removed dependency on installed OpenCL SDK, adapted test to succeed when OpenCL is unavailable

CMakeLists.txt

@@ -53,12 +53,6 @@ if(POLICY CMP0053)
   cmake_policy(SET CMP0053 OLD)
 endif(POLICY CMP0053)
 
-
-include(CMakeCommon/FindOpenCL.cmake)
-IF(NOT OpenCL_FOUND)
-  MESSAGE( STATUS "OpenCL is not there, will build without MTAPI OpenCL Plugin." )
-ENDIF()
-
 # give the user the possibility, to append compiler flags
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${EXTRA_CMAKE_CXX_FLAGS}")
 set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EXTRA_CMAKE_C_FLAGS}")
@@ -88,6 +82,7 @@ option(USE_EXCEPTIONS "Specify whether exceptions should be activated in C++" ON
 option(INSTALL_DOCS "Specify whether Doxygen docs should be installed" ON)
 option(WARNINGS_ARE_ERRORS "Specify whether warnings should be treated as errors" OFF)
 option(USE_AUTOMATIC_INITIALIZATION "Specify whether the MTAPI C++ interface, algorithms and dataflow should automatically intialize the MTAPI node if no explicit initialization is present" ON)
+option(BUILD_OPENCL_PLUGIN "Specify whether the MTAPI OpenCL plugin should be built" OFF)
 
 ## LOCAL INSTALLATION OF SUBPROJECT BINARIES
 #
@@ -146,7 +141,7 @@ set(EXPECTED_EMBB_TEST_EXECUTABLES "embb_algorithms_cpp_test"
                 )
 
 # if opencl is there, we also expect the mtapi opencl test to be generated
-if(OpenCL_FOUND)
+if(BUILD_OPENCL_PLUGIN STREQUAL ON)
   list(APPEND EXPECTED_EMBB_TEST_EXECUTABLES "embb_mtapi_opencl_c_test")
 endif()
 
@@ -182,7 +177,7 @@ add_subdirectory(base_c)
 add_subdirectory(base_cpp)
 add_subdirectory(mtapi_c)
 add_subdirectory(mtapi_network_c)
-if(OpenCL_FOUND)
+if(BUILD_OPENCL_PLUGIN STREQUAL ON)
   add_subdirectory(mtapi_opencl_c)
 endif()
 add_subdirectory(tasks_cpp)

doc/examples/CMakeLists.txt

@@ -21,7 +21,7 @@ include_directories(
   ${CMAKE_CURRENT_SOURCE_DIR}/../../dataflow_cpp/include
   )
 
-if(OpenCL_FOUND)
+if(BUILD_OPENCL_PLUGIN STREQUAL ON)
   # used in source code, to include opencl code
   add_definitions(-DEMBB_WITH_OPENCL)
   # add opencl includes

mtapi_opencl_c/src/embb_mtapi_opencl.c

@@ -259,7 +259,11 @@ void mtapi_opencl_plugin_initialize(
   embb_mtapi_opencl_plugin_t * plugin = &embb_mtapi_opencl_plugin;
 
   err = embb_mtapi_opencl_link_at_runtime();
-  if (err != 0) {
+  if (err <= 0) {
+    // OpenCL not available, or wrong version
+    local_status = MTAPI_ERR_FUNC_NOT_IMPLEMENTED;
+  } else {
+    // all good, go ahead
     err = clGetPlatformIDs(1, &plugin->platform_id, NULL);
     if (CL_SUCCESS == err) {
       err = clGetDeviceIDs(plugin->platform_id, CL_DEVICE_TYPE_DEFAULT,

mtapi_opencl_c/src/embb_mtapi_opencl_runtimelinker.c

@@ -263,7 +263,7 @@ int embb_mtapi_opencl_link_at_runtime() {
   void * opencl_dll_handle = dlopen("libOpenCL.so", RTLD_LAZY);
 #endif
   if (opencl_dll_handle == 0)
-    return 0;
+    return -1;
 
 #ifdef EMBB_PLATFORM_COMPILER_MSVC
 #pragma warning(push)

mtapi_opencl_c/test/embb_mtapi_opencl_test_linker.cc

@@ -34,5 +34,7 @@ LinkerTest::LinkerTest() {
 }
 
 void LinkerTest::TestBasic() {
-  PT_EXPECT(embb_mtapi_opencl_link_at_runtime() != 0);
+  int result = embb_mtapi_opencl_link_at_runtime();
+  bool success = result != 0;
+  PT_EXPECT(success);
 }

mtapi_opencl_c/test/embb_mtapi_opencl_test_task.cc

@@ -75,6 +75,10 @@ void TaskTest::TestBasic() {
   }
 
   mtapi_opencl_plugin_initialize(&status);
+  if (status == MTAPI_ERR_FUNC_NOT_IMPLEMENTED) {
+    // OpenCL unavailable
+    return;
+  }
   MTAPI_CHECK_STATUS(status);
 
   mtapi_initialize(