Merge to XFA: Add Dr. Memory tool

tools/drmemory/scripts/path_utils.py

Index: tools/drmemory/scripts/path_utils.py
diff --git a/tools/drmemory/scripts/path_utils.py b/tools/drmemory/scripts/path_utils.py
new file mode 100644
index 0000000000000000000000000000000000000000..6ab43120434256459f0c9bac2c764698a017ba09
--- /dev/null
+++ b/tools/drmemory/scripts/path_utils.py
@@ -0,0 +1,84 @@
+# Copyright (c) 2011 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.
+
+"""Some utility methods for getting and manipulating paths."""
+
+# TODO(pamg): Have the buildbot use these, too.
+
+
+import errno
+import os
+import sys
+
+class PathNotFound(Exception): pass
+
+def ScriptDir():
+  """Get the full path to the directory containing the current script."""
+  script_filename = os.path.abspath(sys.argv[0])
+  return os.path.dirname(script_filename)
+
+def FindAncestor(start_dir, ancestor):
+  """Finds an ancestor dir in a path.
+
+  For example, FindAncestor('c:\foo\bar\baz', 'bar') would return
+  'c:\foo\bar'.  Unlike FindUpward*, this only looks at direct path ancestors.
+  """
+  start_dir = os.path.abspath(start_dir)
+  path = start_dir
+  while True:
+    (parent, tail) = os.path.split(path)
+    if tail == ancestor:
+      return path
+    if not tail:
+      break
+    path = parent
+  raise PathNotFound("Unable to find ancestor %s in %s" % (ancestor, start_dir))
+
+def FindUpwardParent(start_dir, *desired_list):
+  """Finds the desired object's parent, searching upward from the start_dir.
+
+  Searches start_dir and all its parents looking for the desired directory
+  or file, which may be given in one or more path components. Returns the
+  first directory in which the top desired path component was found, or raises
+  PathNotFound if it wasn't.
+  """
+  desired_path = os.path.join(*desired_list)
+  last_dir = ''
+  cur_dir = start_dir
+  found_path = os.path.join(cur_dir, desired_path)
+  while not os.path.exists(found_path):
+    last_dir = cur_dir
+    cur_dir = os.path.dirname(cur_dir)
+    if last_dir == cur_dir:
+      raise PathNotFound('Unable to find %s above %s' %
+                         (desired_path, start_dir))
+    found_path = os.path.join(cur_dir, desired_path)
+  # Strip the entire original desired path from the end of the one found
+  # and remove a trailing path separator, if present.
+  found_path = found_path[:len(found_path) - len(desired_path)]
+  if found_path.endswith(os.sep):
+    found_path = found_path[:len(found_path) - 1]
+  return found_path
+
+
+def FindUpward(start_dir, *desired_list):
+  """Returns a path to the desired directory or file, searching upward.
+
+  Searches start_dir and all its parents looking for the desired directory
+  or file, which may be given in one or more path components. Returns the full
+  path to the desired object, or raises PathNotFound if it wasn't found.
+  """
+  parent = FindUpwardParent(start_dir, *desired_list)
+  return os.path.join(parent, *desired_list)
+
+
+def MaybeMakeDirectory(*path):
+  """Creates an entire path, if it doesn't already exist."""
+  file_path = os.path.join(*path)
+  try:
+    os.makedirs(file_path)
+  except OSError, e:
+    # errno.EEXIST is "File exists".  If we see another error, re-raise.
+    if e.errno != errno.EEXIST:
+      raise