From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Jason Rumney Newsgroups: gmane.emacs.devel Subject: Re: ABI incompatibilities with MinGW GCC 4.7.0 Date: Sat, 09 Jun 2012 22:44:01 +0800 Message-ID: <878vfwv93i.fsf@gnu.org> References: <83ipf2ustm.fsf@gnu.org> <871ulopu3r.fsf@Rainer.invalid> <83k3zgtywl.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1339253069 31855 80.91.229.3 (9 Jun 2012 14:44:29 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 9 Jun 2012 14:44:29 +0000 (UTC) Cc: Achim Gratz , emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Jun 09 16:44:28 2012 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1SdMtw-0004Ar-C2 for ged-emacs-devel@m.gmane.org; Sat, 09 Jun 2012 16:44:28 +0200 Original-Received: from localhost ([::1]:49349 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SdMtw-00056t-96 for ged-emacs-devel@m.gmane.org; Sat, 09 Jun 2012 10:44:28 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:55038) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SdMts-00055x-TM for emacs-devel@gnu.org; Sat, 09 Jun 2012 10:44:26 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SdMtr-0002dN-8A for emacs-devel@gnu.org; Sat, 09 Jun 2012 10:44:24 -0400 Original-Received: from mail-pz0-f41.google.com ([209.85.210.41]:55162) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SdMtn-0002bM-6C; Sat, 09 Jun 2012 10:44:19 -0400 Original-Received: by dakp5 with SMTP id p5so3887937dak.0 for ; Sat, 09 Jun 2012 07:44:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:references:date:in-reply-to:message-id :user-agent:mime-version:content-type; bh=Rsd1WLMUENVTzEYKttBWNj31dQW/QZvXZLg7UhHjqVA=; b=bJPyB1gaMvfUoDJ4T5uhVF1kbA7ISPf5Rm/tu0kZyndTACVWlC5pIOHwKwC5QYJ9P8 LDDPDKrDQDf4czuQl+F/9IflLUgbIJHZNKADHZbNJrz0TZl+veEjjeVWnAmvY6IPM/ba uibAS3pZ0PimvYPKCoFPFmMfsfQJ4LeqksmBl5wFtn86SAtS2WRYUtZ+6e9Xe6stKtjm htRq/VvMV4r0cVJLGxxXYtww8E7xW2QIE6SbvQ3nGz/u3Gx6PRIY+A66uIk9FaRdIAaq E9PuxsOsqQkVbFMX1MfK8IiJqlILRobJ9omTuYbKZs/LkfLgYjroHyQP52lMc6Srw6YW D1CA== Original-Received: by 10.68.228.2 with SMTP id se2mr7894251pbc.109.1339253055954; Sat, 09 Jun 2012 07:44:15 -0700 (PDT) Original-Received: from home.jasonrumney.net ([180.75.255.11]) by mx.google.com with ESMTPS id np8sm11599171pbc.71.2012.06.09.07.44.12 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 09 Jun 2012 07:44:15 -0700 (PDT) Original-Received: by home.jasonrumney.net (Postfix, from userid 1000) id 6B3DC1363; Sat, 9 Jun 2012 22:44:01 +0800 (MYT) In-Reply-To: <83k3zgtywl.fsf@gnu.org> (Eli Zaretskii's message of "Sat, 09 Jun 2012 16:09:30 +0300") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1.50 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.210.41 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:150858 Archived-At: Eli Zaretskii writes: >> I still think that simply adding '-mno-ms-bitfields' to the build is all >> you need for Emacs > > If we know the libraries out there are not built with GCC 4.7.x, then > this is indeed the way to go. But what about people who like to build > all their libraries themselves? if they use GCC 4.7 to build their > libraries, and don't make a point of using '-mno-ms-bitfields' when > they do, we cannot let them build Emacs with '-mno-ms-bitfields', can > we? The GTK binaries available for Windows have been built with -mms-bitfields for some years now, and the image libraries contained within them have worked without problem with Emacs for all that time. So I think the choice of whether to build with or without that flag is a non-issue for Emacs. > And then there's the issue of other ABI changes, if there are any. > That is the really disturbing part, because the bitfields issue rarely > if at all affects real-life code. It is somewhat disturbing that the MinGW-GCC maintainers themselves are unsure about other ABI changes, but I doubt that any of them will affect pure C code except maybe in more rare corner cases like the bitfield issue. If we were using C++, it might be another story, but for interfaces to third-party libraries that are distributed separately in binary form, C++ has always been a bad choice.