1 # SPDX-License-Identifier: GPL-2.0 1 # SPDX-License-Identifier: GPL-2.0
2 # ============================================ 2 # ==========================================================================
3 # make W=... settings 3 # make W=... settings
4 # 4 #
5 # There are four warning groups enabled by W=1 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 li 6 # They are independent, and can be combined like W=12 or W=123e.
7 # ============================================ 7 # ==========================================================================
8 8
9 # Default set of warnings, always enabled !! 9 KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
10 KBUILD_CFLAGS += -Wall <<
11 KBUILD_CFLAGS += -Wundef <<
12 KBUILD_CFLAGS += -Werror=implicit-function-dec <<
13 KBUILD_CFLAGS += -Werror=implicit-int <<
14 KBUILD_CFLAGS += -Werror=return-type <<
15 KBUILD_CFLAGS += -Werror=strict-prototypes <<
16 KBUILD_CFLAGS += -Wno-format-security <<
17 KBUILD_CFLAGS += -Wno-trigraphs <<
18 KBUILD_CFLAGS += $(call cc-disable-warning,fra <<
19 KBUILD_CFLAGS += $(call cc-disable-warning, ad <<
20 KBUILD_CFLAGS += -Wmissing-declarations <<
21 KBUILD_CFLAGS += -Wmissing-prototypes <<
22 <<
23 ifneq ($(CONFIG_FRAME_WARN),0) <<
24 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_ <<
25 endif <<
26 <<
27 KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror <<
28 KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y) <<
29 KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += <<
30 10
31 ifdef CONFIG_CC_IS_CLANG !! 11 # backward compatibility
32 # The kernel builds with '-std=gnu11' so use o !! 12 KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
33 KBUILD_CFLAGS += -Wno-gnu <<
34 else <<
35 13
36 # gcc inanely warns about local variables call !! 14 ifeq ("$(origin W)", "command line")
37 KBUILD_CFLAGS += -Wno-main !! 15 KBUILD_EXTRA_WARN := $(W)
38 endif 16 endif
39 17
40 # These result in bogus false positives !! 18 export KBUILD_EXTRA_WARN
41 KBUILD_CFLAGS += $(call cc-disable-warning, da <<
42 <<
43 # Variable Length Arrays (VLAs) should not be <<
44 KBUILD_CFLAGS += -Wvla <<
45 <<
46 # disable pointer signed / unsigned warnings i <<
47 KBUILD_CFLAGS += -Wno-pointer-sign <<
48 <<
49 # In order to make sure new function cast mism <<
50 # in the kernel (to avoid tripping CFI checkin <<
51 # globally built with -Wcast-function-type. <<
52 KBUILD_CFLAGS += $(call cc-option, -Wcast-func <<
53 <<
54 # The allocators already balk at large sizes, <<
55 # warnings for bounds checks involving those p <<
56 # -Wno-alloc-size-larger-than would normally b <<
57 # of gcc (<9.1) weirdly don't handle the optio <<
58 # warnings are produced (?!). Using -Walloc-si <<
59 # doesn't work (as it is documented to), silen <<
60 # version 9.1 (and producing an error more rec <<
61 # than PTRDIFF_MAX also don't work prior to ve <<
62 # ignored, continuing to default to PTRDIFF_MA <<
63 # choice, we must perform a versioned check to <<
64 # https://lore.kernel.org/lkml/20210824115859. <<
65 KBUILD_CFLAGS-$(call gcc-min-version, 90100) + <<
66 KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_C <<
67 <<
68 # Prohibit date/time macros, which would make <<
69 KBUILD_CFLAGS += -Werror=date-time <<
70 <<
71 # enforce correct pointer usage <<
72 KBUILD_CFLAGS += $(call cc-option,-Werror=inco <<
73 <<
74 # Require designated initializers for all mark <<
