linux: In diff mode, also print files with init function that calls 0 initializers.

tools/linux/dump-static-initializers.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Dump functions called by static intializers in a Linux Release binary.
 
 Usage example:
   tools/linux/dump-static-intializers.py out/Release/chrome
 
@@ skipping 196 matching lines @@
           note = NOTES[ref]
         elif ref.endswith('_2eproto()'):
           note = 'protocol compiler bug: crbug.com/105626'
 
         if note:
           ref_output.append('%s [%s]' % (ref, note))
         else:
           ref_output.append(ref)
 
     if opts.diffable:
-      print '\n'.join('# ' + qualified_filename + ' ' + r for r in ref_output)
+      if ref_output:
+        print '\n'.join('# ' + qualified_filename + ' ' + r for r in ref_output)
+      else:
+        print '# %s: (empty initializer list)' % qualified_filename
     else:
       print '%s (initializer offset 0x%x size 0x%x)' % (qualified_filename,
                                                         addr, size)
       print ''.join('  %s\n' % r for r in ref_output)
 
   if opts.diffable:
     print '#',
   print 'Found %d static initializers in %d files.' % (initializer_count,
                                                        file_count)
 
   return 0
 
 if '__main__' == __name__:
   sys.exit(main())