# SPDX-License-Identifier: GPL-2.0

  # ==========================================================================

  # make W=... settings
  #

  # There are three warning groups enabled by W=1, W=2, W=3.
  # They are independent, and can be combined like W=12 or W=123.

  # ==========================================================================

  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_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

  KBUILD_CFLAGS += -Wno-format
  KBUILD_CFLAGS += -Wno-sign-compare
  KBUILD_CFLAGS += -Wno-format-zero-length

  endif

  
  endif
  
  #
  # W=2 - warnings which occur quite often but may still be relevant
  #

  ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)

  
  KBUILD_CFLAGS += -Wcast-align
  KBUILD_CFLAGS += -Wdisabled-optimization
  KBUILD_CFLAGS += -Wnested-externs
  KBUILD_CFLAGS += -Wshadow
  KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
  KBUILD_CFLAGS += -Wmissing-field-initializers
  KBUILD_CFLAGS += -Wsign-compare
  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-qual
  KBUILD_CFLAGS += -Wconversion
  KBUILD_CFLAGS += -Wpacked
  KBUILD_CFLAGS += -Wpadded
  KBUILD_CFLAGS += -Wpointer-arith
  KBUILD_CFLAGS += -Wredundant-decls
  KBUILD_CFLAGS += -Wswitch-default
  KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)

  KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3

  endif