[Linux-kernel-mentees] [PATCH v4] checkpatch: add fix option for LOGICAL_CONTINUATIONS

[Joe Perches]

On Sun, 2020-11-22 at 02:34 +0530, Aditya Srivastava wrote:
> Currently, checkpatch warns if logical continuations are placed at the
> start of a line and not at the end of previous line.
> 
> E.g., running checkpatch on commit 3485507fc272 ("staging:
> bcm2835-camera: Reduce length of enum names") reports:
> 
> CHECK:LOGICAL_CONTINUATIONS: Logical continuations should be on the
> previous line
> +	if (!ret
> +	    && camera_port ==
> 
> Provide a simple fix by adding logical operator at the end of previous
> line and removing from current line, if both the lines are additions
> (ie start with '+')
> 
> Signed-off-by: Aditya Srivastava <yashsri421 at gmail.com>
> ---
> changes in v2: quote $operator at substitution
> 
> changes in v3: add a check for previous line ending with comment;
> If so, insert $operator at the last non-comment, non-whitespace char of the previous line
> 
> changes in v4: improve the matching mechanism by matching line termination at comment or white space;
> insert the operator before comments (if any) separated by a whitespace;
> append the comment and its pre-whitespace after the inserted operator (if comment was present),
> ie if no comment was present nothing will be inserted after the operator

nak. I gave you a hint to the match string to use.

$prevline =~ /[\s$;]*$/

this matches either /* foo */ or // foo comment styles
(or optional blanks before EOL)

Try something like:
---
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index fab38b493cef..3c78cf0c219f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3434,8 +3434,15 @@ sub process {
 
 # check for && or || at the start of a line
 		if ($rawline =~ /^\+\s*(&&|\|\|)/) {
-			CHK("LOGICAL_CONTINUATIONS",
-			    "Logical continuations should be on the previous line\n" . $hereprev);
+			my $operator = $1;
+			if (CHK("LOGICAL_CONTINUATIONS",
+				"Logical continuations should be on the previous line\n" . $hereprev) &&
+			    $fix && $prevrawline =~ /^\+/) {
+				# add logical operator to the previous line, remove from current line
+				$prevline =~ /([\s$;]*$)/;
+				substr($fixed[$fixlinenr - 1], $-[0]) = " $operator" . substr($prevrawline, $-[0],$+[0]);
+				$fixed[$fixlinenr] =~ s/\Q$operator\E\s*//;
+			}
 		}
 
 # check indentation starts on a tab stop