| # ========================================================================== | 
 | # | 
 | # 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_CHECKS | 
 | warning-  := $(empty) | 
 |  | 
 | warning-1 := -Wextra -Wunused -Wno-unused-parameter | 
 | warning-1 += -Wmissing-declarations | 
 | warning-1 += -Wmissing-format-attribute | 
 | warning-1 += $(call cc-option, -Wmissing-prototypes) | 
 | warning-1 += -Wold-style-definition | 
 | warning-1 += $(call cc-option, -Wmissing-include-dirs) | 
 | warning-1 += $(call cc-option, -Wunused-but-set-variable) | 
 | warning-1 += $(call cc-option, -Wunused-const-variable) | 
 | warning-1 += $(call cc-disable-warning, missing-field-initializers) | 
 | warning-1 += $(call cc-disable-warning, sign-compare) | 
 |  | 
 | warning-2 := -Waggregate-return | 
 | warning-2 += -Wcast-align | 
 | warning-2 += -Wdisabled-optimization | 
 | warning-2 += -Wnested-externs | 
 | warning-2 += -Wshadow | 
 | warning-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-cast | 
 | warning-3 += -Wcast-qual | 
 | warning-3 += -Wconversion | 
 | warning-3 += -Wpacked | 
 | warning-3 += -Wpadded | 
 | warning-3 += -Wpointer-arith | 
 | warning-3 += -Wredundant-decls | 
 | warning-3 += -Wswitch-default | 
 | warning-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) | 
 | endif | 
 | endif |