mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 22:02:28 +00:00
kbuild: refactor scripts/Makefile.extrawarn
Instead of the warning-[123] magic, let's accumulate compiler options
to KBUILD_CFLAGS directly as the top Makefile does. I think this makes
it easier to understand what is going on in this file.
This commit slightly changes the behavior, I think all of which are OK.
[1] Currently, cc-option calls are needlessly evaluated. For example,
warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
needs evaluating only when W=3, but it is actually evaluated for
W=1, W=2 as well. With this commit, only relevant cc-option calls
will be evaluated. This is a slight optimization.
[2] Currently, unsupported level like W=4 is checked by:
$(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
This will no longer be checked, but I do not think it is a big
deal.
[3] Currently, 4 Clang warnings (Winitializer-overrides, Wformat,
Wsign-compare, Wformat-zero-length) are shown by any of W=1, W=2,
and W=3. With this commit, they will be warned only by W=1. I
think this is a more correct behavior since each warning belongs
to only one group.
For understanding this commit correctly:
We have 3 warning groups, W=1, W=2, and W=3. You may think W=3 has a
higher level than W=1, but they are actually independent. If you like,
you can combine them like W=13. To enable all the warnings, you can
pass W=123. It is shown by 'make help', but not noticed much. Since we
support W= combination, there should not exist intersection among the
three groups. If we enable Winitializer-overrides for W=1, we do not
need to for W=2 or W=3. This is the reason why I think the change [3]
makes sense.
The documentation says -Winitializer-overrides is enabled by default.
(https://clang.llvm.org/docs/DiagnosticsReference.html#winitializer-overrides)
We negate it by passing -Wno-initializer-overrides for the normal
build, but we do not do that for W=1. This means, W=1 effectively
enables -Winitializer-overrides by the clang's default. The same for
the other three.
Add comments in case people are confused with the code.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
This commit is contained in:
Masahiro Yamada
parent
60bef52c7a
commit
64a91907c8
@ -1,14 +1,9 @@
|
||||
# SPDX-License-Identifier: GPL-2.0
|
||||
# ==========================================================================
|
||||
#
|
||||
# make W=... settings
|
||||
#
|
||||
# W=1 - warnings that may be relevant and does not occur too often
|
||||
# W=2 - warnings that occur quite often but may still be relevant
|
||||
# W=3 - the more obscure warnings, can most likely be ignored
|
||||
#
|
||||
# $(call cc-option, -W...) handles gcc -W.. options which
|
||||
# are not supported by all versions of the compiler
|
||||
# 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 += $(call cc-disable-warning, packed-not-aligned)
|
||||
@ -17,58 +12,69 @@ ifeq ("$(origin W)", "command line")
|
||||
export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
|
||||
endif
|
||||
|
||||
ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
|
||||
warning- := $(empty)
|
||||
#
|
||||
# W=1 - warnings which may be relevant and do not occur too often
|
||||
#
|
||||
ifneq ($(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
|
||||
|
||||
warning-1 := -Wextra -Wunused -Wno-unused-parameter
|
||||
warning-1 += -Wmissing-declarations
|
||||
warning-1 += -Wmissing-format-attribute
|
||||
warning-1 += -Wmissing-prototypes
|
||||
warning-1 += -Wold-style-definition
|
||||
warning-1 += -Wmissing-include-dirs
|
||||
warning-1 += $(call cc-option, -Wunused-but-set-variable)
|
||||
warning-1 += $(call cc-option, -Wunused-const-variable)
|
||||
warning-1 += $(call cc-option, -Wpacked-not-aligned)
|
||||
warning-1 += $(call cc-option, -Wstringop-truncation)
|
||||
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
|
||||
warning-1 += -Wno-missing-field-initializers
|
||||
warning-1 += -Wno-sign-compare
|
||||
KBUILD_CFLAGS += -Wno-missing-field-initializers
|
||||
KBUILD_CFLAGS += -Wno-sign-compare
|
||||
|
||||
warning-2 += -Wcast-align
|
||||
warning-2 += -Wdisabled-optimization
|
||||
warning-2 += -Wnested-externs
|
||||
warning-2 += -Wshadow
|
||||
warning-2 += $(call cc-option, -Wlogical-op)
|
||||
warning-2 += -Wmissing-field-initializers
|
||||
warning-2 += -Wsign-compare
|
||||
warning-2 += $(call cc-option, -Wmaybe-uninitialized)
|
||||
warning-2 += $(call cc-option, -Wunused-macros)
|
||||
|
||||
warning-3 := -Wbad-function-cast
|
||||
warning-3 += -Wcast-qual
|
||||
warning-3 += -Wconversion
|
||||
warning-3 += -Wpacked
|
||||
warning-3 += -Wpadded
|
||||
warning-3 += -Wpointer-arith
|
||||
warning-3 += -Wredundant-decls
|
||||
warning-3 += -Wswitch-default
|
||||
warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
|
||||
|
||||
warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
|
||||
warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
|
||||
warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
|
||||
|
||||
ifeq ("$(strip $(warning))","")
|
||||
$(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
|
||||
endif
|
||||
|
||||
KBUILD_CFLAGS += $(warning)
|
||||
else
|
||||
|
||||
# Some diagnostics enabled by default are noisy.
|
||||
# Suppress them by using -Wno... except for W=1.
|
||||
|
||||
ifdef CONFIG_CC_IS_CLANG
|
||||
KBUILD_CFLAGS += -Wno-initializer-overrides
|
||||
KBUILD_CFLAGS += -Wno-format
|
||||
KBUILD_CFLAGS += -Wno-sign-compare
|
||||
KBUILD_CFLAGS += -Wno-format-zero-length
|
||||
endif
|
||||
|
||||
endif
|
||||
|
||||
#
|
||||
# W=2 - warnings which occur quite often but may still be relevant
|
||||
#
|
||||
ifneq ($(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
|
||||
|
||||
KBUILD_CFLAGS += -Wcast-align
|
||||
KBUILD_CFLAGS += -Wdisabled-optimization
|
||||
KBUILD_CFLAGS += -Wnested-externs
|
||||
KBUILD_CFLAGS += -Wshadow
|
||||
KBUILD_CFLAGS += $(call cc-option, -Wlogical-op)
|
||||
KBUILD_CFLAGS += -Wmissing-field-initializers
|
||||
KBUILD_CFLAGS += -Wsign-compare
|
||||
KBUILD_CFLAGS += $(call cc-option, -Wmaybe-uninitialized)
|
||||
KBUILD_CFLAGS += $(call cc-option, -Wunused-macros)
|
||||
|
||||
endif
|
||||
|
||||
#
|
||||
# W=3 - more obscure warnings, can most likely be ignored
|
||||
#
|
||||
ifneq ($(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
|
||||
|
||||
KBUILD_CFLAGS += -Wbad-function-cast
|
||||
KBUILD_CFLAGS += -Wcast-qual
|
||||
KBUILD_CFLAGS += -Wconversion
|
||||
KBUILD_CFLAGS += -Wpacked
|
||||
KBUILD_CFLAGS += -Wpadded
|
||||
KBUILD_CFLAGS += -Wpointer-arith
|
||||
KBUILD_CFLAGS += -Wredundant-decls
|
||||
KBUILD_CFLAGS += -Wswitch-default
|
||||
KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
|
||||
|
||||
endif
|
||||
|
||||
Loading…
Reference in New Issue
Block a user