Add isolate_win_toolchain.py

infra/bots/utils.py

Index: infra/bots/utils.py
diff --git a/infra/bots/utils.py b/infra/bots/utils.py
index ee648a26a4d4c6e3ee8fe0e08dd5ac9b240dab05..a60ebe97b8977b8479317f80dcd770455d9db6af 100644
--- a/infra/bots/utils.py
+++ b/infra/bots/utils.py
@@ -7,6 +7,18 @@
 
 
 import datetime
+import errno
+import os
+import shutil
+import sys
+import subprocess
+import tempfile
+import time
+import uuid
+
+
+GCLIENT = 'gclient.bat' if sys.platform == 'win32' else 'gclient'
+GIT = 'git.bat' if sys.platform == 'win32' else 'git'
 
 
 class print_timings(object):
@@ -21,3 +33,168 @@ class print_timings(object):
     finish = datetime.datetime.utcnow()
     duration = (finish-self._start).total_seconds()
     print 'Task finished at %s GMT (%f seconds)' % (str(finish), duration)
+
+
+class tmp_dir(object):
+  """Helper class used for creating a temporary directory and working in it."""
+  def __init__(self):
+    self._orig_dir = None
+    self._tmp_dir = None
+
+  def __enter__(self):
+    self._orig_dir = os.getcwd()
+    self._tmp_dir = tempfile.mkdtemp()
+    os.chdir(self._tmp_dir)
+    return self
+
+  def __exit__(self, t, v, tb):
+    os.chdir(self._orig_dir)
+    RemoveDirectory(self._tmp_dir)
+
+  @property
+  def name(self):
+    return self._tmp_dir
+
+
+class chdir(object):
+  """Helper class used for changing into and out of a directory."""
+  def __init__(self, d):
+    self._dir = d
+    self._orig_dir = None
+
+  def __enter__(self):
+    self._orig_dir = os.getcwd()
+    os.chdir(self._dir)
+    return self
+
+  def __exit__(self, t, v, tb):
+    os.chdir(self._orig_dir)
+
+
+def git_clone(repo_url, dest_dir):
+  """Clone the given repo into the given destination directory."""
+  subprocess.check_call([GIT, 'clone', repo_url, dest_dir])
+
+
+class git_branch(object):
+  """Check out a temporary git branch.
+
+  On exit, deletes the branch and attempts to restore the original state.
+  """
+  def __init__(self):
+    self._branch = None
+    self._orig_branch = None
+    self._stashed = False
+
+  def __enter__(self):
+    output = subprocess.check_output([GIT, 'stash'])
+    self._stashed = 'No local changes' not in output
+
+    # Get the original branch name or commit hash.
+    self._orig_branch = subprocess.check_output([
+        GIT, 'rev-parse', '--abbrev-ref', 'HEAD']).rstrip()
+    if self._orig_branch == 'HEAD':
+      self._orig_branch = subprocess.check_output([
+          GIT, 'rev-parse', 'HEAD']).rstrip()
+
+    # Check out a new branch, based at updated origin/master.
+    subprocess.check_call([GIT, 'fetch', 'origin'])
+    self._branch = '_tmp_%s' % uuid.uuid4()
+    subprocess.check_call([GIT, 'checkout', '-b', self._branch,
+                           '-t', 'origin/master'])
+    return self
+
+  def __exit__(self, exc_type, _value, _traceback):
+    subprocess.check_call([GIT, 'reset', '--hard', 'HEAD'])
+    subprocess.check_call([GIT, 'checkout', self._orig_branch])
+    if self._stashed:
+      subprocess.check_call([GIT, 'stash', 'pop'])
+    subprocess.check_call([GIT, 'branch', '-D', self._branch])
+
+
+def RemoveDirectory(*path):
+  """Recursively removes a directory, even if it's marked read-only.
+
+  This was copied from:
+  https://chromium.googlesource.com/chromium/tools/build/+/f3e7ff03613cd59a463b2ccc49773c3813e77404/scripts/common/chromium_utils.py#491
+
+  Remove the directory located at *path, if it exists.
+
+  shutil.rmtree() doesn't work on Windows if any of the files or directories
+  are read-only, which svn repositories and some .svn files are.  We need to
+  be able to force the files to be writable (i.e., deletable) as we traverse
+  the tree.
+
+  Even with all this, Windows still sometimes fails to delete a file, citing
+  a permission error (maybe something to do with antivirus scans or disk
+  indexing).  The best suggestion any of the user forums had was to wait a
+  bit and try again, so we do that too.  It's hand-waving, but sometimes it
+  works. :/
+  """
+  file_path = os.path.join(*path)
+  if not os.path.exists(file_path):
+    return
+
+  if sys.platform == 'win32':
+    # Give up and use cmd.exe's rd command.
+    file_path = os.path.normcase(file_path)
+    for _ in xrange(3):
+      print 'RemoveDirectory running %s' % (' '.join(
+          ['cmd.exe', '/c', 'rd', '/q', '/s', file_path]))
+      if not subprocess.call(['cmd.exe', '/c', 'rd', '/q', '/s', file_path]):
+        break
+      print '  Failed'
+      time.sleep(3)
+    return
+
+  def RemoveWithRetry_non_win(rmfunc, path):
+    if os.path.islink(path):
+      return os.remove(path)
+    else:
+      return rmfunc(path)
+
+  remove_with_retry = RemoveWithRetry_non_win
+
+  def RmTreeOnError(function, path, excinfo):
+    r"""This works around a problem whereby python 2.x on Windows has no ability
+    to check for symbolic links.  os.path.islink always returns False.  But
+    shutil.rmtree will fail if invoked on a symbolic link whose target was
+    deleted before the link.  E.g., reproduce like this:
+    > mkdir test
+    > mkdir test\1
+    > mklink /D test\current test\1
+    > python -c "import chromium_utils; chromium_utils.RemoveDirectory('test')"
+    To avoid this issue, we pass this error-handling function to rmtree.  If
+    we see the exact sort of failure, we ignore it.  All other failures we re-
+    raise.
+    """
+
+    exception_type = excinfo[0]
+    exception_value = excinfo[1]
+    # If shutil.rmtree encounters a symbolic link on Windows, os.listdir will
+    # fail with a WindowsError exception with an ENOENT errno (i.e., file not
+    # found).  We'll ignore that error.  Note that WindowsError is not defined
+    # for non-Windows platforms, so we use OSError (of which it is a subclass)
+    # to avoid lint complaints about an undefined global on non-Windows
+    # platforms.
+    if (function is os.listdir) and issubclass(exception_type, OSError):
+      if exception_value.errno == errno.ENOENT:
+        # File does not exist, and we're trying to delete, so we can ignore the
+        # failure.
+        print 'WARNING:  Failed to list %s during rmtree.  Ignoring.\n' % path
+      else:
+        raise
+    else:
+      raise
+
+  for root, dirs, files in os.walk(file_path, topdown=False):
+    # For POSIX:  making the directory writable guarantees removability.
+    # Windows will ignore the non-read-only bits in the chmod value.
+    os.chmod(root, 0770)
+    for name in files:
+      remove_with_retry(os.remove, os.path.join(root, name))
+    for name in dirs:
+      remove_with_retry(lambda p: shutil.rmtree(p, onerror=RmTreeOnError),
+                        os.path.join(root, name))
+
+  remove_with_retry(os.rmdir, file_path)