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 A3D11385700D; Thu, 13 May 2021 15:08:55 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A3D11385700D
From: "richardpku at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/100588] New: Destroying delete shouldn't be called if
 constructor throws
Date: Thu, 13 May 2021 15:08:55 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: richardpku at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.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 target_milestone
Message-ID: <bug-100588-4@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: Thu, 13 May 2021 15:08:55 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100588

            Bug ID: 100588
           Summary: Destroying delete shouldn't be called if constructor
                    throws
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: richardpku at gmail dot com
  Target Milestone: ---

Consider this program:


#include <cstdio>
#include <new>

class A {
 public:
  A() { throw 42; }
  ~A() { puts("A::~A"); }

  void operator delete(void* p) {
    puts("regular delete invoked");
    ::operator delete(p);
  }

  void operator delete(A* p, std::destroying_delete_t) {
    puts("destroying delete invoked");
    p->~A();
    ::operator delete(p);
  }
};

int main() {
  try {
    new A;
  } catch (int) {
  }
}


Output compiled with GCC:

destroying delete invoked
A::~A


Output compiled with Clang:

regular delete invoked


I believe clang has the correct behavior.

A destroying delete function is expected to invoke the destructor explicitl=
y.=20
As a result, the current GCC implementation would indirectly invoke the
destructor on an instance that wasn't successfully constructed, which obvio=
usly
isn't the intended behavior.

It is even worse if class A has a base class, in which case the destructor =
of
the base class is called twice if an exception is thrown in A's constructor=
.=