Re: annoying new gcc 4.6.0 warnings.

[David Daney <ddaney@caviumnetworks.com>]

On 04/21/2011 01:27 PM, Dave Jones wrote:
> On Thu, Apr 21, 2011 at 10:08:36PM +0200, Sam Ravnborg wrote:
>
>   >  My gcc (4.3.2) barfed over -Wno-unused-but-set-variable.
>   >  So your patch needs to check if the option is supported.
>
> I don't have a gcc older than 4.4.0. Can you try this ?
>
> 	Dave
> --
>
> Disable the new -Wunused-but-set-variable that was added in gcc 4.6.0
> It produces more false positives than useful warnings.
>
> This can still be enabled using W=1
>
> Signed-off-by: Dave Jones<davej@redhat.com>
>
> diff --git a/Makefile b/Makefile
> index b967b96..29e16f2 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -559,6 +559,8 @@ ifndef CONFIG_CC_STACKPROTECTOR
>   KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
>   endif
>
> +KBUILD_CFLAGS += $(call cc-option, -Wno-unused-but-set-variable)
> +
>   ifdef CONFIG_FRAME_POINTER
>   KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
>   else
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index d5f925a..30627ab 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -79,6 +79,7 @@ KBUILD_EXTRA_WARNINGS += -Wpointer-arith
>   KBUILD_EXTRA_WARNINGS += -Wredundant-decls
>   KBUILD_EXTRA_WARNINGS += -Wshadow
>   KBUILD_EXTRA_WARNINGS += -Wswitch-default
> +KBUILD_EXTRA_WARNINGS += -Wunused-but-set-variable

Well I didn't test it, but presumably if you need the $(call cc-option, 
-Wno-unused-but-set-variable), you would need similar here.

David Daney