From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 90DD339B4076; Sat, 26 Jun 2021 04:13:57 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 90DD339B4076
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/97566] [[no_unique_address]] causes miscompiles when mixed
 with EBO in constexpr context
Date: Sat, 26 Jun 2021 04:13:57 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 10.2.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Resolution: FIXED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: jason at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 11.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-97566-4-LjwhL9eWKC@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-97566-4@http.gcc.gnu.org/bugzilla/>
References: <bug-97566-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Sat, 26 Jun 2021 04:13:57 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97566

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jason Merrill <jason@gcc.gnu.org>:

https://gcc.gnu.org/g:2168bfb81448ae1bfa4351760a23d4ec051c2a00

commit r12-1827-g2168bfb81448ae1bfa4351760a23d4ec051c2a00
Author: Jason Merrill <jason@redhat.com>
Date:   Thu Jun 24 17:32:02 2021 -0400

    c++: constexpr aggr init of empty class [PR101040]

    This is basically the aggregate initializer version of PR97566; as in t=
hat
    bug, we are trying to initialize empty field 'obj' in 'single' when the=
re's
    no CONSTRUCTOR entry for the 'single' base class subobject of 'derived'=
.=20
As
    with that bug, the fix is to stop trying to add entries for empty field=
s,
    this time in cxx_eval_bare_aggregate.

    The change to the other function isn't necessary for this version of
    the patch, but seems worthwhile for robustness anyway.

            PR c++/101040
            PR c++/97566

    gcc/cp/ChangeLog:

            * class.c (is_empty_field): Handle null argument.
            * constexpr.c (cxx_eval_bare_aggregate): Discard initializer
            for empty field.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/no_unique_address13.C: New test.=