75 KBUILD_CFLAGS += $(call cc-option,-Werror=desi <<
76 <<
77 # Warn if there is an enum types mismatch <<
78 KBUILD_CFLAGS += $(call cc-option,-Wenum-conve <<
79 <<
80 KBUILD_CFLAGS += -Wextra <<
81 KBUILD_CFLAGS += -Wunused <<
82 19
83 # 20 #
84 # W=1 - warnings which may be relevant and do 21 # W=1 - warnings which may be relevant and do not occur too often
85 # 22 #
86 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) 23 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
87 24
>> 25 KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter
>> 26 KBUILD_CFLAGS += -Wmissing-declarations
88 KBUILD_CFLAGS += -Wmissing-format-attribute 27 KBUILD_CFLAGS += -Wmissing-format-attribute
>> 28 KBUILD_CFLAGS += -Wmissing-prototypes
>> 29 KBUILD_CFLAGS += -Wold-style-definition
89 KBUILD_CFLAGS += -Wmissing-include-dirs 30 KBUILD_CFLAGS += -Wmissing-include-dirs
>> 31 KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable)
90 KBUILD_CFLAGS += $(call cc-option, -Wunused-co 32 KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
>> 33 KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned)
>> 34 KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation)
>> 35 # The following turn off the warnings enabled by -Wextra
>> 36 KBUILD_CFLAGS += -Wno-missing-field-initializers
>> 37 KBUILD_CFLAGS += -Wno-sign-compare
>> 38 KBUILD_CFLAGS += -Wno-type-limits
>> 39 KBUILD_CFLAGS += -Wno-shift-negative-value
91 40
92 KBUILD_CPPFLAGS += -Wundef 41 KBUILD_CPPFLAGS += -Wundef
93 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 42 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
94 43
95 else 44 else
96 45
97 # Some diagnostics enabled by default are nois 46 # Some diagnostics enabled by default are noisy.
98 # Suppress them by using -Wno... except for W= 47 # Suppress them by using -Wno... except for W=1.
99 KBUILD_CFLAGS += $(call cc-disable-warning, un <<
100 KBUILD_CFLAGS += $(call cc-disable-warning, un <<
101 KBUILD_CFLAGS += $(call cc-disable-warning, pa <<
102 KBUILD_CFLAGS += $(call cc-disable-warning, fo <<
103 ifdef CONFIG_CC_IS_GCC <<
104 KBUILD_CFLAGS += $(call cc-disable-warning, fo <<
105 else <<
106 # Clang checks for overflow/truncation with '% <<
107 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id <<
108 KBUILD_CFLAGS += $(call cc-disable-warning, fo <<
109 KBUILD_CFLAGS += $(call cc-disable-warning, fo <<
110 endif <<
111 KBUILD_CFLAGS += $(call cc-disable-warning, st <<
112 <<
113 KBUILD_CFLAGS += -Wno-override-init # alias fo <<
114 48
115 ifdef CONFIG_CC_IS_CLANG 49 ifdef CONFIG_CC_IS_CLANG
>> 50 KBUILD_CFLAGS += -Wno-initializer-overrides
116 # Clang before clang-16 would warn on default 51 # Clang before clang-16 would warn on default argument promotions.
117 ifneq ($(call clang-min-version, 160000),y) 52 ifneq ($(call clang-min-version, 160000),y)
118 # Disable -Wformat 53 # Disable -Wformat
119 KBUILD_CFLAGS += -Wno-format 54 KBUILD_CFLAGS += -Wno-format
120 # Then re-enable flags that were part of the - 55 # Then re-enable flags that were part of the -Wformat group that aren't
121 # problematic. 56 # problematic.
122 KBUILD_CFLAGS += -Wformat-extra-args -Wformat- 57 KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier
123 KBUILD_CFLAGS += -Wformat-zero-length -Wnonnul 58 KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull
124 # Requires clang-12+. 59 # Requires clang-12+.
