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| author | Nick Desaulniers <ndesaulniers@google.com> | 2018-08-22 16:37:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-22 17:31:34 -0700 |
| commit | 815f0ddb346c196018d4d8f8f55c12b83da1de3f (patch) | |
| tree | 4805bf7e3cb7ec4e727aba8e62f9211e9001a760 /mm/migrate.c | |
| parent | 899fbc33fd775b9dfa363db28f322272920a2196 (diff) | |
| download | lwn-815f0ddb346c196018d4d8f8f55c12b83da1de3f.tar.gz lwn-815f0ddb346c196018d4d8f8f55c12b83da1de3f.zip | |
include/linux/compiler*.h: make compiler-*.h mutually exclusive
Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
recently exposed a brittle part of the build for supporting non-gcc
compilers.
Both Clang and ICC define __GNUC__, __GNUC_MINOR__, and
__GNUC_PATCHLEVEL__ for quick compatibility with code bases that haven't
added compiler specific checks for __clang__ or __INTEL_COMPILER.
This is brittle, as they happened to get compatibility by posing as a
certain version of GCC. This broke when upgrading the minimal version
of GCC required to build the kernel, to a version above what ICC and
Clang claim to be.
Rather than always including compiler-gcc.h then undefining or
redefining macros in compiler-intel.h or compiler-clang.h, let's
separate out the compiler specific macro definitions into mutually
exclusive headers, do more proper compiler detection, and keep shared
definitions in compiler_types.h.
Fixes: cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Suggested-by: Eli Friedman <efriedma@codeaurora.org>
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 4a83268e23c2..c27e97b5b69d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1131,7 +1131,8 @@ out: * gcc 4.7 and 4.8 on arm get an ICEs when inlining unmap_and_move(). Work * around it. */ -#if (GCC_VERSION >= 40700 && GCC_VERSION < 40900) && defined(CONFIG_ARM) +#if defined(CONFIG_ARM) && \ + defined(GCC_VERSION) && GCC_VERSION < 40900 && GCC_VERSION >= 40700 #define ICE_noinline noinline #else #define ICE_noinline |