From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dedi548.your-server.de (dedi548.your-server.de [85.10.215.148]) by sourceware.org (Postfix) with ESMTPS id 450293857809; Wed, 23 Mar 2022 16:52:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 450293857809 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=embedded-brains.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=embedded-brains.de Received: from sslproxy02.your-server.de ([78.47.166.47]) by dedi548.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1nX4DR-0002pT-Ff; Wed, 23 Mar 2022 17:52:09 +0100 Received: from [82.100.198.138] (helo=mail.embedded-brains.de) by sslproxy02.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nX4DR-000Ahp-CH; Wed, 23 Mar 2022 17:52:09 +0100 Received: from localhost (localhost [127.0.0.1]) by mail.embedded-brains.de (Postfix) with ESMTP id 0902C4800A3; Wed, 23 Mar 2022 17:52:09 +0100 (CET) Received: from mail.embedded-brains.de ([127.0.0.1]) by localhost (zimbra.eb.localhost [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id nE1eVgJoyIvq; Wed, 23 Mar 2022 17:52:08 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by mail.embedded-brains.de (Postfix) with ESMTP id B9DFD480134; Wed, 23 Mar 2022 17:52:08 +0100 (CET) X-Virus-Scanned: amavisd-new at zimbra.eb.localhost Received: from mail.embedded-brains.de ([127.0.0.1]) by localhost (zimbra.eb.localhost [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id XVoH2OHYRN-E; Wed, 23 Mar 2022 17:52:08 +0100 (CET) Received: from [10.10.171.14] (unknown [10.10.171.14]) by mail.embedded-brains.de (Postfix) with ESMTPSA id 75FF94800A3; Wed, 23 Mar 2022 17:52:08 +0100 (CET) Message-ID: Date: Wed, 23 Mar 2022 17:52:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.2 Subject: Re: [PATCH v2] Document that the 'access' and 'nonnull' attributes are independent Content-Language: en-US To: Martin Sebor , David Malcolm , gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org References: <20220323130117.525495-1-dmalcolm@redhat.com> <16768247-eacc-100c-fded-9aa42833867f@gmail.com> From: Sebastian Huber In-Reply-To: <16768247-eacc-100c-fded-9aa42833867f@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Authenticated-Sender: smtp-embedded@poldinet.de X-Virus-Scanned: Clear (ClamAV 0.103.5/26490/Wed Mar 23 09:44:38 2022) X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, NICE_REPLY_A, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE 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@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Mar 2022 16:52:13 -0000 On 23/03/2022 17:31, Martin Sebor via Gcc-patches wrote: >=20 > The concern is that the constraints implied by atttributes access and > nonnull are independent of each other.=C2=A0 I would suggest to documen= t > that without talking about dereferencing because that's not implied > by either of them.=C2=A0 E.g., something like this (feel free to tweak = it > as you see fit): >=20 > =C2=A0 Note that the @code{access} attribute doesn't imply the same > =C2=A0 constraint as attribute @code{nonnull} (@pxref{Attribute nonnul= l}). > =C2=A0 The latter attribute should be used to annotate arguments that = must > =C2=A0 never be null, regardless of the value of the size argument. I would not give an advice on using the nonnull attribute here. This=20 attribute could have pretty dangerous effects in the function definition=20 (removal of null pointer checks). --=20 embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.huber@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht M=C3=BCnchen Registernummer: HRB 157899 Vertretungsberechtigte Gesch=C3=A4ftsf=C3=BChrer: Peter Rasmussen, Thomas= D=C3=B6rfler Unsere Datenschutzerkl=C3=A4rung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/