Re: Could automake-generated Makefiles required GNU make? (was: Re: [gnu-prog-discuss] portability)

[Stefano Lattarini]

Hi Paul, and thanks for the reply.  I really appreciate having the
partecipation of the GNU make maintainer in this discussion :-)

On Monday 21 November 2011, Paul Smith wrote:
> On Mon, 2011-11-21 at 21:56 +0100, Stefano Lattarini wrote:
> >   1. We start requiring GNU make in an "experimental" automake 2.0
> >      development line (which might, and will, break whathever
> >      backward-compatibility gets in its way).
> 
> If you go this route, then it's critical that the "minimal set" of
> capabilities used by this new automake be clearly documented.
>
Absolutely.  And I think the very clear and complete NEWS file in the
GNU make distribution will be of great help in this.

As of now, my opinion is that we'd want to require at least the presence
target-specific variables, of user-defined functions, of the $(eval)
builtin and of the special $(.VARIABLES) variable.  Which, if I'm not
mistaken, means we will have to require at least version 3.80 or later.

> Even something like "all features available as of GNU make 3.76" or
> whatever would be very helpful, although I would prefer an explicit
> list of capabilities.
>
Having an explicit list of required capabilities *and bugfixes* would
probaly be a good idea, esp. to play nice with patched versions of
GNU make (which might have bugfixes backported from later versions).

> There ARE multiple versions of GNU make out there and many distributions
> still ship versions many years old... I regularly get questions on the
> GNU make help lists from users referring to our web manual, which
> obviously documents the latest released version of GNU make, and they
> are confused because their version of GNU make (released in 2006 or
> whatever) does not support some of the documented features.
>

Thanks,
  Stefano