Add friendly names to nGraph nodes generated from ONNX (#4357)

* Add friendly names to nGraph ONNX nodes generated

* Review comments
Co-authored-by: Scott Cyphers <diyessi@users.noreply.github.com>

src/ngraph/frontend/onnx_import/core/graph.cpp

@@ -199,11 +199,28 @@ namespace ngraph
                 m_model->get_operator(onnx_node.op_type(), onnx_node.domain());
 
             const auto ng_node_vector = ng_node_factory(onnx_node);
+            set_friendly_names(onnx_node, ng_node_vector);
             add_provenance_tags(onnx_node, ng_node_vector);
 
             return ng_node_vector;
         }
 
+        void Graph::set_friendly_names(const Node& onnx_node,
+                                       const NodeVector& ng_node_vector) const
+        {
+            for (int i = 0; i < ng_node_vector.size(); ++i)
+            {
+                // Trailing optional outputs may not be specified in the ONNX model.
+                // Other optional outputs should have name set to an empty string.
+                if (i >= onnx_node.get_outputs_size())
+                {
+                    break;
+                }
+
+                ng_node_vector[i]->set_friendly_name(onnx_node.output(i));
+            }
+        }
+
         void Graph::add_provenance_tag_to_initializer(
             const Tensor& tensor, std::shared_ptr<default_opset::Constant> node) const
         {

src/ngraph/frontend/onnx_import/core/graph.hpp

@@ -47,6 +47,8 @@ namespace ngraph
             NodeVector make_ng_nodes(const Node& onnx_node) const;
 
         protected:
+            void set_friendly_names(const Node& onnx_node, const NodeVector& ng_node_vector) const;
+
             void add_provenance_tag_to_initializer(
                 const Tensor& initializer, std::shared_ptr<default_opset::Constant> node) const;
 

test/onnx/onnx_import.in.cpp

@@ -90,6 +90,25 @@ NGRAPH_TEST(onnx_${BACKEND_NAME}, output_names_check)
     }
 }
 
+NGRAPH_TEST(onnx_${BACKEND_NAME}, node_names_check)
+{
+    auto function = onnx_import::import_onnx_model(
+        file_util::path_join(SERIALIZED_ZOO, "onnx/add_abc.prototxt"));
+
+    // Filter out Add nodes from the function graph
+    std::vector<std::shared_ptr<Node>> additions;
+    auto ordered_ops = function->get_ordered_ops();
+    std::copy_if(
+        ordered_ops.begin(),
+        ordered_ops.end(),
+        std::back_inserter(additions),
+        [](std::shared_ptr<Node> op) { return std::string(op->get_type_name()) == "Add"; });
+
+    EXPECT_EQ(additions.size(), 2);
+    EXPECT_EQ(additions.at(0)->get_friendly_name(), "X");
+    EXPECT_EQ(additions.at(1)->get_friendly_name(), "Y");
+}
+
 NGRAPH_TEST(onnx_${BACKEND_NAME}, model_add_abc)
 {
     auto function = onnx_import::import_onnx_model(