An interactive tool to help find owners covering current change list.

owners.py

Index: owners.py
diff --git a/owners.py b/owners.py
index cc667beea3c575f527470d9bd25269b4e95c6bae..d4a1dc7ca3137b4dea88713df9bfaa88f05fed37 100644
--- a/owners.py
+++ b/owners.py
@@ -111,6 +111,9 @@ class Database(object):
     # Mapping of paths to authorized owners.
     self.owners_for = {}
 
+    # Mapping reviewers to the most recent comment in the OWNERS files.
+    self.comments = {}
+
     # Set of paths that stop us from looking above them for owners.
     # (This is implicitly true for the root directory).
     self.stop_looking = set([''])
@@ -195,13 +198,23 @@ class Database(object):
     owners_path = self.os_path.join(self.root, dirpath, 'OWNERS')
     if not self.os_path.exists(owners_path):
       return
-
+    comment = ""
+    last_line_is_comment = False
     lineno = 0
     for line in self.fopen(owners_path):
       lineno += 1
       line = line.strip()
-      if line.startswith('#') or line == '':
+      if line.startswith('#'):
+        if last_line_is_comment:
+          comment += " " + line[1:].strip()
+        else:
+          comment = line[1:].strip()
+        last_line_is_comment = True
         continue
+      if line == '':
+        continue
+      last_line_is_comment = False
+
       if line == 'set noparent':
         self.stop_looking.add(dirpath)
         continue
@@ -218,19 +231,23 @@ class Database(object):
         baselines = self.glob(full_glob_string)
         for baseline in (self.os_path.relpath(b, self.root) for b in baselines):
           self._add_entry(baseline, directive, "per-file line",
-                          owners_path, lineno)
+                          owners_path, lineno, comment)
         continue
 
       if line.startswith('set '):
         raise SyntaxErrorInOwnersFile(owners_path, lineno,
             'unknown option: "%s"' % line[4:].strip())
 
-      self._add_entry(dirpath, line, "line", owners_path, lineno)
+      self._add_entry(dirpath, line, "line", owners_path, lineno, comment)
 
-  def _add_entry(self, path, directive, line_type, owners_path, lineno):
+  def _add_entry(self, path, directive,
+                 line_type, owners_path, lineno, comment):
     if directive == "set noparent":
       self.stop_looking.add(path)
     elif self.email_regexp.match(directive) or directive == EVERYONE:
+      if directive not in self.comments:
+        self.comments[directive] = {}
+      self.comments[directive][self.os_path.dirname(path)] = comment
       self.owned_by.setdefault(directive, set()).add(path)
       self.owners_for.setdefault(path, set()).add(directive)
     else: