[Buildroot] [PATCH] build/advanced: add option to check for use of cdefs.h

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Sun,  4 Dec 2016 11:59:37 +0100, Yann E. MORIN wrote:
> We want to catch programs that directly include sys/cdefs.h so that
> we can fix them not to. So, we want to instrument sys/cdefs.h to emit
> a warning when it is included.

Thanks for working on this. However, I am still not convinced that we
want to merge such an additional complexity (one new Config.in choice
with three sub-options, two additional Config.in options), a cdefs.h
wrapper for glibc/uclibc, etc.

Do we really care about upstream packages using sys/cdefs.h? Is it
really the most important battle to fight against upstream projects
using sys/cdefs.h?

If we start having instrumentation in Buildroot to detect such very
specific "standard violation", then where do we stop? There's plenty of
upstream projects doing bogus things all over the place.

I believe the paranoid checks for bogus -I/-L flags are fine because
they really potentially break cross-compilation. But this cdefs.h
mis-use doesn't break anything, now that we have the cdefs.h
replacement for musl.

Peter, Arnout, what do you think?

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com