Re: [PATCH] drm/amd/amdgpu: introduce DRM_AMDGPU_WERROR

[Hamza Mahfooz <hamza.mahfooz@amd.com>]

On 5/25/23 12:38, Hamza Mahfooz wrote:
> We want to do -Werror builds on our CI. However, non-amdgpu breakages
> have prevented us from doing so thus far. Also, there are a number of
> additional checks that we should enable, that the community cares about
> and are hidden behind -Wextra. So, define DRM_AMDGPU_WERROR to only
> enable -Werror for the amdgpu kernel module and enable -Wextra while
> disabling all of the checks that are too noisy.
> 
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Kenny Ho <kenny.ho@amd.com>
> Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
> Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>

I am able to get clean builds with this enabled on GCC 11-13 and Clang
15, at least as of commit e786aef0869c ("drm/amd/display: remove unused
definition") on amd-staging-drm-next.

> ---
>   drivers/gpu/drm/amd/amdgpu/Kconfig  | 10 ++++++++++
>   drivers/gpu/drm/amd/amdgpu/Makefile |  9 +++++++++
>   2 files changed, 19 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig
> index 07135ffa6d24..334511f331e3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/Kconfig
> +++ b/drivers/gpu/drm/amd/amdgpu/Kconfig
> @@ -66,6 +66,16 @@ config DRM_AMDGPU_USERPTR
>   	  This option selects CONFIG_HMM and CONFIG_HMM_MIRROR if it
>   	  isn't already selected to enabled full userptr support.
>   
> +config DRM_AMDGPU_WERROR
> +	bool "Force the compiler to throw an error instead of a warning when compiling"
> +	depends on DRM_AMDGPU
> +	depends on EXPERT
> +	depends on !COMPILE_TEST
> +	default n
> +	help
> +	  Add -Werror to the build flags for amdgpu.ko.
> +	  Only enable this if you are warning code for amdgpu.ko.
> +
>   source "drivers/gpu/drm/amd/acp/Kconfig"
>   source "drivers/gpu/drm/amd/display/Kconfig"
>   source "drivers/gpu/drm/amd/amdkfd/Kconfig"
> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
> index 74a9aa6fe18c..7ee68b1bbfed 100644
> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
> @@ -39,6 +39,15 @@ ccflags-y := -I$(FULL_AMD_PATH)/include/asic_reg \
>   	-I$(FULL_AMD_DISPLAY_PATH)/amdgpu_dm \
>   	-I$(FULL_AMD_PATH)/amdkfd
>   
> +subdir-ccflags-y := -Wextra
> +subdir-ccflags-y += -Wunused-but-set-variable
> +subdir-ccflags-y += -Wno-unused-parameter
> +subdir-ccflags-y += -Wno-type-limits
> +subdir-ccflags-y += -Wno-sign-compare
> +subdir-ccflags-y += -Wno-missing-field-initializers
> +subdir-ccflags-y += -Wno-override-init
> +subdir-ccflags-$(CONFIG_DRM_AMDGPU_WERROR) += -Werror
> +
>   amdgpu-y := amdgpu_drv.o
>   
>   # add KMS driver
-- 
Hamza