1 files changed, 26 insertions, 2 deletions
diff --git a/tensorflow/contrib/autograph/pyct/qual_names.py b/tensorflow/contrib/autograph/pyct/qual_names.py
index da07013cf4..fb81404edc 100644
--- a/tensorflow/contrib/autograph/pyct/qual_names.py
+++ b/tensorflow/contrib/autograph/pyct/qual_names.py
@@ -30,6 +30,7 @@ import collections
 import gast
 
 from tensorflow.contrib.autograph.pyct import anno
+from tensorflow.contrib.autograph.pyct import parser
 
 
 class Symbol(collections.namedtuple('Symbol', ['name'])):
@@ -89,7 +90,8 @@ class QN(object):
       if not isinstance(base, (str, StringLiteral, NumberLiteral)):
         # TODO(mdan): Require Symbol instead of string.
         raise ValueError(
-            'For simple QNs, base must be a string or a Literal object.')
+            'for simple QNs, base must be a string or a Literal object;'
+            ' got instead "%s"' % type(base))
       assert '.' not in base and '[' not in base and ']' not in base
       self._parent = None
       self.qn = (base,)
@@ -113,6 +115,22 @@ class QN(object):
     return self._parent
 
   @property
+  def owner_set(self):
+    """Returns all the symbols (simple or composite) that own this QN.
+
+    In other words, if this symbol was modified, the symbols in the owner set
+    may also be affected.
+
+    Examples:
+      'a.b[c.d]' has two owners, 'a' and 'a.b'
+    """
+    owners = set()
+    if self.has_attr() or self.has_subscript():
+      owners.add(self.parent)
+      owners.update(self.parent.owner_set)
+    return owners
+
+  @property
   def support_set(self):
     """Returns the set of simple symbols that this QN relies on.
 
@@ -122,7 +140,7 @@ class QN(object):
 
     Examples:
       'a.b' has only one support symbol, 'a'
-      'a[i]' has two roots, 'a' and 'i'
+      'a[i]' has two support symbols, 'a' and 'i'
     """
     # TODO(mdan): This might be the set of Name nodes in the AST. Track those?
     roots = set()
@@ -231,3 +249,9 @@ class QnResolver(gast.NodeTransformer):
 
 def resolve(node):
   return QnResolver().visit(node)
+
+
+def from_str(qn_str):
+  node = parser.parse_expression(qn_str)
+  node = resolve(node)
+  return anno.getanno(node, anno.Basic.QN)