add cmake finder for graphviz dot program and then conditionally compile…

add cmake finder for graphviz dot program and then conditionally compile visualization based on finding

cmake/Modules/FindGraphviz.cmake

+find_program(GRAPHVIZ_EXECUTABLE dot)
+
+# Handle REQUIRED and QUIET arguments
+# this will also set GRAPHVIZ_FOUND to true if GRAPHVIZ_EXECUTABLE exists
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Graphviz
+                     "Failed to locate graphviz executable"
+                     GRAPHVIZ_EXECUTABLE)

src/CMakeLists.txt

@@ -36,15 +36,22 @@ set(NGRAPH_INCLUDE_PATH
     ${CMAKE_CURRENT_SOURCE_DIR}/ngraph
 )
 
+# find_program (GRAPHVIZ dot)
+# message (STATUS "graphviz '${GRAPHVIZ}'")
+find_package(Graphviz)
+if (GRAPHVIZ_FOUND)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DGRAPHVIZ_FOUND")
+endif()
+
 include_directories("${NGRAPH_INCLUDE_PATH}")
 
 add_library(ngraph SHARED ${SRC})
 target_include_directories(ngraph PUBLIC "${NGRAPH_INCLUDE_PATH}")
 
-if ( APPLE )
-    set_property( TARGET ngraph PROPERTY PREFIX "lib" )
-    set_property( TARGET ngraph PROPERTY OUTPUT_NAME "ngraph.so" )
-    set_property( TARGET ngraph PROPERTY SUFFIX "" )
+if (APPLE)
+    set_property(TARGET ngraph PROPERTY PREFIX "lib")
+    set_property(TARGET ngraph PROPERTY OUTPUT_NAME "ngraph.so")
+    set_property(TARGET ngraph PROPERTY SUFFIX "")
 endif()
 
 #-----------------------------------------------------------------------------------------------
@@ -63,7 +70,7 @@ set(CMAKE_INSTALL_PREFIX "$ENV{HOME}/ngraph_dist" CACHE PATH "Install directory"
 message (STATUS "Installation directory: ${CMAKE_INSTALL_PREFIX}")
 message (STATUS "To Override use: cmake -DCMAKE_INSTALL_PREFIX=/foo -P cmake_install.cmake")
 
-install(TARGETS ngraph DESTINATION ${CMAKE_INSTALL_PREFIX} )
+install(TARGETS ngraph DESTINATION ${CMAKE_INSTALL_PREFIX})
 install(DIRECTORY 
     ${CMAKE_CURRENT_SOURCE_DIR}/ngraph 
     DESTINATION ${CMAKE_INSTALL_PREFIX} 

src/ngraph/visualize.cpp

@@ -41,6 +41,7 @@ void Visualize::add(node_ptr p)
 
 void Visualize::save_dot(const string& path) const
 {
+#if GRAPHVIZ_FOUND
     auto     tmp_file = path + ".tmp";
     ofstream out(tmp_file);
     if (out)
@@ -56,6 +57,8 @@ void Visualize::save_dot(const string& path) const
         auto stream = popen(cmd.c_str(), "r");
         pclose(stream);
 
-        // remove(tmp_file.c_str());
+        remove(tmp_file.c_str());
     }
+#else
+#endif
 }