This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PING PATCH, PR 57748] Set mode of structures with zero sized arrays to be BLK
- From: Martin Jambor <mjambor at suse dot cz>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, "Joseph S. Myers" <joseph at codesourcery dot com>
- Date: Tue, 27 Aug 2013 16:03:42 +0200
- Subject: Re: [PING PATCH, PR 57748] Set mode of structures with zero sized arrays to be BLK
- Authentication-results: sourceware.org; auth=none
- References: <20130802114531 dot GE2728 at virgil dot suse> <20130823151122 dot GC32344 at virgil dot suse> <20130823152923 dot GN1814 at tucnak dot redhat dot com>
Hi,
On Fri, Aug 23, 2013 at 05:29:23PM +0200, Jakub Jelinek wrote:
> On Fri, Aug 23, 2013 at 05:11:22PM +0200, Martin Jambor wrote:
> > Hi Jakub and/or Joseph,
> >
> > the reporter of this bug seems to be very anxious to have it fixed in
> > the repository. While Richi is away, do you think you could have a
> > look? It is very small.
>
> Isn't this ABI incompatible change (at least potential on various targets)?
> If so, then it shouldn't be applied to release branches, because it would
> create (potential?) ABI incompatibility between 4.8.[01] and 4.8.2.
>
I don't know. I did a few attempts to observe a change in the calling
convention of a function accepting a zero sized array terminated
structure by value (on x86_64) but I did not succeed. On the other
hand, I assume there are many other ways how a mode can influence ABI.
So I'll try to have a look whether we can hack around this situation
in 4.8's expr.c instead.
Nevertheless, is this patch ok for trunk?
Thanks,
Martin