From patchwork Tue Jan 18 10:10:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Jelinek X-Patchwork-Id: 50147 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 52FAF385801C for ; Tue, 18 Jan 2022 10:11:09 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 52FAF385801C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1642500669; bh=xwFdpNooWAbR+CNcfpjYY5WwS5dQMECEVqjoRj2mH+k=; h=Date:To:Subject:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=k4bj35wv4i1PUmbdF+Wg5v92IHNyF9hWdQiEzc1oAPxq+4TtFveECf9Cs3bEDJJ14 JXZOTtKQvve2tRecTg1pgkjkRJX4LAG5lWsuWzR/DvM4uBiPk0DHrXVMVECH+eYy9E E8dwtUostm4G/WjPlarV00RB2Lxvw/+rtUNTNfps= 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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 717653858D39 for ; Tue, 18 Jan 2022 10:10:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 717653858D39 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-336-SBqtRElGPgKyKwSlFMjNNg-1; Tue, 18 Jan 2022 05:10:32 -0500 X-MC-Unique: SBqtRElGPgKyKwSlFMjNNg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 21AC084DA41 for ; Tue, 18 Jan 2022 10:10:32 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.40.192.74]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ADF6B70D59; Tue, 18 Jan 2022 10:10:07 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.16.1/8.16.1) with ESMTPS id 20IAA5jT3067066 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 18 Jan 2022 11:10:05 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.16.1/8.16.1/Submit) id 20IAA5dZ3067065; Tue, 18 Jan 2022 11:10:05 +0100 Date: Tue, 18 Jan 2022 11:10:05 +0100 To: Jason Merrill Subject: [PATCH] c++: Fix handling of temporaries with consteval ctors and non-trivial dtors [PR104055] Message-ID: <20220118101005.GV2646553@tucnak> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, 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: Jakub Jelinek via Gcc-patches From: Jakub Jelinek Reply-To: Jakub Jelinek Cc: gcc-patches@gcc.gnu.org Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Hi! The following testcase is miscompiled. We see the constructor is immediate, in build_over_call we trigger: if (obj_arg && is_dummy_object (obj_arg)) { call = build_cplus_new (DECL_CONTEXT (fndecl), call, complain); obj_arg = NULL_TREE; } which makes call a TARGET_EXPR with the dtor in TARGET_EXPR_CLEANUP, but then call cxx_constant_value on it. In cxx_eval_outermost_constant_expr it triggers the: else if (TREE_CODE (t) != CONSTRUCTOR) { r = get_target_expr_sfinae (r, tf_warning_or_error | tf_no_cleanup); TREE_CONSTANT (r) = true; } which wraps the CONSTRUCTOR r into a new TARGET_EXPR, but one without dtors (I think we need e.g. the TREE_CONSTANT for the callers), and finally build_over_call uses that. The following patch fixes that by reusing the earlier TARGET_EXPR and overwriting TARGET_EXPR_INITIAL in it; I think the TARGET_EXPR_SLOT can't appear in the TARGET_EXPR_INITIAL, because the CONSTRUCTOR has been built already before get_target_expr_sfinae has been called and addresses of an automatic var aren't constant expression. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2022-01-18 Jakub Jelinek PR c++/104055 * call.c (build_over_call): If in a call to consteval ctor call is a TARGET_EXPR with cleanups and cxx_constant_value returns a different TARGET_EXPR, reuse the original TARGET_EXPR with the new TARGET_EXPR_INITIAL. * g++.dg/cpp2a/consteval27.C: New test. Jakub --- gcc/cp/call.c.jj 2022-01-11 23:11:22.049294946 +0100 +++ gcc/cp/call.c 2022-01-17 11:48:50.272044412 +0100 @@ -9935,7 +9935,14 @@ build_over_call (struct z_candidate *can obj_arg = TREE_OPERAND (addr, 0); } } - call = cxx_constant_value (call, obj_arg); + tree cst_call = cxx_constant_value (call, obj_arg); + if (call != cst_call + && TREE_CODE (call) == TARGET_EXPR + && TARGET_EXPR_CLEANUP (call) + && TREE_CODE (cst_call) == TARGET_EXPR) + TARGET_EXPR_INITIAL (call) = TARGET_EXPR_INITIAL (cst_call); + else + call = cst_call; if (obj_arg && !error_operand_p (call)) call = build2 (INIT_EXPR, void_type_node, obj_arg, call); call = convert_from_reference (call); --- gcc/testsuite/g++.dg/cpp2a/consteval27.C.jj 2022-01-17 11:54:09.656459199 +0100 +++ gcc/testsuite/g++.dg/cpp2a/consteval27.C 2022-01-17 11:54:37.035068677 +0100 @@ -0,0 +1,18 @@ +// PR c++/104055 +// { dg-do run { target c++20 } } + +int g; + +struct A { + ~A () { if (a != 17 || b != 26) __builtin_abort (); g = 42; } + consteval A () : a (17), b (26) {} + int a, b; +}; + +int +main () +{ + A{}; + if (g != 42) + __builtin_abort (); +}