[Buildroot] luajit package fails to build on x86_64 for x86

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

Dear Yann E. MORIN,

On Fri, 7 Mar 2014 18:49:03 +0100, Yann E. MORIN wrote:

> Doing the check in dependencies is not much better than doing it as a
> pre-configure hook: it can be delayed quite late in the build process.
> 
> > Right now i don't know how to check about the presence of the 32bit
> > support on the 64 bit host toolchain.
> 
> What about something like this:
> 
>     ifeq ($(BR2_PACKAGE_LUAJIT),y)
>     ifeq ($(TARGET_32BIT)$(HOST_64BIT),yy)
>     ifneq ($(shell echo 'int main() { return 0; }' |gcc -m32 -o foo -x c - >/dev/null 2>&1 && echo y; rm -f foo),y)
>     $(error Can't build luajit for 32-bit target on this machine (mising 32-bit development packages))
>     endif
>     endif
>     endif
> 
> Not really trivial, but should work with some tweaking...

Why do you invent something crazy here? We already have
BR2_HOSTARCH_NEEDS_IA32_COMPILER which tests exactly what your new test
intends to do. However, I'm not sure this test is actually completely
correct: -m32 is a x86 compiler option. And my understanding is that
Luajit needs to be built with a host that has the same bitness, so for
example building a x86-64 target on a x86 system would not work, and
your test would not catch such a situation.

Best regards,

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