From b45b42405c317bbd77562122f9907961f885c755 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <nathan@kernel.org>
Date: Tue, 14 Sep 2021 12:49:45 -0700
Subject: drm/i915: Clean up disabled warnings
Git-commit: 4b2437f6f7b05ffcc7007f8e8d4f028ab86707dd
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
i915 enables a wider set of warnings with '-Wall -Wextra' then disables
several with cc-disable-warning. If an unknown flag gets added to
KBUILD_CFLAGS when building with clang, all subsequent calls to
cc-{disable-warning,option} will fail, meaning that all of these
warnings do not get disabled [1].
A separate series will address the root cause of the issue by not adding
these flags when building with clang [2]; however, the symptom of these
extra warnings appearing can be addressed separately by just removing
the calls to cc-disable-warning, which makes the build ever so slightly
faster because the compiler does not need to be called as much before
building.
The following warnings are supported by GCC 4.9 and clang 10.0.1, which
are the minimum supported versions of these compilers so the call to
cc-disable-warning is not necessary. Masahiro cleaned this up for the
reset of the kernel in commit 4c8dd95a723d ("kbuild: add some extra
warning flags unconditionally").
* -Wmissing-field-initializers
* -Wsign-compare
* -Wtype-limits
* -Wunused-parameter
-Wunused-but-set-variable was implemented in clang 13.0.0 and
-Wframe-address was implemented in clang 12.0.0 so the
cc-disable-warning calls are kept for these two warnings.
Lastly, -Winitializer-overrides is clang's version of -Woverride-init,
which is disabled for the specific files that are problematic. clang
added a compatibility alias in clang 8.0.0 so -Winitializer-overrides
can be removed.
[1]: https://lore.kernel.org/r/202108210311.CBtcgoUL-lkp@intel.com/
[2]: https://lore.kernel.org/r/20210824022640.2170859-1-nathan@kernel.org/
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914194944.4004260-1-nathan@kernel.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/Makefile | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index b24ff3cc5061..21b05ed0e4e8 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -13,13 +13,11 @@
# 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 += -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 += $(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, initializer-overrides)
subdir-ccflags-y += $(call cc-disable-warning, frame-address)
subdir-ccflags-$(CONFIG_DRM_I915_WERROR) += -Werror
--
2.38.1