Re: 3.3 ABI vs 3.4 ABI (!) vs 3.5 ABI (?)...

[Andreas Jaeger <aj at suse dot de>]

Paolo Carlini <pcarlini@suse.de> writes:

> Hi everyone,
>
> this is only a first heads-up: the issue seems thorny and we should
> discuss it in detail next week or, anyway, as soon as possible.
>
> Indeed, seems time to take some "official" decisions, which will profoundly
> affect the development in mainline and release branches.
>
> Schematically, at least two points:
>  1- Are there any hopes to provide some sort of smooth transition
>  between
>      3.3 and 3.4? To wit, Michael noticed a few days ago that not that many
>      symbols present in 3.3-V3 are not anymore in 3.4. Perhaps, if we really
>      want, we can envisage providing "GLIBCXX_ABI Deprecated" code, as we
>      did between 3.2 and 3.3, or otherwise, fall back to other strategies.
>      On one hand, this is, in my opinion, a "dirty work" ;), which
>      perhaps we
>      would not really enjoy doing, on the other hand, however, *so* many
>      distributions relied and will rely for some time still on 3.3 and
>      therefore would be of *major* benefit to the users.

I see the problem that we changed the C++ ABI between 3.3 and 3.4 and
therefore the C++ library is already ABI incompatible and adding those
missing symbols might not help at all.

>   2- 3.4 vs 3.5: what shall we do? This issue is not less urgent,
>   since shapes
>      the kind of development that will happen in mainline and/or the need of
>      backporting to 3.4 any ABI-breaking change that in the next few
>      weeks of
>      mainline developmente turns out to be really
>      unavoidable. Personally, I'm
>      particularly worried by locale and string, which have already diverged
>      quite a bit (hopefully still not too much from the ABI point of view),
>      but other areas are affected as well.

The 3.5 library should be upward compatible to 3.5 IMO.

Andreas
-- 
 Andreas Jaeger, aj@suse.de, http://www.suse.de/~aj
  SuSE Linux AG, Maxfeldstr. 5, 90409 Nürnberg, Germany
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