diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-24 10:08:39 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-24 10:08:39 -0700 |
commit | ed2d265d1266736bd294332d7f649003943ae36e (patch) | |
tree | 860e5b7bb72933e4a9abacdc2f2d75a0e6254e32 /include/linux/kernel.h | |
parent | f1d38e423a697b7aa06e12d3ca4753bcc1aa3531 (diff) | |
parent | 6c03438edeb5c359af35f060ea016ca65671c269 (diff) |
Merge tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull <linux/bug.h> cleanup from Paul Gortmaker:
"The changes shown here are to unify linux's BUG support under the one
<linux/bug.h> file. Due to historical reasons, we have some BUG code
in bug.h and some in kernel.h -- i.e. the support for BUILD_BUG in
linux/kernel.h predates the addition of linux/bug.h, but old code in
kernel.h wasn't moved to bug.h at that time. As a band-aid, kernel.h
was including <asm/bug.h> to pseudo link them.
This has caused confusion[1] and general yuck/WTF[2] reactions. Here
is an example that violates the principle of least surprise:
CC lib/string.o
lib/string.c: In function 'strlcat':
lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
make[2]: *** [lib/string.o] Error 1
$
$ grep linux/bug.h lib/string.c
#include <linux/bug.h>
$
We've included <linux/bug.h> for the BUG infrastructure and yet we
still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh -
very confusing for someone who is new to kernel development.
With the above in mind, the goals of this changeset are:
1) find and fix any include/*.h files that were relying on the
implicit presence of BUG code.
2) find and fix any C files that were consuming kernel.h and hence
relying on implicitly getting some/all BUG code.
3) Move the BUG related code living in kernel.h to <linux/bug.h>
4) remove the asm/bug.h from kernel.h to finally break the chain.
During development, the order was more like 3-4, build-test, 1-2. But
to ensure that git history for bisect doesn't get needless build
failures introduced, the commits have been reorderd to fix the problem
areas in advance.
[1] https://lkml.org/lkml/2012/1/3/90
[2] https://lkml.org/lkml/2012/1/17/414"
Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul
and linux-next.
* tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
kernel.h: doesn't explicitly use bug.h, so don't include it.
bug: consolidate BUILD_BUG_ON with other bug code
BUG: headers with BUG/BUG_ON etc. need linux/bug.h
bug.h: add include of it to various implicit C users
lib: fix implicit users of kernel.h for TAINT_WARN
spinlock: macroize assert_spin_locked to avoid bug.h dependency
x86: relocate get/set debugreg fcns to include/asm/debugreg.
Diffstat (limited to 'include/linux/kernel.h')
-rw-r--r-- | include/linux/kernel.h | 62 |
1 files changed, 0 insertions, 62 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3e140add536..5db52d0ff1d 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -20,7 +20,6 @@ #include <linux/printk.h> #include <linux/dynamic_debug.h> #include <asm/byteorder.h> -#include <asm/bug.h> #define USHRT_MAX ((u16)(~0U)) #define SHRT_MAX ((s16)(USHRT_MAX>>1)) @@ -677,67 +676,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } const typeof( ((type *)0)->member ) *__mptr = (ptr); \ (type *)( (char *)__mptr - offsetof(type,member) );}) -#ifdef __CHECKER__ -#define BUILD_BUG_ON_NOT_POWER_OF_2(n) -#define BUILD_BUG_ON_ZERO(e) (0) -#define BUILD_BUG_ON_NULL(e) ((void*)0) -#define BUILD_BUG_ON(condition) -#define BUILD_BUG() (0) -#else /* __CHECKER__ */ - -/* Force a compilation error if a constant expression is not a power of 2 */ -#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ - BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) - -/* Force a compilation error if condition is true, but also produce a - result (of value 0 and type size_t), so the expression can be used - e.g. in a structure initializer (or where-ever else comma expressions - aren't permitted). */ -#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) -#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) - -/** - * BUILD_BUG_ON - break compile if a condition is true. - * @condition: the condition which the compiler should know is false. - * - * If you have some code which relies on certain constants being equal, or - * other compile-time-evaluated condition, you should use BUILD_BUG_ON to - * detect if someone changes it. - * - * The implementation uses gcc's reluctance to create a negative array, but - * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments - * to inline functions). So as a fallback we use the optimizer; if it can't - * prove the condition is false, it will cause a link error on the undefined - * "__build_bug_on_failed". This error message can be harder to track down - * though, hence the two different methods. - */ -#ifndef __OPTIMIZE__ -#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) -#else -extern int __build_bug_on_failed; -#define BUILD_BUG_ON(condition) \ - do { \ - ((void)sizeof(char[1 - 2*!!(condition)])); \ - if (condition) __build_bug_on_failed = 1; \ - } while(0) -#endif - -/** - * BUILD_BUG - break compile if used. - * - * If you have some code that you expect the compiler to eliminate at - * build time, you should use BUILD_BUG to detect if it is - * unexpectedly used. - */ -#define BUILD_BUG() \ - do { \ - extern void __build_bug_failed(void) \ - __linktime_error("BUILD_BUG failed"); \ - __build_bug_failed(); \ - } while (0) - -#endif /* __CHECKER__ */ - /* Trap pasters of __FUNCTION__ at compile-time */ #define __FUNCTION__ (__func__) |