From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-prs-return-17726-listarch-gdb-prs=sources.redhat.com@sourceware.org>
Received: (qmail 82744 invoked by alias); 25 Mar 2015 19:37:54 -0000
Mailing-List: contact gdb-prs-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb-prs.sourceware.org>
List-Subscribe: <mailto:gdb-prs-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb-prs/>
List-Post: <mailto:gdb-prs@sourceware.org>
List-Help: <mailto:gdb-prs-help@sourceware.org>, <http://sourceware.org/lists.html#faqs>
Sender: gdb-prs-owner@sourceware.org
Received: (qmail 82720 invoked by uid 48); 25 Mar 2015 19:37:53 -0000
From: "matei at cs dot toronto.edu" <sourceware-bugzilla@sourceware.org>
To: gdb-prs@sourceware.org
Subject: [Bug gdb/18165] New: incorrect evaluation of copy constructor on
 return statement
Date: Wed, 25 Mar 2015 19:42:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gdb
X-Bugzilla-Component: gdb
X-Bugzilla-Version: 7.9
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: matei at cs dot toronto.edu
X-Bugzilla-Status: NEW
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at sourceware dot org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter attachments.created
Message-ID: <bug-18165-4717@http.sourceware.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://sourceware.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-q1/txt/msg00491.txt.bz2

https://sourceware.org/bugzilla/show_bug.cgi?id=18165

            Bug ID: 18165
           Summary: incorrect evaluation of copy constructor on return
                    statement
           Product: gdb
           Version: 7.9
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdb
          Assignee: unassigned at sourceware dot org
          Reporter: matei at cs dot toronto.edu

Created attachment 8207
  --> https://sourceware.org/bugzilla/attachment.cgi?id=8207&action=edit
demonstrates bug

GDB incorrectly executes a copy constructor at the end of a function which
returns its result by value. This bug is new in 7.9, I checked 7.7.1 and 7.8.2
and they both work fine.

Compile with:
g++ -std=c++11 -O0 -g3 -ggdb -Wall -Wextra -pedantic a.cpp -o a

I tried:
gcc-4.9.2 and clang-3.5.0; same result.

Run gdb as follows:
gdb -q -ex 'file a' -ex 'b done' -ex 'r' -ex 'p _a' -ex 'p _a2' -ex 'p a()' -ex
q

With gdb-7.9, I see:
$1 = {_val = 15}
$2 = {_val = 15}
$3 = {_val = 0}

With gdb-7.8.2, I see:
$1 = {_val = 15}
$2 = {_val = 15}
$3 = {_val = 15}

Strangely enough, I noticed that commenting out the "= default" statement makes
the bug disappear. But having it there is valid code, so it should work.

-- 
You are receiving this mail because:
You are on the CC list for the bug.