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References: <20221012180118.331005-1-masahiroy@kernel.org> <Y0mIUW7Ozx9tseeG@dev-arch.thelio-3990X>
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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Fri, 14 Oct 2022 13:19:13 -0700
Message-ID: <CAKwvOdmm9FsH2G76bZ2Qr5Bbnbdb55JwONP5WG7oa_iMZUycXQ@mail.gmail.com>
Subject: Re: [PATCH v3 1/2] kbuild: move -Werror from KBUILD_CFLAGS to KBUILD_CPPFLAGS
To:     Nathan Chancellor <nathan@kernel.org>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org, llvm@lists.linux.dev
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On Fri, Oct 14, 2022 at 9:03 AM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On Thu, Oct 13, 2022 at 03:01:17AM +0900, Masahiro Yamada wrote:
> > CONFIG_WERROR turns warnings into errors, which  happens only for *.c
> > files because -Werror is added to KBUILD_CFLAGS.
> >
> > Adding it to KBUILD_CPPFLAGS makes more sense because preprocessors
> > understand the -Werror option.
> >
> For what it's worth, this is going to break 32-bit ARM builds with clang
> plus the integrated assembler due to
> https://github.com/ClangBuiltLinux/linux/issues/1315:
>
> clang-16: error: argument unused during compilation: '-march=armv7-a' [-Werror,-Wunused-command-line-argument]

Ah, sorry, I should have finished off that series back then. I've
rebased the series and sent a v4.
https://lore.kernel.org/llvm/20221014201354.3190007-1-ndesaulniers@google.com/

You mentioned to me on IRC
https://lore.kernel.org/linux-next/CAK7LNARg8OpqLR_71PJV3ZoLuDV8+mz9mphg=CzEeEEMY0G3rw@mail.gmail.com/
maybe will be a conflict.

>
> Ultimately, I want -Wunused-command-line-argument to be an error anyways
> (https://github.com/ClangBuiltLinux/linux/issues/1587) but it would be
> nice to get these cleaned up before this goes in.
>
> Cheers,
> Nathan


-- 
Thanks,
~Nick Desaulniers