Re: checking Mac OS X headers

[Vincent Torri]

On Fri, 12 Feb 2010, Braden McDaniel wrote:

> > > > 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.
> >
> > 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

Actually, if everything is in the configure, i know how to avoid the 
problem:

m4_ifdef([AC_PROG_OBJC],
   [
    AC_PROG_OBJC
    _AM_DEPENDENCIES(OBJC)
   ],
   [
    AC_CHECK_TOOL([OBJC], [gcc])
    AC_SUBST([OBJC])
    AC_SUBST([OBJCFLAGS])
   ])
AC_PROG_CC

if test "x${ac_cv_objc_compiler_gnu}" = "xyes" ; then
   AC_LANG_PUSH([Objective C])
   AC_CHECK_HEADER([Cocoa/Cocoa.h],
      [
       have_quartz="yes"
       quartz_ldflags="-framework Cocoa"
      ],
      [have_quartz="no"])
   AC_LANG_POP([Objective C])
fi

but doing the same test in the m4 macro does not work. I don't understand 
why.

Vincent Torri