From patchwork Tue Jun 2 18:57:53 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Palka X-Patchwork-Id: 136328 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from vm01.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id E233C4BA2E1C for ; Tue, 2 Jun 2026 18:58:38 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E233C4BA2E1C Authentication-Results: sourceware.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=PWG2WiPO 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 ESMTP id 1F1014BA2E04 for ; Tue, 2 Jun 2026 18:57:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1F1014BA2E04 Authentication-Results: sourceware.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 1F1014BA2E04 Authentication-Results: sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1780426678; cv=none; b=YXwRnUbqJx0GRIyfjcMyLWKlcbIX6FYEgPMsU8NG3/3gAPnrpINoZWx5qG0+OXuHO16/5BxPZgrWCMSUAL/MYdYIDF/14MEc1pSqxX5aqR8riHy6zz1VUoj1ZZ1xn772CPsGbU9FGidbILdaPk+tpFXMwA2AMr4YVi507pJAbNI= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1780426678; c=relaxed/simple; bh=riev49NwjhOvLzwwTLL/llzLz37gDtglvISn+dN2jlI=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=VTavarBv2YqVWMUXX8Pvf0dtsz9kTkNsloKUvCJUqigV4Szc13Q2c9I8kPG12P6JwSLgXmJXCkz6LiS5vpDXGV0S1n4yGsUBp5Pz92AzFCRQoUNjPTQRWOOdWEqEA0IdoEiwgdrS+8/5xHfODtjVg81O7EmfMsxZhz/XLDO/LkA= ARC-Authentication-Results: i=1; sourceware.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=PWG2WiPO DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1F1014BA2E04 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1780426677; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=GbcQ0vT3hptQRA0ToLFnS6JRLd8H9LzRwnrVI5+7QMg=; b=PWG2WiPOSo2NdAIOBkigvugGm12OXqe4oYWnqKBCM8G0Kd1C6+3B5Z3yoSFaZswh4XHaUV M43wpX6r0lZlR8w4d7GEWruYAEFWUoYnDPkVvOJAvvmD945xgLholKxMp+UQpJUSHkhkh5 F7iTkqjo5bWHkwbewaqnCBU6ri9v/AQ= Received: from mail-qk1-f197.google.com (mail-qk1-f197.google.com [209.85.222.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-563-5QheddriOnOUNN73PWNTSw-1; Tue, 02 Jun 2026 14:57:56 -0400 X-MC-Unique: 5QheddriOnOUNN73PWNTSw-1 X-Mimecast-MFC-AGG-ID: 5QheddriOnOUNN73PWNTSw_1780426676 Received: by mail-qk1-f197.google.com with SMTP id af79cd13be357-915827fb1a3so15646185a.2 for ; Tue, 02 Jun 2026 11:57:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780426676; x=1781031476; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=GbcQ0vT3hptQRA0ToLFnS6JRLd8H9LzRwnrVI5+7QMg=; b=DtgoUOOKAYJZGmcdRk9Z6iYcL91PC4Vo5uk2giE7FpEY/zuMPpXbrB9AM4gWdCsP9A ILxmjf5amHfUJPHrXY/czR6+c01jR744wxDhlRXJJxvfXCy2BkbcKiZKiC+UJKOavBIq 8qJtpNyzZfiYlc3rLmUrS7pJviffU5sHzFGUzLO+C0LBSpb4VAnRHBEahlIOI9qWsbhs 6kwGlfRbxfmPtXTDSstPyqrvR+LQmNwlskkrb1J0lx+KNrTny+gv9D7tABqbG8dIfZKS /AV3vaxYWFZtGT5tgDd4tL0mBQ0azm7h7vhyToJfRB7g2dmDoGucCatNzGK3+E602tAq xsQg== X-Gm-Message-State: AOJu0YzfkhAf2rihpvmrVM+JAgc4j30oL0Bc2vdP1vMrK9JxWtMPTOgE BTYmak9A5erzvTXJXkCVLwDzPGOHnHncGEunVD1LXeH/+NaZfA/lotokPLdxs/C59x8/6/5BEt/ AD6dvcMYzC4fvbFMPg0GDExAkHiCjf2wZyjdZdTQOPz1F7uDKLArUZKD8jXAHILgvI9kYmkmEmZ k6FOUNNemVUgBFSc2t0GTLta2K45moGTYuyd7EVFQf X-Gm-Gg: Acq92OElQGh4zDnPTV3W9MDPEfYGq3TDUgBDk12Ld5bvmZMoSdHXo3avD0BdzULPshs MfaDvSRwXzY+sjTLY60VWIjvetNZcj9TS7VnPdWrj147AahMxXY23iOYqMWpJT1jJjGgoQ4ZdQz UaAXqknbTjXfnujwBsxHAwuAd+WNu1m3XEaMzByloVnl1POJNqq1qLzZWzY5PC05CAosyMAeN2D Ivq+HVbX/OIblsW+gjX8kdv9bdRDmXihTFXNzU1SW4bH7h5aWprV7kBbBiD+sWtzDhGezIjGMh5 