Re: Adding GNAT/GCC-Ada to Guix

[Denis 'GNUtoo' Carikli]

On Sun, 16 Jul 2023 08:47:41 +0000
Fernando Oleo Blanco <irvise_ml@irvise.xyz> wrote:

> Dear Guix community,
Hi,

> Why did I tell all of this?
> Because I would like to add GCC-Ada to Guix and I am fully aware of
> the work that the Guix and the #bootstrappable people are doing
> towards a fully transparent compilation history. Opaque binaries are
> not allowed for that purpose. Sadly that is not currently possible
> with Ada. Therefore, I would like to get permission to add GCC-Ada as
> a binary up until there is a bootstrapping path available. I am aware
> that some languages/tools have received this treatment before.
I don't know well the exact policies with that regard (I'm not a Guix
maintainer, just an occasional contributor) but I found the following
compilers in Guix source code:

- The haskell is not and was never bootstrapped from source. Though
  the binaries used to bootstrap it changed over time.

- There are also other compilers like vala and nim that convert vala
  and nim source code to C. The issue is that they are written in vala
  and nim, and Guix uses generated "source code" (generated C that is
  very hard to read) to build the compilers. People usually don't
  modify nor audit that kind of generated source unless it is for
  debugging purposes.

> 3. What can Ada provide to Guix?
> 
> Apart from being an official language of the GCC toolsuite, it is
> also used in some important and unique places. For example, the
> graphics stack of Coreboot/Libreboot among other drivers are written
> in Ada [3] (you can find more by running `find . -type f -name
> "*.ad*"` on Coreboot's root folder).
Nowadays Libreboot includes nonfree software in its releases, so
because of that me and Adrien 'Neox' Bourmault started working to
continue the original spirit of the old Libreboot that didn't contain
any nonfree software.

And while we don't have a release yet, in the longer run we're
interested in using Guix for building it because Guix is FSDG compliant
and it can be installed on top of most GNU/Linux distributions.

It would also make the maintenance easier and shared with other users of
Guix, enable to easily rebuild older releases, have faster build
times, etc.

Since it's also possible to inherit packages, in the long run it
would probably makes sense for us to move most of our work in Guix.

So having some ways to build software written in Ada with Guix would
make a big difference here as without that we would probably only be
able to use Guix only for some parts (like for building GRUB, SeaBIOS
etc for Coreboot).

Without that, Guix users would also need to use another distribution
with Guix inside to be able to build it.

> It is also the base programming
> language of SPARK [4], a verifiable, GPLv3 licensed, programming
> language, used for the ARIANE rockets and the Rosetta space probe for
> example. And of course, there are plenty of libraries, tools and
> programs written in Ada! Without a compiler, none of this can be
> packaged in Guix...
At the last FOSDEM, I was also shown at the ADA table that it was
also possible to build software for micro-controllers with it.

Though I've no idea if there are interesting free software firmwares
written in Ada worth packaging in Guix.

Anyway, Thanks a lot for all your work on this.

Denis.

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