shutil recipe_module: port chromium_utils rmtree implementation.

recipe_modules/shutil/resources/rmtree.py

Index: recipe_modules/shutil/resources/rmtree.py
diff --git a/recipe_modules/shutil/resources/rmtree.py b/recipe_modules/shutil/resources/rmtree.py
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+# Copyright 2016 The LUCI Authors. All rights reserved.
+# Use of this source code is governed under the Apache License, Version 2.0
+# that can be found in the LICENSE file.
+
+# Copy of RemoveDirectory from scripts/common/chromium_utils.
+# See also http://crbug.com/584783.
+# The only difference is that now the method will properly report failures.
+# The recipe can choose to ignore them explicitely with ok_ret='any'.
+
+import argparse
+import os
+import shutil
+import subprocess
+import sys
+import time
+
+
+def RemoveDirectory(file_path):
+  """Recursively removes a directory, even if it's marked read-only.
+
+  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. :/
+  """
+  if not os.path.exists(file_path):
+    return 0
+
+  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]):
+        return 0
+      print '  Failed'
+      time.sleep(3)
+    return 1
+
+  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)
+  return 0
+
+
+def main(args):
+  parser = argparse.ArgumentParser()
+  parser.add_argument('path', help='Absolute path to remove')
+  options = parser.parse_args(args)
+  return RemoveDirectory(options.path)
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))