On Tue, Oct 16, 2018 at 06:10:52PM +0900, Masahiro Yamada wrote: > Another behavioral change is, missing libelf for CONFIG_STACK_VALIDATION > was previously a warning, but now a error. This behavioral change should be fine. It was already an error for UNWINDER_ORC, so this would only upgrade a warning to an error for people using STACK_VALIDATION without ORC, which should be a small number of people by this point. > diff --git a/scripts/Makefile.toolcheck b/scripts/Makefile.toolcheck > index f3c165d..bc26fc0 100644 > --- a/scripts/Makefile.toolcheck > +++ b/scripts/Makefile.toolcheck > @@ -12,6 +12,11 @@ include include/config/auto.conf > __toolcheck: > @: > > +chk_stack_validation = echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - > +msg_stack_validation = "libelf is necessary for building the objtool." \ > + "Please install libelf-dev, libelf-devel or elfutils-libelf-devel." > +toolcheck-$(CONFIG_STACK_VALIDATION) += stack_validation > + > PHONY += $(toolcheck-y) > __toolcheck: $(toolcheck-y) This is a nice improvement. It would probably be a good idea to clarify to the user which config option(s) are the cause for the error, by putting "CONFIG_STACK_VALIDATION" in the error string, for example. Though, for this particular case, it would be clearer to have a different error, based on which option is enabled, like we had before. Like: ifdef CONFIG_UNWINDER_ORC chk_unwinder_orc = echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - msg_unwinder_orc = "Cannot build objtool to generate ORC metadata for CONFIG_UNWINDER_ORC=y. " \ "Please install libelf-dev, libelf-devel or elfutils-libelf-devel." toolcheck-$(CONFIG_UNWINDER_ORC) += unwinder_orc else chk_stack_validation = echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf - msg_stack_validation = "Cannot build objtool for CONFIG_STACK_VALIDATION=y. " \ "Please install libelf-dev, libelf-devel or elfutils-libelf-devel." toolcheck-$(CONFIG_STACK_VALIDATION) += stack_validation endif What do you think? -- Josh