mirror of
https://github.com/torvalds/linux.git
synced 2024-11-29 23:51:37 +00:00
44929bface
Commit 4a5838ad9d ("kbuild: Add extra gcc checks") added the
-Wpacked-bitfield-compat flag, but there is no need to add it
explicitly.
GCC manual says:
"This warning is enabled by default. Use -Wno-packed-bitfield-compat
to disable this warning."
The test code in the manual:
struct foo
{
char a:4;
char b:8;
} __attribute__ ((packed));
... emits "note: offset of packed bit-field ‘b’ has changed in GCC 4.4"
without W=3.
Let's remove it, as it is a default with GCC.
Clang does not support this flag, so its removal will not affect Clang
builds.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
208 lines
7.1 KiB
Makefile
208 lines
7.1 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
# ==========================================================================
|
|
# make W=... settings
|
|
#
|
|
# There are four warning groups enabled by W=1, W=2, W=3, and W=e
|
|
# They are independent, and can be combined like W=12 or W=123e.
|
|
# ==========================================================================
|
|
|
|
# Default set of warnings, always enabled
|
|
KBUILD_CFLAGS += -Wall
|
|
KBUILD_CFLAGS += -Wundef
|
|
KBUILD_CFLAGS += -Werror=implicit-function-declaration
|
|
KBUILD_CFLAGS += -Werror=implicit-int
|
|
KBUILD_CFLAGS += -Werror=return-type
|
|
KBUILD_CFLAGS += -Werror=strict-prototypes
|
|
KBUILD_CFLAGS += -Wno-format-security
|
|
KBUILD_CFLAGS += -Wno-trigraphs
|
|
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
|
|
KBUILD_CFLAGS += -Wmissing-declarations
|
|
KBUILD_CFLAGS += -Wmissing-prototypes
|
|
|
|
ifneq ($(CONFIG_FRAME_WARN),0)
|
|
KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
|
|
endif
|
|
|
|
KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
|
|
KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
|
|
KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
|
|
|
|
ifdef CONFIG_CC_IS_CLANG
|
|
# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
|
|
KBUILD_CFLAGS += -Wno-gnu
|
|
else
|
|
|
|
# gcc inanely warns about local variables called 'main'
|
|
KBUILD_CFLAGS += -Wno-main
|
|
endif
|
|
|
|
# These warnings generated too much noise in a regular build.
|
|
# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
|
|
|
|
# These result in bogus false positives
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
|
|
|
|
# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
|
|
KBUILD_CFLAGS += -Wvla
|
|
|
|
# disable pointer signed / unsigned warnings in gcc 4.0
|
|
KBUILD_CFLAGS += -Wno-pointer-sign
|
|
|
|
# In order to make sure new function cast mismatches are not introduced
|
|
# in the kernel (to avoid tripping CFI checking), the kernel should be
|
|
# globally built with -Wcast-function-type.
|
|
KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
|
|
|
|
# The allocators already balk at large sizes, so silence the compiler
|
|
# warnings for bounds checks involving those possible values. While
|
|
# -Wno-alloc-size-larger-than would normally be used here, earlier versions
|
|
# of gcc (<9.1) weirdly don't handle the option correctly when _other_
|
|
# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
|
|
# doesn't work (as it is documented to), silently resolving to "0" prior to
|
|
# version 9.1 (and producing an error more recently). Numeric values larger
|
|
# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
|
|
# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
|
|
# choice, we must perform a versioned check to disable this warning.
|
|
# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
|
|
KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
|
|
KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
|
|
|
|
# Prohibit date/time macros, which would make the build non-deterministic
|
|
KBUILD_CFLAGS += -Werror=date-time
|
|
|
|
# enforce correct pointer usage
|
|
KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
|
|
|
|
# Require designated initializers for all marked structures
|
|
KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
|
|
|
|
# Warn if there is an enum types mismatch
|
|
KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion)
|
|
|
|
#
|
|
# W=1 - warnings which may be relevant and do not occur too often
|
|
#
|
|
ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
|
|
|
|
KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter
|
|
KBUILD_CFLAGS += $(call cc-option, -Wrestrict)
|
|
KBUILD_CFLAGS += -Wmissing-format-attribute
|
|
KBUILD_CFLAGS += -Wold-style-definition
|
|
KBUILD_CFLAGS += -Wmissing-include-dirs
|
|
KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable)
|
|
KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
|
|
KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned)
|
|
KBUILD_CFLAGS += $(call cc-option, -Wformat-overflow)
|
|
KBUILD_CFLAGS += $(call cc-option, -Wformat-truncation)
|
|
KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation)
