Re: [gdm-list] at-spi-registryd not starting automatically in gdm [was multiple at-spi...]

["Dan Nicholson" <dbn lists gmail com>]

On 9/2/07, Brian Cameron <Brian Cameron sun com> wrote:
>
> Dan:
>
> I don't think Francesco needs to really test this change.  The patch
> looks right and it should work.  I'd say that the build folks at
> Ubuntu should probably just make sure this patch fixes GDM to set
> this value properly.  As long as Francesco knows how to workaround
> the problem, he can continue with his development work.  Another
> workaround would just be to create a symlink.

Right, I thought of that later. He should just force the right value
into gui/gdmcommon.c for now.

> > I put this part into my patch to be consistent, but I don't think it's
> > necessary, and it's still error prone. What if I, for some reason, I
> > set --libexecdir='${libdir}'? It's not necessary here since the
> > variables are used in the Makefile and they will be recursively
> > resolved by make. Also, wouldn't it be better to use AS_AC_EXPAND like
> > elsewhere in configure.ac? Then, at least you're being consistent with
> > the hack.
>
> I think you misunderstand this.  The code is checking to see if
> libexecdir contains a literal string of '${exec_prefix}' (an
> unresolved variable, in other words).  If so, it just expands
> the variable for you.  Otherwise you get an invalid directory.
> If you actually set libexecdir to something by using the
> --libexecdir flag, then the value you specify will be used.

No, that's exactly what I'm driving at. My example wasn't clear
enough. What we're trying to workaround is the fact that there may be
a variable referencing a variable and we need that to be resolved to
get a full path. The ssh_libexec example only supports the case there
the referenced variable is ${exec_prefix}, but what if it was
something else like ${datadir}?

> It would probably be better to use something like AS_AC_EXPAND.  If
> you wanted to provide a tested patch that fix the way configure.ac is
> doing this, I'd be delighted.

I believe if you move all the AS_AC_EXPAND calls to the beginning, you
can then reference $LIBEXECDIR and you'll have it fully expanded.
Actually, I use AS_AC_EXPAND in a different project of mine, and I've
come to decide that it's a hack for the reason above (it only handles
the case where the referenced variable is $prefix or $exec_prefix).

The only way to reliably do this is to do the substitutions in make
where they will be fully resolved. But that's beyond the scope of this
change, so I'll send you a cleanup patch so that the AS_AC_EXPANDed
vars are used throughout configure.ac.

--
Dan