diff mbox series

[v2,06/14] powerpc/vdso: Remove unused '-s' flag from ASFLAGS

Message ID 20221228-drop-qunused-arguments-v2-6-9adbddd20d86@kernel.org (mailing list archive)
State New, archived
Headers show
Series Remove clang's -Qunused-arguments from KBUILD_CPPFLAGS | expand

Commit Message

Nathan Chancellor Jan. 12, 2023, 3:05 a.m. UTC 
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
warns:

  clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument]

The compiler's '-s' flag is a linking option (it is passed along to the
linker directly), which means it does nothing when the linker is not
invoked by the compiler. The kernel builds all .o files with '-c', which
stops the compilation pipeline before linking, so '-s' can be safely
dropped from ASFLAGS.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
---
Cc: mpe@ellerman.id.au
Cc: npiggin@gmail.com
Cc: christophe.leroy@csgroup.eu
Cc: linuxppc-dev@lists.ozlabs.org

As I mentioned before, it is possible that we should add '-s' to
ldflags-y in the following patch but I assume someone would have noticed
by now if that was a problem.
---
 arch/powerpc/kernel/vdso/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Michael Ellerman Jan. 25, 2023, 4:12 a.m. UTC | #1 
Nathan Chancellor <nathan@kernel.org> writes:
> When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
> warns:
>
>   clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument]
>
> The compiler's '-s' flag is a linking option (it is passed along to the
> linker directly), which means it does nothing when the linker is not
> invoked by the compiler. The kernel builds all .o files with '-c', which
> stops the compilation pipeline before linking, so '-s' can be safely
> dropped from ASFLAGS.
>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
> ---
> Cc: mpe@ellerman.id.au

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
index 6a977b0d8ffc..45c0cc5d34b6 100644
--- a/arch/powerpc/kernel/vdso/Makefile
+++ b/arch/powerpc/kernel/vdso/Makefile
@@ -51,10 +51,10 @@  ccflags-y := -shared -fno-common -fno-builtin -nostdlib -Wl,--hash-style=both
 ccflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld)
 
 CC32FLAGS := -Wl,-soname=linux-vdso32.so.1 -m32
-AS32FLAGS := -D__VDSO32__ -s
+AS32FLAGS := -D__VDSO32__
 
 CC64FLAGS := -Wl,-soname=linux-vdso64.so.1
-AS64FLAGS := -D__VDSO64__ -s
+AS64FLAGS := -D__VDSO64__
 
 targets += vdso32.lds
 CPPFLAGS_vdso32.lds += -P -C -Upowerpc