125 ifeq ($(call clang-min-version, 120000),y) 60 ifeq ($(call clang-min-version, 120000),y)
126 KBUILD_CFLAGS += -Wformat-insufficient-args 61 KBUILD_CFLAGS += -Wformat-insufficient-args
127 endif 62 endif
128 endif 63 endif
>> 64 KBUILD_CFLAGS += -Wno-sign-compare
129 KBUILD_CFLAGS += $(call cc-disable-warning, po 65 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
130 KBUILD_CFLAGS += -Wno-tautological-constant-ou 66 KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
131 KBUILD_CFLAGS += $(call cc-disable-warning, un 67 KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access)
132 KBUILD_CFLAGS += -Wno-enum-compare-conditional !! 68 KBUILD_CFLAGS += $(call cc-disable-warning, cast-function-type-strict)
133 KBUILD_CFLAGS += -Wno-enum-enum-conversion <<
134 endif 69 endif
135 70
136 endif 71 endif
137 72
138 # 73 #
139 # W=2 - warnings which occur quite often but m 74 # W=2 - warnings which occur quite often but may still be relevant
140 # 75 #
141 ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) 76 ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
142 77
143 KBUILD_CFLAGS += -Wdisabled-optimization 78 KBUILD_CFLAGS += -Wdisabled-optimization
144 KBUILD_CFLAGS += -Wshadow 79 KBUILD_CFLAGS += -Wshadow
145 KBUILD_CFLAGS += $(call cc-option, -Wlogical-o 80 KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
>> 81 KBUILD_CFLAGS += -Wmissing-field-initializers
>> 82 KBUILD_CFLAGS += -Wtype-limits
>> 83 KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized)
146 KBUILD_CFLAGS += $(call cc-option, -Wunused-ma 84 KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
147 85
148 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2 86 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2
149 87
150 else <<
151 <<
152 # The following turn off the warnings enabled <<
153 KBUILD_CFLAGS += -Wno-missing-field-initialize <<
154 KBUILD_CFLAGS += -Wno-type-limits <<
155 KBUILD_CFLAGS += -Wno-shift-negative-value <<
156 <<
157 ifdef CONFIG_CC_IS_GCC <<
158 KBUILD_CFLAGS += -Wno-maybe-uninitialized <<
159 endif <<
160 <<
161 endif 88 endif
162 89
163 # 90 #
164 # W=3 - more obscure warnings, can most likely 91 # W=3 - more obscure warnings, can most likely be ignored
165 # 92 #
166 ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) 93 ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),)
167 94
168 KBUILD_CFLAGS += -Wbad-function-cast 95 KBUILD_CFLAGS += -Wbad-function-cast
169 KBUILD_CFLAGS += -Wcast-align 96 KBUILD_CFLAGS += -Wcast-align
170 KBUILD_CFLAGS += -Wcast-qual 97 KBUILD_CFLAGS += -Wcast-qual
171 KBUILD_CFLAGS += -Wconversion 98 KBUILD_CFLAGS += -Wconversion
172 KBUILD_CFLAGS += -Wpacked 99 KBUILD_CFLAGS += -Wpacked
173 KBUILD_CFLAGS += -Wpadded 100 KBUILD_CFLAGS += -Wpadded
174 KBUILD_CFLAGS += -Wpointer-arith 101 KBUILD_CFLAGS += -Wpointer-arith
175 KBUILD_CFLAGS += -Wredundant-decls 102 KBUILD_CFLAGS += -Wredundant-decls
176 KBUILD_CFLAGS += -Wsign-compare 103 KBUILD_CFLAGS += -Wsign-compare
177 KBUILD_CFLAGS += -Wswitch-default 104 KBUILD_CFLAGS += -Wswitch-default
>> 105 KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
178 106
179 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 107 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
180 <<
181 else <<
182 <<
183 # The following turn off the warnings enabled <<
184 KBUILD_CFLAGS += -Wno-sign-compare <<
185 KBUILD_CFLAGS += -Wno-unused-parameter <<
186 108
187 endif 109 endif
188 110
189 # 111 #
190 # W=e - error out on warnings 112 # W=e - error out on warnings
191 # 113 #
192 ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),) 114 ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
193 115
194 KBUILD_CFLAGS += -Werror 116 KBUILD_CFLAGS += -Werror
195 117
196 endif 118 endif
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