enable visualize graph even if graphviz is not installed because it just doesn't matter (#2225)

src/ngraph/pass/visualize_tree.cpp

@@ -151,9 +151,8 @@ std::string pass::VisualizeTree::get_file_ext()
 
 void pass::VisualizeTree::render() const
 {
-#ifdef GRAPHVIZ_FOUND
-    auto tmp_file = m_name + ".tmp";
-    ofstream out(tmp_file);
+    auto dot_file = m_name + ".dot";
+    ofstream out(dot_file);
     if (out)
     {
         out << "digraph ngraph\n{\n";
@@ -163,15 +162,12 @@ void pass::VisualizeTree::render() const
 
         stringstream ss;
 
-        ss << "dot -T" << get_file_ext() << " " << tmp_file << " -o " << m_name;
+        ss << "dot -T" << get_file_ext() << " " << dot_file << " -o " << m_name;
         auto cmd = ss.str();
         auto stream = popen(cmd.c_str(), "r");
         if (stream)
         {
             pclose(stream);
         }
-
-        remove(tmp_file.c_str());
     }
-#endif
 }

test/util.cpp

@@ -25,6 +25,8 @@
 #include "ngraph/function.hpp"
 #include "ngraph/graph_util.hpp"
 #include "ngraph/ngraph.hpp"
+#include "ngraph/pass/manager.hpp"
+#include "ngraph/pass/visualize_tree.hpp"
 #include "ngraph/serializer.hpp"
 #include "util/all_close.hpp"
 #include "util/autodiff/backprop_function.hpp"
@@ -409,3 +411,16 @@ TEST(graph_util, test_subgraph_topological_sort_control_dependencies)
     std::list<std::shared_ptr<Node>> expected{A, D, add, mul};
     ASSERT_EQ(expected, sorted);
 }
+
+TEST(pass, visualize_tree)
+{
+    Shape shape{2, 2};
+    auto A = make_shared<op::Parameter>(element::f32, shape);
+    auto B = make_shared<op::Parameter>(element::f32, shape);
+    auto C = make_shared<op::Parameter>(element::f32, shape);
+    auto f = make_shared<Function>((A + B) * C, ParameterVector{A, B, C});
+
+    ngraph::pass::Manager pm;
+    pm.register_pass<pass::VisualizeTree>("test_viz.png");
+    pm.run_passes(f);
+}