mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 16:24:13 +08:00
c8e9c2b52c
commit1cf5f151d2upstream. -Wunaligned-access is a new warning in clang that is default enabled for arm and arm64 under certain circumstances within the clang frontend (see LLVM commit below). On v5.17-rc2, an ARCH=arm allmodconfig build shows 1284 total/70 unique instances of this warning (most of the instances are in header files), which is quite noisy. To keep a normal build green through CONFIG_WERROR, only show this warning with W=1, which will allow automated build systems to catch new instances of the warning so that the total number can be driven down to zero eventually since catching unaligned accesses at compile time would be generally useful. Cc: stable@vger.kernel.org Link:35737df4dcLink: https://github.com/ClangBuiltLinux/linux/issues/1569 Link: https://github.com/ClangBuiltLinux/linux/issues/1576 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
96 lines
2.8 KiB
Makefile
96 lines
2.8 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
# ==========================================================================
|
|
# make W=... settings
|
|
#
|
|
# There are three warning groups enabled by W=1, W=2, W=3.
|
|
# They are independent, and can be combined like W=12 or W=123.
|
|
# ==========================================================================
|
|
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
|
|
|
|
# backward compatibility
|
|
KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
|
|
|
|
ifeq ("$(origin W)", "command line")
|
|
KBUILD_EXTRA_WARN := $(W)
|
|
endif
|
|
|
|
export KBUILD_EXTRA_WARN
|
|
|
|
#
|
|
# W=1 - warnings which may be relevant and do not occur too often
|
|
#
|
|
ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
|
|
|
|
KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter
|
|
KBUILD_CFLAGS += -Wmissing-declarations
|
|
KBUILD_CFLAGS += -Wmissing-format-attribute
|
|
KBUILD_CFLAGS += -Wmissing-prototypes
|
|
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, -Wstringop-truncation)
|
|
# The following turn off the warnings enabled by -Wextra
|
|
KBUILD_CFLAGS += -Wno-missing-field-initializers
|
|
KBUILD_CFLAGS += -Wno-sign-compare
|
|
KBUILD_CFLAGS += -Wno-type-limits
|
|
|
|
KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1
|
|
|
|
else
|
|
|
|
# Some diagnostics enabled by default are noisy.
|
|
# Suppress them by using -Wno... except for W=1.
|
|
|
|
ifdef CONFIG_CC_IS_CLANG
|
|
KBUILD_CFLAGS += -Wno-initializer-overrides
|
|
KBUILD_CFLAGS += -Wno-format
|
|
KBUILD_CFLAGS += -Wno-sign-compare
|
|
KBUILD_CFLAGS += -Wno-format-zero-length
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
|
|
KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare
|
|
KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access)
|
|
endif
|
|
|
|
endif
|
|
|
|
#
|
|
# W=2 - warnings which occur quite often but may still be relevant
|
|
#
|
|
ifneq ($(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 += $(call cc-option, -Wunused-macros)
|
|
|
|
KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2
|
|
|
|
endif
|
|
|
|
#
|
|
# W=3 - more obscure warnings, can most likely be ignored
|
|
#
|
|
ifneq ($(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_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
|
|
|
|
KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
|
|
|
|
endif
|