Re: gnatmake: "ada.numerics.real_arrays" is not a predefined library unit

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Samuel Tardieu writes:
>>>>>> "Ludovic" == Ludovic Brenta <ludovic@ludovic-brenta.org> writes:
>
> Ludovic> It's been in the back of my mind for a few months that I
> Ludovic> should build a shared libgnala.so, package it separately from
> Ludovic> libgnat-4.3.so, and arrange for it to depend on
> Ludovic> lapack. Patches to that effect are, of course, welcome and
> Ludovic> will be gratefully accepted.
>
> Maybe we can work out the shared/static issue in GCC sources. Patches
> welcome too there :)

Definitely; this is an area where all distributions would benefit.
However, Debian is a bit peculiar since it patches the library
building process (in gcc/ada/Makefile.in) heavily so as to build both
the zero-cost and setjump/longjump versions of the library.  So, if I
produce a patch, someone will have to adjust it for upstream GCC.

> Concerning the distribution, why separate libgnala.so from libgnat?
> You don't need a dependency on lapack/blas, only a "suggests" or
> "recommends" if people want to build applications requiring annex g
> support. As far as compiled applications are concerned, the
> lapack/blas dependency will be recored as part of a regular Debian
> dependency.

"Suggests" or "Recommends" is not good enough because it would foil
the automatic dependency management Debian is renowned for.  The
proper solution is to place libgnala.so in a separate package
(suggested or recommended by gnat-4.3) but that Depends on
(i.e. requires) lapack to be installed.  This way, if someone builds a
package where they use Annex G, their package will automatically
depend on libgnala.so and, indirectly, on lapack.  With your proposal,
this would not happen as lapack would be only recommended.

-- 
Ludovic Brenta.