Re: [Ada] GCC Ada bootstrap suggestion

[Daniel Kraft <d at domob dot eu>]

Arnaud Charlet wrote:
> > For half a year now, I've been working on the GCC Fortran front-end; but 
> > I'm also quite interested in Ada as a language.  However, I don't quite 
> > like the idea that one needs a working Ada compiler to bootstrap the Ada 
> > front-end.  Well, it's the same with a C compiler to bootstrap GCC, but 
> > anyways :D
>
> Also, at some point GCC will require C++ to bootstrap, so the same issues
> will arise there.

Well, the point is, I'm using a GNU/Linux system I mainly built from 
scratch, so there's no easy package-installer available for me and I've 
to built everything from source (which is, of course, "my own fault"). 
My system started out with a gcc C compiler, so I could easily bootstrap 
and install any newer GCC, including C++, Java or Fortran, as I wanted.

And even if gcc eventually moves on to C++, there will still be an older 
gcc I could bootstrap with a C compiler only and use that version's C++ 
compiler for the newest release.

With Ada, however, I'm at least not aware of another compiler I could 
bootstrap using my C compiler and use that one subsequentally to 
bootstrap GNAT.  At the moment, I'm trying to bootstrap it using a 
binary GNAT 3.15p which was also somewhat hard to find on the net; and 
this does not quite work out at the moment, as the included gcc (2.8.1 
IIRC) is far too old and buggy to build even gcc-3.1 with Ada support 
for bootstrapping the gcc-4.3 release.  At least I don't quite find it 
an easy task to get a recent GNAT build from source...

> > I had the idea, based upon how gfortran works, that one could implement 
> > some basic AST-to-C translation component (it would be quite easy for the 
> > Fortran AST) that could then be used as a very basic Ada-to-C compiler 
> > re-using most of the existing Ada compiler.  With this new tool, one could 
> > compile the Ada front-end sources to C files.
>
> Sure, this could theoretically be done, but so far, there has not been much
> interest in doing that, given that cross compiling GCC is always available
> as an option.

So you think I should boot into Microsoft Windows, install the cygwin 
GNAT binaries and use those to cross-compile gcc-4.3 for my GNU/Linux 
system?  Or at least boot up a live-cd that has the option to use a 
package installer for an existing GNAT and compile GCC with that?  At 
least to me this sounds somewhat disgusting.

I believe it would be at least some nice idea to make some 
binary-distributions easily available (and in a place they can be found).

If I give my idea some further thoughts (and finally manage to build 
GNAT on my system) and it seems to be quite easily doable, are you 
interested in results of my research and experiments?

Cheers,
Daniel

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