From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754199AbaKMS5k (ORCPT ); Thu, 13 Nov 2014 13:57:40 -0500 Received: from smtprelay0172.hostedemail.com ([216.40.44.172]:57774 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753906AbaKMS5j (ORCPT ); Thu, 13 Nov 2014 13:57:39 -0500 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::,RULES_HIT:41:355:379:541:800:960:973:982:988:989:1260:1277:1311:1313:1314:1345:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2197:2199:2393:2553:2559:2562:2828:3138:3139:3140:3141:3142:3352:3653:3865:3866:3867:3868:3870:3872:4250:5007:6119:6261:8957:10004:10400:10848:11026:11232:11473:11658:11914:12043:12517:12519:12555:13019:13069:13095:13311:13357:14394:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: toy75_83180cd3482a X-Filterd-Recvd-Size: 2034 Message-ID: <1415905054.4223.7.camel@perches.com> Subject: [PATCH] checkpatch: add --strict "pointer comparison to NULL" test From: Joe Perches To: Andrew Morton Cc: Dan Carpenter , Greg KH , LKML Date: Thu, 13 Nov 2014 10:57:34 -0800 Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.12.7-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It seems there are more and more uses of "if (!ptr)" in preference to "if (ptr == NULL)" so add a --strict test to emit a message when using the latter form. This also finds (ptr != NULL). Fix it too if desired. Signed-off-by: Joe Perches --- Seeing no objections, so submitting it. scripts/checkpatch.pl | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 24d6702..d4e08bc 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -4490,6 +4490,20 @@ sub process { "Possible precedence defect with mask then right shift - may need parentheses\n" . $herecurr); } +# check for pointer comparisons to NULL + if ($^V && $^V ge 5.10.0) { + while ($line =~ /\b$LvalOrFunc\s*(==|\!=)\s*NULL\b/g) { + my $val = $1; + my $equal = "!"; + $equal = "" if ($4 eq "!="); + if (CHK("COMPARISON_TO_NULL", + "Comparison to NULL could be written \"${equal}${val}\"\n" . $herecurr) && + $fix) { + $fixed[$fixlinenr] =~ s/\b\Q$val\E\s*(?:==|\!=)\s*NULL\b/$equal$val/; + } + } + } + # check for bad placement of section $InitAttribute (e.g.: __initdata) if ($line =~ /(\b$InitAttribute\b)/) { my $attr = $1;