Always emit original sources from scan_sources.

build/scan_sources.py

 #!/usr/bin/python
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 import re
 import sys
 
 """Header Scanner.
@@ skipping 240 matching lines @@
       includes = self.scanner.ScanFile(scan_name)
       # Add the directory of the current scanned file for resolving includes
       # while processing includes for this file.
       scan_dir = PathConverter().dirname(scan_name)
       added_dir = not self.resolver.AddOneDirectory(scan_dir)
       for include_file in includes:
         self.PushIfNew(include_file)
       if added_dir:
         self.resolver.RemoveOneDirectory(scan_dir)
       scan_name = self.PopIfAvail()
-    return sorted(self.added_set)
+    return self.added_set
 
 
 def DoMain(argv):
   """Entry point used by gyp's pymod_do_main feature."""
   global debug
 
   resolver = Resolver()
   files = []
 
   arg_type = ''
   for arg in argv:
     if arg in ['-I', '-S']:
       arg_type = arg
     elif arg == '-D':
       debug = True
     elif arg_type == '-I':
       # Skip generated include directories. These files may not exist and
       # there should be explicit dependency on the target that generates
       # these files.
       if arg.startswith('$!PRODUCT_DIR'):
         continue
       resolver.AddDirectories([arg])
     elif arg_type == '-S':
       files.append(arg)
 
   workQ = WorkQueue(resolver)
   for filename in files:
     workQ.PushIfNew(filename)
 
-  sorted_list = workQ.Run()
+  sources_set = workQ.Run()
+
+  # If any of the original files requested aren't found, add them anyway.
+  # This is so that source files that will be generated are still returned in
+  # the program output.
+  sources_set = sources_set.union(set(files))
+
+  sorted_list = sorted(sources_set)
   return '\n'.join(sorted_list) + '\n'
 
 
 def Main():
   result = DoMain(sys.argv[1:])
   sys.stdout.write(result)
 
 
 if __name__ == '__main__':
   Main()