From: Michael Ellerman <mpe@ellerman.id.au>
To: Nathan Chancellor <nathan@kernel.org>, masahiroy@kernel.org
Cc: ndesaulniers@google.com, nicolas@fjasle.eu, trix@redhat.com,
linux-kbuild@vger.kernel.org, llvm@lists.linux.dev,
Nathan Chancellor <nathan@kernel.org>,
npiggin@gmail.com, christophe.leroy@csgroup.eu,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 05/14] powerpc: Remove linker flag from KBUILD_AFLAGS
Date: Wed, 25 Jan 2023 15:11:25 +1100 [thread overview]
Message-ID: <871qnjqmmq.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <20221228-drop-qunused-arguments-v2-5-9adbddd20d86@kernel.org>
Nathan Chancellor <nathan@kernel.org> writes:
> When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
> points out that KBUILD_AFLAGS contains a linker flag, which will be
> used:
Should that say "unused" ?
> clang: error: -Wl,-a32: 'linker' input unused [-Werror,-Wunused-command-line-argument]
>
> This was likely supposed to be '-Wa,-a$(BITS)'. However, this change is
> unnecessary, as all supported versions of clang and gcc will pass '-a64'
> or '-a32' to GNU as based on the value of '-m'; the behavior of the
> latest stable release of the oldest supported major version of each
> compiler is shown below and each compiler's latest release exhibits the
> same behavior (GCC 12.2.0 and Clang 15.0.6).
>
> $ powerpc64-linux-gcc --version | head -1
> powerpc64-linux-gcc (GCC) 5.5.0
>
> $ powerpc64-linux-gcc -m64 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as '
> .../as -a64 -mppc64 -many -mbig -o /dev/null /tmp/cctwuBzZ.s
>
> $ powerpc64-linux-gcc -m32 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as '
> .../as -a32 -mppc -many -mbig -o /dev/null /tmp/ccaZP4mF.sg
>
> $ clang --version | head -1
> Ubuntu clang version 11.1.0-++20211011094159+1fdec59bffc1-1~exp1~20211011214622.5
>
> $ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \
> -x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as
> "/usr/bin/powerpc64-linux-gnu-as" "-a64" "-mppc64" "-many" "-o" "/dev/null" "/tmp/null-80267c.s"
>
> $ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \
> -x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as
> "/usr/bin/powerpc64-linux-gnu-as" "-a32" "-mppc" "-many" "-o" "/dev/null" "/tmp/null-ab8f8d.s"
>
> Remove this flag altogether to avoid future issues.
>
> Fixes: 1421dc6d4829 ("powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> Cc: mpe@ellerman.id.au
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
cheers
next prev parent reply other threads:[~2023-01-25 4:21 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-12 3:04 [PATCH v2 00/14] Remove clang's -Qunused-arguments from KBUILD_CPPFLAGS Nathan Chancellor
2023-01-12 3:04 ` [PATCH v2 01/14] x86/boot/compressed: prefer cc-option for CFLAGS additions Nathan Chancellor
2023-01-12 3:04 ` [PATCH v2 02/14] MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 03/14] MIPS: Prefer cc-option for additions to cflags Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 04/14] kbuild: Update assembler calls to use proper flags and language target Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 05/14] powerpc: Remove linker flag from KBUILD_AFLAGS Nathan Chancellor
2023-01-25 4:11 ` Michael Ellerman [this message]
2023-01-26 1:29 ` Masahiro Yamada
2023-01-26 2:07 ` Nathan Chancellor
2023-01-26 4:22 ` Masahiro Yamada
2023-01-26 10:05 ` Michael Ellerman
2023-01-12 3:05 ` [PATCH v2 06/14] powerpc/vdso: Remove unused '-s' flag from ASFLAGS Nathan Chancellor
2023-01-25 4:12 ` Michael Ellerman
2023-01-12 3:05 ` [PATCH v2 07/14] powerpc/vdso: Improve linker flags Nathan Chancellor
2023-01-12 18:02 ` Sedat Dilek
2023-01-12 18:21 ` Nathan Chancellor
2023-01-12 18:47 ` Sedat Dilek
2023-01-22 17:27 ` Masahiro Yamada
2023-01-22 18:01 ` Nathan Chancellor
2023-01-23 15:07 ` Segher Boessenkool
2023-01-24 16:14 ` Nathan Chancellor
2023-01-24 16:30 ` Segher Boessenkool
2023-01-12 3:05 ` [PATCH v2 08/14] powerpc/vdso: Remove an unsupported flag from vgettimeofday-32.o with clang Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 09/14] s390/vdso: Drop unused '-s' flag from KBUILD_AFLAGS_64 Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 10/14] s390/vdso: Drop '-shared' from KBUILD_CFLAGS_64 Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 11/14] s390/purgatory: Remove unused '-MD' and unnecessary '-c' flags Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 12/14] drm/amd/display: Do not add '-mhard-float' to dml_ccflags for clang Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 13/14] kbuild: Turn a couple more of clang's unused option warnings into errors Nathan Chancellor
2023-01-12 3:05 ` [PATCH v2 14/14] kbuild: Stop using '-Qunused-arguments' with clang Nathan Chancellor
2023-01-22 17:28 ` [PATCH v2 00/14] Remove clang's -Qunused-arguments from KBUILD_CPPFLAGS Masahiro Yamada
2023-01-23 13:58 ` Naresh Kamboju
2023-01-23 16:11 ` Nathan Chancellor
2023-01-24 15:29 ` Naresh Kamboju
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