Re: Recursive targets for the user

[Ralf Wildenhues]

Hi Stefano,

* Stefano Lattarini wrote on Mon, Aug 02, 2010 at 12:10:10PM CEST:
> At Sunday 01 August 2010, Ralf Wildenhues wrote:
> > So, here's the deal: currently, Automake has
> >   RECURSIVE_TARGETS
> >   RECURSIVE_CLEAN_TARGETS
> >   AM_RECURSIVE_TARGETS
> Is there any good reason (apart from naybe backward-compatibility)
> for keeping these as three separate variables?

Well, yes.  clean targets need to a different subdir traversal order,
and currently, the latter lists more than the sum of the former: it
also lists targets that invoke `make' recursively within the same
directory.  The latter is needed in some cases (mostly for hidden
dependencies), and listing them is needed in order to avoid unwanted
parallel execution; writing a section about this necessity has been
on my todo list for a while: the deal is that you should not run
  make -jN T1 T2

if both T1 and T2 are listed in $(AM_RECURSIVE_TARGETS).

And yes, backward compatibility is very important, too.  I've checked
codesearch now, these variables are used elsewhere already.  :-/

> > 
> > 1) What to name them?
> >   RECURSIVE_USER_TARGETS
> >   RECURSIVE_USER_CLEAN_TARGETS
> >   ALL_RECURSIVE_USER_TARGETS

> What about `EXTRA_RECURSIVE_TARGETS' etc. instead?

Ah, that's a good idea; thanks.

> Also, I'd like to have a way to specify a recursive targers which 
> should recurse in a limited set of a projects' subdirectories, and not 
> in all of $(SUBDIRS).  Do you think this would be possible/worthwhile?

Can you give an example what this would be good for?  My idea was that
if the user adds a recursive target but then doesn't specify an *-am
rule in some directory, that the rule would just traverse that directory
without doing anything by default.  So your suggestion would be
optimization only, right?

Thanks,
Ralf