Commit b5e8736a authored by Joe Perches's avatar Joe Perches Committed by Linus Torvalds
Browse files

checkpatch: improve blank line after declaration test 

Avoid multiple false positives by ignoring attributes.

Various attributes like volatile and ____cacheline_aligned_in_smp cause
checkpatch to emit invalid "Missing a blank line after declarations"
messages.

Use copies of $sline and $prevline, remove $Attribute and $Sparse, and use
the existing tests to avoid these false positives.

Miscellanea:

o Add volatile to $Attribute

This also reduces checkpatch runtime a bit by moving the indentation
comparison test to the start of the block to avoid multiple unnecessary
regex tests.

Link: https://lkml.kernel.org/r/9015fd00742bf4e5b824ad6d7fd7189530958548.camel@perches.com


Signed-off-by: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4945cca2

scripts/checkpatch.pl

+29 −23
Original line number Diff line number Diff line
@@ -382,6 +382,7 @@ our $InitAttribute = qr{$InitAttributeData|$InitAttributeConst|$InitAttributeIni 
# We need \b after 'init' otherwise 'initconst' will cause a false positive in a check

our $Attribute	= qr{

			const|

			volatile|

			__percpu|

			__nocast|

			__safe|
@@ -3776,45 +3777,50 @@ sub process { 
		}



# check for missing blank lines after declarations

		if ($sline =~ /^\+\s+\S/ &&			#Not at char 1

			# actual declarations

		    ($prevline =~ /^\+\s+$Declare\s*$Ident\s*[=,;:\[]/ ||

# (declarations must have the same indentation and not be at the start of line)

		if (($prevline =~ /\+(\s+)\S/) && $sline =~ /^\+$1\S/) {

			# use temporaries

			my $sl = $sline;

			my $pl = $prevline;

			# remove $Attribute/$Sparse uses to simplify comparisons

			$sl =~ s/\b(?:$Attribute|$Sparse)\b//g;

			$pl =~ s/\b(?:$Attribute|$Sparse)\b//g;

			if (($pl =~ /^\+\s+$Declare\s*$Ident\s*[=,;:\[]/ ||

			# function pointer declarations

		     $prevline =~ /^\+\s+$Declare\s*\(\s*\*\s*$Ident\s*\)\s*[=,;:\[\(]/ ||

			     $pl =~ /^\+\s+$Declare\s*\(\s*\*\s*$Ident\s*\)\s*[=,;:\[\(]/ ||

			# foo bar; where foo is some local typedef or #define

		     $prevline =~ /^\+\s+$Ident(?:\s+|\s*\*\s*)$Ident\s*[=,;\[]/ ||

			     $pl =~ /^\+\s+$Ident(?:\s+|\s*\*\s*)$Ident\s*[=,;\[]/ ||

			# known declaration macros

		     $prevline =~ /^\+\s+$declaration_macros/) &&

			     $pl =~ /^\+\s+$declaration_macros/) &&

			# for "else if" which can look like "$Ident $Ident"

		    !($prevline =~ /^\+\s+$c90_Keywords\b/ ||

			    !($pl =~ /^\+\s+$c90_Keywords\b/ ||

			# other possible extensions of declaration lines

		      $prevline =~ /(?:$Compare|$Assignment|$Operators)\s*$/ ||

			      $pl =~ /(?:$Compare|$Assignment|$Operators)\s*$/ ||

			# not starting a section or a macro "\" extended line

		      $prevline =~ /(?:\{\s*|\\)$/) &&

			      $pl =~ /(?:\{\s*|\\)$/) &&

			# looks like a declaration

		    !($sline =~ /^\+\s+$Declare\s*$Ident\s*[=,;:\[]/ ||

			    !($sl =~ /^\+\s+$Declare\s*$Ident\s*[=,;:\[]/ ||

			# function pointer declarations

		      $sline =~ /^\+\s+$Declare\s*\(\s*\*\s*$Ident\s*\)\s*[=,;:\[\(]/ ||

			      $sl =~ /^\+\s+$Declare\s*\(\s*\*\s*$Ident\s*\)\s*[=,;:\[\(]/ ||

			# foo bar; where foo is some local typedef or #define

		      $sline =~ /^\+\s+$Ident(?:\s+|\s*\*\s*)$Ident\s*[=,;\[]/ ||

			      $sl =~ /^\+\s+$Ident(?:\s+|\s*\*\s*)$Ident\s*[=,;\[]/ ||

			# known declaration macros

		      $sline =~ /^\+\s+$declaration_macros/ ||

			      $sl =~ /^\+\s+$declaration_macros/ ||

			# start of struct or union or enum

		      $sline =~ /^\+\s+(?:static\s+)?(?:const\s+)?(?:union|struct|enum|typedef)\b/ ||

			      $sl =~ /^\+\s+(?:static\s+)?(?:const\s+)?(?:union|struct|enum|typedef)\b/ ||

			# start or end of block or continuation of declaration

		      $sline =~ /^\+\s+(?:$|[\{\}\.\#\"\?\:\(\[])/ ||

			      $sl =~ /^\+\s+(?:$|[\{\}\.\#\"\?\:\(\[])/ ||

			# bitfield continuation

		      $sline =~ /^\+\s+$Ident\s*:\s*\d+\s*[,;]/ ||

			      $sl =~ /^\+\s+$Ident\s*:\s*\d+\s*[,;]/ ||

			# other possible extensions of declaration lines

		      $sline =~ /^\+\s+\(?\s*(?:$Compare|$Assignment|$Operators)/) &&

			# indentation of previous and current line are the same

		    (($prevline =~ /\+(\s+)\S/) && $sline =~ /^\+$1\S/)) {

			      $sl =~ /^\+\s+\(?\s*(?:$Compare|$Assignment|$Operators)/)) {

				if (WARN("LINE_SPACING",

					 "Missing a blank line after declarations\n" . $hereprev) &&

				    $fix) {

					fix_insert_line($fixlinenr, "\+");

				}

			}

		}



# check for spaces at the beginning of a line.

# Exceptions: