[gentoo-dev] Re: gnatbuild.eclass refactoring: new/transitory eclass?

[Michael Haubenwallner]

Hi George,

On 09/03/2015 04:00 PM, George Shapovalov wrote:
> I am about to start a long-overdue refactoring of the gnat (Ada compilers)
> build system, governed by the gnatbuild.eclass. Given that nature of the
> packages concerned and, for quite some time, I was the only person brave
> enough to even touch this beast this probably does not concern too many
> people. However, since I am likely to produce some observable effects, such as
> introduction of a (possibly transitory) new eclass, I am giving a requisite
> heads-up here.
>
> First a short but necessary introduction:
> gnatbuild.eclass is a complex and ancient beast controlling the build of the
> two Ada compilers we have in the tree - gnat-gcc (by FSF) and gnat-gpl (by
> AdaCore). It has been created some 10 years ago, following the toolchain.eclas
> of then, long before even functions like src_prepare were envisioned and the
> term pms existed only in medical terminology. Correspondingly, it is composed
> of big blocks of code, not very modular and can benefit greatly of new
> practices.
>
> The catch is that all the gnat-xxx ebuilds depend on it and replacing the
> eclass would require modifying all of the ebuilds at the same time. Given the
> typical adjustmentsto address gcc backend gets bumps and the differences
> between two implementations, doing a big, all-in-one change like that is a
> perfect recipe for disaster that would likely lead to total breakage of gnat
> build system and the project that is never complete at the same time.
> Therefore I am thinking to do it in a more usual and gradual manner:

Just wondering whether you are aware of https://bugs.gentoo.org/547358 already:

Although I'm not an Ada dev, as gcc upstream committer I've need to bootstrap
the Ada parts within gcc as well, but faced that neither AdaCore nor gnat-xxx
ebuilds provide a C,C++,Ada compiler. Given that AdaCore seems to not provide
anything up-to-date at all any more, my idea was to provide the recent FSF Ada
compiler via toolchain.eclass only.

Thanks!
/haubi/