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

Julia Lawall
2015-05-23T11:32:25Z

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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