We enable a bunch more compiler warnings than the kernel defaults. However, they've drifted to become a unique set of warnings, and have increasingly fallen behind from the W=1 set. Align with the W=1 warnings from scripts/Makefile.extrawarn for clarity, by copy-pasting them with s/KBUILD_CFLAGS/subdir-ccflags-y/ to make it easier to compare in the future. Some of the -Wextra warnings do need to be disabled, just like in Makefile.extrawarn, but take care to not disable them for W=2 or W=3 builds, depending on the warning. v2: Add back some -Wextra warning disables (Nathan) Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: Nathan Chancellor <nathan@xxxxxxxxxx> Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> --- drivers/gpu/drm/i915/Makefile | 42 ++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 623f81217442..94f84befa38f 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -3,22 +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 -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 -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 := -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 +# 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, $(KBUILD_EXTRA_WARN)),) +KBUILD_CFLAGS += -Wno-missing-field-initializers +KBUILD_CFLAGS += -Wno-type-limits +KBUILD_CFLAGS += -Wno-shift-negative-value +endif +ifeq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) +KBUILD_CFLAGS += -Wno-sign-compare +endif +# --- end copy-paste + +# Enable -Werror in CI and development subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror # Fine grained warnings disable -- 2.39.2
