linux/scripts/gcc-plugins/Makefile
Masahiro Yamada 5aadfdeb8d kcov: test compiler capability in Kconfig and correct dependency
As Documentation/kbuild/kconfig-language.txt notes, 'select' should be
be used with care - it forces a lower limit of another symbol, ignoring
the dependency.  Currently, KCOV can select GCC_PLUGINS even if arch
does not select HAVE_GCC_PLUGINS.  This could cause the unmet direct
dependency.

Now that Kconfig can test compiler capability, let's handle this in a
more sophisticated way.

There are two ways to enable KCOV; use the compiler that natively
supports -fsanitize-coverage=trace-pc, or build the SANCOV plugin if
the compiler has ability to build GCC plugins.  Hence, the correct
dependency for KCOV is:

  depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS

You do not need to build the SANCOV plugin if the compiler already
supports -fsanitize-coverage=trace-pc.  Hence, the select should be:

  select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC

With this, GCC_PLUGIN_SANCOV is selected only when necessary, so
scripts/Makefile.gcc-plugins can be cleaner.

I also cleaned up Kconfig and scripts/Makefile.kcov as well.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-06-11 09:14:08 +09:00

35 lines
1.2 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
GCC_PLUGINS_DIR := $(shell $(CC) -print-file-name=plugin)
ifeq ($(PLUGINCC),$(HOSTCC))
HOSTLIBS := hostlibs
HOST_EXTRACFLAGS += -I$(GCC_PLUGINS_DIR)/include -I$(src) -std=gnu99 -ggdb
export HOST_EXTRACFLAGS
else
HOSTLIBS := hostcxxlibs
HOST_EXTRACXXFLAGS += -I$(GCC_PLUGINS_DIR)/include -I$(src) -std=gnu++98 -fno-rtti
HOST_EXTRACXXFLAGS += -fno-exceptions -fasynchronous-unwind-tables -ggdb
HOST_EXTRACXXFLAGS += -Wno-narrowing -Wno-unused-variable
export HOST_EXTRACXXFLAGS
endif
export HOSTLIBS
$(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h
quiet_cmd_create_randomize_layout_seed = GENSEED $@
cmd_create_randomize_layout_seed = \
$(CONFIG_SHELL) $(srctree)/$(src)/gen-random-seed.sh $@ $(objtree)/include/generated/randomize_layout_hash.h
$(objtree)/$(obj)/randomize_layout_seed.h: FORCE
$(call if_changed,create_randomize_layout_seed)
targets = randomize_layout_seed.h randomize_layout_hash.h
$(HOSTLIBS)-y := $(foreach p,$(GCC_PLUGIN),$(if $(findstring /,$(p)),,$(p)))
always := $($(HOSTLIBS)-y)
$(foreach p,$($(HOSTLIBS)-y:%.so=%),$(eval $(p)-objs := $(p).o))
subdir-y := $(GCC_PLUGIN_SUBDIR)
subdir- += $(GCC_PLUGIN_SUBDIR)
clean-files += *.so