Commit 59f53855 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

gcc-plugins: test plugin support in Kconfig and clean up Makefile 



Run scripts/gcc-plugin.sh from Kconfig so that users can enable
GCC_PLUGINS only when the compiler supports building plugins.

Kconfig defines a new symbol, PLUGIN_HOSTCC.  This will contain
the compiler (g++ or gcc) used for building plugins, or empty
if the plugin can not be supported at all.

This allows us to remove all ugly testing in Makefile.gcc-plugins.

Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: default avatarKees Cook <keescook@chromium.org>
parent 8034c2fb

arch/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -398,6 +398,15 @@ config SECCOMP_FILTER 


	  See Documentation/prctl/seccomp_filter.txt for details.



preferred-plugin-hostcc := $(if-success,[ $(gcc-version) -ge 40800 ],$(HOSTCXX),$(HOSTCC))



config PLUGIN_HOSTCC

	string

	default "$(shell,$(srctree)/scripts/gcc-plugin.sh "$(preferred-plugin-hostcc)" "$(HOSTCXX)" "$(CC)")"

	help

	  Host compiler used to build GCC plugins.  This can be $(HOSTCXX),

	  $(HOSTCC), or a null string if GCC plugin is unsupported.



config HAVE_GCC_PLUGINS

	bool

	help
@@ -407,6 +416,7 @@ config HAVE_GCC_PLUGINS 
menuconfig GCC_PLUGINS

	bool "GCC plugins"

	depends on HAVE_GCC_PLUGINS

	depends on PLUGIN_HOSTCC != ""

	depends on !COMPILE_TEST

	help

	  GCC plugins are loadable modules that provide extra features to the

scripts/Kconfig.include

+3 −0
Original line number Diff line number Diff line
@@ -25,3 +25,6 @@ cc-option = $(success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null) 
# $(ld-option,<flag>)

# Return y if the linker supports <flag>, n otherwise

ld-option = $(success,$(LD) -v $(1))



# gcc version including patch level

gcc-version := $(shell,$(srctree)/scripts/gcc-version.sh -p $(CC) | sed 's/^0*//')

scripts/Makefile.gcc-plugins

+22 −57
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

ifdef CONFIG_GCC_PLUGINS

  __PLUGINCC := $(call cc-ifversion, -ge, 0408, $(HOSTCXX), $(HOSTCC))

  PLUGINCC := $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-plugin.sh "$(__PLUGINCC)" "$(HOSTCXX)" "$(CC)")



  SANCOV_PLUGIN := -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so



gcc-plugin-$(CONFIG_GCC_PLUGIN_CYC_COMPLEXITY)	+= cyc_complexity_plugin.so



gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY)	+= latent_entropy_plugin.so
@@ -13,15 +7,7 @@ ifdef CONFIG_GCC_PLUGINS 
    DISABLE_LATENT_ENTROPY_PLUGIN			+= -fplugin-arg-latent_entropy_plugin-disable

endif



  ifdef CONFIG_GCC_PLUGIN_SANCOV

      # It is needed because of the gcc-plugin.sh and gcc version checks.

gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV)		+= sancov_plugin.so



      ifeq ($(PLUGINCC),)

        $(warning warning: cannot use CONFIG_KCOV: -fsanitize-coverage=trace-pc is not supported by compiler)

      endif

  endif



gcc-plugin-$(CONFIG_GCC_PLUGIN_STRUCTLEAK)	+= structleak_plugin.so

gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE)	+= -fplugin-arg-structleak_plugin-verbose

gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)	+= -fplugin-arg-structleak_plugin-byref-all
@@ -33,40 +19,19 @@ ifdef CONFIG_GCC_PLUGINS 


GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))



  export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR

export GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR

export DISABLE_LATENT_ENTROPY_PLUGIN



  ifneq ($(PLUGINCC),)

    # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.

    GCC_PLUGINS_CFLAGS := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGINS_CFLAGS))

  endif

# sancov_plugin.so can be only in CFLAGS_KCOV because avoid duplication.

GCC_PLUGINS_CFLAGS := $(filter-out %/sancov_plugin.so, $(GCC_PLUGINS_CFLAGS))



KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)

GCC_PLUGIN := $(gcc-plugin-y)

GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y)

endif



# If plugins aren't supported, abort the build before hard-to-read compiler

# errors start getting spewed by the main build.

PHONY += gcc-plugins-check

gcc-plugins-check: FORCE

ifdef CONFIG_GCC_PLUGINS

  ifeq ($(PLUGINCC),)

    ifneq ($(GCC_PLUGINS_CFLAGS),)

      ifeq ($(call cc-ifversion, -ge, 0405, y), y)

	$(Q)$(srctree)/scripts/gcc-plugin.sh --show-error "$(__PLUGINCC)" "$(HOSTCXX)" "$(CC)" || true

	@echo "Cannot use CONFIG_GCC_PLUGINS: your gcc installation does not support plugins, perhaps the necessary headers are missing?" >&2 && exit 1

      else

	@echo "Cannot use CONFIG_GCC_PLUGINS: your gcc version does not support plugins, you should upgrade it to at least gcc 4.5" >&2 && exit 1

      endif

    endif

  endif

endif

	@:



# Actually do the build, if requested.

PHONY += gcc-plugins

gcc-plugins: scripts_basic gcc-plugins-check

gcc-plugins: scripts_basic

ifdef CONFIG_GCC_PLUGINS

	$(Q)$(MAKE) $(build)=scripts/gcc-plugins

endif

scripts/gcc-plugins/Makefile

+1 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

PLUGINCC := $(CONFIG_PLUGIN_HOSTCC:"%"=%)

GCC_PLUGINS_DIR := $(shell $(CC) -print-file-name=plugin)



ifeq ($(PLUGINCC),$(HOSTCC))

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