[PATCH v2] checkpatch: add fix option for ASSIGNMENT_CONTINUATIONS

[PATCH v2] checkpatch: add fix option for ASSIGNMENT_CONTINUATIONS

[Aditya Srivastava]

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 '+')

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

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index c9aaaa443265..e0cb36369b2f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3542,8 +3542,14 @@ 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/$operator\s*//;
+			}
 		}
 
 # check for && or || at the start of a line
-- 
2.17.1

Re: [PATCH v2] checkpatch: add fix option for ASSIGNMENT_CONTINUATIONS

[Joe Perches]

On Tue, 2020-11-17 at 16:22 +0530, Aditya Srivastava wrote:
> Currently, checkpatch warns us if an assignment operator is placed
> at the start of a line and not at the end of previous line.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -3542,8 +3542,14 @@ 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/$operator\s*//;

As $operator could be a division, I believe it needs to be quoted.