Clang is updating to support -Wimplicit-fallthrough on C https://reviews.llvm.org/D64838. Since clang does not support the comment version of fallthrough annotations this update causes an additional 50k warnings. Most of these warnings (>49k) are duplicates from header files. This patch is intended to be reverted after the warnings have been cleaned up. Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx> --- Makefile | 4 ++++ scripts/Makefile.extrawarn | 3 +++ 2 files changed, 7 insertions(+) diff --git a/Makefile b/Makefile index 1b23f95db176..93b9744e66a2 100644 --- a/Makefile +++ b/Makefile @@ -846,7 +846,11 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) KBUILD_CFLAGS += -Wdeclaration-after-statement # Warn about unmarked fall-throughs in switch statement. +# If the compiler is clang, this warning is only enabled if W=1 in +# Makefile.extrawarn +ifndef CONFIG_CC_IS_CLANG KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,) +endif # Variable Length Arrays (VLAs) should not be used anywhere in the kernel KBUILD_CFLAGS += -Wvla diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index a74ce2e3c33e..e12359d69bb7 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -30,6 +30,9 @@ warning-1 += $(call cc-option, -Wunused-but-set-variable) warning-1 += $(call cc-option, -Wunused-const-variable) warning-1 += $(call cc-option, -Wpacked-not-aligned) warning-1 += $(call cc-option, -Wstringop-truncation) +ifdef CONFIG_CC_IS_CLANG +KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,) +endif # The following turn off the warnings enabled by -Wextra warning-1 += -Wno-missing-field-initializers warning-1 += -Wno-sign-compare -- 2.23.0.rc1.153.gdeed80330f-goog