YxdBckL8NGnGO0Q9dWaW/SFciykynZugniOOzSfzGinXM5vSLQvxj/6eIB69inimDJ1jgAse8OO dPS4VZ85l2qW7x59ZRckkKZI= X-Received: by 2002:a05:620a:2846:b0:915:79da:a898 with SMTP id af79cd13be357-9158a3d6b55mr50497185a.8.1780426675644; Tue, 02 Jun 2026 11:57:55 -0700 (PDT) X-Received: by 2002:a05:620a:2846:b0:915:79da:a898 with SMTP id af79cd13be357-9158a3d6b55mr50490985a.8.1780426674910; Tue, 02 Jun 2026 11:57:54 -0700 (PDT) Received: from idea ([2600:4040:aa66:bf00:9e8e:99ff:fed1:71f]) by smtp.gmail.com with ESMTPSA id af79cd13be357-9158a009fb2sm29697385a.5.2026.06.02.11.57.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Jun 2026 11:57:54 -0700 (PDT) From: Patrick Palka To: gcc-patches@gcc.gnu.org Cc: jason@redhat.com, Patrick Palka Subject: [PATCH] c++: 'A op B' constraint-expression is unchecked [PR125490] Date: Tue, 2 Jun 2026 14:57:53 -0400 Message-ID: <20260602185753.1801445-1-ppalka@redhat.com> X-Mailer: git-send-email 2.54.0.rc1.54.g60f07c4f5c MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: -PHZ6w5GeEKHIrIyzwbCCVgqJsPGyHuRq5bDCCQ5p7o_1780426676 X-Mimecast-Originator: redhat.com content-type: text/plain; charset="US-ASCII"; x-default=true X-Spam-Status: No, score=-13.8 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_BLOCKED, SPF_HELO_PASS, SPF_NONE, TXREP, URIBL_BLOCKED shortcircuit=no autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gcc-patches-bounces~patchwork=sourceware.org@gcc.gnu.org Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk/16? -- >8 -- Here the nonsensical constraint-expression f() == 42 isn't getting rejected ahead of time ultimately because we pass no_toplevel_fold_p=true to cp_parser_binary_expression which makes it use build_min instead of build_x_binary_op to avoid undesirable folding/canonicalization for sake of OpenMP for loop parsing (r145014). But this certainly doesn't happen during templated parsing, and constraint-expressions are always templated, so we might as well pass no_toplevel_fold_p=false here. PR c++/125490 gcc/cp/ChangeLog: * parser.cc (cp_parser_constraint_expression): Pass no_toplevel_fold_p=false instead of =true to cp_parser_binary_expression. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-pr125490.C: New test. --- gcc/cp/parser.cc | 2 +- gcc/testsuite/g++.dg/cpp2a/concepts-pr125490.C | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-pr125490.C diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index b5c8c62118cc..c1797191b833 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -34761,7 +34761,7 @@ cp_parser_constraint_expression (cp_parser *parser) { processing_constraint_expression_sentinel parsing_constraint; ++processing_template_decl; - cp_expr expr = cp_parser_binary_expression (parser, false, true, + cp_expr expr = cp_parser_binary_expression (parser, false, false, PREC_NOT_OPERATOR, NULL); --processing_template_decl; if (check_for_bare_parameter_packs (expr)) diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr125490.C b/gcc/testsuite/g++.dg/cpp2a/concepts-pr125490.C new file mode 100644 index 000000000000..a33416b232d1 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr125490.C @@ -0,0 +1,10 @@ +// PR c++/125490 +// { dg-do compile { target c++20 } } + +void f(); + +template +concept C = f() == 42; // { dg-error "invalid operands" } + +template +concept D = requires { requires f() == 42; }; // { dg-error "invalid operands" }