checkpatch: warn when a patch doesn't have a description

Potential patches should have a commit description.  Emit a warning when
there isn't one.

[akpm@linux-foundation.org: s/else if/elsif/]
Link: http://lkml.kernel.org/r/1b099f4d8373aa583a17011992676bf0f3f09eee.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 b5eade9..25adf98 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2253,6 +2253,7 @@ sub process {
        my $in_header_lines = $file ? 0 : 1;
        my $in_commit_log = 0;          #Scanning lines before patch
        my $has_commit_log = 0;         #Encountered lines before patch
+       my $commit_log_lines = 0;       #Number of commit log lines
        my $commit_log_possible_stack_dump = 0;
        my $commit_log_long_line = 0;
        my $commit_log_has_diff = 0;
@@ -2510,6 +2511,18 @@ sub process {
 
                $cnt_lines++ if ($realcnt != 0);
 
+# Verify the existence of a commit log if appropriate
+# 2 is used because a $signature is counted in $commit_log_lines
+               if ($in_commit_log) {
+                       if ($line !~ /^\s*$/) {
+                               $commit_log_lines++;    #could be a $signature
+                       }
+               } elsif ($has_commit_log && $commit_log_lines < 2) {
+                       WARN("COMMIT_MESSAGE",
+                            "Missing commit description - Add an appropriate one\n");
+                       $commit_log_lines = 2;  #warn only once
+               }
+
 # Check if the commit log has what seems like a diff which can confuse patch
                if ($in_commit_log && !$commit_log_has_diff &&
                    (($line =~ m@^\s+diff\b.*a/[\w/]+@ &&