Re: how to override precious variables for subdirs

[Ralf Wildenhues]

Hello Chris,

* Chris Frey wrote on Mon, Apr 25, 2011 at 09:28:51PM CEST:
> On Sat, Apr 23, 2011 at 12:13:13PM +0200, Ralf Wildenhues wrote:
> > It is possible to amend or modify $ac_configure_args from within the
> > toplevel configure (watch out with quoting, its contents are to be
> > eval'ed later), but that might mean you'd have to turn off config.cache.
> 
> There is no API to do this, though, is there?

Not really.

> As I understand it,
> $ac_configure_args is just one long string containing the arguments.

Yes.  But they are quoted suitably to survive being eval'ed.  This
latter bit is important: you cannot analyze them either without using
eval.

> I did try to hack the individual $ac_env_PKG_CONFIG_PATH_value and
> $ac_cv_env_*_value variables, but the command line arguments for
> subdir processing seem to be generated before any user code.
> By the time my code runs, the arguments are set.

Right.

> > Incidentally, a patch has been proposed quite recently to add extra
> > arguments to (some) sub package configure invocations.  It is still
> > pending copyright assignment clearance before review, but definitely
> > interesting.  It might help you.  However, given the preciousness it
> > might also mean that an eventual config.cache file cannot be shared
> > between the different configure scripts.
> 
> Where might I find this patch?  Maybe I could give it a try.

http://thread.gmane.org/gmane.comp.sysutils.autoconf.general/13805/focus=13828

As I said, it wouldn't yet solve the config.cache issues with your
approach (so you shouldn't use -C with it for now).

Cheers,
Ralf