patman: Add a call to get_maintainer.pl if it exists

For Linux the best way to figure out where to send a patch is with the
"get_maintainer.pl" script.  Add support for calling it from patman.
Support is added unconditionally for "scripts/get_maintainer.pl" in
case it is helpful for any other projects.

Signed-off-by: Doug Anderson <dianders@chromium.org>

tools/patman/get_maintainer.py

@@ -0,0 +1,63 @@
+# Copyright (c) 2012 The Chromium OS Authors.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+import command
+import gitutil
+import os
+
+def FindGetMaintainer():
+    """Look for the get_maintainer.pl script.
+
+    Returns:
+        If the script is found we'll return a path to it; else None.
+    """
+    try_list = [
+        os.path.join(gitutil.GetTopLevel(), 'scripts'),
+        ]
+    # Look in the list
+    for path in try_list:
+        fname = os.path.join(path, 'get_maintainer.pl')
+        if os.path.isfile(fname):
+            return fname
+
+    return None
+
+def GetMaintainer(fname, verbose=False):
+    """Run get_maintainer.pl on a file if we find it.
+
+    We look for get_maintainer.pl in the 'scripts' directory at the top of
+    git.  If we find it we'll run it.  If we don't find get_maintainer.pl
+    then we fail silently.
+
+    Args:
+        fname: Path to the patch file to run get_maintainer.pl on.
+
+    Returns:
+        A list of email addresses to CC to.
+    """
+    get_maintainer = FindGetMaintainer()
+    if not get_maintainer:
+        if verbose:
+            print "WARNING: Couldn't find get_maintainer.pl"
+        return []
+
+    stdout = command.Output(get_maintainer, '--norolestats', fname)
+    return stdout.splitlines()