Messages in this thread | | | From | Nick Desaulniers <> | Date | Mon, 26 Sep 2022 09:50:44 -0700 | Subject | Re: mainline build failure for x86_64 and arm64 with clang |
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On Mon, Sep 26, 2022 at 8:40 AM Nathan Chancellor <nathan@kernel.org> wrote: > > Thanks for testing and the report! I noticed this over the weekend, it > comes from a new warning in clang: > > https://github.com/llvm/llvm-project/commit/e07ead85a368173a56e96a21d6841aa497ad80f8 > > It was brought up on GitHub as well: > > https://github.com/ClangBuiltLinux/linux/issues/1720 > > I have reported this to the clang developers upstream to see if there is > any way that the diagnostic could be improved: > > https://reviews.llvm.org/D134461#3815298 > > Otherwise, we will just have to disable it, which I will send a patch > for later if the warning is not going to be adjusted in any way. > > If you wanted to continue testing with upstream LLVM, you can either > just revert that commit or explicitly disable -Wvoid-ptr-dereference in > the main Makefile like so, which is ultimately what I will send if I > need to. > > Cheers, > Nathan
Thanks for the reports. It sounds like the Clang developers will pare back the warning for unevaluated contexts (sizeof, typeof). If it takes longer than a few days for that to land, let's send your below patch to help keep CI systems green.
Consider putting the below into scripts/Makefile.extrawarn
> > diff --git a/Makefile b/Makefile > index 647a42a1f800..0bf60134f13c 100644 > --- a/Makefile > +++ b/Makefile > @@ -967,6 +967,9 @@ KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow) > # Another good warning that we'll want to enable eventually > KBUILD_CFLAGS += $(call cc-disable-warning, restrict) > > +# New warning from clang that is quite noisy due to '__is_constexpr' > +KBUILD_CFLAGS += $(call cc-disable-warning, void-ptr-dereference) > + > # Enabled with W=2, disabled by default as noisy > ifdef CONFIG_CC_IS_GCC > KBUILD_CFLAGS += -Wno-maybe-uninitialized
-- Thanks, ~Nick Desaulniers
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