From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 973D83858C5E for ; Fri, 11 Nov 2022 07:43:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 973D83858C5E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668152590; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type; bh=m79dWaLafBrNQRYgb9irlXlQzFANYFR+KAfAnJPAiKo=; b=QI+PXhXYzqMG0l7JDzNrCB6XQ32EPbksWLt5LxFIKmTV4ek8jixq7fKrHMNbwr6TY5hZMo Ke3xgOw+oeFNGFFfk/O6XawQ2YKTXcK6UreUOq9ctk1TrkwNciswOAZPhyxJ80UpWWh8Nx fq72O3FiVwRffttOHT6+S9+K2daKuNQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-156-3UMWzAOZMqy9hz3KbKMcxA-1; Fri, 11 Nov 2022 02:43:06 -0500 X-MC-Unique: 3UMWzAOZMqy9hz3KbKMcxA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A7C448027EB for ; Fri, 11 Nov 2022 07:43:06 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 69CB740C83C5; Fri, 11 Nov 2022 07:43:06 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 2AB7h4jq3247628 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 11 Nov 2022 08:43:04 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 2AB7h3Cf3247627; Fri, 11 Nov 2022 08:43:03 +0100 Date: Fri, 11 Nov 2022 08:43:03 +0100 From: Jakub Jelinek To: Jason Merrill Cc: gcc-patches@gcc.gnu.org Subject: [PATCH] c++: Implement CWG 2654 - Un-deprecation of compound volatile assignments Message-ID: Reply-To: Jakub Jelinek MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi! Again, because stage1 close is near, posting the following patch to implement CWG 2654. Ok for trunk if it passes bootstrap/regtest and is voted into C++23 and C++20 as a DR? 2022-11-11 Jakub Jelinek * typeck.cc (cp_build_modify_expr): Implement CWG 2654 - Un-deprecation of compound volatile assignments. Remove -Wvolatile warning about compound volatile assignments. * g++.dg/cpp2a/volatile1.C (fn2, fn3, racoon): Adjust expected diagnostics. * g++.dg/cpp2a/volatile3.C (fn2, fn3, racoon): Likewise. * g++.dg/cpp2a/volatile5.C (f): Likewise. --- gcc/cp/typeck.cc.jj 2022-11-09 11:22:42.617628059 +0100 +++ gcc/cp/typeck.cc 2022-11-10 23:19:00.394228067 +0100 @@ -9513,19 +9513,6 @@ cp_build_modify_expr (location_t loc, tr && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype))) || MAYBE_CLASS_TYPE_P (lhstype))); - /* An expression of the form E1 op= E2. [expr.ass] says: - "Such expressions are deprecated if E1 has volatile-qualified - type and op is not one of the bitwise operators |, &, ^." - We warn here rather than in cp_genericize_r because - for compound assignments we are supposed to warn even if the - assignment is a discarded-value expression. */ - if (modifycode != BIT_AND_EXPR - && modifycode != BIT_IOR_EXPR - && modifycode != BIT_XOR_EXPR - && (TREE_THIS_VOLATILE (lhs) || CP_TYPE_VOLATILE_P (lhstype))) - warning_at (loc, OPT_Wvolatile, - "compound assignment with %-qualified left " - "operand is deprecated"); /* Preevaluate the RHS to make sure its evaluation is complete before the lvalue-to-rvalue conversion of the LHS: --- gcc/testsuite/g++.dg/cpp2a/volatile1.C.jj 2022-08-16 13:15:22.739043862 +0200 +++ gcc/testsuite/g++.dg/cpp2a/volatile1.C 2022-11-10 23:23:18.949717772 +0100 @@ -74,17 +74,17 @@ fn2 () decltype(i = vi = 42) x3 = i; // Compound assignments. - vi += i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } - vi -= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } - vi %= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } + vi += i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } + vi -= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } + vi %= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi ^= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi |= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi &= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } - vi /= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } + vi /= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi = vi += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } vi += vi = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } i *= vi; - decltype(vi -= 42) x2 = vi; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } + decltype(vi -= 42) x2 = vi; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } // Structured bindings. int a[] = { 10, 5 }; @@ -107,12 +107,12 @@ fn3 () volatile U u; u.c = 42; i = u.c = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } - u.c += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } + u.c += 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } volatile T t; t.a = 3; j = t.a = 3; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } - t.a += 3; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } + t.a += 3; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } volatile int *src = &i; *src; // No assignment, don't warn. @@ -135,7 +135,7 @@ void raccoon () volatile T t, u; t = 42; u = t = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } - t += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } } + t += 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } t &= 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } } --- gcc/testsuite/g++.dg/cpp2a/volatile3.C.jj 2022-08-16 13:15:22.753043682 +0200 +++ gcc/testsuite/g++.dg/cpp2a/volatile3.C 2022-11-10 23:24:24.781823998 +0100 @@ -75,17 +75,17 @@ fn2 () decltype(i = vi = 42) x3 = i; // Compound assignments. - vi += i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } - vi -= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } - vi %= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } + vi += i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } + vi -= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } + vi %= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi ^= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi |= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi &= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } - vi /= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } + vi /= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } vi = vi += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } vi += vi = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } i *= vi; - decltype(vi -= 42) x2 = vi; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } + decltype(vi -= 42) x2 = vi; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } // Structured bindings. int a[] = { 10, 5 }; @@ -108,12 +108,12 @@ fn3 () volatile U u; u.c = 42; i = u.c = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } - u.c += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } + u.c += 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } volatile T t; t.a = 3; j = t.a = 3; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } - t.a += 3; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } + t.a += 3; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } volatile int *src = &i; *src; // No assignment, don't warn. @@ -136,7 +136,7 @@ void raccoon () volatile T t, u; t = 42; u = t = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } - t += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" } + t += 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } t &= 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" } } --- gcc/testsuite/g++.dg/cpp2a/volatile5.C.jj 2022-08-16 13:15:22.778043359 +0200 +++ gcc/testsuite/g++.dg/cpp2a/volatile5.C 2022-11-10 23:25:07.445244776 +0100 @@ -7,7 +7,7 @@ void f (bool b) { (b ? x : y) = 1; - (b ? x : y) += 1; // { dg-warning "compound assignment" "" { target c++20 } } + (b ? x : y) += 1; // { dg-bogus "compound assignment" } z = (b ? x : y) = 1; // { dg-warning "using value of assignment" "" { target c++20 } } ((z = 2) ? x : y) = 1; // { dg-warning "using value of assignment" "" { target c++20 } } (b ? (x = 2) : y) = 1; // { dg-warning "using value of assignment" "" { target c++20 } } Jakub