Updates to Visual Studio project generation to accomodate...

site_scons/site_tools/_Node_MSVS.py

 #
 # __COPYRIGHT__
 #
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
 # "Software"), to deal in the Software without restriction, including
 # without limitation the rights to use, copy, modify, merge, publish,
 # distribute, sublicense, and/or sell copies of the Software, and to
 # permit persons to whom the Software is furnished to do so, subject to
 # the following conditions:
@@ skipping 945 matching lines @@
     """
     executor = target.get_executor()
     base_cl = map(str, base_env.subst_list(executor)[0])
     file_cl = map(str, file_env.subst_list(executor)[0])
     if base_cl == file_cl:
       return
 
     base_tool = self.cl_to_tool(base_cl)
     file_tool = self.cl_to_tool(file_cl)
 
+    if not base_tool or not_file_tool:
+      return
+
     file_tool.diff(base_tool)
 
     self.AddFileConfig(source, name, tools=[file_tool])
 
   def _AddFileConfigurations(self, env):
     """Adds per-file configurations for the buildtarget's sources.
 
     Args:
       env: The base construction environment for the project.
     """
     if not self.buildtargets:
       return
 
     for bt in self.buildtargets:
       executor = bt.get_executor()
       build_env = bt.get_build_env()
       bt_cl = map(str, build_env.subst_list(executor)[0])
       tool = self.cl_to_tool(bt_cl)
       default_tool = self.cl_to_tool([bt_cl[0]])
       if default_tool:
         tool.diff(default_tool)
       else:
-        print "no tool for %r" % bt_cl[0]
+        # TODO(sgk):  print a message unconditionally is too
+        # verbose for things like Python function actions,
+        # but doing nothing runs the risk of burying problems.
+        # Work out a better solution.
+        #print "no tool for %r" % bt_cl[0]
+        pass
       for t in bt.sources:
         e = t.get_build_env()
         additional_files = SCons.Util.UniqueList()
         for s in t.sources:
           s = env.arg2nodes([s])[0].srcnode()
           if not self.FindFile(s):
             additional_files.append(s)
           if not build_env is e:
             # TODO(sgk):  This test may be bogus, but it works for now.
             # We're trying to figure out if the file configuration
@@ skipping 363 matching lines @@
   LookupAdd(item, result)
   return result
 
 import __builtin__
 
 __builtin__.MSVSConfig = MSVSConfig
 __builtin__.MSVSFilter = MSVSFilter
 __builtin__.MSVSProject = MSVSProject
 __builtin__.MSVSSolution = MSVSSolution
 __builtin__.MSVSTool = MSVSTool