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
38KBUILD_CFLAGS += -Wno-type-limits
39
40KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
41
42else
43
44# Some diagnostics enabled by default are noisy.
45# Suppress them by using -Wno... except for W=1.
46
47ifdef CONFIG_CC_IS_CLANG
48KBUILD_CFLAGS += -Wno-initializer-overrides
49KBUILD_CFLAGS += -Wno-format
50KBUILD_CFLAGS += -Wno-sign-compare
51KBUILD_CFLAGS += -Wno-format-zero-length
52KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
53KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
54endif
55
56endif
57
58#
59# W=2 - warnings which occur quite often but may still be relevant
60#
61ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
62
63KBUILD_CFLAGS += -Wdisabled-optimization
64KBUILD_CFLAGS += -Wnested-externs
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