Re: Integrating libtool head into GraphicsMagick

[Ralf Wildenhues]

* Bob Friesenhahn wrote on Tue, Dec 06, 2005 at 03:48:04AM CET:
> On Mon, 5 Dec 2005, Bob Friesenhahn wrote:
> >
> >So I am at a loss as to why Automake fails to build ltdl/libltdlc.la 
> >before attempting to use it.
> 
> FYI, a quick fix to the build-order problem is
> 
>   # Convince libltdl to be built before the library which needs it.
>   $(LIBMAGICK): $(LIBLTDL)
> 
> but this feels wrong to me.  Automake should already know about this 
> dependency.

Hmm.  It's also a bad hack: you're exploiting the fact that Automake
does not see that $(LIBMAGICK) is in fact magick/libMagick.la, thus it
won't remove its own target rule.

> Is it possible that the problem is due to libtool using
> 
>   LIBLTDL = ${top_builddir}/ltdl/libltdlc.la
> 
> rather than
> 
>   LIBLTDL = ltdl/libltdlc.la
> 
> ???

A little test shows that it is rather due to the fact that LIBLTDL is
AC_SUBSTed, thus only known at config.status time, and not at automake
time.  Automake thus cannot know what $(LIBLTDL) will contain, and if
that is good to put on a dependency list.

No, at the moment I don't see a way around your quick-fix (suitably
guarded by Automake conditionals, so that it is commented out in case
  LIBLTDL = -lltdl
holds).  You may want to file an Automake bug though, maybe Alexandre
sees a better way around this.  It certainly feels weird.

But say, why has this not triggered earlier?  This doesn't look like
a newly introduced issue.

Cheers,
Ralf