Commit 77342a02 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

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: default avatarMasahiro Yamada <masahiroy@kernel.org>
Acked-by: default avatarKees Cook <keescook@chromium.org>
parent afe956c5

scripts/Kconfig.include

+0 −3
Original line number Diff line number Diff line
@@ -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.

scripts/Makefile.build

+1 −1
Original line number Diff line number Diff line
@@ -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

scripts/Makefile.clean

+0 −1
Original line number Diff line number Diff line
@@ -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))

scripts/Makefile.host

+1 −22
Original line number Diff line number Diff line
@@ -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)

scripts/gcc-plugin.sh

+4 −51
Original line number Diff line number Diff line 
#!/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 <<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

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 <<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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