From 79a6b30bb7e8e4ef1baffd8adca2ae594781b4ce Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 29 Mar 2020 20:08:32 +0900 Subject: [PATCH 3/7] gcc-plugins: drop support for GCC <= 4.7 Nobody was opposed to raising minimum GCC version to 4.8 [1] So, we will drop GCC <= 4.7 support sooner or later. We always use C++ compiler for building plugins for GCC >= 4.8. This commit drops the plugin support for GCC <= 4.7 a bit earlier, which allows us to dump lots of code. [1] https://lkml.org/lkml/2020/1/23/545 Signed-off-by: Masahiro Yamada Acked-by: Kees Cook --- scripts/Kconfig.include | 3 -- scripts/Makefile.build | 2 +- scripts/Makefile.clean | 1 - scripts/Makefile.host | 23 +-------------- scripts/gcc-plugin.sh | 55 +++--------------------------------- scripts/gcc-plugins/Kconfig | 12 ++------ scripts/gcc-plugins/Makefile | 21 ++++---------- 7 files changed, 14 insertions(+), 103 deletions(-) diff --git a/scripts/Kconfig.include b/scripts/Kconfig.include index 496d11c92c97..033f6efd92d3 100644 --- a/scripts/Kconfig.include +++ b/scripts/Kconfig.include @@ -42,9 +42,6 @@ $(error-if,$(failure,command -v $(LD)),linker '$(LD)' not found) # Fail if the linker is gold as it's not capable of linking the kernel proper $(error-if,$(success, $(LD) -v | grep -q gold), gold linker '$(LD)' not supported) -# gcc version including patch level -gcc-version := $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) - # machine bit flags # $(m32-flag): -m32 if the compiler supports it, or an empty string otherwise. # $(m64-flag): -m64 if the compiler supports it, or an empty string otherwise. diff --git a/scripts/Makefile.build b/scripts/Makefile.build index a1730d42e5f3..eec789d7a63a 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -46,7 +46,7 @@ include $(kbuild-file) include scripts/Makefile.lib # Do not include host rules unless needed -ifneq ($(hostprogs)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),) +ifneq ($(hostprogs)$(hostcxxlibs-y)$(hostcxxlibs-m),) include scripts/Makefile.host endif diff --git a/scripts/Makefile.clean b/scripts/Makefile.clean index 1e4206566a82..075f0cc2d8d7 100644 --- a/scripts/Makefile.clean +++ b/scripts/Makefile.clean @@ -30,7 +30,6 @@ subdir-ymn := $(addprefix $(obj)/,$(subdir-ymn)) __clean-files := $(extra-y) $(extra-m) $(extra-) \ $(always) $(always-y) $(always-m) $(always-) $(targets) $(clean-files) \ $(hostprogs) $(hostprogs-y) $(hostprogs-m) $(hostprogs-) \ - $(hostlibs-y) $(hostlibs-m) $(hostlibs-) \ $(hostcxxlibs-y) $(hostcxxlibs-m) __clean-files := $(filter-out $(no-clean-files), $(__clean-files)) diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 3b7121d43324..2045855d0b75 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -39,7 +39,6 @@ $(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE # They are linked as C++ code to the executable qconf __hostprogs := $(sort $(hostprogs)) -host-cshlib := $(sort $(hostlibs-y) $(hostlibs-m)) host-cxxshlib := $(sort $(hostcxxlibs-y) $(hostcxxlibs-m)) # C code @@ -63,7 +62,6 @@ host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m))) host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs))) # Object (.o) files used by the shared libaries -host-cshobjs := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs)))) host-cxxshobjs := $(sort $(foreach m,$(host-cxxshlib),$($(m:.so=-objs)))) host-csingle := $(addprefix $(obj)/,$(host-csingle)) @@ -71,9 +69,7 @@ host-cmulti := $(addprefix $(obj)/,$(host-cmulti)) host-cobjs := $(addprefix $(obj)/,$(host-cobjs)) host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti)) host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs)) -host-cshlib := $(addprefix $(obj)/,$(host-cshlib)) host-cxxshlib := $(addprefix $(obj)/,$(host-cxxshlib)) -host-cshobjs := $(addprefix $(obj)/,$(host-cshobjs)) host-cxxshobjs := $(addprefix $(obj)/,$(host-cxxshobjs)) ##### @@ -140,13 +136,6 @@ quiet_cmd_host-cxxobjs = HOSTCXX $@ $(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE $(call if_changed_dep,host-cxxobjs) -# Compile .c file, create position independent .o file -# host-cshobjs -> .o -quiet_cmd_host-cshobjs = HOSTCC -fPIC $@ - cmd_host-cshobjs = $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $< -$(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE - $(call if_changed_dep,host-cshobjs) - # Compile .c file, create position independent .o file # Note that plugin capable gcc versions can be either C or C++ based # therefore plugin source files have to be compilable in both C and C++ mode. @@ -157,16 +146,6 @@ quiet_cmd_host-cxxshobjs = HOSTCXX -fPIC $@ $(host-cxxshobjs): $(obj)/%.o: $(src)/%.c FORCE $(call if_changed_dep,host-cxxshobjs) -# Link a shared library, based on position independent .o files -# *.o -> .so shared library (host-cshlib) -quiet_cmd_host-cshlib = HOSTLLD -shared $@ - cmd_host-cshlib = $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -shared -o $@ \ - $(addprefix $(obj)/, $($(target-stem)-objs)) \ - $(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem).so) -$(host-cshlib): FORCE - $(call if_changed,host-cshlib) -$(call multi_depend, $(host-cshlib), .so, -objs) - # Link a shared library, based on position independent .o files # *.o -> .so shared library (host-cxxshlib) quiet_cmd_host-cxxshlib = HOSTLLD -shared $@ @@ -178,4 +157,4 @@ $(host-cxxshlib): FORCE $(call multi_depend, $(host-cxxshlib), .so, -objs) targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\ - $(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs) $(host-cxxshlib) $(host-cxxshobjs) + $(host-cxxmulti) $(host-cxxobjs) $(host-cxxshlib) $(host-cxxshobjs) diff --git a/scripts/gcc-plugin.sh b/scripts/gcc-plugin.sh index d3caefe53eab..b79fd0bea838 100755 --- a/scripts/gcc-plugin.sh +++ b/scripts/gcc-plugin.sh @@ -1,49 +1,14 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 -srctree=$(dirname "$0") - -SHOW_ERROR= -if [ "$1" = "--show-error" ] ; then - SHOW_ERROR=1 - shift || true -fi - -gccplugins_dir=$($3 -print-file-name=plugin) -plugincc=$($1 -E -x c++ - -o /dev/null -I"${srctree}"/gcc-plugins -I"${gccplugins_dir}"/include 2>&1 <= 4008 || defined(ENABLE_BUILD_WITH_CXX) -#warning $2 CXX -#else -#warning $1 CC -#endif -EOF -) -if [ $? -ne 0 ] -then - if [ -n "$SHOW_ERROR" ] ; then - echo "${plugincc}" >&2 - fi - exit 1 -fi +set -e -case "$plugincc" in - *"$1 CC"*) - echo "$1" - exit 0 - ;; - - *"$2 CXX"*) - # the c++ compiler needs another test, see below - ;; +srctree=$(dirname "$0") - *) - exit 1 - ;; -esac +gccplugins_dir=$($* -print-file-name=plugin) # we need a c++ compiler that supports the designated initializer GNU extension -plugincc=$($2 -c -x c++ -std=gnu++98 - -fsyntax-only -I"${srctree}"/gcc-plugins -I"${gccplugins_dir}"/include 2>&1 </dev/null <&2 -fi -exit 1 diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig index e3569543bdac..fd31ed5b435f 100644 --- a/scripts/gcc-plugins/Kconfig +++ b/scripts/gcc-plugins/Kconfig @@ -1,13 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only -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)")" if CC_IS_GCC - 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 @@ -17,7 +8,8 @@ config HAVE_GCC_PLUGINS menuconfig GCC_PLUGINS bool "GCC plugins" depends on HAVE_GCC_PLUGINS - depends on PLUGIN_HOSTCC != "" + depends on CC_IS_GCC && GCC_VERSION >= 40800 + depends on $(success,$(srctree)/scripts/gcc-plugin.sh $(CC)) default y help GCC plugins are loadable modules that provide extra features to the diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile index f2ee8bd7abc6..f22858b2c3d6 100644 --- a/scripts/gcc-plugins/Makefile +++ b/scripts/gcc-plugins/Makefile @@ -1,18 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 -PLUGINCC := $(CONFIG_PLUGIN_HOSTCC:"%"=%) 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$(src) -std=gnu++98 -fno-rtti - HOST_EXTRACXXFLAGS += -fno-exceptions -fasynchronous-unwind-tables -ggdb - HOST_EXTRACXXFLAGS += -Wno-narrowing -Wno-unused-variable - export HOST_EXTRACXXFLAGS -endif +HOST_EXTRACXXFLAGS += -I$(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 -Wno-c++11-compat $(obj)/randomize_layout_plugin.o: $(objtree)/$(obj)/randomize_layout_seed.h quiet_cmd_create_randomize_layout_seed = GENSEED $@ @@ -22,9 +13,9 @@ $(objtree)/$(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-y := $($(HOSTLIBS)-y) +hostcxxlibs-y := $(foreach p,$(GCC_PLUGIN),$(if $(findstring /,$(p)),,$(p))) +always-y := $(hostcxxlibs-y) -$(foreach p,$($(HOSTLIBS)-y:%.so=%),$(eval $(p)-objs := $(p).o)) +$(foreach p,$(hostcxxlibs-y:%.so=%),$(eval $(p)-objs := $(p).o)) clean-files += *.so -- 2.26.2