[cr tool] Make context implicit

tools/cr/cr/context.py

Index: tools/cr/cr/context.py
diff --git a/tools/cr/cr/context.py b/tools/cr/cr/context.py
deleted file mode 100644
index 176961edb29447bd6b305df5035996fe63793f08..0000000000000000000000000000000000000000
--- a/tools/cr/cr/context.py
+++ /dev/null
@@ -1,223 +0,0 @@
-# Copyright 2013 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-"""Application context management for the cr tool.
-
-Contains all the support code to enable the shared context used by the cr tool.
-This includes the configuration variables and command line handling.
-"""
-
-import argparse
-import os
-import cr
-
-
-class _DumpVisitor(cr.visitor.ExportVisitor):
-  """A visitor that prints all variables in a config hierarchy."""
-
-  def __init__(self, with_source):
-    super(_DumpVisitor, self).__init__({})
-    self.to_dump = {}
-    self.with_source = with_source
-
-  def StartNode(self):
-    if self.with_source:
-      self._DumpNow()
-    super(_DumpVisitor, self).StartNode()
-
-  def EndNode(self):
-    if self.with_source or not self.stack:
-      self._DumpNow()
-    super(_DumpVisitor, self).EndNode()
-    if not self.stack:
-      self._DumpNow()
-
-  def Visit(self, key, value):
-    super(_DumpVisitor, self).Visit(key, value)
-    if key in self.store:
-      str_value = str(self.store[key])
-      if str_value != str(os.environ.get(key, None)):
-        self.to_dump[key] = str_value
-
-  def _DumpNow(self):
-    if self.to_dump:
-      if self.with_source:
-        print 'From', self.Where()
-      for key in sorted(self.to_dump.keys()):
-        print '  ', key, '=', self.to_dump[key]
-      self.to_dump = {}
-
-
-class _ShowHelp(argparse.Action):
-  """An argparse action to print the help text.
-
-  This is like the built in help text printing action, except it knows to do
-  nothing when we are just doing the early speculative parse of the args.
-  """
-
-  def __call__(self, parser, namespace, values, option_string=None):
-    if parser.context.speculative:
-      return
-    command = cr.Command.GetActivePlugin(parser.context)
-    if command:
-      command.parser.print_help()
-    else:
-      parser.print_help()
-    exit(1)
-
-
-class _ArgumentParser(argparse.ArgumentParser):
-  """An extension of an ArgumentParser to enable speculative parsing.
-
-  It supports doing an early parse that never produces errors or output, to do
-  early collection of arguments that may affect what other arguments are
-  allowed.
-  """
-
-  def error(self, message):
-    if self.context.speculative:
-      return
-    super(_ArgumentParser, self).error(message)
-
-  def parse_args(self):
-    if self.context.speculative:
-      result = self.parse_known_args()
-      if result:
-        return result[0]
-      return None
-    return super(_ArgumentParser, self).parse_args()
-
-  def parse_known_args(self, args=None, namespace=None):
-    result = super(_ArgumentParser, self).parse_known_args(args, namespace)
-    if result is None:
-      return namespace, None
-    return result
-
-
-class Context(cr.config.Config, cr.loader.AutoExport):
-  """The base context holder for the cr system.
-
-  This is passed to almost all methods in the cr system, and holds the common
-  context they all shared. Mostly this is stored in the Config structure of
-  variables.
-  """
-
-  def __init__(self, description='', epilog=''):
-    super(Context, self).__init__('Context')
-    self._args = None
-    self._arguments = cr.config.Config('ARGS')
-    self._derived = cr.config.Config('DERIVED')
-    self.AddChildren(*cr.config.GLOBALS)
-    self.AddChildren(
-        cr.config.Config('ENVIRONMENT', literal=True, export=True).Set(
-            {k: self.ParseValue(v) for k, v in os.environ.items()}),
-        self._arguments,
-        self._derived,
-    )
-    # Build the command line argument parser
-    self._parser = _ArgumentParser(add_help=False, description=description,
-                                   epilog=epilog)
-    self._parser.context = self
-    self._subparsers = self.parser.add_subparsers()
-    # Add the global arguments
-    self.AddCommonArguments(self._parser)
-    self._gclient = {}
-    # Try to detect the current client information
-    cr.base.client.DetectClient(self)
-
-  def AddSubParser(self, source):
-    parser = source.AddArguments(self._subparsers)
-    parser.context = self
-
-  @classmethod
-  def AddCommonArguments(cls, parser):
-    """Adds the command line arguments common to all commands in cr."""
-    parser.add_argument(
-        '-h', '--help',
-        action=_ShowHelp, nargs=0,
-        help='show the help message and exit.'
-    )
-    parser.add_argument(
-        '--dry-run', dest='CR_DRY_RUN',
-        action='store_true', default=None,
-        help="""
-          Don't execute commands, just print them. Implies verbose.
-          Overrides CR_DRY_RUN
-          """
-    )
-    parser.add_argument(
-        '-v', '--verbose', dest='CR_VERBOSE',
-        action='count', default=None,
-        help="""
-          Print information about commands being performed.
-          Repeating multiple times increases the verbosity level.
-          Overrides CR_VERBOSE
-          """
-    )
-
-  @property
-  def args(self):
-    return self._args
-
-  @property
-  def arguments(self):
-    return self._arguments
-
-  @property
-  def speculative(self):
-    return self._speculative
-
-  @property
-  def derived(self):
-    return self._derived
-
-  @property
-  def parser(self):
-    return self._parser
-
-  @property
-  def remains(self):
-    remains = getattr(self._args, '_remains', None)
-    if remains and remains[0] == '--':
-      remains = remains[1:]
-    return remains
-
-  @property
-  def verbose(self):
-    if self.autocompleting:
-      return False
-    return self.Find('CR_VERBOSE') or self.dry_run
-
-  @property
-  def dry_run(self):
-    if self.autocompleting:
-      return True
-    return self.Find('CR_DRY_RUN')
-
-  @property
-  def autocompleting(self):
-    return 'COMP_WORD' in os.environ
-
-  @property
-  def gclient(self):
-    if not self._gclient:
-      self._gclient = cr.base.client.ReadGClient(self)
-    return self._gclient
-
-  def WriteGClient(self):
-    if self._gclient:
-      cr.base.client.WriteGClient(self)
-
-  def ParseArgs(self, speculative=False):
-    cr.plugin.DynamicChoices.only_active = not speculative
-    self._speculative = speculative
-    self._args = self._parser.parse_args()
-    self._arguments.Wipe()
-    if self._args:
-      self._arguments.Set(
-          {k: v for k, v in vars(self._args).items() if v is not None})
-
-  def DumpValues(self, with_source):
-    _DumpVisitor(with_source).VisitNode(self)
-