[Intel-gfx] [PATCH 1/2] drm/i915: drop -Wall and related disables from cflags as redundant

[Nathan Chancellor]

On Fri, Oct 06, 2023 at 03:34:46PM +0300, Jani Nikula wrote:
> The kernel top level Makefile, and recently scripts/Makefile.extrawarn,
> have included -Wall, and the disables -Wno-format-security and
> $(call cc-disable-warning,frame-address,) for a very long time. They're
> redundant in our local subdir-ccflags-y and can be dropped.
> 
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Nick Desaulniers <ndesaulniers at google.com>
> Cc: Nathan Chancellor <nathan at kernel.org>
> Cc: Masahiro Yamada <masahiroy at kernel.org>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Yeah, this seems totally reasonable. I always assumed the intention of
-Wall was to re-enable some warnings that the rest of the kernel had
turned off but I think we are getting better about auditing what
warnings are explicitly turned off and getting some of those turned back
on for the whole kernel, so I expect this to basically be a no-op.

Reviewed-by: Nathan Chancellor <nathan at kernel.org>

> ---
>  drivers/gpu/drm/i915/Makefile | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index dec78efa452a..623f81217442 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -5,22 +5,20 @@
>  
>  # Add a set of useful warning flags and enable -Werror for CI to prevent
>  # trivial mistakes from creeping in. We have to do this piecemeal as we reject
> -# any patch that isn't warning clean, so turning on -Wall -Wextra (or W=1) we
> +# any patch that isn't warning clean, so turning on -Wextra (or W=1) we
>  # need to filter out dubious warnings.  Still it is our interest
>  # to keep running locally with W=1 C=1 until we are completely clean.
>  #
> -# Note the danger in using -Wall -Wextra is that when CI updates gcc we
> +# Note the danger in using -Wextra is that when CI updates gcc we
>  # will most likely get a sudden build breakage... Hopefully we will fix
>  # new warnings before CI updates!
> -subdir-ccflags-y := -Wall -Wextra
> -subdir-ccflags-y += -Wno-format-security
> +subdir-ccflags-y := -Wextra
>  subdir-ccflags-y += -Wno-unused-parameter
>  subdir-ccflags-y += -Wno-type-limits
>  subdir-ccflags-y += -Wno-missing-field-initializers
>  subdir-ccflags-y += -Wno-sign-compare
>  subdir-ccflags-y += -Wno-shift-negative-value
>  subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
> -subdir-ccflags-y += $(call cc-disable-warning, frame-address)
>  subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
>  
>  # Fine grained warnings disable
> -- 
> 2.39.2
>