Re: Plans for ABI migration

[Marc Espie <espie at quatramaran dot ens dot fr>]

In article <01010921385201.28923@beetle> you write:
>Hello,

>did the steering comitee already set a roadmap to ease the
>migration from the old C++ ABI (gcc 2.9x) to the new one
>(gcc 3.x)?

> This is expecially needed for systems using gcc as their
>official C++ compiler, such as Linux and *BSD.

This is a weird message, you start off sounding like you
want to ask for general questions, then all the rest of
your post is completely linux and glibc-centric.


As far as OpenBSD goes, things are rather simple: we'll
test gcc 3.0 as it comes near completion. If it works,
we'll adopt it (and we'll complain loudly if the pre-versions
don't work... well, I hope not, but in reality, I think we won't
be able to switch until gcc 3.0.1 or gcc 3.0.2).

As far as the C++ API goes, things are simple: nothing that
was built before will have a chance to work with the new API.
Put simply, this means major version number changes for EVERY
C++ library in the system...

Considering that there aren't that many C++ libraries around,
this shouldn't be hard.  It is just a question of providing the
newer C++ libraries along with the newer system.

As compared to other systems, there are merits to having development
proceed at a safe pace, with releases every six months. Our releases
are perceived as dependable, and people don't shirk the update, as,
say, in some other world, where no-one updates to version 11.0, 
everyone's waiting for 11.1 which is said to be less buggy and actually 
work.

Also note that everything that happens outside of those six months is
developer's issue: the intermediate steps might not be smooth, but we don't
really have to care. Those people who go through intermediate snapshots are
not ordinary users.  They take the risk, they can live with it.


Personally, finally having a somewhat dependable C++ API, and a decent
library, is something I can't wait to have. This has been one of the
major shortcomings of C++ (practically) that I've seen people oppose me
with, so gcc 3.0 is definitely a good thing. I believe that we will have
to start worrying about C++ updates *after* 3.0, if for whatever reason
it doesn't deliver on the stable ABI plan.