[PATCH 4.4 to 4.19] Makefile: Move -Wno-unused-but-set-variable out of GCC only block

[PATCH 4.4 to 4.19] Makefile: Move -Wno-unused-but-set-variable out of GCC only block

[Nathan Chancellor]

commit 885480b084696331bea61a4f7eba10652999a9c1 upstream.

Currently, -Wunused-but-set-variable is only supported by GCC so it is
disabled unconditionally in a GCC only block (it is enabled with W=1).
clang currently has its implementation for this warning in review so
preemptively move this statement out of the GCC only block and wrap it
with cc-disable-warning so that both compilers function the same.

Cc: stable@vger.kernel.org
Link: https://reviews.llvm.org/D100581
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nc: Backport, workaround lack of e2079e93f562 in older branches]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 9ff7a4b7b8cb..cda7a18b925a 100644
--- a/Makefile
+++ b/Makefile
@@ -716,12 +716,11 @@ KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 # See modpost pattern 2
 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
-else
+endif
 
 # These warnings generated too much noise in a regular build.
 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
-endif
 
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 ifdef CONFIG_FRAME_POINTER

base-commit: eb575cd5d7f60241d016fdd13a9e86d962093c9b
-- 
2.32.0.93.g670b81a890

Re: [PATCH 4.4 to 4.19] Makefile: Move -Wno-unused-but-set-variable out of GCC only block

[Sasha Levin]

On Wed, Jun 23, 2021 at 10:26:12AM -0700, Nathan Chancellor wrote:
>commit 885480b084696331bea61a4f7eba10652999a9c1 upstream.
>
>Currently, -Wunused-but-set-variable is only supported by GCC so it is
>disabled unconditionally in a GCC only block (it is enabled with W=1).
>clang currently has its implementation for this warning in review so
>preemptively move this statement out of the GCC only block and wrap it
>with cc-disable-warning so that both compilers function the same.
>
>Cc: stable@vger.kernel.org
>Link: https://reviews.llvm.org/D100581
>Signed-off-by: Nathan Chancellor <nathan@kernel.org>
>Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>Tested-by: Nick Desaulniers <ndesaulniers@google.com>
>Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
>[nc: Backport, workaround lack of e2079e93f562 in older branches]

Can we just take the above patch instead?

-- 
Thanks,
Sasha

Re: [PATCH 4.4 to 4.19] Makefile: Move -Wno-unused-but-set-variable out of GCC only block

[Nathan Chancellor]

On 6/24/2021 5:04 AM, Sasha Levin wrote:
> On Wed, Jun 23, 2021 at 10:26:12AM -0700, Nathan Chancellor wrote:
>> commit 885480b084696331bea61a4f7eba10652999a9c1 upstream.
>>
>> Currently, -Wunused-but-set-variable is only supported by GCC so it is
>> disabled unconditionally in a GCC only block (it is enabled with W=1).
>> clang currently has its implementation for this warning in review so
>> preemptively move this statement out of the GCC only block and wrap it
>> with cc-disable-warning so that both compilers function the same.
>>
>> Cc: stable@vger.kernel.org
>> Link: https://reviews.llvm.org/D100581
>> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
>> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
>> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
>> [nc: Backport, workaround lack of e2079e93f562 in older branches]
> 
> Can we just take the above patch instead?

No because that patch has a prerequisite of commit a035d552a93b 
("Makefile: Globally enable fall-through warning"), which is not 
suitable for stable because there were hundreds of warnings fixed before 
that was enabled.

Cheers,
Nathan

Re: [PATCH 4.4 to 4.19] Makefile: Move -Wno-unused-but-set-variable out of GCC only block

[Greg Kroah-Hartman]

On Wed, Jun 23, 2021 at 10:26:12AM -0700, Nathan Chancellor wrote:
> commit 885480b084696331bea61a4f7eba10652999a9c1 upstream.
> 
> Currently, -Wunused-but-set-variable is only supported by GCC so it is
> disabled unconditionally in a GCC only block (it is enabled with W=1).
> clang currently has its implementation for this warning in review so
> preemptively move this statement out of the GCC only block and wrap it
> with cc-disable-warning so that both compilers function the same.
> 
> Cc: stable@vger.kernel.org
> Link: https://reviews.llvm.org/D100581
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> [nc: Backport, workaround lack of e2079e93f562 in older branches]
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>  Makefile | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Now queued up, thanks.

greg k-h