Re: Ada files now checked in

[dewar at gnat dot com]

<<By appearing to support it, we are leading people to believe that it
will work, but the period of time for which that statement is true is
likely to be very small (and may, in fact, be zero: has anybody
actually *tried* to bootstrap starting from that distribution?).
>>

Someone reported that they could indeed bootstrap from the Debian version,
and that is not at all surprising for the current sources, which are in
fact speced to be compilable with a version 3.13 gnat.

But indeed it is not the case that this will be true for ever, or even for
very long (I already gave two cases of kludges in the source that are just
waiting to be removed -- indeed in our normal procedures we would have
stepped up to 3.14 for the prior version, but kept 3.13 as a base precisely
to ease transitions for GCC 3).

One thing that concerns me is that if people decide that it is useful to
be able to bootstrap with the current Debian package, then it is only a
small step to decide that it definitely should work, and then it is only
a small step to decide that if in the future it does not work, that is a
bug which needs fixing, and suddenly we have an influence that makes it
hard to clean up these bootstrap issues, and in some cases, harder to
improve the technology. That would be unfortunate (and would of course
also lead to greater divergence between the FSF and ACT versions -- right
now, it is our intention to try to keep the FSF and ACT versions in very
close sync, since this makes it more practical to ensure that our changes
and development can be reflected in the FSF tree, we have even discussed
whether we could use the FSF tree directly for ACT development in the
future).

Just to state our current philosophy, it is that the current version of
GNAT requires the most recent *official* release to compile (that's a bit
different from Richard's more general statement of a recent version).

What we would like to guarantee at any particular point is that the FSF
GNAT snapshots are compilable starting either with the most recent FSF
release, or with starter binaries maintained at the ACT libre site. For
now we don't have anything like an official FSF release although we will
also try to ensure that the most recent snapshot can compile itself (this
is a normal bootstrap requirement after all). That means that the starter
binaries are the only *guaranteed* starting point. By the way I have asked
that the starter binaries be made available in any case at the libre site
early this coming week. We will post an announcement here.