Add support for building targets directly from gyp.

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 296 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('--build', dest='configs', action='append',
+                    help='configuration for build after project generation')
   # --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 162 matching lines @@
 
     # TODO(mark): Pass |data| for now because the generator needs a list of
     # build files that came in.  In the future, maybe it should just accept
     # a list, and not the whole data dict.
     # NOTE: flat_list is the flattened dependency graph specifying the order
     # that targets may be built.  Build systems that operate serially or that
     # 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)
 
+    if options.configs:
+      valid_configs = targets[flat_list[0]]['configurations'].keys()
+      for conf in options.configs:
+        if conf not in valid_configs:
+          raise GypError('Invalid config specified via --build: %s' % conf)
+      generator.PerformBuild(data, options.configs, params)
+
   # Done
   return 0
 
 
 def main(args):
   try:
     return gyp_main(args)
   except GypError, e:
     sys.stderr.write("gyp: %s\n" % e)
     return 1
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))