Re: auto-regenerating Makefile.in and Makefile files

[Tom Tromey]

>>>>> "Akim" == Akim Demaille <address@hidden> writes:

Akim> We can add --update to config.status, so that it only recreates
Akim> its obsolete offsprings.  Would that help Automake?

It turns out Alexandre Oliva had some nice ideas that are logged in PR
automake/46:

     Maybe we could run config.status without setting any environment
     variables only for the top-level Makefile.

     Another solution is to arrange that all recursive rules ensure that
     subdir/Makefile exists, and generate it otherwise.  This could be
     accomplished by arranging that *-recursive rules depend on all
     $(SUBDIRS)/Makefile that are output by configure, or by explicitly
     checking for the existence of such Makefile before recursing.

Either one of these is probably workable.

The first one is simple and relies on the user running `make' at the
top-level for this feature to work.

The second one is more complex but will work at any depth.

We could put more smarts into config.status, but then we're still left
with the problem of how to generate Makefile.in.  Either of
Alexandre's ideas is easily extended to solve that problem too.

Tom