1# SPDX-License-Identifier: GPL-2.0 2# ========================================================================== 3# make W=... settings 4# 5# There are four warning groups enabled by W=1, W=2, W=3, and W=e 6# They are independent, and can be combined like W=12 or W=123e. 7# ========================================================================== 8 9KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) 10 11# backward compatibility 12KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS) 13 14ifeq ("$(origin W)", "command line") 15 KBUILD_EXTRA_WARN := $(W) 16endif 17 18export KBUILD_EXTRA_WARN 19 20# 21# W=1 - warnings which may be relevant and do not occur too often 22# 23ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) 24 25KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter 26KBUILD_CFLAGS += -Wmissing-declarations 27KBUILD_CFLAGS += -Wmissing-format-attribute 28KBUILD_CFLAGS += -Wmissing-prototypes 29KBUILD_CFLAGS += -Wold-style-definition 30KBUILD_CFLAGS += -Wmissing-include-dirs 31KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable) 32KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable) 33KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned) 34KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) 35# The following turn off the warnings enabled by -Wextra 36KBUILD_CFLAGS += -Wno-missing-field-initializers 37KBUILD_CFLAGS += -Wno-sign-compare 38KBUILD_CFLAGS += -Wno-type-limits 39KBUILD_CFLAGS += -Wno-shift-negative-value 40 41KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 42 43else 44 45# Some diagnostics enabled by default are noisy. 46# Suppress them by using -Wno... except for W=1. 47 48ifdef CONFIG_CC_IS_CLANG 49KBUILD_CFLAGS += -Wno-initializer-overrides 50KBUILD_CFLAGS += -Wno-format 51KBUILD_CFLAGS += -Wno-sign-compare 52KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) 53KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare 54KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) 55endif 56 57endif 58 59# 60# W=2 - warnings which occur quite often but may still be relevant 61# 62ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) 63 64KBUILD_CFLAGS += -Wdisabled-optimization 65KBUILD_CFLAGS += -Wshadow 66KBUILD_CFLAGS += $(call cc-option, -Wlogical-op) 67KBUILD_CFLAGS += -Wmissing-field-initializers 68KBUILD_CFLAGS += -Wtype-limits 69KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized) 70KBUILD_CFLAGS += $(call cc-option, -Wunused-macros) 71 72KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2 73 74endif 75 76# 77# W=3 - more obscure warnings, can most likely be ignored 78# 79ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) 80 81KBUILD_CFLAGS += -Wbad-function-cast 82KBUILD_CFLAGS += -Wcast-align 83KBUILD_CFLAGS += -Wcast-qual 84KBUILD_CFLAGS += -Wconversion 85KBUILD_CFLAGS += -Wpacked 86KBUILD_CFLAGS += -Wpadded 87KBUILD_CFLAGS += -Wpointer-arith 88KBUILD_CFLAGS += -Wredundant-decls 89KBUILD_CFLAGS += -Wsign-compare 90KBUILD_CFLAGS += -Wswitch-default 91KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat) 92 93KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 94 95endif 96 97# 98# W=e - error out on warnings 99# 100ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),) 101 102KBUILD_CFLAGS += -Werror 103 104endif 105