Re: C++ binary compatibility between GCC 3.1 and GCC 3.2?

[Mark Mitchell <mark@codesourcery.com>]

--On Friday, July 05, 2002 02:28:38 PM -0700 David O'Brien 
<obrien@FreeBSD.org> wrote:

> On Fri, Jul 05, 2002 at 12:51:17PM -0700, Mark Mitchell wrote:
>> In any case, GCC 3.1 and GCC 3.2 will not be 100% binary compatible
>> with respect to the C++ ABI.
>>
>> I can't say what that might mean as a distributor.
>
> I can -- MAJOR pain and difficulty.  It would probably prevent FreeBSD
> using GCC 3.2 in our 5.1 and later 5.x releases.  That means 1-2 years
> before the compiler can be upgraded for our users.
>
> I urge you as strongly as I can to back port (#define wrap if needed) the
> changes so that GCC 3.1.1 can be built to be 100% C++ ABI compatible with
> GCC 3.2.  FreeBSD can much more easily accept breakage between 3.1[.0]
> and 3.1.1, than between 3.1.1 and 3.2[.0] as we are still developing 5.0
> and can take ABI hits right now.

It's not the job of the FSF maintainers to do this.

If FreeBSD wants to backport patches, for its version, that's fine.
My goal, as RM, is for FSF users to be able to go from 3.1 to 3.1.1
without difficulty.

(The point of the minor releases is to fix critical bugs.)

We can't possibly know when we release 3.1.1 -- soon -- what changes may
or not be in 3.2 -- which is still months away.

I, of all people, appreciate the importance of binary compatibility
in C++.  There's really very little we can do, other than trying to
find and fix all the problems.

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com