Messages in this thread | | | Date | Wed, 26 Aug 2020 14:42:28 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH] compiler-clang: add build check for clang 10.0.1 |
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On Wed, Aug 26, 2020 at 01:14:19PM -0700, Nick Desaulniers wrote: > During Plumbers 2020, we voted to just support the latest release of > Clang for now. Add a compile time check for this. > > Older clang's may work, but we will likely drop workarounds for older > versions.
I think this part of the commit message is a little wishy-washy. If we are breaking the build for clang < 10.0.1, we are not saying "may work", we are saying "won't work". Because of this, we should take the opportunity to clean up behind us and revert/remove parts of:
87e0d4f0f37f ("kbuild: disable clang's default use of -fmerge-all-constants") b0fe66cf0950 ("ARM: 8905/1: Emit __gnu_mcount_nc when using Clang 10.0.0 or newer") b9249cba25a5 ("arm64: bti: Require clang >= 10.0.1 for in-kernel BTI support") 3acf4be23528 ("arm64: vdso: Fix compilation with clang older than 8")
This could be a series or a part of this commit, I do not have a strong preference. If we are not going to clean up behind us, this should be a warning and not an error.
> Link: https://github.com/ClangBuiltLinux/linux/issues/9 > Link: https://github.com/ClangBuiltLinux/linux/issues/941 > Suggested-by: Sedat Dilek <sedat.dilek@gmail.com> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Otherwise, I agree with Kees's comments. With them addressed, feel free to add:
Acked-by: Nathan Chancellor <natechancellor@gmail.com>
> --- > include/linux/compiler-clang.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h > index cee0c728d39a..7338d3ffd240 100644 > --- a/include/linux/compiler-clang.h > +++ b/include/linux/compiler-clang.h > @@ -3,6 +3,14 @@ > #error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead." > #endif > > +#define CLANG_VERSION (__clang_major__ * 10000 \ > + + __clang_minor__ * 100 \ > + + __clang_patchlevel__) > + > +#if CLANG_VERSION < 100001 > +# error Sorry, your compiler is too old - please upgrade it. > +#endif > + > /* Compiler specific definitions for Clang compiler */ > > /* same as gcc, this was present in clang-2.6 so we can assume it works > -- > 2.28.0.297.g1956fa8f8d-goog >
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