From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 6E564138247 for ; Thu, 19 Dec 2013 15:17:51 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id A2426E0BC0; Thu, 19 Dec 2013 15:17:45 +0000 (UTC) Received: from latimerie.flaska.net (latimerie.flaska.net [46.28.111.182]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id A38BDE0BB6 for ; Thu, 19 Dec 2013 15:17:44 +0000 (UTC) Received: by latimerie.flaska.net (Postfix, from userid 1000) id BEDE960408; Thu, 19 Dec 2013 16:17:41 +0100 (CET) From: =?iso-8859-1?Q?Jan_Kundr=E1t?= To: Subject: Re: [gentoo-dev] How to support C++11 in =?iso-8859-1?Q?libraries=3F?= Date: Thu, 19 Dec 2013 16:17:41 +0100 User-Agent: Trojita/v0.3.96-154-gef050ca; Qt/4.8.5; X11; Linux; Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@lists.gentoo.org Reply-to: gentoo-dev@lists.gentoo.org MIME-Version: 1.0 Message-ID: <5a63ac96-210a-4abd-bb87-062020ac8655@gentoo.org> In-Reply-To: <20131219101855.5a34fd03@gentoo.org> References: <20131218085447.56d1e133@gentoo.org> <86sitqtg5s.fsf@moguhome00.in.awa.tohoku.ac.jp> <04adfe90-a18b-45d5-9f81-90070c5090c0@gentoo.org> <52B1CF64.8020407@pathscale.com> <52B1D5EA.7020106@pathscale.com> <613ecc5f-13f1-4fba-b0f1-9257908fff50@gentoo.org> <86mwjxty58.fsf@moguhome00.in.awa.tohoku.ac.jp> <20131219101855.5a34fd03@gentoo.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 00ffd1ce-9242-4cd2-bbd4-2821300fc98e X-Archives-Hash: cc4fecf0b1f282b890cb0f9af0819db1 On Thursday, 19 December 2013 10:18:55 CEST, Micha=C5=82 G=C3=B3rny wrote: > Would it be possible to have a consistent ABI for both C++03 and C++11? > The simpler changes like adding new fields can be backported quite > easily (even if it would mean having dummy fields in C++03), I have no > idea about the more complex changes. I don't know, but from a bystander's point of view, I surely hope that it=20 will be possible. Otherwise there would be no option but providing a=20 multilib-like setup for C++11, after all. Some messages on gcc's ML indicate that there are software vendors who are=20= *very* afraid of doing the SONAME change again. Given that C++11 forbids a=20= refcounted std::string while libstdc++ currently use just that for its=20 implementation, I suspect that the upstream developers have a very=20 interesting problem to solve. (And there's much more.) It is pretty clear to me that even the gcc people have not reach a=20 consensus on how the ABI of the standard library will look like in 4.9, so=20= maybe it is premature for us to talk about how to solve this. The ball is=20 on their side. > Well, if they considered the C++11 ABI in gcc-4.9 stable, we could > consider changing the default to C++11. Then, we could do our > bump/switch thing as a matter of gcc-4.9 upgrade problem. To put things into perspective, *if* the ABI changes and if the new version=20= is compatible between C++98 and C++11, then we're talking something very=20 similar to an upgrade from GCC 3.3. Cheers, Jan