[PATCH v3] checkpatch: add fix option for MAINTAINERS_STYLE

[Aditya Srivastava]

Checkpatch expects entries in MAINTAINERS file in a specific order and
warns if the changes made do not follow the specified order.

E.g., running checkpatch on commit b33bc2b878e0 ("nexthop: Add entry to
MAINTAINERS") reports this warning:

WARNING: Misordered MAINTAINERS entry - list file patterns in
alphabetic order
+F:	include/uapi/linux/nexthop.h
+F:	include/net/netns/nexthop.h

Provide a simple fix by swapping the unordered lines, if both the lines
are additions (start with '+')

Signed-off-by: Aditya Srivastava <yashsri421@xxxxxxxxx>
---
Changes in v2:
modified commit message

Changes in v3:
add check if both the lines are additions(ie start with '+')

 scripts/checkpatch.pl | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2749f32dffe9..7ee3f05c354d 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3299,13 +3299,22 @@ sub process {
 					     "Unknown MAINTAINERS entry type: '$cur'\n" . $herecurr);
 				} else {
 					if ($previndex >= 0 && $curindex < $previndex) {
-						WARN("MAINTAINERS_STYLE",
-						     "Misordered MAINTAINERS entry - list '$cur:' before '$prev:'\n" . $hereprev);
+						if (WARN("MAINTAINERS_STYLE",
+							 "Misordered MAINTAINERS entry - list '$cur:' before '$prev:'\n" . $hereprev) &&
+						    $fix && $prevrawline =~ /^\+[A-Z]:/) {
+							# swap these lines
+							$fixed[$fixlinenr - 1] = $rawline;
+							$fixed[$fixlinenr] = $prevrawline;
+						}
 					} elsif ((($prev eq 'F' && $cur eq 'F') ||
 						  ($prev eq 'X' && $cur eq 'X')) &&
 						 ($prevval cmp $curval) > 0) {
-						WARN("MAINTAINERS_STYLE",
-						     "Misordered MAINTAINERS entry - list file patterns in alphabetic order\n" . $hereprev);
+						if (WARN("MAINTAINERS_STYLE",
+							 "Misordered MAINTAINERS entry - list file patterns in alphabetic order\n" . $hereprev) &&
+						    $fix && $prevrawline =~ /^\+[A-Z]:/) {
+							$fixed[$fixlinenr - 1] = $rawline;
+							$fixed[$fixlinenr] = $prevrawline;
+						}
 					}
 				}
 			}
-- 
2.17.1