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Re: GCC 5.1.1 Status Report (2015-06-22)

On Tue, 30 Jun 2015, Jason Merrill wrote:

> I'm interested in your thoughts on fixing c++/65945 in 5.2.
> It's trivial to fix the alignment of nullptr_t, but I was concerned about ABI
> impact.  On further research it seems that it won't cause any trouble with
> argument alignment, since that doesn't seem to rely on TYPE_ALIGN at all; I
> think the only ABI breakage would come from unaligned nullptr_t fields in
> classes, which I expect to be very rare. The testcases that were breaking on
> SPARC and ARM without this fix have to do with local stack slots, which are
> not part of an interface.
> So I think we can change this without breaking a significant amount of code,
> and better to break it now than after we've settled into the new library ABI.
> We should certainly mention it prominently in the release notes if we do, and
> I've added a -Wabi warning for the field alignment change.
> Does this make sense to you?

Yes, that makes sense to me.


> Jason

Richard Biener <>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)

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