Re: [PATCH] checkpatch: Categorize some long line length checks

[Julia Lawall <julia.lawall@lip6.fr>]

On Fri, 22 May 2015, Joe Perches wrote:

> Many lines of code extend beyond the maximum line length.
> Some of these are possibly justified by use type.
>
> For instance:
>
> structure definitions where comments are added per member like
>
> struct foo {
> 	type member;		/* some long description */

I'm not super fond of the comment one.  Perhaps people could express
themselves more concisely, or put the details elsewhere?

julia

> }
>
> And lines that don't fit the typical logging message style
> where a string constant is used like:
>
> 	SOME_MACRO(args, "Some long string");
>
> Categorize these long line types so that checkpatch can use
> a command-line --ignore=<type> option to avoid emitting some
> long line warnings.
>
> Comment the code a bit better too.
>
> Signed-off-by: Joe Perches <joe@perches.com>
> ---
>  scripts/checkpatch.pl | 54 +++++++++++++++++++++++++++++++++++++++++----------
>  1 file changed, 44 insertions(+), 10 deletions(-)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 89b1df4..99ce3f4 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2510,16 +2510,50 @@ sub process {
>  # check we are in a valid source file if not then ignore this hunk
>  		next if ($realfile !~ /\.(h|c|s|S|pl|sh|dtsi|dts)$/);
>
> -#line length limit
> -		if ($line =~ /^\+/ && $prevrawline !~ /\/\*\*/ &&
> -		    $rawline !~ /^.\s*\*\s*\@$Ident\s/ &&
> -		    !($line =~ /^\+\s*$logFunctions\s*\(\s*(?:(KERN_\S+\s*|[^"]*))?$String\s*(?:|,|\)\s*;)\s*$/ ||
> -		      $line =~ /^\+\s*$String\s*(?:\s*|,|\)\s*;)\s*$/ ||
> -		      $line =~ /^\+\s*#\s*define\s+\w+\s+$String$/) &&
> -		    $length > $max_line_length)
> -		{
> -			WARN("LONG_LINE",
> -			     "line over $max_line_length characters\n" . $herecurr);
> +# line length limit (with some exclusions)
> +#
> +# There are 3 different line length message types:
> +# LONG_LINE_COMMENT	a comment starts before but extends beyond length
> +# LONG_LINE_STRING	a string starts before but extends beyond length
> +# LONG_LINE		all other lines longer than $max_line_length
> +#
> +# if LONG_LINE is ignored, the other 2 types are also ignored
> +#
> +# LONG_LINE has a few types of lines that may extend beyong $max_line_length
> +#	kernel-doc arguments
> +#	logging functions like pr_info that end in a string
> +#	lines with a single string
> +#	#defines that are a single string
> +
> +		if ($length > $max_line_length) {
> +			my $msg_type = "";
> +
> +			# comment starts before $max_line_length
> +			if ($line =~ /([\s$;]+)$/ &&
> +			    length(expand_tabs(substr($line, 1, length($line) - length($1) - 1))) <= $max_line_length) {
> +				$msg_type = "LONG_LINE_COMMENT"
> +
> +			# quoted string starts before $max_line_length
> +			} elsif ($sline =~ /\s*($String(?:\s*(?:\\|,\s*|\)\s*;\s*))?)$/ &&
> +				 length(expand_tabs(substr($line, 1, length($line) - length($1) - 1))) <= $max_line_length) {
> +				$msg_type = "LONG_LINE_STRING"
> +
> +			# general long longs
> +				# exclude kernel-doc argument lines
> +			} elsif ($line =~ /^\+/ && $prevrawline !~ /\/\*\*/ &&
> +				 $rawline !~ /^.\s*\*\s*\@$Ident\s/ &&
> +				# exclude logging functions that end in a string
> +				 !($line =~ /^\+\s*$logFunctions\s*\(\s*(?:(KERN_\S+\s*|[^"]*))?$String\s*(?:|,|\)\s*;)\s*$/ ||
> +				# exclude lines with only strings
> +				   $line =~ /^\+\s*$String\s*(?:\s*|,|\)\s*;)\s*$/ ||
> +				# exclude #defines with only strings
> +				   $line =~ /^\+\s*#\s*define\s+\w+\s+$String$/)) {
> +				$msg_type = "LONG_LINE";
> +			}
> +			if ($msg_type ne "" && show_type("LONG_LINE")) {
> +				WARN($msg_type,
> +				     "line over $max_line_length characters\n" . $herecurr);
> +			}
>  		}
>
>  # check for adding lines without a newline.
>
>
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