|
|
|
|
KBUILD_CPPFLAGS += -Wundef
|
|
KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
|
|
|
|
else
|
|
|
|
# Some diagnostics enabled by default are noisy.
|
|
# Suppress them by using -Wno... except for W=1.
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
|
|
|
|
ifdef CONFIG_CC_IS_CLANG
|
|
# Clang before clang-16 would warn on default argument promotions.
|
|
ifneq ($(call clang-min-version, 160000),y)
|
|
# Disable -Wformat
|
|
KBUILD_CFLAGS += -Wno-format
|
|
# Then re-enable flags that were part of the -Wformat group that aren't
|
|
# problematic.
|
|
KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier
|
|
KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull
|
|
# Requires clang-12+.
|
|
ifeq ($(call clang-min-version, 120000),y)
|
|
KBUILD_CFLAGS += -Wformat-insufficient-args
|
|
endif
|
|
endif
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
|
|
KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access)
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, cast-function-type-strict)
|
|
KBUILD_CFLAGS += -Wno-enum-compare-conditional
|
|
KBUILD_CFLAGS += -Wno-enum-enum-conversion
|
|
endif
|
|
|
|
endif
|
|
|
|
#
|
|
# W=2 - warnings which occur quite often but may still be relevant
|
|
#
|
|
ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
|
|
|
|
KBUILD_CFLAGS += -Wdisabled-optimization
|
|
KBUILD_CFLAGS += -Wshadow
|
|
KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
|
|
KBUILD_CFLAGS += -Wmissing-field-initializers
|
|
KBUILD_CFLAGS += -Wtype-limits
|
|
KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized)
|
|
KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
|
|
|
|
ifdef CONFIG_CC_IS_CLANG
|
|
KBUILD_CFLAGS += -Winitializer-overrides
|
|
endif
|
|
|
|
KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2
|
|
|
|
else
|
|
|
|
# The following turn off the warnings enabled by -Wextra
|
|
KBUILD_CFLAGS += -Wno-missing-field-initializers
|
|
KBUILD_CFLAGS += -Wno-type-limits
|
|
KBUILD_CFLAGS += -Wno-shift-negative-value
|
|
|
|
ifdef CONFIG_CC_IS_CLANG
|
|
KBUILD_CFLAGS += -Wno-initializer-overrides
|
|
else
|
|
KBUILD_CFLAGS += -Wno-maybe-uninitialized
|
|
endif
|
|
|
|
endif
|
|
|
|
#
|
|
# W=3 - more obscure warnings, can most likely be ignored
|
|
#
|
|
ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),)
|
|
|
|
KBUILD_CFLAGS += -Wbad-function-cast
|
|
KBUILD_CFLAGS += -Wcast-align
|
|
KBUILD_CFLAGS += -Wcast-qual
|
|
KBUILD_CFLAGS += -Wconversion
|
|
KBUILD_CFLAGS += -Wpacked
|
|
KBUILD_CFLAGS += -Wpadded
|
|
KBUILD_CFLAGS += -Wpointer-arith
|
|
KBUILD_CFLAGS += -Wredundant-decls
|
|
KBUILD_CFLAGS += -Wsign-compare
|
|
KBUILD_CFLAGS += -Wswitch-default
|
|
|
|
KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
|
|
|
|
else
|
|
|
|
# The following turn off the warnings enabled by -Wextra
|
|
KBUILD_CFLAGS += -Wno-sign-compare
|
|
|
|
endif
|
|
|
|
#
|
|
# W=e - error out on warnings
|
|
#
|
|
ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
|
|
|
|
KBUILD_CFLAGS += -Werror
|
|
|
|
endif
|