xref: /linux/scripts/Makefile.extrawarn (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3#
4# make W=... settings
5#
6# W=1 - warnings that may be relevant and does not occur too often
7# W=2 - warnings that occur quite often but may still be relevant
8# W=3 - the more obscure warnings, can most likely be ignored
9#
10# $(call cc-option, -W...) handles gcc -W.. options which
11# are not supported by all versions of the compiler
12# ==========================================================================
13
14KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
15
16ifeq ("$(origin W)", "command line")
17  export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
18endif
19
20ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
21warning-  := $(empty)
22
23warning-1 := -Wextra -Wunused -Wno-unused-parameter
24warning-1 += -Wmissing-declarations
25warning-1 += -Wmissing-format-attribute
26warning-1 += -Wmissing-prototypes
27warning-1 += -Wold-style-definition
28warning-1 += -Wmissing-include-dirs
29warning-1 += $(call cc-option, -Wunused-but-set-variable)
30warning-1 += $(call cc-option, -Wunused-const-variable)
31warning-1 += $(call cc-option, -Wpacked-not-aligned)
32warning-1 += $(call cc-option, -Wstringop-truncation)
33# The following turn off the warnings enabled by -Wextra
34warning-1 += -Wno-missing-field-initializers
35warning-1 += -Wno-sign-compare
36
37warning-2 := -Waggregate-return
38warning-2 += -Wcast-align
39warning-2 += -Wdisabled-optimization
40warning-2 += -Wnested-externs
41warning-2 += -Wshadow
42warning-2 += $(call cc-option, -Wlogical-op)
43warning-2 += -Wmissing-field-initializers
44warning-2 += -Wsign-compare
45warning-2 += $(call cc-option, -Wmaybe-uninitialized)
46warning-2 += $(call cc-option, -Wunused-macros)
47
48warning-3 := -Wbad-function-cast
49warning-3 += -Wcast-qual
50warning-3 += -Wconversion
51warning-3 += -Wpacked
52warning-3 += -Wpadded
53warning-3 += -Wpointer-arith
54warning-3 += -Wredundant-decls
55warning-3 += -Wswitch-default
56warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
57
58warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
59warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
60warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
61
62ifeq ("$(strip $(warning))","")
63        $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
64endif
65
66KBUILD_CFLAGS += $(warning)
67else
68
69ifdef CONFIG_CC_IS_CLANG
70KBUILD_CFLAGS += -Wno-initializer-overrides
71KBUILD_CFLAGS += -Wno-unused-value
72KBUILD_CFLAGS += -Wno-format
73KBUILD_CFLAGS += -Wno-sign-compare
74KBUILD_CFLAGS += -Wno-format-zero-length
75KBUILD_CFLAGS += -Wno-uninitialized
76endif
77endif
78