Messages in this thread | | | Date | Tue, 16 Oct 2018 11:15:36 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH 2/3] objtool: move libelf check out of top Makefile |
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On Wed, Oct 17, 2018 at 12:51:40AM +0900, Masahiro Yamada wrote: > > 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? > > > It is ugly. > > Do you need such detailed information like ORC metadata stuff here? > > This Makefile aims to error out, showing why the build failed. > That's it.
Yeah, it is kind of ugly. But the "showing why the build failed" part is important. I was trying to give the user a clear error message, similar to what we have today.
Without context, the user won't know what objtool is, or why it needs to be built.
If we have just a single error message for all cases, it should at least mention the config option. Like
"Cannot build objtool for CONFIG_STACK_VALIDATION."
But then, most users will only have that enabled because of ORC. So an ORC-specific message would be more appropriate in most cases.
So maybe it can just be something more vague:
msg_stack_validation = "Cannot build objtool for CONFIG_UNWINDER_ORC and/or CONFIG_STACK_VALIDATION. " \ "Please install libelf-dev, libelf-devel or elfutils-libelf-devel."
That would probably be good enough. Then we could drop the ugly ifdef.
-- Josh
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