From patchwork Wed Dec 1 15:16:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Polacek X-Patchwork-Id: 1562229 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.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=X9MQQgbm; dkim-atps=neutral Authentication-Results: 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=) 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 RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4J42vD2mRJz9sCD for ; Thu, 2 Dec 2021 02:24:40 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id C9E79385781D for ; Wed, 1 Dec 2021 15:24:37 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C9E79385781D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1638372277; bh=u8/ozn7u0lhnzLHaIx7fIIsogwDjfDyXyjLPnXTktWk=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=X9MQQgbmMjth0GB5UbXTKqJpfeobP/9n580NNz2R3rGi0vp95WHB+Vus602rIzPXO +3RegLuOCIIbhjWG3b1pyVObeN1Y96RJ4QgZxxm5Rz8SBDyyr8fM0wCffhk/bzi6Js etcSo3wmG8m+8QXOl7bg2Ynw+p4HzS69e/tPYIjY= 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 60D14385C410 for ; Wed, 1 Dec 2021 15:16:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 60D14385C410 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-351-JrtY9s7MPLG12L4mGjVn4g-1; Wed, 01 Dec 2021 10:16:23 -0500 X-MC-Unique: JrtY9s7MPLG12L4mGjVn4g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D9F1D81CCB4 for ; Wed, 1 Dec 2021 15:16:22 +0000 (UTC) Received: from pdp-11.redhat.com (unknown [10.22.17.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 847E960C0F; Wed, 1 Dec 2021 15:16:22 +0000 (UTC) To: GCC Patches , Jason Merrill Subject: [PATCH] c++: Handle auto(x) in parameter-declaration-clause [PR103401] Date: Wed, 1 Dec 2021 10:16:14 -0500 Message-Id: <20211201151614.1497902-1-polacek@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-14.2 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, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Marek Polacek via Gcc-patches From: Marek Polacek Reply-To: Marek Polacek Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" In C++23, auto(x) is valid, so decltype(auto(x)) should also be valid, so void f(decltype(auto(0))); should be just as void f(int); but currently, everytime we see 'auto' in a parameter-declaration-clause, we try to synthesize_implicit_template_parm for it, creating a new template parameter list. The code above actually has us calling s_i_t_p twice; once from cp_parser_decltype_expr -> cp_parser_postfix_expression which fails and then again from cp_parser_decltype_expr -> cp_parser_expression. So it looks like we have f and we accept ill-formed code. So we need to be more careful about synthesizing the implicit template parameter. cp_parser_postfix_expression looked like a sensible place. The r11-1913 change is OK: we need to make sure that we see '(auto)' after decltype to go ahead with 'decltype(auto)'. Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? PR c++/103401 gcc/cp/ChangeLog: * parser.c (cp_parser_postfix_expression): Set auto_is_implicit_function_template_parm_p when parsing a postfix expression. gcc/testsuite/ChangeLog: * g++.dg/cpp23/auto-fncast7.C: New test. * g++.dg/cpp23/auto-fncast8.C: New test. --- gcc/cp/parser.c | 2 ++ gcc/testsuite/g++.dg/cpp23/auto-fncast7.C | 9 ++++++++ gcc/testsuite/g++.dg/cpp23/auto-fncast8.C | 28 +++++++++++++++++++++++ 3 files changed, 39 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp23/auto-fncast7.C create mode 100644 gcc/testsuite/g++.dg/cpp23/auto-fncast8.C base-commit: e5440bc08e07fd491dcccd47e1b86a5985ee117c diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 55e6a1a8b3a..c43b180f888 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -7508,6 +7508,8 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p, looking at a functional cast. We could also be looking at an id-expression. So, we try the functional cast, and if that doesn't work we fall back to the primary-expression. */ + auto cleanup = make_temp_override + (parser->auto_is_implicit_function_template_parm_p, false); cp_parser_parse_tentatively (parser); /* Look for the simple-type-specifier. */ ++parser->prevent_constrained_type_specifiers; diff --git a/gcc/testsuite/g++.dg/cpp23/auto-fncast7.C b/gcc/testsuite/g++.dg/cpp23/auto-fncast7.C new file mode 100644 index 00000000000..763164f3e5b --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/auto-fncast7.C @@ -0,0 +1,9 @@ +// PR c++/103401 +// { dg-do compile { target c++23 } } + +void f(decltype(auto(0))) { } + +int main() +{ + f(0); // { dg-error "no matching function" } +} diff --git a/gcc/testsuite/g++.dg/cpp23/auto-fncast8.C b/gcc/testsuite/g++.dg/cpp23/auto-fncast8.C new file mode 100644 index 00000000000..760827a5d6e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/auto-fncast8.C @@ -0,0 +1,28 @@ +// PR c++/103401 +// { dg-do compile { target c++23 } } + +void f1 (decltype(auto(0))); +void f2 (decltype(auto{0})); +void f3 (int = auto(42)); +void f4 (int = auto{42}); +void f5 (decltype(auto(0)) = auto(42)); +void f6 (auto (x)); +void f7 (int[auto(10)]); +void f8 (int[auto{10}]); + +void +g () +{ + f1 (1); + f2 (1); + f3 (); + f3 (1); + f4 (); + f4 (1); + f5 (); + f5 (1); + f6 ('a'); + int a[10]; + f7 (&a[0]); + f8 (&a[0]); +}