On 1/10/24 12:39, Jani Nikula wrote:
At least the i915 and amd drivers enable a bunch more compiler warnings
than the kernel defaults.
Extend most of the W=1 warnings to the entire drm subsystem by
default. Use the copy-pasted warnings from scripts/Makefile.extrawarn
with s/KBUILD_CFLAGS/subdir-ccflags-y/ to make it easier to compare and
keep up with them in the future.
This is similar to the approach currently used in i915.
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.
There are too many -Wformat-truncation warnings to cleanly fix up front;
leave that warning disabled for now.
v2:
- Drop -Wformat-truncation (too many warnings)
- Drop -Wstringop-overflow (enabled by default upstream)
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: Christian König <[email protected]>
Cc: Pan, Xinhui <[email protected]>
Cc: Karol Herbst <[email protected]>
Cc: Lyude Paul <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Abhinav Kumar <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: Marijn Suijten <[email protected]>
Cc: Hamza Mahfooz <[email protected]>
Acked-by: Javier Martinez Canillas <[email protected]>
Acked-by: Thomas Zimmermann <[email protected]>
Acked-by: Sui Jingfeng <[email protected]>
Signed-off-by: Jani Nikula <[email protected]>
---
drivers/gpu/drm/Makefile | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 104b42df2e95..8b6be830f7c3 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -5,6 +5,33 @@
CFLAGS-$(CONFIG_DRM_USE_DYNAMIC_DEBUG) += -DDYNAMIC_DEBUG_MODULE
+# 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)
It would be safer to do something along the lines of:
cond-flags := $(call cc-option, -Wrestrict) \
$(call cc-option, -Wunused-but-set-variable) \
$(call cc-option, -Wunused-const-variable) \
$(call cc-option, -Wunused-const-variable) \
$(call cc-option, -Wformat-overflow) \
$(call cc-option, -Wstringop-truncation)
subdir-ccflags-y += $(cond-flags)
Otherwise, you will end up breaking `$ make M=drivers/gpu/drm`
for a bunch of people.
+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)
+# FIXME: fix -Wformat-truncation warnings and uncomment
+#subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
+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
+
drm-y := \
drm_aperture.o \
drm_atomic.o \
--
Hamza
