RE: reparsing makefile

[Paul Smith]

On Thu, 2011-12-15 at 08:45 +0100, Per Jessen wrote:
> Warlich, Christof wrote:
> 
> >  > > Thus, I need to reparse the Makefile whenever mounting was
> >  > > needed.
> > 
> >> An include file might help you with that.
> > 
> > I reread the section about the include directive in the manual,
> > but I'm not sure if I really understand: As the whole point is
> > about reparsing, I assume you refer to make's ability to generate
> > non-existing include files? An if I got the idea behind that right,
> > Make will then repase its Makefile (and the newly generated include
> > file)?
> 
> I haven't thought it through, but yes, something like that.  IIRC, Make
> will first check for dependencies on include files, and do any
> rebuilds. If an include file is update, Make will start over and
> reparse the Makefile.

If you create a sentinel makefile that exists on the filesystem and you
"include" it (it can even be empty), and your makefile has a rule to
build it and that rule involves mounting the partition then touching the
file for example, then:

make will try to include the file, see that it doesn't exist, run the
rule to create it (which will mount the partition), then re-exec itself
to re-read the makefile.

Should work.

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