Re: [PATCH 3/3] drm/xe: Enable W=1 warnings by default

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Dec 14, 2023 at 01:39:54PM -0800, Lucas De Marchi wrote:
> Like done in commit 2250c7ead8ad ("drm/i915: enable W=1 warnings by default")
> for i915, enable W=1 warnings by default in xe.

I'm afraid we might have one more case before we can enable it:

drivers/gpu/drm/xe/display/ext/i915_utils.c:18:5: warning: no previous prototype for ‘__i915_inject_probe_error’ [-Wmissing-prototypes]
   18 | int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~

> 
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>  drivers/gpu/drm/xe/Makefile | 47 ++++++++++++++++++++++---------------
>  1 file changed, 28 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index f4ae063a7005..6790c049d89e 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -3,25 +3,34 @@
>  # Makefile for the drm device driver.  This driver provides support for the
>  # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
>  
> -# 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
> -# 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
> -# 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 += $(call cc-disable-warning, unused-parameter)
> -subdir-ccflags-y += $(call cc-disable-warning, type-limits)
> -subdir-ccflags-y += $(call cc-disable-warning, missing-field-initializers)
> -subdir-ccflags-y += $(call cc-disable-warning, unused-but-set-variable)
> -# clang warnings
> -subdir-ccflags-y += $(call cc-disable-warning, sign-compare)
> -subdir-ccflags-y += $(call cc-disable-warning, sometimes-uninitialized)
> -subdir-ccflags-y += $(call cc-disable-warning, initializer-overrides)
> -subdir-ccflags-y += $(call cc-disable-warning, frame-address)
> +# Unconditionally enable W=1 warnings locally
> +# --- begin copy-paste W=1 warnings from scripts/Makefile.extrawarn
> +subdir-ccflags-y += -Wextra -Wunused -Wno-unused-parameter
> +subdir-ccflags-y += -Wmissing-declarations
> +subdir-ccflags-y += $(call cc-option, -Wrestrict)
> +subdir-ccflags-y += -Wmissing-format-attribute
> +subdir-ccflags-y += -Wmissing-prototypes
> +subdir-ccflags-y += -Wold-style-definition
> +subdir-ccflags-y += -Wmissing-include-dirs
> +subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
> +subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)
> +subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
> +subdir-ccflags-y += $(call cc-option, -Wformat-overflow)
> +subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
> +subdir-ccflags-y += $(call cc-option, -Wstringop-overflow)
> +subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
> +# The following turn off the warnings enabled by -Wextra
> +ifeq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
> +subdir-ccflags-y += -Wno-missing-field-initializers
> +subdir-ccflags-y += -Wno-type-limits
> +subdir-ccflags-y += -Wno-shift-negative-value
> +endif
> +ifeq ($(findstring 3, $(KBUILD_EXTRA_WARN)),)
> +subdir-ccflags-y += -Wno-sign-compare
> +endif
> +# --- end copy-paste
> +
> +# Enable -Werror in CI and development
>  subdir-ccflags-$(CONFIG_DRM_XE_WERROR) += -Werror
>  
>  subdir-ccflags-y += -I$(obj) -I$(srctree)/$(src)
> -- 
> 2.40.1
>