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 += -Wno-format-zero-length
53KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
54KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
55KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access)
56endif
57
58endif
59
60#
61# W=2 - warnings which occur quite often but may still be relevant
62#
63ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
64
65KBUILD_CFLAGS += -Wdisabled-optimization
66KBUILD_CFLAGS += -Wshadow
67KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
68KBUILD_CFLAGS += -Wmissing-field-initializers
69KBUILD_CFLAGS += -Wtype-limits
70KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized)
71KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
72
73KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2
74
75endif
76
77#
78# W=3 - more obscure warnings, can most likely be ignored
79#
80ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),)
81
82KBUILD_CFLAGS += -Wbad-function-cast
83KBUILD_CFLAGS += -Wcast-align
84KBUILD_CFLAGS += -Wcast-qual
85KBUILD_CFLAGS += -Wconversion
86KBUILD_CFLAGS += -Wpacked
87KBUILD_CFLAGS += -Wpadded
88KBUILD_CFLAGS += -Wpointer-arith
89KBUILD_CFLAGS += -Wredundant-decls
90KBUILD_CFLAGS += -Wsign-compare
91KBUILD_CFLAGS += -Wswitch-default
92KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
93
94KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
95
96endif
97
98#
99# W=e - error out on warnings
100#
101ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
102
103KBUILD_CFLAGS += -Werror
104
105endif
106