Re: checking Mac OS X headers

[Braden McDaniel]

On Fri, 2010-02-12 at 16:34 +0100, Vincent Torri wrote: 
> 
> On Fri, 12 Feb 2010, Braden McDaniel wrote:
> 
> > On Fri, 2010-02-12 at 11:04 +0100, Vincent Torri wrote:
> >> Hey,
> >>
> >> I restart this thread.
> >>
> >> So, what I would like to do is checking Mac OS X headers in an m4 macro.
> >> If the objective C compiler is installed, no problem. If it is not, i
> >> would like that, in the m4 macro, the test not to be done.
> >
> > Why do you want the test to be conditional?
> >
> > My experience is that, in general, conditional tests add complexity with
> > very little return.  Why not just let the test fail where the requisite
> > bits are missing and decide if that actually matters later in the
> > script?
> 
> i think that you didn't understood the problem or i didn't explain it 
> very well.

Well, I think you would have been able to describe the problem better if
you had simplified your test.

AFAICT, this is all you need to demonstrate the problem:

        AC_INIT([test], [0.0])
        AM_INIT_AUTOMAKE
        
        LT_INIT
        
        AC_PROG_OBJC
        AC_PROG_OBJCPP
        
        AC_CONFIG_FILES([Makefile])
        
        AC_OUTPUT

The problem is that running this on a system without an Objective-C
compiler results in configure failing; and I don't see anything in the
documentation of either AC_PROG_OBC or AC_PROG_OBJCPP describing how to
avoid this (or even suggesting that it will happen).

Interestingly, the failure mode changes a bit depending on the presence
of LT_INIT.  If you comment it out, AC_PROG_OBJC will kill configure;
otherwise, AC_PROG_OBJCPP kills it.

-- 
Braden McDaniel <address@hidden>