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 9BE4C3861029; Tue, 30 Jun 2020 12:46:28 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9BE4C3861029
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1593521188;
 bh=9waTJWkLaQUT0cw+K1qiobvfJU903FxfMA3g+zqsC2M=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=qHcgMfAh7197hGR2rvh2EMAOpH/UbPtmokp6hhQ6NBobIZ72cyuaV3f6S8zehDeUs
 GnmO/dr9WJtpMU2rntcdAR0wg35mhXSUYdoaVju3WZzLstwi0cFER/fKsIApNy06FE
 VcE7XEHWwTP8OL97IGVL+6CpRX+zHMHzP0CvkPO8=
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/95736] coroutine method improperly copies awaitable
Date: Tue, 30 Jun 2020 12:46:28 +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: 10.1.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: iains at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 10.2
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-95736-4-K4mpiIQvdL@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-95736-4@http.gcc.gnu.org/bugzilla/>
References: <bug-95736-4@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: <http://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: <http://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Tue, 30 Jun 2020 12:46:28 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95736

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Iain D Sandoe
<iains@gcc.gnu.org>:

https://gcc.gnu.org/g:c5a90f61ace5aca821224a658c223881d5b02388

commit r10-8394-gc5a90f61ace5aca821224a658c223881d5b02388
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Tue Jun 30 08:18:34 2020 +0100

    coroutines: Handle awaiters that are sub-objects [PR95736]

    Move deciding on initializers for awaitables to the build of the
    co_await, this allows us to analyse cases that do not need
    a temporary at that point.

    As the PR shows, the late analysis meant that we  were not
    checking properly for the case that an awaiter is a sub-object
    of an existing variable outside the current function scope (and
    therefore does not need to be duplicated in the frame).

    gcc/cp/ChangeLog:

            PR c++/95736
            * coroutines.cc (get_awaitable_var): New helper.
            (build_co_await): Check more carefully before
            copying an awaitable.
            (expand_one_await_expression): No initializer
            is required when the awaitable is not a temp.
            (register_awaits): Remove handling that is now
            completed when the await expression is built.

    gcc/testsuite/ChangeLog:

            PR c++/95736
            * g++.dg/coroutines/pr95736.C: New test.

    (cherry picked from commit daaed0199ee57013ae011421a7e90b7bdd295373)=