From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3058 invoked by alias); 20 Dec 2011 17:45:03 -0000 Received: (qmail 2892 invoked by uid 22791); 20 Dec 2011 17:45:01 -0000 X-SWARE-Spam-Status: No, hits=-2.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 20 Dec 2011 17:44:47 +0000 From: "ebotcazou at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/51628] __attribute__((packed)) is unsafe in some cases Date: Tue, 20 Dec 2011 17:45:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: ebotcazou at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2011-12/txt/msg02287.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51628 --- Comment #14 from Eric Botcazou 2011-12-20 17:43:07 UTC --- > What Ada does looks just like a workaround for what should be done properly in > the expander. So no, IMHO we shouldn't be changing all other FEs and the > middle-end (when it wants to generate them e.g. for memcpy) to do what Ada > does, but we should change the expander. Of course I have the exactly opposite viewpoint, since I think that we should keep the invariants we have: integral modes are naturally aligned and TYPE_ALIGN >= MODE_ALIGN (TYPE_MODE). Breaking them for a few pathological cases that the C compiler has shun for years doesn't seem the best course of action.