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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 8F4A4C63798 for ; Sat, 28 Nov 2020 21:55:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AB6220857 for ; Sat, 28 Nov 2020 21:55:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404280AbgK1Vza (ORCPT ); Sat, 28 Nov 2020 16:55:30 -0500 Received: from smtprelay0088.hostedemail.com ([216.40.44.88]:46520 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387655AbgK1UJ2 (ORCPT ); Sat, 28 Nov 2020 15:09:28 -0500 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay07.hostedemail.com (Postfix) with ESMTP id 14B37181D341E; Sat, 28 Nov 2020 20:08:47 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: spade01_050cf5f27393 X-Filterd-Recvd-Size: 4048 Received: from XPS-9350.home (unknown [47.151.128.180]) (Authenticated sender: joe@perches.com) by omf03.hostedemail.com (Postfix) with ESMTPA; Sat, 28 Nov 2020 20:08:45 +0000 (UTC) Message-ID: <60fdeb69192219bfce0a0caf0ec2ea043b82100f.camel@perches.com> Subject: Re: [PATCH v4] checkpatch: add warning for unnecessary use of %h[xudi] and %hh[xudi] From: Joe Perches To: Dwaipayan Ray , Andrew Morton Cc: linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org, lukas.bulwahn@gmail.com Date: Sat, 28 Nov 2020 12:08:44 -0800 In-Reply-To: <20201128200046.78739-1-dwaipayanray1@gmail.com> References: <20201128200046.78739-1-dwaipayanray1@gmail.com> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.38.1-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2020-11-29 at 01:30 +0530, Dwaipayan Ray wrote: > Modifiers %h and %hh should never be used. Seems OK, thanks. Acked-by: Joe Perches > 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*>>/ &&