Enable correct prefix for TestSharedLib directory

Signed-off-by: Shreyas Atre <shreyasatre16@gmail.com>

unittests/CppInterOp/CMakeLists.txt

@@ -22,12 +22,16 @@ export_executable_symbols(CppInterOpTests)
 
 unset(LLVM_LINK_COMPONENTS)
 
-add_cppinterop_unittest(DynamicLibraryManagerTests DynamicLibraryManagerTest.cpp)
+add_cppinterop_unittest(DynamicLibraryManagerTests DynamicLibraryManagerTest.cpp ${LLVM_OPTIONAL_SOURCES})
 target_link_libraries(DynamicLibraryManagerTests
   PRIVATE
   clangCppInterOp
   )
 
+target_compile_definitions(DynamicLibraryManagerTests
+  PRIVATE CPPINTEROP_LIB_TestSharedLib_DIR_PREFIX=${CMAKE_BINARY_DIR}/unittests/bin/$<CONFIG>/
+)
+
 set_output_directory(DynamicLibraryManagerTests BINARY_DIR ${CMAKE_BINARY_DIR}/unittests/bin/$<CONFIG>/)
 
 add_dependencies(DynamicLibraryManagerTests TestSharedLib)

unittests/CppInterOp/DynamicLibraryManagerTest.cpp

@@ -7,6 +7,9 @@
 
 #include "../../lib/Interpreter/Paths.h"
 
+#define XCPP_INTEROP_STRINGIFY(x) #x
+#define CPP_INTEROP_STRINGIFY(x) XCPP_INTEROP_STRINGIFY(x)
+
 // This function isn't referenced outside its translation unit, but it
 // can't use the "static" keyword because its address is used for
 // GetMainExecutable (since some platforms don't support taking the
@@ -59,15 +62,23 @@ TEST(DynamicLibraryManagerTest, Sanity) {
 
 TEST(UtilsPlatform, DLTest) {
   std::string err = "";
+  // CPPINTEROP_LIB_TestSharedLib_DIR_PREFIX specified by cmake though target
+  // definitions
 #if defined(__APPLE__)
   auto dlopen_handle = Cpp::utils::platform::DLOpen(
-      "./libTestSharedLib.dylib", err);
+      CPP_INTEROP_STRINGIFY(
+          CPPINTEROP_LIB_TestSharedLib_DIR_PREFIX) "./libTestSharedLib.dylib",
+      err);
 #elif defined(_WIN32)
   auto dlopen_handle = Cpp::utils::platform::DLOpen(
-      "./libTestSharedLib.dll", err);
+      CPP_INTEROP_STRINGIFY(
+          CPPINTEROP_LIB_TestSharedLib_DIR_PREFIX) "./libTestSharedLib.dll",
+      err);
 #else
-  auto dlopen_handle =
-      Cpp::utils::platform::DLOpen("../bin/libTestSharedLib.so", err);
+  auto dlopen_handle = Cpp::utils::platform::DLOpen(
+      CPP_INTEROP_STRINGIFY(
+          CPPINTEROP_LIB_TestSharedLib_DIR_PREFIX) "./libTestSharedLib.so",
+      err);
 #endif
   EXPECT_TRUE(dlopen_handle);
   EXPECT_TRUE(err.empty());