From f153b82121b0366fe0e5f9553545cce237335175 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 2 Jan 2009 09:23:03 -0800 Subject: Sanitize gcc version header includes - include the gcc version-dependent header files from the generic gcc header file, rather than the other way around (iow: don't make the non-gcc header file have to know about gcc versions) - don't include compiler-gcc4.h for gcc 5 (for whenever it gets released). That's just confusing and made us do odd things in the gcc4 header file (testing that we really had version 4!) - generate the name from the __GNUC__ version directly, rather than having a mess of #if conditionals. Signed-off-by: Linus Torvalds --- include/linux/compiler-gcc4.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'include/linux/compiler-gcc4.h') diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 974f5b7bb20..aa426214331 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -2,9 +2,6 @@ #error "Please don't include directly, include instead." #endif -/* These definitions are for GCC v4.x. */ -#include - #define __used __attribute__((__used__)) #define __must_check __attribute__((warn_unused_result)) #define __compiler_offsetof(a,b) __builtin_offsetof(a,b) @@ -16,7 +13,7 @@ */ #define uninitialized_var(x) x = x -#if !(__GNUC__ == 4 && __GNUC_MINOR__ < 3) +#if __GNUC_MINOR__ >= 3 /* Mark functions as cold. gcc will assume any path leading to a call to them will be unlikely. This means a lot of manual unlikely()s are unnecessary now for any paths leading to the usual suspects -- cgit v1.2.3-70-g09d2 From f9d14250071eda9972e4c9cea745a11185952114 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 2 Jan 2009 09:29:43 -0800 Subject: Disallow gcc versions 4.1.{0,1} These compiler versions are known to miscompile __weak functions and thus generate kernels that don't necessarily work correctly. If a weak function is int he same compilation unit as a caller, gcc may end up inlining it, and thus binding the weak function too early. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27781 for details. Cc: Adrian Bunk Cc: Helge Deller Cc: Rusty Russell Cc: Ingo Molnar Signed-off-by: Linus Torvalds --- include/linux/compiler-gcc4.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/compiler-gcc4.h') diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index aa426214331..09992718f9e 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -2,6 +2,11 @@ #error "Please don't include directly, include instead." #endif +/* GCC 4.1.[01] miscompiles __weak */ +#if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1 +# error Your version of gcc miscompiles the __weak directive +#endif + #define __used __attribute__((__used__)) #define __must_check __attribute__((warn_unused_result)) #define __compiler_offsetof(a,b) __builtin_offsetof(a,b) -- cgit v1.2.3-70-g09d2