Messages in this thread | | | Date | Mon, 31 Aug 2020 21:55:16 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH v2 2/7] Revert "kbuild: disable clang's default use of -fmerge-all-constants" |
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On Mon, Aug 31, 2020 at 05:23:21PM -0700, Nick Desaulniers wrote: > This reverts commit 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79. > > This was fixed in clang-6; the minimum supported version of clang in the > kernel is clang-10 (10.0.1). > > Link: https://reviews.llvm.org/rL329300. > Link: https://github.com/ClangBuiltLinux/linux/issues/9 > Suggested-by: Nathan Chancellor <natechancellor@gmail.com> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> --- > Makefile | 9 --------- > 1 file changed, 9 deletions(-) > > diff --git a/Makefile b/Makefile > index 37739ee53f27..144ac6a073ff 100644 > --- a/Makefile > +++ b/Makefile > @@ -932,15 +932,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized) > # disable invalid "can't wrap" optimizations for signed / pointers > KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) > > -# clang sets -fmerge-all-constants by default as optimization, but this > -# is non-conforming behavior for C and in fact breaks the kernel, so we > -# need to disable it here generally. > -KBUILD_CFLAGS += $(call cc-option,-fno-merge-all-constants) > - > -# for gcc -fno-merge-all-constants disables everything, but it is fine > -# to have actual conforming behavior enabled. > -KBUILD_CFLAGS += $(call cc-option,-fmerge-constants) > - > # Make sure -fstack-check isn't enabled (like gentoo apparently did) > KBUILD_CFLAGS += $(call cc-option,-fno-stack-check,) > > -- > 2.28.0.402.g5ffc5be6b7-goog >
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