From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13796C4321A for ; Sat, 29 Jun 2019 07:49:26 +0000 (UTC) Received: from isis.lip6.fr (isis.lip6.fr [132.227.60.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AD680214AF for ; Sat, 29 Jun 2019 07:49:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD680214AF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lip6.fr Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=cocci-bounces@systeme.lip6.fr Received: from systeme.lip6.fr (systeme.lip6.fr [132.227.104.7]) by isis.lip6.fr (8.15.2/8.15.2) with ESMTP id x5T7n8Gj025748; Sat, 29 Jun 2019 09:49:08 +0200 (CEST) Received: from systeme.lip6.fr (systeme.lip6.fr [127.0.0.1]) by systeme.lip6.fr (Postfix) with ESMTP id CD2E07775; Sat, 29 Jun 2019 09:49:08 +0200 (CEST) Received: from isis.lip6.fr (isis.lip6.fr [132.227.60.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by systeme.lip6.fr (Postfix) with ESMTPS id 1B4AB7770 for ; Sat, 29 Jun 2019 09:49:07 +0200 (CEST) Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by isis.lip6.fr (8.15.2/8.15.2) with ESMTP id x5T7n5iD018924 for ; Sat, 29 Jun 2019 09:49:05 +0200 (CEST) X-IronPort-AV: E=Sophos;i="5.63,430,1557180000"; d="scan'208";a="311853501" Received: from abo-12-105-68.mrs.modulonet.fr (HELO hadrien) ([85.68.105.12]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jun 2019 09:49:04 +0200 Date: Sat, 29 Jun 2019 09:49:04 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@hadrien To: Markus Elfring In-Reply-To: <76641efc-2e3e-8664-03b2-4eb82f01c275@web.de> Message-ID: References: <1561690732-20694-1-git-send-email-wen.yang99@zte.com.cn> <904b9362-cd01-ffc9-600b-0c48848617a0@web.de> <76641efc-2e3e-8664-03b2-4eb82f01c275@web.de> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-766857525-1561794544=:2579" X-Greylist: Sender IP whitelisted, Sender e-mail whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Sat, 29 Jun 2019 09:49:09 +0200 (CEST) X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Sat, 29 Jun 2019 09:49:05 +0200 (CEST) X-Scanned-By: MIMEDefang 2.78 on 132.227.60.2 X-Scanned-By: MIMEDefang 2.78 on 132.227.60.2 Cc: Yi Wang , Michal Marek , Nicolas Palix , linux-kernel@vger.kernel.org, Wen Yang , cocci@systeme.lip6.fr Subject: Re: [Cocci] [v2] coccinelle: semantic code search for missing of_node_put X-BeenThere: cocci@systeme.lip6.fr X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cocci-bounces@systeme.lip6.fr Errors-To: cocci-bounces@systeme.lip6.fr This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-766857525-1561794544=:2579 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT On Sat, 29 Jun 2019, Markus Elfring wrote: > >> +if (x == NULL || ...) S > >> +... when != e = (T)x > >> + when != true x == NULL > > > > I wonder if this code exclusion specification is really required > > after a null pointer was checked before. > > I would like to add another view for this implementation detail. > > The when constraint can express a software desire which can be reasonable > to some degree. You would like to be sure that a null pointer will not occur > after a corresponding check succeeded. He wants to be sure that the true branch through a NULL pointer check is not taken. > * But I feel unsure about the circumstances under which the Coccinelle software > can determine this aspect actually. > > * I find that it can eventually make sense only after the content of > the local variable (which is identified by “x”) was modified. > Thus I would find the exclusion of assignments more useful at this place. I assume that it was added because it was found to be useful. Please actually try things out before declaring them to be useless. julia --8323329-766857525-1561794544=:2579 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci --8323329-766857525-1561794544=:2579--