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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 /drivers/gpu/drm/i915/i915_utils.h | |
| parent | 899fbc33fd775b9dfa363db28f322272920a2196 (diff) | |
| download | linux-815f0ddb346c196018d4d8f8f55c12b83da1de3f.tar.gz | |
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 'drivers/gpu/drm/i915/i915_utils.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_utils.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index 00165ad55fb3..395dd2511568 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -43,7 +43,7 @@ #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \ __stringify(x), (long)(x)) -#if GCC_VERSION >= 70000 +#if defined(GCC_VERSION) && GCC_VERSION >= 70000 #define add_overflows(A, B) \ __builtin_add_overflow_p((A), (B), (typeof((A) + (B)))0) #else |