# ==========================================================================## make W=... settings## W=1 - warnings that may be relevant and does not occur too often# W=2 - warnings that occur quite often but may still be relevant# W=3 - the more obscure warnings, can most likely be ignored## $(call cc-option, -W...) handles gcc -W.. options which# are not supported by all versions of the compiler# ========================================================================== ifeq ("$(origin W)", "command line")  export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)endif ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKSwarning-  := $(empty) warning-1 := -Wextra -Wunused -Wno-unused-parameterwarning-1 += -Wmissing-declarationswarning-1 += -Wmissing-format-attributewarning-1 += $(call cc-option, -Wmissing-prototypes)warning-1 += -Wold-style-definitionwarning-1 += $(call cc-option, -Wmissing-include-dirs)warning-1 += $(call cc-option, -Wunused-but-set-variable)warning-1 += $(call cc-disable-warning, missing-field-initializers)warning-1 += $(call cc-disable-warning, sign-compare) warning-2 := -Waggregate-returnwarning-2 += -Wcast-alignwarning-2 += -Wdisabled-optimizationwarning-2 += -Wnested-externswarning-2 += -Wshadowwarning-2 += $(call cc-option, -Wlogical-op)warning-2 += $(call cc-option, -Wmissing-field-initializers)warning-2 += $(call cc-option, -Wsign-compare) warning-3 := -Wbad-function-castwarning-3 += -Wcast-qualwarning-3 += -Wconversionwarning-3 += -Wpackedwarning-3 += -Wpaddedwarning-3 += -Wpointer-arithwarning-3 += -Wredundant-declswarning-3 += -Wswitch-defaultwarning-3 += $(call cc-option, -Wpacked-bitfield-compat)warning-3 += $(call cc-option, -Wvla) warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) ifeq ("$(strip $(warning))","")        $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)endif KBUILD_CFLAGS += $(warning)else ifeq ($(cc-name),clang)KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)KBUILD_CFLAGS += $(call cc-disable-warning, format)KBUILD_CFLAGS += $(call cc-disable-warning, unknown-warning-option)KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)endifendif