[PATCH] checkpatch: Categorize some long line length checks

Joe Perches
2015-05-23T06:28:20Z

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 */
}

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.