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

[Yann E. MORIN <yann.morin.1998@free.fr>]

Thomas, All,

On 2014-03-07 20:40 +0100, Thomas Petazzoni spake thusly:
> 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.

Gah.. I forgot about that one.

To my defense, the test is not completely crazy, as it's exactly what
support/dependencies/dependencies.sh does. ;-)

> 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.

Indeed not. I was just randoly throwing some rough ideasa at the problem
at stake. A final solution would have anyway had to be much more
involved.

Regards,
Yann E. MORIN.

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