checkpatch: add a multiple blank lines test

Multiple consecutive blank lines waste screen space.  Emit a --strict
only message with these blank lines.

Signed-off-by: Joe Perches <joe@perches.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 9e4ba9f..fad2116 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1642,6 +1642,8 @@ sub process {
 
        my $non_utf8_charset = 0;
 
+       my $last_blank_line = 0;
+
        our @report = ();
        our $cnt_lines = 0;
        our $cnt_error = 0;
@@ -2308,6 +2310,15 @@ sub process {
                            "Please use a blank line after function/struct/union/enum declarations\n" . $hereprev);
                }
 
+# check for multiple consecutive blank lines
+               if ($prevline =~ /^[\+ ]\s*$/ &&
+                   $line =~ /^\+\s*$/ &&
+                   $last_blank_line != ($linenr - 1)) {
+                       CHK("LINE_SPACING",
+                           "Please don't use multiple blank lines\n" . $hereprev);
+                       $last_blank_line = $linenr;
+               }
+
 # check for missing blank lines after declarations
                if ($sline =~ /^\+\s+\S/ &&                     #Not at char 1
                        # actual declarations