[PATCH v2 19/21] gcc-plugins: test GCC plugin support in Kconfig

From: Masahiro Yamada
Date: Tue Mar 27 2018 - 01:33:42 EST


Run scripts/gcc-plugin.sh from Kconfig. Users can enable GCC_PLUGINS
only when it is supported.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2: None

arch/Kconfig | 4 +++
scripts/Makefile.gcc-plugins | 82 ++++++++++++++++----------------------------
scripts/gcc-plugin.sh | 1 -
3 files changed, 33 insertions(+), 54 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index b42378d..88cc925 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -407,9 +407,13 @@ config HAVE_GCC_PLUGINS
An arch should select this symbol if it supports building with
GCC plugins.

+config CC_HAS_GCC_PLUGINS
+ bool
+
menuconfig GCC_PLUGINS
bool "GCC plugins"
depends on HAVE_GCC_PLUGINS
+ depends on $(success $srctree/scripts/gcc-plugin.sh $HOSTCXX $CC)
depends on !COMPILE_TEST
help
GCC plugins are loadable modules that provide extra features to the
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
index 25da4c0..19d0d5b 100644
--- a/scripts/Makefile.gcc-plugins
+++ b/scripts/Makefile.gcc-plugins
@@ -1,71 +1,47 @@
# SPDX-License-Identifier: GPL-2.0
-ifdef CONFIG_GCC_PLUGINS
- PLUGINCC := $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-plugin.sh $(HOSTCXX) $(CC))
-
- SANCOV_PLUGIN := -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so
+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_CYC_COMPLEXITY) += cyc_complexity_plugin.so

- gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so
- gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += -DLATENT_ENTROPY_PLUGIN
- ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
- DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable
- endif
+gcc-plugin-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += latent_entropy_plugin.so
+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) += -DLATENT_ENTROPY_PLUGIN
+ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
+ DISABLE_LATENT_ENTROPY_PLUGIN += -fplugin-arg-latent_entropy_plugin-disable
+endif

- ifdef CONFIG_GCC_PLUGIN_SANCOV
- ifeq ($(CFLAGS_KCOV),)
- # It is needed because of the gcc-plugin.sh and gcc version checks.
- gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so
+ifdef CONFIG_GCC_PLUGIN_SANCOV
+ ifeq ($(CFLAGS_KCOV),)
+ # It is needed because of the gcc-plugin.sh and gcc version checks.
+ gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so

- ifneq ($(PLUGINCC),)
- CFLAGS_KCOV := $(SANCOV_PLUGIN)
- else
- $(warning warning: cannot use CONFIG_KCOV: -fsanitize-coverage=trace-pc is not supported by compiler)
- endif
- endif
+ CFLAGS_KCOV := $(SANCOV_PLUGIN)
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-$(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL) += -fplugin-arg-structleak_plugin-byref-all
- gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += -DSTRUCTLEAK_PLUGIN
-
- gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += randomize_layout_plugin.so
- gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += -DRANDSTRUCT_PLUGIN
- gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) += -fplugin-arg-randomize_layout_plugin-performance-mode
+gcc-plugin-$(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
+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STRUCTLEAK) += -DSTRUCTLEAK_PLUGIN

- GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))
+gcc-plugin-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += randomize_layout_plugin.so
+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT) += -DRANDSTRUCT_PLUGIN
+gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_RANDSTRUCT_PERFORMANCE) += -fplugin-arg-randomize_layout_plugin-performance-mode

- export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR
- export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN
+GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y))

- ifneq ($(PLUGINCC),)
- # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.
- GCC_PLUGINS_CFLAGS := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGINS_CFLAGS))
- endif
+export GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR
+export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN

- KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
- GCC_PLUGIN := $(gcc-plugin-y)
- GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y)
-endif
+# SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.
+GCC_PLUGINS_CFLAGS := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGINS_CFLAGS))

-# 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),)
- $(Q)$(srctree)/scripts/gcc-plugin.sh --show-error $(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
- endif
- endif
-endif
- @:
+KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
+GCC_PLUGIN := $(gcc-plugin-y)
+GCC_PLUGIN_SUBDIR := $(gcc-plugin-subdir-y)

# 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
diff --git a/scripts/gcc-plugin.sh b/scripts/gcc-plugin.sh
index 0edbdae..b18c69c 100755
--- a/scripts/gcc-plugin.sh
+++ b/scripts/gcc-plugin.sh
@@ -24,7 +24,6 @@ EOF

if [ $? -eq 0 ]
then
- echo "$1"
exit 0
fi

--
2.7.4