Bug Fix: Codegen - macos system header path is hard wired for mojave. (#4276)

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

src/ngraph/codegen/CMakeLists.txt

@@ -61,6 +61,10 @@ if(NGRAPH_TBB_ENABLE)
     set_source_files_properties(compiler.cpp PROPERTIES COMPILE_DEFINITIONS "NGRAPH_TBB_ENABLE")
 endif()
 
+if(APPLE)
+    list(APPEND HEADER_SEARCH_DEFINES CMAKE_OSX_SYSROOT="${CMAKE_OSX_SYSROOT}")
+endif()
+
 set_source_files_properties(compiler.cpp PROPERTIES COMPILE_DEFINITIONS "${HEADER_SEARCH_DEFINES}")
 
 # Generate the resource file containing all headers used by the codegen compiler

src/ngraph/codegen/compiler.cpp

@@ -441,12 +441,9 @@ void codegen::CompilerCore::configure_search_path()
     add_header_search_path("/Library/Developer/CommandLineTools/usr/include/c++/v1");
     add_header_search_path("/usr/local/include");
     add_header_search_path(CLANG_BUILTIN_HEADERS_PATH);
-    std::string mojave_isysroot = file_util::path_join(
-        "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs",
-        "MacOSX10.14.sdk");
-    if (file_util::exists(mojave_isysroot))
+    if (file_util::exists(CMAKE_OSX_SYSROOT))
     {
-        add_header_search_path(file_util::path_join(mojave_isysroot, "usr/include"));
+        add_header_search_path(file_util::path_join(CMAKE_OSX_SYSROOT, "usr/include"));
     }
     else
     {