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Date: Thu, 06 Apr 2017 14:43:00 -0000
From: Jonathan Wakely <jwakely@redhat.com>
To: Richard Biener <rguenther@suse.de>
Cc: Florian Weimer <fweimer@redhat.com>,	Bernd Edlinger <bernd.edlinger@hotmail.de>,	Jakub Jelinek <jakub@redhat.com>,	GCC Patches <gcc-patches@gcc.gnu.org>,	Jason Merrill <jason@redhat.com>, Jeff Law <law@redhat.com>
Subject: Re: [PATCH] Add a new type attribute always_alias (PR79671)
Message-ID: <20170406144326.GT4425@redhat.com>
References: <20170405160333.GR4425@redhat.com> <20170405160849.GV17461@tucnak> <AM4PR0701MB2162884DCF4538DC0FF5C2F1E40A0@AM4PR0701MB2162.eurprd07.prod.outlook.com> <AM4PR0701MB21623337A5C0C1850D3DF4C7E40A0@AM4PR0701MB2162.eurprd07.prod.outlook.com> <alpine.LSU.2.20.1704060925130.30715@zhemvz.fhfr.qr> <20170406075104.GA17461@tucnak> <alpine.LSU.2.20.1704060952480.30715@zhemvz.fhfr.qr> <AM4PR0701MB216235AC9FDCC6D5F8D7C96DE40D0@AM4PR0701MB2162.eurprd07.prod.outlook.com> <7d17b3b7-2d38-6184-8bd6-eb9f96f87912@redhat.com> <alpine.LSU.2.20.1704061623150.30715@zhemvz.fhfr.qr>
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On 06/04/17 16:23 +0200, Richard Biener wrote:
>On Thu, 6 Apr 2017, Florian Weimer wrote:
>
>> On 04/06/2017 04:11 PM, Bernd Edlinger wrote:
>>
>> > I think it is not too complicated to done in the C++ FE.
>> > The FE looks for array of std::byte and unsigned char,
>> > and sets the attribute when the final type is constructed.
>> >
>> > What I am trying to do is just extend the semantic of may_alias
>> > a bit, and then have the C++ FE use it in the way it has to.
>>
>> We also need this for some POSIX and Linux kernel interfaces.  A C++-only
>> solution would not help with that.
>
>Example(s)?

sockaddr_storage comes to mind.