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=-8.1 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,PLING_QUERY,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 BEF32C43331 for ; Fri, 6 Sep 2019 20:20:02 +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 1BD76207FC for ; Fri, 6 Sep 2019 20:20:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BD76207FC 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 x86KJZls004321; Fri, 6 Sep 2019 22:19:35 +0200 (CEST) Received: from systeme.lip6.fr (systeme.lip6.fr [127.0.0.1]) by systeme.lip6.fr (Postfix) with ESMTP id 209F27797; Fri, 6 Sep 2019 22:19:35 +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 72EA77793 for ; Fri, 6 Sep 2019 22:19:31 +0200 (CEST) Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by isis.lip6.fr (8.15.2/8.15.2) with ESMTP id x86KJL3o004369 for ; Fri, 6 Sep 2019 22:19:21 +0200 (CEST) X-IronPort-AV: E=Sophos;i="5.64,474,1559512800"; d="scan'208";a="400644695" Received: from abo-12-105-68.mrs.modulonet.fr (HELO hadrien) ([85.68.105.12]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Sep 2019 22:19:21 +0200 Date: Fri, 6 Sep 2019 22:19:21 +0200 (CEST) From: Julia Lawall X-X-Sender: jll@hadrien To: Denis Efremov In-Reply-To: <20190829171013.22956-1-efremov@linux.com> Message-ID: References: <20190825130536.14683-1-efremov@linux.com> <20190829171013.22956-1-efremov@linux.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 X-Greylist: Sender IP whitelisted, Sender e-mail whitelisted, not delayed by milter-greylist-4.4.3 (isis.lip6.fr [132.227.60.2]); Fri, 06 Sep 2019 22:19:35 +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]); Fri, 06 Sep 2019 22:19:21 +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: Michal Marek , Rasmus Villemoes , Nicolas Palix , linux-kernel@vger.kernel.org, Markus Elfring , Joe Perches , cocci@systeme.lip6.fr Subject: Re: [Cocci] [PATCH v2] scripts: coccinelle: check for !(un)?likely usage 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: cocci-bounces@systeme.lip6.fr Errors-To: cocci-bounces@systeme.lip6.fr On Thu, 29 Aug 2019, Denis Efremov wrote: > This patch adds coccinelle script for detecting !likely and > !unlikely usage. These notations are confusing. It's better > to replace !likely(x) with unlikely(!x) and !unlikely(x) with > likely(!x) for readability. > > The rule transforms !likely(x) to unlikely(!x) based on this logic: > !likely(x) iff > !__builtin_expect(!!(x), 1) iff > __builtin_expect(!!!(x), 0) iff > unlikely(!x) > > For !unlikely(x) to likely(!x): > !unlikely(x) iff > !__builtin_expect(!!(x), 0) iff > __builtin_expect(!!!(x), 1) iff > likely(!x) > > Signed-off-by: Denis Efremov > Cc: Julia Lawall > Cc: Gilles Muller > Cc: Nicolas Palix > Cc: Michal Marek > Cc: Markus Elfring > Cc: Joe Perches > Cc: Rasmus Villemoes Acked-by: Julia Lawall A small improvement though would be to improve the explicit dependency of the last four python rules on r1 and r2. Those rules won't execute unless the inherited metavariable has a value, which makes the same dependency. julia > --- > scripts/coccinelle/misc/neg_unlikely.cocci | 89 ++++++++++++++++++++++ > 1 file changed, 89 insertions(+) > create mode 100644 scripts/coccinelle/misc/neg_unlikely.cocci > > diff --git a/scripts/coccinelle/misc/neg_unlikely.cocci b/scripts/coccinelle/misc/neg_unlikely.cocci > new file mode 100644 > index 000000000000..9aac0a7ff042 > --- /dev/null > +++ b/scripts/coccinelle/misc/neg_unlikely.cocci > @@ -0,0 +1,89 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/// Use unlikely(!x) instead of !likely(x) and vice versa. > +/// Notations !unlikely(x) and !likely(x) are confusing. > +// > +// Confidence: High > +// Copyright: (C) 2019 Denis Efremov, ISPRAS. > +// Options: --no-includes --include-headers > + > +virtual patch > +virtual context > +virtual org > +virtual report > + > +//---------------------------------------------------------- > +// For context mode > +//---------------------------------------------------------- > + > +@depends on context disable unlikely@ > +expression E; > +@@ > + > +*! \( likely \| unlikely \) (E) > + > +//---------------------------------------------------------- > +// For patch mode > +//---------------------------------------------------------- > + > +@depends on patch disable unlikely@ > +expression E; > +@@ > + > +( > +-!likely(!E) > ++unlikely(E) > +| > +-!likely(E) > ++unlikely(!E) > +| > +-!unlikely(!E) > ++likely(E) > +| > +-!unlikely(E) > ++likely(!E) > +) > + > +//---------------------------------------------------------- > +// For org and report mode > +//---------------------------------------------------------- > + > +@r1 depends on (org || report) disable unlikely@ > +expression E; > +position p; > +@@ > + > +!likely@p(E) > + > +@r2 depends on (org || report) disable unlikely@ > +expression E; > +position p; > +@@ > + > +!unlikely@p(E) > + > +@script:python depends on org && r1@ > +p << r1.p; > +@@ > + > +coccilib.org.print_todo(p[0], "unlikely(!x) is more readable than !likely(x)") > + > +@script:python depends on org && r2@ > +p << r2.p; > +@@ > + > +coccilib.org.print_todo(p[0], "likely(!x) is more readable than !unlikely(x)") > + > +@script:python depends on report && r1@ > +p << r1.p; > +@@ > + > +coccilib.report.print_report(p[0], > + "unlikely(!x) is more readable than !likely(x)") > + > +@script:python depends on report && r2@ > +p << r2.p; > +@@ > + > +coccilib.report.print_report(p[0], > + "likely(!x) is more readable than !unlikely(x)") > + > -- > 2.21.0 > > _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci