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authorNick Desaulniers <ndesaulniers@google.com>2018-08-22 16:37:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-22 17:31:34 -0700
commit815f0ddb346c196018d4d8f8f55c12b83da1de3f (patch)
tree4805bf7e3cb7ec4e727aba8e62f9211e9001a760 /include/linux/compiler-intel.h
parent899fbc33fd775b9dfa363db28f322272920a2196 (diff)
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 'include/linux/compiler-intel.h')
-rw-r--r--include/linux/compiler-intel.h13
1 files changed, 4 insertions, 9 deletions
diff --git a/include/linux/compiler-intel.h b/include/linux/compiler-intel.h
index 547cdc920a3c..4c7f9befa9f6 100644
--- a/include/linux/compiler-intel.h
+++ b/include/linux/compiler-intel.h
@@ -14,10 +14,6 @@
/* Intel ECC compiler doesn't support gcc specific asm stmts.
* It uses intrinsics to do the equivalent things.
*/
-#undef barrier
-#undef barrier_data
-#undef RELOC_HIDE
-#undef OPTIMIZER_HIDE_VAR
#define barrier() __memory_barrier()
#define barrier_data(ptr) barrier()
@@ -38,13 +34,12 @@
#endif
-#ifndef __HAVE_BUILTIN_BSWAP16__
/* icc has this, but it's called _bswap16 */
#define __HAVE_BUILTIN_BSWAP16__
#define __builtin_bswap16 _bswap16
-#endif
-/*
- * icc defines __GNUC__, but does not implement the builtin overflow checkers.
+/* The following are for compatibility with GCC, from compiler-gcc.h,
+ * and may be redefined here because they should not be shared with other
+ * compilers, like clang.
*/
-#undef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
+#define __visible __attribute__((externally_visible))