[gentoo-dev] Integrating Ada into toolchain.eclass, again

[Luke A. Guest]

Hi,

I posted a bug back in August,
https://bugs.gentoo.org/show_bug.cgi?id=592060, to discuss adding Ada
support into Gentoo's toolchain.eclass. The reasons for this are twofold:

1) GNAT is supplied with the source of GCC and should be available in
Gentoo's sys-devel/gcc with USE=ada
2) Automatically gain cross compilers with sys-devel/crossdev, also has
been tested with my patch.

I saw a few new dev-ada packages being added to the tree yesterday. I
don't check this ml often, but just checking and seeing the various
discussions on Ada. I wonder why my bug has been ignored, surely the bug
tracker should've been checked first by Alfredo? He basically wanted
this as well.

** Current problems **

The above link provides other links and discussion including an error
I'm getting compiling GCC 6.x within emerge only. There are new
bootstraps for amd64 (so far) also.

** GNAT GPL **

I think that if anyone wants GNAT GPL versions, they should be installed
in /opt and bought into a person's environment manually by the people
using these compilers. I only really consider this compiler useful as a
means for testing source that fails with bug boxes using the FSF GCC due
to the fact that software built with GNAT GPL is automatically GPL v3.

** Roadmap **

I would suggest the following, but is fluid as it starts off really
messy due to cyclic dependencies:

* Add my patch to the toolchain.eclass to get at least part of the
problem sorted out, a start.
* Build bootstraps for the other platforms and at various compiler
versions, this is simple enough to do.
* Purge all current Ada/GNAT stuff from the portage tree as it's really
old and tbh, a mess.
* Start discussing the problem of a Gentoo Ada policy, this is mentioned
by Steve Arnold in the above link, he has started on an eclass for gnatmake.
* For 4.9.x and early 5.x compilers, add gnatutils, this is removed in
later versions of the tools as apparently it's not required anymore.
* gprbuild needs to be bootstrapped by makefile where it builds it's own
gnatutils and xmlada
* eselect plugin for applications built with GNAT, they will need to be
slotted where they use shared libs which were also Ada sources.
* gpr.eclass  so other ebuilds can use the various gpr tools for building.
* gnatcoll, xmlada, asis ebuilds added to dev-ada
* gprbuild really needs to be rebuilt using the installed tools and libs.
* other libs.
* gps ebuild.
* Extend USE=ada to other Gentoo targets, more gnatboot strap compilers.

** Bootstraps **

Steve has bootstraps built for amd64, x86, arm for gcc-4.9, I have added
5.4 and 6.3 for amd64 in
https://www.dropbox.com/sh/stljjvpj9201n8t/AAAzVG67ppskZ9UKiWTWz9Q_a?dl=0,
I've not looked into a canadian cross with Gentoo yet, it's on the todo
list I suppose.

Thoughts?

Thanks,
Luke.