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 56461385780B; Fri, 30 Oct 2020 13:06:35 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 56461385780B
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/97412] [10/11 Regression] [concepts] ICE with requires
 requires and parameter packs
Date: Fri, 30 Oct 2020 13:06:35 +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: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: ppalka at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 10.3
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-97412-4-U0yt2XjkAV@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-97412-4@http.gcc.gnu.org/bugzilla/>
References: <bug-97412-4@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: Fri, 30 Oct 2020 13:06:35 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97412

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:5ab7959ee18980d676892fa6579f1ca09c5ecc08

commit r10-8957-g5ab7959ee18980d676892fa6579f1ca09c5ecc08
Author: Patrick Palka <ppalka@redhat.com>
Date:   Thu Oct 29 14:02:59 2020 -0400

    c++: Tolerate empty initial args during normalization [PR97412]

    When normalizing the constraint-expression of a nested-requirement, we
    pass NULL_TREE as the initial template arguments for normalization, but
    tsubst_argument_pack is not prepared to handle a NULL_TREE args vector.
    This causes us to ICE when normalizing a variadic concept as part of a
    nested-requirement.

    This patch fixes the ICE by guarding the call to tsubst_template_args in
    normalize_concept_check appropriately.  This will also enable us to
    simplify many of the normalization routines to just pass NULL_TREE
    (instead of a set of generic template arguments) as the initial template
    arguments.

    gcc/cp/ChangeLog:

            PR c++/97412
            * constraint.cc (normalize_concept_check): Don't call
            tsubst_template_args when 'args' is NULL.

    gcc/testsuite/ChangeLog:

            PR c++/97412
            * g++.dg/cpp2a/concepts-variadic2.C: New test.

    (cherry picked from commit 5681668765e233735b4c5e6a305e73ae1f80a328)=