btrfs-progs/Makefile.extrawarn
David Sterba 9a1d86a9ac btrfs-progs: build: disable -Waddress-of-packed-member by default
Gcc 9 adds the flag to default warnings and this produces a lot of
warnings that don't seem to be harmful as we know the address is
aligned, but this could be hidden in the function call chain.
It's still available under W=1.

Issue: #180
Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-14 15:09:53 +02:00

101 lines
3.6 KiB
Makefile

# From linux.git/scripts/Kbuild.include
#
# try-run
# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
# Exit code chooses option. "$$TMP" is can be used as temporary file and
# is automatically cleaned up.
try-run = $(shell set -e; \
TMP="$(TMPOUT).$$$$.tmp"; \
TMPO="$(TMPOUT).$$$$.o"; \
if ($(1)) >/dev/null 2>&1; \
then echo "$(2)"; \
else echo "$(3)"; \
fi; \
rm -f "$$TMP" "$$TMPO")
# cc-option
# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
cc-option = $(call try-run,\
$(CC) $(CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
# cc-disable-warning
# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
cc-disable-warning = $(call try-run, \
$(CC) -Werror $(CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
# From linux.git/scripts/Makefile.extrawarn
# ==========================================================================
#
# 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
#
# $(call cc-option, -W...) handles gcc -W.. options which
# are not supported by all versions of the compiler
# ==========================================================================
ifeq ("$(origin W)", "command line")
export BUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
endif
ifdef BUILD_ENABLE_EXTRA_GCC_CHECKS
warning- := $(empty)
warning-1 := -Wextra -Wunused -Wno-unused-parameter
warning-1 += -Wmissing-declarations
warning-1 += -Wmissing-format-attribute
warning-1 += $(call cc-option, -Wmissing-prototypes)
warning-1 += -Wold-style-definition
warning-1 += $(call cc-option, -Wmissing-include-dirs)
warning-1 += $(call cc-option, -Wunused-but-set-variable)
warning-1 += $(call cc-disable-warning, missing-field-initializers)
warning-1 += $(call cc-disable-warning, format-truncation)
warning-1 += $(call cc-disable-warning, sign-compare)
warning-2 += $(call cc-option, -Waddress-of-packed-member)
warning-2 := -Waggregate-return
warning-2 += -Wcast-align
warning-2 += -Wdisabled-optimization
warning-2 += -Wnested-externs
warning-2 += -Wshadow
warning-2 += $(call cc-option, -Wlogical-op)
warning-2 += $(call cc-option, -Wmissing-field-initializers)
warning-2 += $(call cc-option, -Wformat-truncation)
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-3 += $(call cc-option, -Wvla)
warning-3 += $(call cc-option, -Wsign-compare)
warning := $(warning-$(findstring 1, $(BUILD_ENABLE_EXTRA_GCC_CHECKS)))
warning += $(warning-$(findstring 2, $(BUILD_ENABLE_EXTRA_GCC_CHECKS)))
warning += $(warning-$(findstring 3, $(BUILD_ENABLE_EXTRA_GCC_CHECKS)))
ifeq ("$(strip $(warning))","")
$(error W=$(BUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
endif
EXTRAWARN_CFLAGS += $(warning)
else
ifeq ($(COMPILER),clang)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, initializer-overrides)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, unused-value)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, format)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, unknown-warning-option)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, sign-compare)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, format-zero-length)
EXTRAWARN_CFLAGS += $(call cc-disable-warning, uninitialized)
endif
endif