Re: non recursive makefiles

[Richard Frith-Macdonald]

On 12 Jan 2005, at 13:58, MJ Ray wrote:

> Nicola Pero <nicola@brainstorm.co.uk> wrote:
> > Thanks, MJ Ray -- your comments make a good point -- the main problem 
> > is
> > that 'make' does not provide you with a full-fledged programming 
> > language.
>
> Recursion or not doesn't change that either way.  If you have a 
> specific
> point about a frequently-necessary feature that requires recursion,
> please restate it.

I haven't been paying much attention to this, but I believe subprojects 
and
modular coding (semi-separate namespaces) were the things mentioned
that recursion is used for.

> > It's extremely limited and we're already pushing it over the edge.  
> > The
> > first obvious objection is that if you remove recursive invocations 
> > and
> > just include everything in the top-level GNUmakefile, then everything
> > defined in any GNUmakefile included by the top-level execution would 
> > be in
> > the same namespace.
>
> Yes, the subprojects that you use in one project have to be compatible,
> but that's already true. Recursion doesn't change that fundamentally
> either.  A higher-level makefile can easily pollute the environment
> variables in a way that breaks lower levels, can't it? Not isolation
> at all. Assuming isolation seems dangerous to me.

Hmm ... my understanding is that during recursion into a directory, 
certain
variables are reset by the makefile system, while the remainder 
continue to
use their original values.
Seems analagous to a procedure call, where  variables which
are reset can be seen as local to the procedure.
These 'local' variables provide the 'isolation'.

> Recursion does allow "dirty" makefile practices to continue longer. 
> Maybe
> sometimes recursion would be necessary, but I don't see why it seems to
> be the default for so many GNUstep packages. Is it just lack of time to
> hack an elegant solution, which is what your message suggests?

I haven't noticed any suggestions as to how one might implement an 
'elegant'
solution at all.  Do you have a description of what an elegant solution 
might be?
My reading of Nicola's postings is that he believes that the current 
design is the
most elegant one possible within the constraints imposed by the 'make' 
program,
and I haven't seen any proposed alternatives which might suggest he's 
wrong.