Plumb in subcommand options

shell/main.py

 #!/usr/bin/python
 #
 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Main file for the chromite shell."""
 
 # Python imports
 import optparse
@@ skipping 75 matching lines @@
   else:
     choice = text_menu.TextMenu(possible_choices, 'Which chromite command',
                                 menu_width=0)
 
   if choice is None:
     cros_lib.Die('OK, cancelling...')
   else:
     return possible_cmds[choice]
 
 
+# Helper function to parse arguments and split into one we understand, and

[diandersAtChromium, 2011/04/08 20:35:41]

Last nit: can you make this a docstring instead of a header comment?

[sjg, 2011/04/08 21:00:19]

doh.

+# ones to pass on to sub-commands.
+# We want to parse only the options that we understand at the top level of
+# Chromite. Our heuristic here is that anything after the first positional
+# parameter (which we assume is the command) is ignored at this level, and
+# is passed down to the command level to handle.
+# TODO(sjg): Revisit this to include tolerant option parser instead
+# http://codereview.chromium.org/6469035/
+#
+# Args:
+#   parser: Option parser.
+#   argv:   List of program arguments
+#
+# Returns:
+#   options:  Top level options (returned from optparse).
+#   cmd_str:  Subcommand to run
+#   cmd_args: Arguments intended for subcommands.
+def _ParseArguments(parser, argv):
+  our_args = []
+  cmd_args = list(argv)
+  cmd_str = ''
+  args = []   # Nothing until we call optparse
+  while not cmd_str:
+    if our_args:
+      (options, args) = parser.parse_args(our_args)
+    if len(args) > 1:
+      cmd_str = args[1].lower()
+    elif cmd_args:
+      # We don't have a command yet. Transfer a positional arg from from
+      # cmd_args to our_args to see if that does the trick. We move over any
+      # options we find also.
+      while cmd_args:
+        arg = cmd_args.pop(0)
+        our_args.append(arg)
+        if not arg.startswith( '-'):
+          break
+    else:
+      # No more cmd_args to consume.
+      break
+
+  # We must run the parser, even if it dies due to lack of arguments
+  if not args:
+    (options, args) = parser.parse_args(our_args)
+  return options, cmd_str, cmd_args
+
 def main():
   """Main function for the chromite shell."""
 
   # Hack it so that argv[0] is 'chromite' so that it doesn't tell user to run
   # 'main.py' in help commands...
   # TODO(dianders): Remove this hack, since it is ugly.  Shouldn't be needed
   # once we change the way that the chromite wrapper works.
   sys.argv[0] = 'chromite'
 
   # Support EnterChroot().
@@ skipping 15 matching lines @@
       """%(prog)s [chromite_options] [cmd [args]]\n"""
       """\n"""
       """The chromite script is a wrapper to make it easy to do various\n"""
       """build tasks.  For a list of commands, run without any arguments."""
   ) % {'prog': os.path.basename(sys.argv[0])}
 
   parser = optparse.OptionParser()
 
   # Verbose defaults to full for now, just to keep people acclimatized to
   # vast amounts of comforting output.
-  parser.add_option('-v', dest='verbose', default=3,
+  parser.add_option('-v', dest='verbose', default=3, type='int',
       help='Control verbosity: 0=silent, 1=progress, 3=full')
   parser.add_option('-q', action='store_const', dest='verbose', const=0,
       help='Be quieter (sets verbosity to 1)')
   if not cros_lib.IsInsideChroot():
     parser.add_option('--chroot', action='store', type='string',
         dest='chroot_name', default='chroot',
         help="Chroot spec to use. Can be an absolute path to a spec file "
             "or a substring of a chroot spec name (without .spec suffix)")
   parser.usage = help_str
-  try:
-    (options, args) = parser.parse_args()
-  except:
-    sys.exit(1)
+
+  # Parse the arguments and separate them into top-level and subcmd arguments.
+  options, cmd_str, cmd_args = _ParseArguments(parser, sys.argv)
 
   # Set up the cros system.
   cros_env = chromite_env.ChromiteEnv()
 
   # Configure the operation setup.
   oper = cros_env.GetOperation()
   oper.verbose = options.verbose >= 3
   oper.progress = options.verbose >= 1
 
   # Look for special "--chroot" argument to allow for alternate chroots
   if not cros_lib.IsInsideChroot():
     chroot_spec_path = utils.FindSpec(options.chroot_name,
                                       spec_type=utils.CHROOT_SPEC_TYPE)
 
     oper.Info('Using chroot "%s"' % os.path.relpath(chroot_spec_path))
 
     chroot_config = utils.ReadConfig(chroot_spec_path)
   else:
     # Already in the chroot; no need to get config...
     chroot_config = None
 
-  # Get command and arguments
-  if args:
-    cmd_str = args[0].lower()
-    args = args[1:]
-  else:
-    cmd_str = ''
-
   # Validate the subcmd, popping a menu if needed.
   cmd_str = _FindCommand(cmd_str)
   oper.Info("Running command '%s'." % cmd_str)
 
   # Finally, call the function w/ standard argv.
   cmd_cls = _COMMAND_HANDLERS[_COMMAND_STRS.index(cmd_str)]
   cmd_obj = cmd_cls()
   cmd_obj.SetChromiteEnv(cros_env)
   try:
-    cmd_obj.Run([cmd_str] + args, chroot_config=chroot_config)
+    cmd_obj.Run([cmd_str] + cmd_args, chroot_config=chroot_config)
 
   # Handle an error in one of the scripts: print a message and exit.
   except chromite_env.ChromiteError, msg:
     sys.exit(1)
 
 if __name__ == '__main__':
   main()