Support Mac android cross compile.

pylib/gyp/__init__.py

 #!/usr/bin/env python
 
 # 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 gyp.input
 import optparse
 import os.path
@@ skipping 280 matching lines @@
                     env_name='GYP_GENERATOR_OUTPUT',
                     help='puts generated build files under DIR')
   parser.add_option('--ignore-environment', dest='use_environment',
                     action='store_false', default=True, regenerate=False,
                     help='do not read options from environment variables')
   parser.add_option('--check', dest='check', action='store_true',
                     help='check format of gyp files')
   parser.add_option('--toplevel-dir', dest='toplevel_dir', action='store',
                     default=None, metavar='DIR', type='path',
                     help='directory to use as the root of the source tree')
+  parser.add_option('--host-flavor', dest='host_flavor', action='store',
+                    env_name='GYP_HOST_FLAVOR', regenerate=False,
+                    help='To override the value of the build os')

[Torne, 2012/08/14 11:04:01]

Help messages don't start with a capital, and "to" is redundant. How about
"overrides host OS flavor used to crosscompile" ?

   # --no-circular-check disables the check for circular relationships between
   # .gyp files.  These relationships should not exist, but they've only been
   # observed to be harmful with the Xcode generator.  Chromium's .gyp files
   # currently have some circular relationships on non-Mac platforms, so this
   # option allows the strict behavior to be used on Macs and the lenient
   # behavior to be used elsewhere.
   # TODO(mark): Remove this option when http://crbug.com/35878 is fixed.
   parser.add_option('--no-circular-check', dest='circular_check',
                     action='store_false', default=True, regenerate=False,
                     help="don't check for circular relationships between files")
@@ skipping 11 matching lines @@
       if not os.path.exists(home_dot_gyp):
         home_dot_gyp = None
       else:
         break
 
   # TODO(thomasvl): add support for ~/.gyp/defaults
 
   options, build_files_arg = parser.parse_args(args)
   build_files = build_files_arg
 
+  if not options.host_flavor:

[Torne, 2012/08/14 11:04:01]

needs to also be "and options.use_environment"

+    options.host_flavor = os.environ.get('GYP_HOST_FLAVOR', '')
+
   if not options.formats:
     # If no format was given on the command line, then check the env variable.
     generate_formats = []
     if options.use_environment:
       generate_formats = os.environ.get('GYP_GENERATORS', [])
     if generate_formats:
       generate_formats = re.split('[\s,]', generate_formats)
     if generate_formats:
       options.formats = generate_formats
     else:
@@ skipping 139 matching lines @@
     # need to have dependencies defined before dependents reference them should
     # generate targets in the order specified in flat_list.
     generator.GenerateOutput(flat_list, targets, data, params)
 
   # Done
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))