Re: How do I configure Makefile.am to run a program?

[David Fang]

> > Don't use make to do this - just use autoconf, and let your configure
> > script deal with it:
> >
> > configure.ac
> > ------------
> > AC_INIT(...)
> > ...
> > svnrev=`svnversion .`
> > AC_SUBST(svnrev)
> > ...
> > AC_CONFIG_FILES([Makefile ... poll.spec)
> > AC_OUTPUT
> > ------------
> >
> > Now create a file called poll.spec.in that contains an exact copy of your
> > existing poll.spec, but add the autoconf substitution variable, @svnrev@
> > where it make sense.
> >
> > In a Makefile.am in the directory containing your poll.spec file, add
> >
> > EXTRA_DIST = ... poll.spec
> >
> > I use this trick all the time and it works great! In fact, I generate most
> > of my rpm and debian build scripts this way.
>
> Thanks, but the problem with this solution is that I would have to rerun the
> .configure step each time.  Forgetting to do that is as as easy as
> forgetting to edit the spec file.

Hi,
	Doesn't AC_CONFIG_FILES automatically add regenerations rules to 
the Makefile? usually resembles something like:

# somewhere in Makefile.in
config-generated-file: [config-generated-file.in]
        cd $(top-srcdir) && ./config.status config-generated-file

If the command run to generate it is some script (which is used by 
config.status), you should be able to append a dependency:

# to Makefile.am
config-generated-file: generating-script

Anytime config.status or your generating script changes, it should 
automatically be regenerated.  (And if only your generating script changes 
(not configure.ac), it won't re-run all of configure, just 
that output phase, config.status.)

And if you want the target to always be up-to-date,
add it to BUILT_SOURCES=, or all-local:, as others suggested.

I let 'make' take care of any dependencies, basically.

HTH,


Fang


David Fang
Computer Systems Laboratory
Electrical & Computer Engineering
Cornell University
http://www.csl.cornell.edu/~fang/
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