Print a grit debugging hint to stdout when a parse exception occurs

tools/grit/grit/grd_reader.py

 #!/usr/bin/python2.4
-# Copyright (c) 2010 The Chromium Authors. All rights reserved.
+# Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 '''Class for reading GRD files into memory, without processing them.
 '''
 
 import os.path
 import types
 import xml.sax
 import xml.sax.handler
@@ skipping 114 matching lines @@
     grit.exception.Parsing
   '''
   handler = GrdContentHandler(stop_after=stop_after, debug=debug,
                               defines=defines)
   try:
     xml.sax.parse(filename_or_stream, handler)
   except StopParsingException:
     assert stop_after
     pass
   except:
+    if not debug:
+      print "parse exception: run GRIT with the -x flag to debug .grd problems"
     raise
 
   if not flexible_root or hasattr(handler.root, 'SetOwnDir'):
     assert isinstance(filename_or_stream, types.StringType) or dir != None
     if not dir:
       dir = util.dirname(filename_or_stream)
       if len(dir) == 0:
         dir = '.'
     # Fix up the base_dir so it is relative to the input file.
     handler.root.SetOwnDir(dir)
 
   # Assign first ids to the nodes that don't have them.
   if isinstance(handler.root, misc.GritNode) and first_id_filename != '':
     handler.root.AssignFirstIds(filename_or_stream, first_id_filename, defines)
 
   return handler.root
 
 
 if __name__ == '__main__':
   util.ChangeStdoutEncoding()
   print unicode(Parse(sys.argv[1]))