gcc-plugins: abort builds cleanly when not supported
When the compiler doesn't support gcc plugins (either due to missing
headers or too old a version), report the problem and abort the build
instead of emitting a warning and letting the build founder with arcane
compiler errors.
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/Makefile b/Makefile
index 70de144..8c504f3 100644
--- a/Makefile
+++ b/Makefile
@@ -635,13 +635,6 @@
# 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) $(build)=scripts/gcc-plugins
-endif
- @:
-
include scripts/Makefile.gcc-plugins
ifdef CONFIG_READABLE_ASM
diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins
index 5e22b60..bbca1f4 100644
--- a/scripts/Makefile.gcc-plugins
+++ b/scripts/Makefile.gcc-plugins
@@ -23,21 +23,37 @@
export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN SANCOV_PLUGIN
- ifeq ($(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 := $(gcc-plugin-y)
-
endif
+
+# If plugins aren't supported, abort the build before hard-to-read compiler
+# errors start getting spewed by the main build.
+PHONY += gcc-plugins-check
+gcc-plugins-check: FORCE
+ifdef CONFIG_GCC_PLUGINS
+ ifeq ($(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) $(build)=scripts/gcc-plugins
+endif
+ @:
diff --git a/scripts/gcc-plugin.sh b/scripts/gcc-plugin.sh
index fb92075..b65224b 100755
--- a/scripts/gcc-plugin.sh
+++ b/scripts/gcc-plugin.sh
@@ -1,5 +1,12 @@
#!/bin/sh
srctree=$(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 @@
if [ $? -ne 0 ]
then
+ if [ -n "$SHOW_ERROR" ] ; then
+ echo "${plugincc}" >&2
+ fi
exit 1
fi
@@ -48,4 +58,8 @@
echo "$2"
exit 0
fi
+
+if [ -n "$SHOW_ERROR" ] ; then
+ echo "${plugincc}" >&2
+fi
exit 1