Re: [PATCH v3] Compiler Attributes: remove CONFIG_ENABLE_MUST_CHECK

[Guenter Roeck]

On Sun, Nov 29, 2020 at 04:33:35AM +0900, Masahiro Yamada wrote:
> Revert commit cebc04ba9aeb ("add CONFIG_ENABLE_MUST_CHECK").
> 
> A lot of warn_unused_result warnings existed in 2006, but until now
> they have been fixed thanks to people doing allmodconfig tests.
> 
> Our goal is to always enable __must_check where appropriate, so this
> CONFIG option is no longer needed.
> 
> I see a lot of defconfig (arch/*/configs/*_defconfig) files having:
> 
>     # CONFIG_ENABLE_MUST_CHECK is not set
> 
> I did not touch them for now since it would be a big churn. If arch
> maintainers want to clean them up, please go ahead.
> 
> While I was here, I also moved __must_check to compiler_attributes.h
> from compiler_types.h
> 
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Acked-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
> Acked-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

This patch results in:

arch/sh/kernel/cpu/sh4a/smp-shx3.c: In function 'shx3_prepare_cpus':
arch/sh/kernel/cpu/sh4a/smp-shx3.c:76:3: error: ignoring return value of 'request_irq' declared with attribute 'warn_unused_result'

when building sh:defconfig. Checking for calls to request_irq()
suggests that there will be other similar errors in various builds.
Reverting the patch fixes the problem.

Guenter