From patchwork Tue Sep 27 10:35:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Wakely X-Patchwork-Id: 1683146 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=2620:52:3:1:0:246e:9693:128c; helo=sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.a=rsa-sha256 header.s=default header.b=igBxK08U; dkim-atps=neutral Received: from sourceware.org (server2.sourceware.org [IPv6:2620:52:3:1:0:246e:9693:128c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4McGHs6Jctz1ypH for ; Tue, 27 Sep 2022 20:36:09 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id C3CAC3857BAB for ; Tue, 27 Sep 2022 10:36:07 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C3CAC3857BAB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1664274967; bh=fa10asfYCu6LBr6bh9vWZDlJKRcWOrwM+rioRFBwSRg=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=igBxK08UbFGekohw4Qb57eY7SKcGNHXBfO3sPC8j4G51M/g5Y4jPb44rsYTtqV1yL V76v4Ng3Uq3sks/U/Tpe/Trvw4Yr57fwhX+cccHJGYcoFZx1SEu9lqsIMEX+Ot4KUS 6Pvwr5/Aq7EmC7rijK7yjrygN506WhTnPc+Bav/0= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 0ACF638582B7 for ; Tue, 27 Sep 2022 10:35:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0ACF638582B7 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-39-D2fSTe8pOnqKfXbPIcBowQ-1; Tue, 27 Sep 2022 06:35:11 -0400 X-MC-Unique: D2fSTe8pOnqKfXbPIcBowQ-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3D9CB1C05159; Tue, 27 Sep 2022 10:35:11 +0000 (UTC) Received: from localhost (unknown [10.33.36.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id F19DC483EFB; Tue, 27 Sep 2022 10:35:10 +0000 (UTC) To: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org Subject: [PATCH] c++: Make __is_{, nothrow_}convertible SFINAE on access [PR107049] Date: Tue, 27 Sep 2022 11:35:10 +0100 Message-Id: <20220927103510.2321453-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.8 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Jonathan Wakely via Gcc-patches From: Jonathan Wakely Reply-To: Jonathan Wakely Cc: Marek Polacek Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" Tested powerpc64le-linux. OK for trunk? -- >8 -- The is_convertible built-ins should return false if the conversion fails an access check, not report an error. PR c++/107049 gcc/cp/ChangeLog: * method.cc (is_convertible_helper): Use access check sentinel. gcc/testsuite/ChangeLog: * g++.dg/ext/is_convertible4.C: New test. * g++.dg/ext/is_nothrow_convertible4.C: New test. libstdc++-v3/ChangeLog: * testsuite/20_util/is_convertible/requirements/access.cc: New test. --- gcc/cp/method.cc | 1 + gcc/testsuite/g++.dg/ext/is_convertible4.C | 33 +++++++++++++++++++ .../g++.dg/ext/is_nothrow_convertible4.C | 33 +++++++++++++++++++ .../is_convertible/requirements/access.cc | 18 ++++++++++ 4 files changed, 85 insertions(+) create mode 100644 gcc/testsuite/g++.dg/ext/is_convertible4.C create mode 100644 gcc/testsuite/g++.dg/ext/is_nothrow_convertible4.C create mode 100644 libstdc++-v3/testsuite/20_util/is_convertible/requirements/access.cc diff --git a/gcc/cp/method.cc b/gcc/cp/method.cc index 9f917f13134..55af5c43c18 100644 --- a/gcc/cp/method.cc +++ b/gcc/cp/method.cc @@ -2246,6 +2246,7 @@ is_convertible_helper (tree from, tree to) return integer_one_node; cp_unevaluated u; tree expr = build_stub_object (from); + deferring_access_check_sentinel acs (dk_no_deferred); return perform_implicit_conversion (to, expr, tf_none); } diff --git a/gcc/testsuite/g++.dg/ext/is_convertible4.C b/gcc/testsuite/g++.dg/ext/is_convertible4.C new file mode 100644 index 00000000000..8a7724c5852 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/is_convertible4.C @@ -0,0 +1,33 @@ +// PR c++/107049 +// { dg-do compile { target c++11 } } +// Failed access check should be a substitution failure, not an error. + +template +struct bool_constant { static constexpr bool value = B; }; + +template +struct is_convertible +: public bool_constant<__is_convertible(From, To)> +{ }; + +#if __cpp_variable_templates +template +constexpr bool is_convertible_v = __is_convertible(From, To); +#endif + +class Private +{ + operator int() const + { + static_assert( not is_convertible::value, "" ); +#if __cpp_variable_templates + static_assert( not is_convertible_v, "" ); +#endif + return 0; + } +}; + +static_assert( not is_convertible::value, "" ); +#if __cpp_variable_templates +static_assert( not is_convertible_v, "" ); +#endif diff --git a/gcc/testsuite/g++.dg/ext/is_nothrow_convertible4.C b/gcc/testsuite/g++.dg/ext/is_nothrow_convertible4.C new file mode 100644 index 00000000000..f81b5944ca2 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/is_nothrow_convertible4.C @@ -0,0 +1,33 @@ +// PR c++/107049 +// { dg-do compile { target c++11 } } +// Failed access check should be a substitution failure, not an error. + +template +struct bool_constant { static constexpr bool value = B; }; + +template +struct is_nt_convertible +: public bool_constant<__is_nothrow_convertible(From, To)> +{ }; + +#if __cpp_variable_templates +template +constexpr bool is_nt_convertible_v = __is_nothrow_convertible(From, To); +#endif + +class Private +{ + operator int() const + { + static_assert( not is_nt_convertible::value, "" ); +#if __cpp_variable_templates + static_assert( not is_nt_convertible_v, "" ); +#endif + return 0; + } +}; + +static_assert( not is_nt_convertible::value, "" ); +#if __cpp_variable_templates +static_assert( not is_nt_convertible_v, "" ); +#endif diff --git a/libstdc++-v3/testsuite/20_util/is_convertible/requirements/access.cc b/libstdc++-v3/testsuite/20_util/is_convertible/requirements/access.cc new file mode 100644 index 00000000000..04a8c525961 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/is_convertible/requirements/access.cc @@ -0,0 +1,18 @@ +// { dg-do compile { target c++11 } } +// PR c++/107049 + +#include + +class Private +{ + operator int() const + { + static_assert( not std::is_convertible::value, "" ); +#if __cpp_lib_type_trait_variable_templates + static_assert( not std::is_convertible_v, "" ); +#endif + return 0; + } +}; + +static_assert( not std::is_convertible::value, "" );