Make generators robust in the face of generator_flags being defined....

trunk/pylib/gyp/generator/msvs.py

 #!/usr/bin/python
 
 
 import os
 import re
 import subprocess
 import sys
 import gyp.common
 import gyp.MSVSNew as MSVSNew
 import gyp.MSVSToolFile as MSVSToolFile
@@ skipping 844 matching lines @@
       dependencies=deps)
   # Store it to the list of objects.
   project_objs[qualified_target] = obj
   # Return project object.
   return obj
 
 
 def CalculateVariables(default_variables, params):
   """Generated variables that require params to be known."""
 
-  generator_flags = params['generator_flags']
+  generator_flags = params.get('generator_flags', {})
 
   # Select project file format version (if unset, default to auto detecting).
   msvs_version = \
     MSVSVersion.SelectVisualStudioVersion(generator_flags.get('msvs_version',
                                                               'auto'))
   # Stash msvs_version for later (so we don't have to probe the system twice).
   params['msvs_version'] = msvs_version
 
   # Set a variable so conditions can be based on msvs_version.
   default_variables['MSVS_VERSION'] = msvs_version.ShortName()
@@ skipping 13 matching lines @@
   """Generate .sln and .vcproj files.
 
   This is the entry point for this generator.
   Arguments:
     target_list: List of target pairs: 'base/base.gyp:base'.
     target_dicts: Dict of target properties keyed on target pair.
     data: Dictionary containing per .gyp data.
   """
 
   options = params['options']
-  generator_flags = params['generator_flags']
+  generator_flags = params.get('generator_flags', {})
 
   # Get the project file format version back out of where we stashed it in
   # GeneratorCalculatedVariables.
   msvs_version = params['msvs_version']
 
   # Prepare the set of configurations.
   configs = set()
   for qualified_target in target_list:
     build_file = gyp.common.BuildFileAndTarget('', qualified_target)[0]
     spec = target_dicts[qualified_target]
@@ skipping 34 matching lines @@
       _ProjectObject(sln_path, p, project_objs, projects)
     # Create folder hierarchy.
     root_entries = _GatherSolutionFolders(project_objs)
     # Create solution.
     sln = MSVSNew.MSVSSolution(sln_path,
                                entries=root_entries,
                                variants=configs,
                                websiteProperties=False,
                                version=msvs_version)
     sln.Write()