1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# make W=... settings
4#
5# There are three warning groups enabled by W=1, W=2, W=3.
6# They are independent, and can be combined like W=12 or W=123.
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 += $(call cc-option, -Wstringop-truncation)
35# The following turn off the warnings enabled by -Wextra
36KBUILD_CFLAGS += -Wno-missing-field-initializers
37KBUILD_CFLAGS += -Wno-sign-compare
38
39KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
40
41else
42
43# Some diagnostics enabled by default are noisy.
44# Suppress them by using -Wno... except for W=1.
45
46ifdef CONFIG_CC_IS_CLANG
47KBUILD_CFLAGS += -Wno-initializer-overrides
48KBUILD_CFLAGS += -Wno-format
49KBUILD_CFLAGS += -Wno-sign-compare
50KBUILD_CFLAGS += -Wno-format-zero-length
51endif
52
53endif
54
55#
56# W=2 - warnings which occur quite often but may still be relevant
57#
58ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
59
60KBUILD_CFLAGS += -Wcast-align
61KBUILD_CFLAGS += -Wdisabled-optimization
62KBUILD_CFLAGS += -Wnested-externs
63KBUILD_CFLAGS += -Wshadow
64KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
65KBUILD_CFLAGS += -Wmissing-field-initializers
66KBUILD_CFLAGS += -Wsign-compare
67KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized)
68KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
69
70KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2
71
72endif
73
74#
75# W=3 - more obscure warnings, can most likely be ignored
76#
77ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),)
78
79KBUILD_CFLAGS += -Wbad-function-cast
80KBUILD_CFLAGS += -Wcast-qual
81KBUILD_CFLAGS += -Wconversion
82KBUILD_CFLAGS += -Wpacked
83KBUILD_CFLAGS += -Wpadded
84KBUILD_CFLAGS += -Wpointer-arith
85KBUILD_CFLAGS += -Wredundant-decls
86KBUILD_CFLAGS += -Wswitch-default
87KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
88
89KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
90
91endif
92