[PATCH v4] checkpatch: add fix option for ASSIGNMENT_CONTINUATIONS

From: Aditya Srivastava <yashsri421@gmail.com>
To: joe@perches.com
Cc: yashsri421@gmail.com, lukas.bulwahn@gmail.com,
	linux-kernel-mentees@lists.linuxfoundation.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v4] checkpatch: add fix option for ASSIGNMENT_CONTINUATIONS
Date: Sat, 21 Nov 2020 17:34:07 +0530	[thread overview]
Message-ID: <20201121120407.22942-1-yashsri421@gmail.com> (raw)
In-Reply-To: <1d7692d0-359f-6b6a-32d4-1627ebd8b100@gmail.com>

Currently, checkpatch warns us if an assignment operator is placed
at the start of a line and not at the end of previous line.

E.g., running checkpatch on commit 8195b1396ec8 ("hv_netvsc: fix
deadlock on hotplug") reports:

CHECK: Assignment operator '=' should be on the previous line
+	struct netvsc_device *nvdev
+		= container_of(w, struct netvsc_device, subchan_work);

Provide a simple fix by appending assignment operator to the previous
line and removing from the current line, if both the lines are additions
(ie start with '+')

Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
---
Changes in v2:
add check if both the lines are additions (ie start with '+')

Changes in v3:
quote $operator; test with division assignment operator ('/=')

Changes in v4:
fix incorrect use of quote

 scripts/checkpatch.pl | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2749f32dffe9..d4c8d42cb13e 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3533,8 +3533,14 @@ sub process {
 
 # check for assignments on the start of a line
 		if ($sline =~ /^\+\s+($Assignment)[^=]/) {
-			CHK("ASSIGNMENT_CONTINUATIONS",
-			    "Assignment operator '$1' should be on the previous line\n" . $hereprev);
+			my $operator = $1;
+			if (CHK("ASSIGNMENT_CONTINUATIONS",
+				"Assignment operator '$1' should be on the previous line\n" . $hereprev) &&
+			    $fix && $prevrawline =~ /^\+/) {
+				# add assignment operator to the previous line, remove from current line
+				$fixed[$fixlinenr - 1] .= " $operator";
+				$fixed[$fixlinenr] =~ s/\Q$operator\E\s*//;
+			}
 		}
 
 # check for && or || at the start of a line
-- 
2.17.1

