Re: Need more EXTRA_PROGRAMS variables

[Ralf Wildenhues]

* Behdad Esfahbod wrote on Thu, Jun 21, 2007 at 01:42:18AM CEST:
> On Tue, 2007-06-19 at 09:18 +0200, Ralf Wildenhues wrote:
> > 
> > All fair.  Except I simply don't see a use case for this yet, nor do I
> > see what `something' should mean in this case.  If you can create a
> > sensible use case, let's see how to implement it.  IOW: where do you
> > need EXEEXT rewriting for something that is not an optionally built
> > program?
> 
> Ok, maybe I have a wrong idea of what the committed fix was.  I want
> to be able to have something like this work:
> 
> ============
> EXTRA_PROGRAMS = 
> 
> DANCE_PROGS = dance1 dance2 dance3
> EXTRA_PROGRAMS += $(DANCE_PROGS)
> dance: $(DANCE_PROGS)
>       ./perform-dance # uses progs dance1, dance2, and dance3
> ============
> 
> Now does automake rewrite DANCE_PROGS to include EXEEXT?

No, it doesn't.  Thanks for the example, I think I understand now
and I see that this requires another variable, e.g., in order to also
have

SWIM_PROGS = swim1
EXTRA_PROGRAMS += $(SWIM_PROGS)
swim: $(SWIM_PROGS)
        ./perform_swim # ...

in which case you could not just use $(EXTRA_PROGRAMS) as prerequisite
of dance any more (as that would be suboptimal).

> ============
> EXTRA_DANCE_PROGRAMS = dance1 dance2 dance3
> dance: $(EXTRA_DANCE_PROGRAMS)
>       ./perform-dance # uses progs dance1, dance2, and dance3
> ============
> 
> It will do. (and since it's a "EXTRA_" var, there is no need for
> DANCEdir to be defined).

I'm not yet totally convinced that this is the best solution, but
currently I fail to see technical issues with it.  Are you motivated to
work on a patch?  If yes, then look at automake.in:handle_programs and
automake.in:am_install_var to get going.  If you'd rather not venture
into that, it'd help a lot already if you wrote a documentation patch
and (used above in) a test.

FWIW, here's a couple of random ideas about why this naming is maybe
not ideal: it deviates from there where_HOW principle used in Automake.
The EXTRA_ bit is all clear, but the DANCE_ bit suddenly carries no
obvious meaning, unlike other variables.  Such special cases IMHO make
Automake's semantics more difficult to grasp for newcomers (and they
also make the documentation more difficult to write in a concise
manner).  OTOH I don't see an obvious better choice either.

Since this would be a new feature, and pose a small incompatibility:
  EXTRA_FOO_PROGRAMS = p
  EXTRA_FOOdir = $(bindir)

will be treated differently with the patch than without the change
(wrt. what's build at 'all' time and what's installed),
this change is suitable for HEAD but not for branch-1-10.

Thanks for your patience with me.

Cheers,
Ralf