Try to fix defines containing '#' characters with cl.exe.

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 676 matching lines @@
     print >> sys.stderr, ('Warning: MSVS may misinterpret the odd number of ' +
                           'quotes in ' + s)
   return s
 
 
 def _EscapeCppDefineForMSVS(s):
   """Escapes a CPP define so that it will reach the compiler unaltered."""
   s = _EscapeEnvironmentVariableExpansion(s)
   s = _EscapeCommandLineArgumentForMSVS(s)
   s = _EscapeVCProjCommandLineArgListItem(s)
+  # cl.exe replaces literal # characters with = in preprocesor definitions for
+  # some reason. Octal-encode to work around that.
+  s = s.replace('#', '\\%03o' % ord('#'))
   return s
 
 
 quote_replacer_regex2 = re.compile(r'(\\+)"')
 
 
 def _EscapeCommandLineArgumentForMSBuild(s):
   """Escapes a Windows command-line argument for use by MSBuild."""
 
   def _Replace(match):
@@ skipping 2397 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)