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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 40ACBC64E7B for ; Sat, 28 Nov 2020 21:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07F2C208CA for ; Sat, 28 Nov 2020 21:55:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="H14FXKXp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404241AbgK1VzP (ORCPT ); Sat, 28 Nov 2020 16:55:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387635AbgK1UBf (ORCPT ); Sat, 28 Nov 2020 15:01:35 -0500 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 987D1C0613D1 for ; Sat, 28 Nov 2020 12:00:55 -0800 (PST) Received: by mail-pf1-x444.google.com with SMTP id n137so7410869pfd.3 for ; Sat, 28 Nov 2020 12:00:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nZU8qf4YgD6zzI9n1LIw7CWJC/0Je3ODzydn48QlHPM=; b=H14FXKXpkIVQ0pwwBAhxN7Byw/nmqxb22FlD21mBVlQDOrB/YrD2CnNvGNfDv/+tT/ mkd5VaVKhDu1x4TYr8nNOZSCbN/jSRhhEmBaM7Cpgybo7/QzS2AofQRNvyN5Cc29b9zf P5QvM+5HgiBw/rg3ONHdLcMso5lkWI+7V9qQTletNZQUX0C5nmjkCNY38tAUh7TW7tbA qGtSfzeDa0QJzdy90pWfgvgMArF11rqXuydRBJcdxXZOFYO4ftU3zRdhqRCAFx/wTlmO Uar1GCfIM6nw+mnG2bpbXnAXl7nxiuoPdUuNqtLaxtOYVKnfaxTjHhGLrb/e2iHeYbX9 g/cQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nZU8qf4YgD6zzI9n1LIw7CWJC/0Je3ODzydn48QlHPM=; b=GMvp03I6Yk/ItH3mFaRtHbBXmle8VtLbxd/+9DsXeI2OzLl0syylFGF+wkvleKDXA4 9Rxb8KVX+GzUorS4jsjuq/EmTj1xzP8O/Sz4Ab3dP9hipCpEi7LjWA00ZQIcmLi92PYQ e3I3Lo0f6gsWs45gLv/I2ikOojM6+dLewIBtfjQ31S2PLmS5s3Gmx2yaLqu9bZBpOxGc DN7csx84YRkNjbnH7iXvJvCuhteIlzlgUyJWKwGQNoYwvW+qAo1xbX1yKWMGNR3TCdpr oflkWQthkjP7evKZNWButDmBVWVuvn2EzsrbxUpHML1sHYQSK3lXHRiFZvWYhHdpp2ND D39w== X-Gm-Message-State: AOAM533IS8kF9RDbHbXIdTkizIvlGBq1RLh0ps+UZPT9QjRijzX34tbU zUCQDw4s7iwYLtSPR5GG6LI= X-Google-Smtp-Source: ABdhPJzGfT6TnNIkWw4wmxuh5ospbXqG8HO5n37D6R3i5y+O/21sL+ABmSlEBKf85z/xi/THPCpC+A== X-Received: by 2002:a17:90b:2344:: with SMTP id ms4mr3584506pjb.43.1606593654833; Sat, 28 Nov 2020 12:00:54 -0800 (PST) Received: from localhost.localdomain ([2405:201:9004:60e2:4a86:2299:c009:477b]) by smtp.gmail.com with ESMTPSA id o2sm2946450pgq.63.2020.11.28.12.00.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 28 Nov 2020 12:00:53 -0800 (PST) From: Dwaipayan Ray To: joe@perches.com Cc: linux-kernel-mentees@lists.linuxfoundation.org, dwaipayanray1@gmail.com, linux-kernel@vger.kernel.org, lukas.bulwahn@gmail.com Subject: [PATCH v4] checkpatch: add warning for unnecessary use of %h[xudi] and %hh[xudi] Date: Sun, 29 Nov 2020 01:30:46 +0530 Message-Id: <20201128200046.78739-1-dwaipayanray1@gmail.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Modifiers %h and %hh should never be used. Commit cbacb5ab0aa0 ("docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]") specifies that: "Standard integer promotion is already done and %hx and %hhx is useless so do not encourage the use of %hh[xudi] or %h[xudi]." "The "h" and "hh" things should never be used. The only reason for them being used if you have an "int", but you want to print it out as a "char" (and honestly, that is a really bad reason, you'd be better off just using a proper cast to make the code more obvious)." Add a new check to emit a warning on finding an unneeded use of %h or %hh modifier. Also add a fix option to the check. Link: https://lore.kernel.org/lkml/4910042649a4f3ab22fac93191b8c1fa0a2e17c3.camel@perches.com/ Suggested-by: Joe Perches Suggested-by: Lukas Bulwahn Signed-off-by: Dwaipayan Ray --- Changes in v4: - Change warning type and message - Use $stat_real and calculate line offset during matches - fix option now works for any patch line - # was added to format block to match %#06hh Changes in v3: - Change warning message - Fix regex match to include capture group - Warn on every unnecesary use of %h on a line - Add fix option when the format line matches current line Changes in v2: - Use $logFunctions instead of the manual list. - Relocate the check to after logging continuations check. - Remove perl_version_ok check scripts/checkpatch.pl | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 7dc094445d83..3c86ea737e9c 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -6027,6 +6027,28 @@ sub process { "Avoid logging continuation uses where feasible\n" . $herecurr); } +# check for unnecessary use of %h[xudi] and %hh[xudi] in logging functions + if (defined $stat && + $line =~ /\b$logFunctions\s*\(/ && + index($stat, '"') >= 0) { + my $lc = $stat =~ tr@\n@@; + $lc = $lc + $linenr; + my $stat_real = get_stat_real($linenr, $lc); + pos($stat_real) = index($stat_real, '"'); + while ($stat_real =~ /[^\"%]*(%[\#\d\.\*\-]*(h+)[idux])/g) { + my $pspec = $1; + my $h = $2; + my $lineoff = substr($stat_real, 0, $-[1]) =~ tr@\n@@; + if (WARN("UNNECESSARY_MODIFIER", + "Integer promotion: Using '$h' in '$pspec' is unnecessary\n" . "$here\n$stat_real\n") && + $fix && $fixed[$fixlinenr + $lineoff] =~ /^\+/) { + my $nspec = $pspec; + $nspec =~ s/h//g; + $fixed[$fixlinenr + $lineoff] =~ s/\Q$pspec\E/$nspec/; + } + } + } + # check for mask then right shift without a parentheses if ($perl_version_ok && $line =~ /$LvalOrFunc\s*\&\s*($LvalOrFunc)\s*>>/ && -- 2.27.0