linux/scripts/Makefile.extrawarn

1 # SPDX-License-Identifier: GPL-2.0
6 # They are independent, and can be combined like W=12 or W=123e.
10 KBUILD_CFLAGS += -Wall
11 KBUILD_CFLAGS += -Wundef
12 KBUILD_CFLAGS += -Werror=implicit-function-declaration
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,frame-address,)
19 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
22 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
25 KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
26 KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
27 KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
30 # The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
31 KBUILD_CFLAGS += -Wno-gnu
35 # which can result in unexpected behavior. However, in many audited cases of
38 # other non-const members, or the containing object is not const so the field
39 # can be modified via memcpy() / memset(). While the variable warning also gets
41 # because -Wuninitialized will still flag when an uninitialized const variable
43 KBUILD_CFLAGS += $(call cc-disable-warning, default-const-init-unsafe)
47 KBUILD_CFLAGS += -Wno-main
52 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
53 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
56 KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
59 KBUILD_CFLAGS += -Wvla
61 # disable pointer signed / unsigned warnings in gcc 4.0
62 KBUILD_CFLAGS += -Wno-pointer-sign
66 # globally built with -Wcast-function-type.
67 KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
71 # -Wno-alloc-size-larger-than would normally be used here, earlier versions
73 # warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
78 # choice, we must perform a versioned check to disable this warning.
80 KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
81 KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
83 # Prohibit date/time macros, which would make the build non-deterministic
84 KBUILD_CFLAGS += -Werror=date-time
87 KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
90 KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
93 KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion)
105 # W=1 - warnings which may be relevant and do not occur too often
109 KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter
110 KBUILD_CFLAGS += -Wmissing-declarations
111 KBUILD_CFLAGS += $(call cc-option, -Wrestrict)
112 KBUILD_CFLAGS += -Wmissing-format-attribute
113 KBUILD_CFLAGS += -Wmissing-prototypes
114 KBUILD_CFLAGS += -Wold-style-definition
115 KBUILD_CFLAGS += -Wmissing-include-dirs
116 KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable)
117 KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
118 KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned)
119 KBUILD_CFLAGS += $(call cc-option, -Wformat-overflow)
120 KBUILD_CFLAGS += $(call cc-option, -Wformat-truncation)
121 KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow)
122 KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation)
124 KBUILD_CPPFLAGS += -Wundef
125 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
130 # Suppress them by using -Wno... except for W=1.
131 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
132 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
133 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
134 KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
135 KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
136 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
137 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
138 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
141 # Clang before clang-16 would warn on default argument promotions.
142 ifneq ($(call clang-min-version, 160000),y)
143 # Disable -Wformat
144 KBUILD_CFLAGS += -Wno-format
145 # Then re-enable flags that were part of the -Wformat group that aren't
147 KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier
148 KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull
149 # Requires clang-12+.
150 ifeq ($(call clang-min-version, 120000),y)
151 KBUILD_CFLAGS += -Wformat-insufficient-args
154 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
155 KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
156 KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access)
157 KBUILD_CFLAGS += $(call cc-disable-warning, cast-function-type-strict)
158 KBUILD_CFLAGS += -Wno-enum-compare-conditional
164 # W=2 - warnings which occur quite often but may still be relevant
168 KBUILD_CFLAGS += -Wdisabled-optimization
169 KBUILD_CFLAGS += -Wshadow
170 KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
171 KBUILD_CFLAGS += -Wmissing-field-initializers
172 KBUILD_CFLAGS += -Wtype-limits
173 KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized)
174 KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
177 KBUILD_CFLAGS += -Winitializer-overrides
180 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2
184 # The following turn off the warnings enabled by -Wextra
185 KBUILD_CFLAGS += -Wno-missing-field-initializers
186 KBUILD_CFLAGS += -Wno-type-limits
187 KBUILD_CFLAGS += -Wno-shift-negative-value
190 KBUILD_CFLAGS += -Wno-enum-enum-conversion
194 KBUILD_CFLAGS += -Wno-initializer-overrides
196 KBUILD_CFLAGS += -Wno-maybe-uninitialized
202 # W=3 - more obscure warnings, can most likely be ignored
206 KBUILD_CFLAGS += -Wbad-function-cast
207 KBUILD_CFLAGS += -Wcast-align
208 KBUILD_CFLAGS += -Wcast-qual
209 KBUILD_CFLAGS += -Wconversion
210 KBUILD_CFLAGS += -Wpacked
211 KBUILD_CFLAGS += -Wpadded
212 KBUILD_CFLAGS += -Wpointer-arith
213 KBUILD_CFLAGS += -Wredundant-decls
214 KBUILD_CFLAGS += -Wsign-compare
215 KBUILD_CFLAGS += -Wswitch-default
216 KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
218 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
222 # The following turn off the warnings enabled by -Wextra
223 KBUILD_CFLAGS += -Wno-sign-compare
228 # W=e - error out on warnings
232 KBUILD_CFLAGS += -Werror