msvs: error out on actions w/o inputs

pylib/gyp/generator/msvs.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import copy
 import ntpath
 import os
 import posixpath
 import re
 import subprocess
@@ skipping 1256 matching lines @@
     The sources will be relative to the gyp file.
   """
   sources = set()
   _AddNormalizedSources(sources, spec.get('sources', []))
   excluded_sources = set()
   # Add in the gyp file.
   sources.add(gyp_file)
 
   # Add in 'action' inputs and outputs.
   for a in spec.get('actions', []):
-    inputs = a.get('inputs', [])
+    inputs = a['inputs']
     inputs = [_NormalizedSource(i) for i in inputs]
     # Add all inputs to sources and excluded sources.
     inputs = set(inputs)
     sources.update(inputs)
     excluded_sources.update(inputs)
     if int(a.get('process_outputs_as_sources', False)):
       _AddNormalizedSources(sources, a.get('outputs', []))
   # Add in 'copies' inputs and outputs.
   for cpy in spec.get('copies', []):
     _AddNormalizedSources(sources, cpy.get('files', []))
@@ skipping 1829 matching lines @@
   action_spec.extend(
       # TODO(jeanluc) 'Document' for all or just if as_sources?
       [['FileType', 'Document'],
        ['Command', command],
        ['Message', description],
        ['Outputs', outputs]
       ])
   if additional_inputs:
     action_spec.append(['AdditionalInputs', additional_inputs])
   actions_spec.append(action_spec)