Separate dynamic loading from static linking (#3456)

* Separate dynamic loading from static linking

* Missed find_my_pathname

CMakeLists.txt

@@ -185,6 +185,7 @@ option(NGRAPH_JSON_ENABLE "Enable JSON based serialization and tracing features"
 option(NGRAPH_STATIC_LIB_ENABLE "Enable build nGraph static library" FALSE)
 option(NGRAPH_INTERPRETER_STATIC_LIB_ENABLE "Enable build INTERPRETER backend static library" FALSE)
 option(NGRAPH_CPU_STATIC_LIB_ENABLE "Enable build CPU backend static library" FALSE)
+option(NGRAPH_DYNAMIC_COMPONENTS_ENABLE "Enable dynamic loading of components" TRUE)
 
 if (NGRAPH_CPU_ENABLE
         AND
@@ -263,6 +264,7 @@ NORMALIZE_BOOL(NGRAPH_JSON_ENABLE)
 NORMALIZE_BOOL(NGRAPH_STATIC_LIB_ENABLE)
 NORMALIZE_BOOL(NGRAPH_INTERPRETER_STATIC_LIB_ENABLE)
 NORMALIZE_BOOL(NGRAPH_CPU_STATIC_LIB_ENABLE)
+NORMALIZE_BOOL(NGRAPH_DYNAMIC_COMPONENTS_ENABLE)
 
 message(STATUS "NGRAPH_UNIT_TEST_ENABLE:              ${NGRAPH_UNIT_TEST_ENABLE}")
 message(STATUS "NGRAPH_TOOLS_ENABLE:                  ${NGRAPH_TOOLS_ENABLE}")
@@ -289,6 +291,7 @@ message(STATUS "NGRAPH_JSON_ENABLE:                   ${NGRAPH_JSON_ENABLE}")
 message(STATUS "NGRAPH_STATIC_LIB_ENABLE:             ${NGRAPH_STATIC_LIB_ENABLE}")
 message(STATUS "NGRAPH_INTERPRETER_STATIC_LIB_ENABLE: ${NGRAPH_INTERPRETER_STATIC_LIB_ENABLE}")
 message(STATUS "NGRAPH_CPU_STATIC_LIB_ENABLE:         ${NGRAPH_CPU_STATIC_LIB_ENABLE}")
+message(STATUS "NGRAPH_DYNAMIC_COMPONENTS_ENABLE:     ${NGRAPH_DYNAMIC_COMPONENTS_ENABLE}")
 
 #-----------------------------------------------------------------------------------------------
 # Installation logic...
@@ -402,6 +405,10 @@ if (NGRAPH_STATIC_LIB_ENABLE)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNGRAPH_STATIC_LIB_ENABLE")
 endif()
 
+if (NGRAPH_DYNAMIC_COMPONENTS_ENABLE)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNGRAPH_DYNAMIC_COMPONENTS_ENABLE")
+endif()
+
 if (NGRAPH_PLAIDML_ENABLE)
     find_package(PlaidML CONFIG)
     if (NOT PLAIDML_FOUND)

src/ngraph/runtime/backend.cpp

@@ -37,9 +37,7 @@ std::string runtime::Backend::s_backend_shared_library_search_directory;
 // This finds the full path of the containing shared library
 static string find_my_pathname()
 {
-#ifdef NGRAPH_STATIC_LIB_ENABLE
-    return "";
-#else
+#ifdef NGRAPH_DYNAMIC_COMPONENTS_ENABLE
 #ifdef _WIN32
     HMODULE hModule = GetModuleHandleW(L"ngraph.dll");
     WCHAR wpath[MAX_PATH];
@@ -55,6 +53,8 @@ static string find_my_pathname()
     dladdr(reinterpret_cast<void*>(find_my_pathname), &dl_info);
     return dl_info.dli_fname;
 #endif
+#else
+    return "";
 #endif
 }
 

src/ngraph/runtime/backend_manager.cpp

@@ -32,9 +32,7 @@
 using namespace std;
 using namespace ngraph;
 
-#ifdef NGRAPH_STATIC_LIB_ENABLE
-#define DLERROR() ""
-#else
+#ifdef NGRAPH_DYNAMIC_COMPONENTS_ENABLE
 #ifdef _WIN32
 #define CLOSE_LIBRARY(a) FreeLibrary(a)
 #define DLSYM(a, b) GetProcAddress(a, b)
@@ -44,6 +42,8 @@ using namespace ngraph;
 #define DLSYM(a, b) dlsym(a, b)
 #define DLERROR() dlerror()
 #endif
+#else
+#define DLERROR() ""
 #endif
 
 unordered_map<string, runtime::BackendConstructor*>& runtime::BackendManager::get_registry()
@@ -107,7 +107,7 @@ shared_ptr<runtime::Backend> runtime::BackendManager::create_backend(const std::
     }
     else
     {
-#ifndef NGRAPH_STATIC_LIB_ENABLE
+#ifdef NGRAPH_DYNAMIC_COMPONENTS_ENABLE
         DL_HANDLE handle = open_shared_library(type);
         if (!handle)
         {
@@ -153,7 +153,7 @@ DL_HANDLE runtime::BackendManager::open_shared_library(string type)
     string lib_suffix = SHARED_LIB_SUFFIX;
 
     DL_HANDLE handle = nullptr;
-#ifndef NGRAPH_STATIC_LIB_ENABLE
+#ifdef NGRAPH_DYNAMIC_COMPONENTS_ENABLE
 
     // strip off attributes, IE:CPU becomes IE
     auto colon = type.find(":");
@@ -190,7 +190,7 @@ DL_HANDLE runtime::BackendManager::open_shared_library(string type)
 map<string, string> runtime::BackendManager::get_registered_device_map()
 {
     map<string, string> rc;
-#ifndef NGRAPH_STATIC_LIB_ENABLE
+#ifdef NGRAPH_DYNAMIC_COMPONENTS_ENABLE
     string my_directory =
         file_util::get_directory(Backend::get_backend_shared_library_search_directory());
     vector<string> backend_list;