Re: GCC withdraw

Only a few comments in reply to avoid banging my head against a brick wall and then I'm done:

On Friday, August 30, 2013 3:33:21 am David Chisnall wrote:
> On 29 Aug 2013, at 18:44, John Baldwin <jhb_at_freebsd.org> wrote:
> > Also, unless you plan on desupporting all non-x86 platforms, you _still_
> > have to do all this work while those platforms require GCC anyway.  Just
> > turning off GCC on x86 doesn't change this problem one iota.  And that point
> > is actually relevant to many of the other concerns you raised.  It's not at
> > all clear what disabling GCC on x86 will buy you unless you are intending on
> > short-changing support for GCC on non-x86.
> 
> It gives us a much cleaner deprecation strategy.  Ports on tier-2 are best effort.  We don't need to be quite as careful to ensure that they build 
with the base system compiler on tier-2 architectures.  We don't make as strong guarantees about compatibility on tier-2 architectures, so removing 
gcc from their build at some point over the next five years is fine, but this is not the case for tier 1 architectures, where we can be reasonably 
expected to support anything that is in the base system for the next five years.  

> [snip]

So my take away from this is that you have no plans to support any platform that
doesn't support clang as you just expect ia64 and sparc64 to die and not be
present in 11.0.  That may be the best path, but I've certainly not seen that
goal discussed publically.

> > Don't get me wrong, I don't love GCC per se, and on my laptop I've hacked
> > the relevant ports so that everything is built with clang.  I would also
> > love to be able to build the base system with GCC 47 instead of 42, it just
> > doesn't seem that we are there yet.
> 
> The time to raise objections for this was when the plan was originally raised over a year ago, or at any of the points when it's been discussed in 
between.  It is not after we're ready to flip the switch.

So I think the crux of the issue might be this:

I have no doubt that this has been discussed extensively on toolchain_at_ and in
toolchain-specific devsummit sessions.  The proposal to disable GCC by default
does not appear to have been discussed in a wider audience from what I can
tell.  (I can't find any relevant threads on arch_at_ or current_at_ prior to this
one.)  While this is a toolchain-specific decision, it is a very broad
decision.  Also, we aren't here because of a new thread started intentionally
to say "Hey, we as the toolchain folks think we should disable GCC by default
on 10 for x86".  Instead, we started off in a thread about adding AES
instructions to our binutils and out of left field there is an e-mail of
"Oh, don't bother cause I'm disabling GCC next week" (paraphrase).  Can you
appreciate at all that this is a total surprise to people who aren't
subscribed to toolchain_at_ and haven't been to a toolchain session at a 
devsummit and that this looks like a drive-by change?

-- 
John Baldwin