersson | 9c69520 | 2010-06-29 15:05:25 -0700 | [diff] [blame] | 44 | |
| 45 | /* Mark a function definition as prohibited from being cloned. */ |
| 46 | #define __noclone __attribute__((__noclone__)) |
| 47 | |
David Daney | 38938c8 | 2009-12-04 17:44:50 -0800 | [diff] [blame] | 48 | #endif |
Andi Kleen | a586df0 | 2007-07-21 17:10:00 +0200 | [diff] [blame] | 49 | #endif |
Arjan van de Ven | 9f0cf4a | 2009-09-26 14:33:01 +0200 | [diff] [blame] | 50 | |
Andrew Morton | 7cff7ce | 2009-10-09 00:01:39 -0700 | [diff] [blame] | 51 | #if __GNUC_MINOR__ > 0 |
Arjan van de Ven | 9f0cf4a | 2009-09-26 14:33:01 +0200 | [diff] [blame] | 52 | #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) |
Andrew Morton | 7cff7ce | 2009-10-09 00:01:39 -0700 | [diff] [blame] | 53 | #endif |
Arjan van de Ven | 4a31276 | 2009-09-30 13:05:23 +0200 | [diff] [blame] | 54 | #if __GNUC_MINOR__ >= 4 |
| 55 | #define __compiletime_warning(message) __attribute__((warning(message))) |
Arjan van de Ven | 63312b6 | 2009-10-02 07:50:50 -0700 | [diff] [blame] | 56 | #define __compiletime_error(message) __attribute__((error(message))) |
Arjan van de Ven | 4a31276 | 2009-09-30 13:05:23 +0200 | [diff] [blame] | 57 | #endif |