Re: [PATCH v3] checkpatch: add fix option for LOGICAL_CONTINUATIONS

[Joe Perches]

On Sat, 2020-11-21 at 23:43 +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@xxxxxxxxx>
> ---
> changes in v2: quote $operator at substitution
> 
> changes in v3: add a check for previous line ending with comment;
> If so, insert $operator at the last non-comment, non-whitespace char of the previous line
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -3553,8 +3553,22 @@ sub process {
>  
> 
>  # check for && or || at the start of a line
>  		if ($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 && $prevrawline =~ /^\+/) {
> +				# add logical operator to the previous line, remove from current line
> +				# if last line ends with a comment
> +				if ($prevrawline =~ /(\/\/.*)$/) {

Not the best mechanism.

check $prevline =~ /[\s$;]*$/ and use the starting position of any
match as the insertion point, and then insert the operator and
matching bits from the $prevrawline.

I'll leave that as an exercise for you for now.

> +					my $comment = trim($1);
> +					$fixed[$fixlinenr - 1] =~ s/\s*$comment//;
> +					$fixed[$fixlinenr - 1] .= " $operator $comment";