Re: generating pc file

[Nick Bowler]

On 2012-09-20 13:14 -0700, Russ Allbery wrote:
> Nick Bowler <address@hidden> writes:
> 
> > I wonder if all that's needed is an option to override a configure- time
> > decision when you run config.status?  Then you could use the
> > config.status machinery to perform substitutions by calling it at make
> > time, and not have to maintain your own code that does the same thing.
> > Then the makefile could have a rule (either automatically provided by
> > Automake or hand-written by the user) that looks something like:
> 
> config.status also doesn't fully expand the variables, though, which is
> something that you'd want for this sort of application.  Otherwise, you
> have to know all of the possible ways in which one variable could
> reference another so that you can set all of them (and you can only write
> files that have a variable resolution system, although pkg-config does
> have one).  Note that the user can do things like
> --libdir='${datadir}/foo' at configure time, even if it's not common.

Ah, but make will fully expand the variables.

Suppose you have:

  prefix = /usr
  datadir = ${prefix}/share

then with my example make rule extended to include an override for
datadir, it would have

  $(SHELL) $(top_builddir)/config.status --override datadir=$(datadir)
  ...

and config.status will see

 --override datadir=/usr/share

so it would replace @datadir@ with /usr/share.
 
Cheers,
-- 
Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)