Standardize name scopes used during model construction in v2.

PiperOrigin-RevId: 301852763
Change-Id: I3b4281f64ec4f3fe8e5f25901a1581ebc63de057

tensorflow/python/keras/engine/BUILD

@@ -111,6 +111,7 @@ py_library(
         ":base_layer_utils",
         "//tensorflow/core:protos_all_py",
         "//tensorflow/python:constant_op",
+        "//tensorflow/python:tf2",
         "//tensorflow/python/data",
         "//tensorflow/python/distribute:distribute_coordinator",
         "//tensorflow/python/distribute:distribute_lib",

tensorflow/python/keras/engine/base_layer.py

@@ -30,6 +30,7 @@ from six.moves import zip  # pylint: disable=redefined-builtin
 
 from google.protobuf import json_format
 from tensorflow.core.framework import node_def_pb2
+from tensorflow.python import tf2
 from tensorflow.python.autograph.core import ag_ctx
 from tensorflow.python.autograph.impl import api as autograph
 from tensorflow.python.distribute import distribution_strategy_context as ds_context
@@ -2083,7 +2084,18 @@ class Layer(module.Module, version_utils.LayerVersionSelector):
     self._dtype_policy = policy.Policy(value)
 
   def _name_scope(self):
-    return self.name
+    if not tf2.enabled():
+      return self.name
+    name_scope = self.name
+    current_name_scope = ops.get_name_scope()
+    if current_name_scope:
+      name_scope = current_name_scope + '/' + name_scope
+    if name_scope:
+      # Note that the trailing `/` prevents autogenerated
+      # numerical suffixes to get appended. It will also fully reset
+      # nested name scope (i.e. the outer name scope has no effect).
+      name_scope += '/'
+    return name_scope
 
   def _init_set_name(self, name, zero_based=True):
     if not name:

tensorflow/python/keras/engine/base_layer_test.py

@@ -936,6 +936,30 @@ class NameScopingTest(keras_parameterized.TestCase):
     self.assertEqual(layer.bias.name, 'MyName/bias:0')
     self.assertEqual(layer.kernel.name, 'MyName/kernel:0')
 
+  def test_name_scope_functional_api(self):
+    inputs = input_layer.Input((3,))
+    layer = layers.Dense(10, name='MyName')
+    _ = layer(inputs)
+    self.assertEqual(layer.bias.name, 'MyName/bias:0')
+    self.assertEqual(layer.kernel.name, 'MyName/kernel:0')
+
+  def test_name_scope_functional_api_nested(self):
+
+    class NestedLayer(base_layer.Layer):
+
+      def __init__(self, name='OuterName'):
+        super(NestedLayer, self).__init__(name=name)
+        self.dense = layers.Dense(10, name='InnerName')
+
+      def call(self, inputs):
+        return self.dense(inputs)
+
+    inputs = input_layer.Input((3,))
+    layer = NestedLayer()
+    _ = layer(inputs)
+    self.assertEqual(layer.dense.bias.name, 'OuterName/InnerName/bias:0')
+    self.assertEqual(layer.dense.kernel.name, 'OuterName/InnerName/kernel:0')
+
   def test_name_scope_sublayer(self):
 
     class NameScopeTracker(base_layer.Layer):