checkpatch: test multiple line block comment alignment

Warn when block comments are not aligned on the *

/*
 * block comment, no warning
 */

/*
  * block comment, emit warning
  */

Link: http://lkml.kernel.org/r/edb57bd330adfe024b95ec2a807d4aa7f0c8b112.1472261299.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 1c82b01..894f8c6 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2979,6 +2979,25 @@ sub process {
                             "Block comments use a trailing */ on a separate line\n" . $herecurr);
                }
 
+# Block comment * alignment
+               if ($prevline =~ /$;[ \t]*$/ &&                 #ends in comment
+                   (($prevrawline =~ /^\+.*?\/\*/ &&           #starting /*
+                     $prevrawline !~ /\*\/[ \t]*$/) ||         #no trailing */
+                    $prevrawline =~ /^\+[ \t]*\*/) &&          #starting *
+                   $rawline =~ /^\+[ \t]*\*/) {                #rawline *
+                       $prevrawline =~ m@^\+([ \t]*/?)\*@;
+                       my $oldindent = expand_tabs($1);
+                       $rawline =~ m@^\+([ \t]*)\*@;
+                       my $newindent = $1;
+                       my $test_comment = '^\\+' . "$;" x (length($newindent) + 1);
+                       $newindent = expand_tabs($newindent);
+                       if ($line =~ /$test_comment/ &&
+                           length($oldindent) ne length($newindent)) {
+                               WARN("BLOCK_COMMENT_STYLE",
+                                    "Block comments should align the * on each line\n" . $hereprev);
+                       }
+               }
+
 # check for missing blank lines after struct/union declarations
 # with exceptions for various attributes and macros
                if ($prevline =~ /^[\+ ]};?\s*$/ &&