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 <masahiroy@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Masahiro Yamada 2020-03-29 20:08:32 +09:00
parent afe956c577
commit 77342a02ff
7 changed files with 15 additions and 104 deletions

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@ -48,9 +48,6 @@ $(error-if,$(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.

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@ -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

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@ -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))

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@ -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)

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@ -1,49 +1,14 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
set -e
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 <<EOF
#include "gcc-common.h"
#if BUILDING_GCC_VERSION >= 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 "${plugincc}" >&2
fi
exit 1
fi
case "$plugincc" in
*"$1 CC"*)
echo "$1"
exit 0
;;
*"$2 CXX"*)
# the c++ compiler needs another test, see below
;;
*)
exit 1
;;
esac
gccplugins_dir=$($* -print-file-name=plugin)
# we need a c++ compiler that supports the designated initializer GNU extension
plugincc=$($2 -c -x c++ -std=gnu++98 - -fsyntax-only -I"${srctree}"/gcc-plugins -I"${gccplugins_dir}"/include 2>&1 <<EOF
$HOSTCC -c -x c++ -std=gnu++98 - -fsyntax-only -I $srctree/gcc-plugins -I $gccplugins_dir/include 2>/dev/null <<EOF
#include "gcc-common.h"
class test {
public:
@ -52,15 +17,3 @@ public:
.test = 1
};
EOF
)
if [ $? -eq 0 ]
then
echo "$2"
exit 0
fi
if [ -n "$SHOW_ERROR" ] ; then
echo "${plugincc}" >&2
fi
exit 1

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@ -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

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@ -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$(src) -std=gnu++98 -fno-rtti
HOST_EXTRACXXFLAGS += -fno-exceptions -fasynchronous-unwind-tables -ggdb
HOST_EXTRACXXFLAGS += -Wno-narrowing -Wno-unused-variable -Wno-c++11-compat
export HOST_EXTRACXXFLAGS
endif
HOST_EXTRACXXFLAGS += -I$(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