Re: Problem using AC_LANG_PROGRAM with AC_EGREP_CPP

[Braden McDaniel]

On Sat, 2009-03-28 at 07:27 -0600, Eric Blake wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> According to Braden McDaniel on 3/27/2009 11:02 PM:
> > When I try to use AC_LANG_PROGRAM in conjunction with AC_EGREP_CPP, I'm
> > seeing this error:
> > 
> >         configure.ac:97: error: possibly undefined macro: AC_LANG_PROGRAM
> >               If this token and others are legitimate, please use 
> > m4_pattern_allow.
> >               See the Autoconf documentation.
> 
> It sounds like something is overquoted in your configure.ac file.
> 
> > 
> > My invocation of AC_EGREP_CPP looks like this:
> > 
> >         AC_EGREP_CPP([HAVE_GL_GLU_H], [AC_LANG_PROGRAM([[foo]], [[bar]])],
> >                      [OPENVRML_HAVE_GL_GLU_H=1],
> >                      [OPENVRML_HAVE_GL_GLU_H=0])
> 
> In isolation, I don't see any quoting problems with this example.  But I'm
> almost certain you didn't copy and paste from your configure.ac, so maybe
> in the rewrite for this email, you changed the quoting?

In fact, that was copied and pasted from my configure.ac.  (Though it's
not what my configure.ac looks like now; I've given up on this approach
for now and I'm using AC_COMPILE_IFELSE instead.)

All I'm trying to do here is see if running a previous macro caused a
symbol to be AC_DEFINE'd.  I tried a number of different invocations of
AC_LANG_PROGRAM; including using no arguments, using one argument, and
using an empty first argument.

> > If I have an instance of AC_LANG_PROGRAM usage earlier in the file that
> > has been working fine.  However, the error message will point to it.
> > Only if I remove the first occurrence does the error message point at
> > the second invocation (the one mentioned listed above).
> 
> Can you post a complete configure.ac file that reproduces the problem
> (preferably trimming to a minimal testcase first), so we can see if
> something earlier in the file may be impacting how this line is expanded?

I'm having no trouble reproducing this error with a *very* minimal test
case.  It's attached.

-- 
Braden McDaniel                           e-mail: <address@hidden>
<http://endoframe.com>                    Jabber: <address@hidden>

configure.ac
Description: Text document