Added virtualenv for depot_tools

bootstrap/run_helper.py

Index: bootstrap/run_helper.py
diff --git a/bootstrap/run_helper.py b/bootstrap/run_helper.py
new file mode 100755
index 0000000000000000000000000000000000000000..5af50f975f52f2680572ef80928f5864954a23d4
--- /dev/null
+++ b/bootstrap/run_helper.py
@@ -0,0 +1,124 @@
+#!/usr/bin/env python
+# Copyright 2014 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.
+
+"""Code supporting run.py implementation.
+
+Reused across infra/run.py and infra_internal/run.py.
+"""
+
+import os
+import sys
+
+
+def is_in_venv(env_path):
+  """True if already running in virtual env."""
+  abs_prefix = os.path.abspath(sys.prefix)
+  abs_env_path = os.path.abspath(env_path)
+  if abs_prefix == abs_env_path:
+    return True
+  # Ordinarily os.path.abspath(sys.prefix) == env_path is enough. But it doesn't
+  # work when virtual env is deployed as CIPD package. CIPD uses symlinks to
+  # stage files into installation root. When booting venv, something (python
+  # binary itself?) resolves the symlink ENV/bin/python to the target, making
+  # sys.prefix look like "<root>/.cipd/.../ENV". Note that "<root>/ENV" is not
+  # a symlink itself, but "<root>/ENV/bin/python" is.
+  if sys.platform == 'win32':
+    # TODO(vadimsh): Make it work for Win32 too.
+    return False
+  try:
+    return os.path.samefile(
+        os.path.join(abs_prefix, 'bin', 'python'),
+        os.path.join(abs_env_path, 'bin', 'python'))
+  except OSError:
+    return False
+
+
+def boot_venv(script, env_path):
+  """Reexecs the top-level script in a virtualenv (if necessary)."""
+  RUN_PY_RECURSION_BLOCKER = 'RUN_PY_RECURSION'
+
+  if not is_in_venv(env_path):
+    if RUN_PY_RECURSION_BLOCKER in os.environ:
+      print >> sys.stderr, 'TOO MUCH RECURSION IN RUN.PY'
+      sys.exit(-1)
+
+    # not in the venv
+    if sys.platform.startswith('win'):
+      python = os.path.join(env_path, 'Scripts', 'python.exe')
+    else:
+      python = os.path.join(env_path, 'bin', 'python')
+    if os.path.exists(python):
+      os.environ[RUN_PY_RECURSION_BLOCKER] = "1"
+      os.environ.pop('PYTHONPATH', None)
+      os.execv(python, [python, script] + sys.argv[1:])
+      print >> sys.stderr, "Exec is busted :("
+      sys.exit(-1)  # should never reach
+
+    print 'You must use the virtualenv in ENV for scripts in the infra repo.'
+    print 'Running `gclient runhooks` will create this environment for you.'
+    sys.exit(1)
+
+  # In case some poor script ends up calling run.py, don't explode them.
+  os.environ.pop(RUN_PY_RECURSION_BLOCKER, None)
+
+
+def run_py_main(args, runpy_path, env_path, package):
+  boot_venv(runpy_path, env_path)
+
+  import argparse
+  import runpy
+  import shlex
+  import textwrap
+
+  import argcomplete
+
+  os.chdir(os.path.dirname(runpy_path))
+
+  # Impersonate the argcomplete 'protocol'
+  completing = os.getenv('_ARGCOMPLETE') == '1'
+  if completing:
+    assert not args
+    line = os.getenv('COMP_LINE')
+    args = shlex.split(line)[1:]
+    if len(args) == 1 and not line.endswith(' '):
+      args = []
+
+  if not args or not args[0].startswith('%s.' % package):
+    commands = []
+    for root, _, files in os.walk(package):
+      if '__main__.py' in files:
+        commands.append(root.replace(os.path.sep, '.'))
+
+    if completing:
+      # Argcomplete is listening for strings on fd 8
+      with os.fdopen(8, 'wb') as f:
+        print >> f, '\n'.join(commands)
+      return
+
+    print textwrap.dedent("""\
+    usage: run.py %s.<module.path.to.tool> [args for tool]
+
+    %s
+
+    Available tools are:""") % (
+        package, sys.modules['__main__'].__doc__.strip())
+    for command in commands:
+      print '  *', command
+    return 1
+
+  if completing:
+    to_nuke = ' ' + args[0]
+    os.environ['COMP_LINE'] = os.environ['COMP_LINE'].replace(to_nuke, '', 1)
+    os.environ['COMP_POINT'] = str(int(os.environ['COMP_POINT']) - len(to_nuke))
+    orig_parse_args = argparse.ArgumentParser.parse_args
+    def new_parse_args(self, *args, **kwargs):
+      argcomplete.autocomplete(self)
+      return orig_parse_args(*args, **kwargs)
+    argparse.ArgumentParser.parse_args = new_parse_args
+  else:
+    # remove the module from sys.argv
+    del sys.argv[1]
+
+  runpy.run_module(args[0], run_name='__main__', alter_sys=True)