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 DC4FA3939C1E; Wed, 19 May 2021 11:13:22 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org DC4FA3939C1E
From: "joachim at joameyer dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/100676] New: Redeclaring __failed_assertion() at
 every point of use of __glibcxx_assert breaks Clang CUDA
Date: Wed, 19 May 2021 11:13:22 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: joachim at joameyer dot de
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-100676-4@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: Wed, 19 May 2021 11:13:23 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100676

            Bug ID: 100676
           Summary: Redeclaring __failed_assertion() at every point of use
                    of __glibcxx_assert breaks Clang CUDA
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: joachim at joameyer dot de
  Target Milestone: ---

As noted in https://bugs.llvm.org/show_bug.cgi?id=3D50383 the use of
__glibcxx_assert in the complex functions breaks using the complex header w=
ith
Clang CUDA. The way Clang CUDA handles that might not be ideal, but the
libstdc++ issue seems to be present anyways:

In every use of __glibcxx_assert the function __failed_assertion is redecla=
red
and btw. never defined, which might break other projects as well, and then =
is
used as an assertion in constant evaluated contexts, as it is a non constex=
pr
function.

I wasn't able to come up with an entirely better approach so far, but I gue=
ss
most of the issues, that I could think of so far, would be solved by moving=
 the
void __failed_assertion(); declaration out of the macro.

This would fix the issues with Clang CUDA for example:
https://cuda.godbolt.org/z/GTMnxez7j=