|  | # SPDX-License-Identifier: GPL-2.0 | 
|  | # ========================================================================== | 
|  | # make W=... settings | 
|  | # | 
|  | # There are four warning groups enabled by W=1, W=2, W=3, and W=e | 
|  | # They are independent, and can be combined like W=12 or W=123e. | 
|  | # ========================================================================== | 
|  |  | 
|  | KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned) | 
|  |  | 
|  | # backward compatibility | 
|  | KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS) | 
|  |  | 
|  | ifeq ("$(origin W)", "command line") | 
|  | KBUILD_EXTRA_WARN := $(W) | 
|  | endif | 
|  |  | 
|  | export KBUILD_EXTRA_WARN | 
|  |  | 
|  | # | 
|  | # W=1 - warnings which may be relevant and do not occur too often | 
|  | # | 
|  | ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) | 
|  |  | 
|  | KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter | 
|  | KBUILD_CFLAGS += -Wmissing-declarations | 
|  | KBUILD_CFLAGS += -Wmissing-format-attribute | 
|  | KBUILD_CFLAGS += -Wmissing-prototypes | 
|  | KBUILD_CFLAGS += -Wold-style-definition | 
|  | KBUILD_CFLAGS += -Wmissing-include-dirs | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable) | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable) | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned) | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) | 
|  | # The following turn off the warnings enabled by -Wextra | 
|  | KBUILD_CFLAGS += -Wno-missing-field-initializers | 
|  | KBUILD_CFLAGS += -Wno-sign-compare | 
|  | KBUILD_CFLAGS += -Wno-type-limits | 
|  | KBUILD_CFLAGS += -Wno-shift-negative-value | 
|  |  | 
|  | KBUILD_CPPFLAGS += -Wundef | 
|  | KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 | 
|  |  | 
|  | else | 
|  |  | 
|  | # Some diagnostics enabled by default are noisy. | 
|  | # Suppress them by using -Wno... except for W=1. | 
|  |  | 
|  | ifdef CONFIG_CC_IS_CLANG | 
|  | KBUILD_CFLAGS += -Wno-initializer-overrides | 
|  | # Clang before clang-16 would warn on default argument promotions. | 
|  | ifneq ($(call clang-min-version, 160000),y) | 
|  | # Disable -Wformat | 
|  | KBUILD_CFLAGS += -Wno-format | 
|  | # Then re-enable flags that were part of the -Wformat group that aren't | 
|  | # problematic. | 
|  | KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier | 
|  | KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull | 
|  | # Requires clang-12+. | 
|  | ifeq ($(call clang-min-version, 120000),y) | 
|  | KBUILD_CFLAGS += -Wformat-insufficient-args | 
|  | endif | 
|  | endif | 
|  | KBUILD_CFLAGS += -Wno-sign-compare | 
|  | KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) | 
|  | KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare | 
|  | KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) | 
|  | KBUILD_CFLAGS += $(call cc-disable-warning, cast-function-type-strict) | 
|  | endif | 
|  |  | 
|  | endif | 
|  |  | 
|  | # | 
|  | # W=2 - warnings which occur quite often but may still be relevant | 
|  | # | 
|  | ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) | 
|  |  | 
|  | KBUILD_CFLAGS += -Wdisabled-optimization | 
|  | KBUILD_CFLAGS += -Wshadow | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wlogical-op) | 
|  | KBUILD_CFLAGS += -Wmissing-field-initializers | 
|  | KBUILD_CFLAGS += -Wtype-limits | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized) | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wunused-macros) | 
|  |  | 
|  | KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2 | 
|  |  | 
|  | endif | 
|  |  | 
|  | # | 
|  | # W=3 - more obscure warnings, can most likely be ignored | 
|  | # | 
|  | ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) | 
|  |  | 
|  | KBUILD_CFLAGS += -Wbad-function-cast | 
|  | KBUILD_CFLAGS += -Wcast-align | 
|  | KBUILD_CFLAGS += -Wcast-qual | 
|  | KBUILD_CFLAGS += -Wconversion | 
|  | KBUILD_CFLAGS += -Wpacked | 
|  | KBUILD_CFLAGS += -Wpadded | 
|  | KBUILD_CFLAGS += -Wpointer-arith | 
|  | KBUILD_CFLAGS += -Wredundant-decls | 
|  | KBUILD_CFLAGS += -Wsign-compare | 
|  | KBUILD_CFLAGS += -Wswitch-default | 
|  | KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat) | 
|  |  | 
|  | KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 | 
|  |  | 
|  | endif | 
|  |  | 
|  | # | 
|  | # W=e - error out on warnings | 
|  | # | 
|  | ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),) | 
|  |  | 
|  | KBUILD_CFLAGS += -Werror | 
|  |  | 
|  | endif |