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 7B6403995097; Fri,  7 Jun 2024 16:14:02 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7B6403995097
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1717776842;
	bh=37FI2zdef2Z2KwnEz4Cuyn5dyLReHz8ClRxDP+DPgtM=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=OmcyZBJTc40I/196v75q3SXVz8LmB0RorC3VzJygVoPzn0W8DmIUkkPgJMz5zc784
	 jBUnPV2cZqKk+SntK1UJ3A1C6LA0Wuitep62X7eMvSALbOuEE5olMVij5AY7tnfj5C
	 5smBfU0MWatboZnvJDE89qzjkV4UcH7dmtckTS10=
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/115378] [14/15 Regression] ICE with lambda function as a
 default template argument with variadic templates in some cases
Date: Fri, 07 Jun 2024 16:14:02 +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: 15.0
X-Bugzilla-Keywords: c++-lambda, ice-on-valid-code
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: 14.2
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-115378-4-jZ6KOzBUnO@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-115378-4@http.gcc.gnu.org/bugzilla/>
References: <bug-115378-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D115378

--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:5c761395402a730535983a5e49ef1775561ebc61

commit r15-1103-g5c761395402a730535983a5e49ef1775561ebc61
Author: Patrick Palka <ppalka@redhat.com>
Date:   Fri Jun 7 12:12:30 2024 -0400

    c++: lambda in pack expansion [PR115378]

    Here find_parameter_packs_r is incorrectly treating the 'auto' return
    type of a lambda as a parameter pack due to Concepts-TS specific logic
    added in r6-4517, leading to confusion later when expanding the pattern.

    Since we intend on removing Concepts TS support soon anyway, this patch
    fixes this by restricting the problematic logic with flag_concepts_ts.
    Doing so revealed that add_capture was relying on this logic to set
    TEMPLATE_TYPE_PARAMETER_PACK for the 'auto' type of an pack expansion
    init-capture, which we now need to do explicitly.

            PR c++/115378

    gcc/cp/ChangeLog:

            * lambda.cc (lambda_capture_field_type): Set
            TEMPLATE_TYPE_PARAMETER_PACK on the auto type of an init-capture
            pack expansion.
            * pt.cc (find_parameter_packs_r) <case TEMPLATE_TYPE_PARM>:
            Restrict TEMPLATE_TYPE_PARAMETER_PACK promotion with
            flag_concepts_ts.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp1y/decltype-auto-103497.C: Adjust expected diagnost=
ic.
            * g++.dg/template/pr95672.C: Likewise.
            * g++.dg/cpp2a/lambda-targ5.C: New test.

    Reviewed-by: Jason Merrill <jason@redhat.com>=