Several fixes/improvements for the gcc plugin infrastructure:

- Fixes a problem with gcc plugins interfering with cc-option tests.
 - Aborts more gracefully when gcc plugin headers or compiler support is
   missing.
 - Improves the gcc plugin rule generation to be more dynamic, pass arguments,
   and build from subdirectories.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 Comment: Kees Cook <kees@outflux.net>
 
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Merge tag 'gcc-plugin-infrastructure-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc plugin improvements from Kees Cook:
 "Several fixes/improvements for the gcc plugin infrastructure:

   - fix a problem with gcc plugins interfering with cc-option tests.

   - abort more gracefully when gcc plugin headers or compiler support
     is missing.

   - improve the gcc plugin rule generation to be more dynamic, pass
     arguments, and build from subdirectories"

* tag 'gcc-plugin-infrastructure-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  gcc-plugins: Add support for plugin subdirectories
  gcc-plugins: Automate make rule generation
  gcc-plugins: Add support for passing plugin arguments
  gcc-plugins: abort builds cleanly when not supported
  kbuild: no gcc-plugins during cc-option tests
This commit is contained in:
Linus Torvalds 2016-08-09 10:30:07 -07:00
commit b79f34d6ae
5 changed files with 58 additions and 28 deletions

View File

@ -635,13 +635,6 @@ endif
# Tell gcc to never replace conditional load with a non-conditional one
KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
PHONY += gcc-plugins
gcc-plugins: scripts_basic
ifdef CONFIG_GCC_PLUGINS
$(Q)$(MAKE) $(build)=scripts/gcc-plugins
endif
@:
include scripts/Makefile.gcc-plugins
ifdef CONFIG_READABLE_ASM

View File

@ -108,16 +108,20 @@ as-option = $(call try-run,\
as-instr = $(call try-run,\
printf "%b\n" "$(1)" | $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" -,$(2),$(3))
# Do not attempt to build with gcc plugins during cc-option tests.
# (And this uses delayed resolution so the flags will be up to date.)
CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS))
# cc-option
# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
cc-option = $(call try-run,\
$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
cc-option-yn = $(call try-run,\
$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
# cc-option-align
# Prefix align with either -falign or -malign
@ -127,7 +131,7 @@ cc-option-align = $(subst -functions=0,,\
# cc-disable-warning
# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
cc-disable-warning = $(call try-run,\
$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
$(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
# cc-name
# Expands to either gcc or clang

View File

@ -19,25 +19,42 @@ ifdef CONFIG_GCC_PLUGINS
endif
endif
GCC_PLUGINS_CFLAGS := $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y))
GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN SANCOV_PLUGIN
export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR SANCOV_PLUGIN
ifeq ($(PLUGINCC),)
ifneq ($(GCC_PLUGINS_CFLAGS),)
ifeq ($(call cc-ifversion, -ge, 0405, y), y)
PLUGINCC := $(shell $(CONFIG_SHELL) -x $(srctree)/scripts/gcc-plugin.sh "$(__PLUGINCC)" "$(HOSTCXX)" "$(CC)")
$(warning warning: your gcc installation does not support plugins, perhaps the necessary headers are missing?)
else
$(warning warning: your gcc version does not support plugins, you should upgrade it to gcc 4.5 at least)
endif
endif
else
ifneq ($(PLUGINCC),)
# SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.
GCC_PLUGINS_CFLAGS := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGINS_CFLAGS))
endif
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
ifdef CONFIG_GCC_PLUGINS
$(Q)$(MAKE) $(build)=scripts/gcc-plugins
endif
@:

View File

@ -1,5 +1,12 @@
#!/bin/sh
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"
@ -13,6 +20,9 @@ EOF
if [ $? -ne 0 ]
then
if [ -n "$SHOW_ERROR" ] ; then
echo "${plugincc}" >&2
fi
exit 1
fi
@ -48,4 +58,8 @@ then
echo "$2"
exit 0
fi
if [ -n "$SHOW_ERROR" ] ; then
echo "${plugincc}" >&2
fi
exit 1

View File

@ -12,16 +12,18 @@ else
export HOST_EXTRACXXFLAGS
endif
export GCCPLUGINS_DIR HOSTLIBS
ifneq ($(CFLAGS_KCOV), $(SANCOV_PLUGIN))
GCC_PLUGIN := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGIN))
endif
$(HOSTLIBS)-y := $(GCC_PLUGIN)
export HOSTLIBS
$(HOSTLIBS)-y := $(foreach p,$(GCC_PLUGIN),$(if $(findstring /,$(p)),,$(p)))
always := $($(HOSTLIBS)-y)
cyc_complexity_plugin-objs := cyc_complexity_plugin.o
sancov_plugin-objs := sancov_plugin.o
$(foreach p,$($(HOSTLIBS)-y:%.so=%),$(eval $(p)-objs := $(p).o))
subdir-y := $(GCC_PLUGIN_SUBDIR)
subdir- += $(GCC_PLUGIN_SUBDIR)
clean-files += *.so