[SYCL] Add a test case interop_handle accepting placeholder accessor

SYCL/HostInteropTask/interop-task.cpp

@@ -37,9 +37,9 @@ void copy(buffer<DataT, 1> &Src, buffer<DataT, 1> &Dst, queue &Q) {
     auto DstA = Dst.template get_access<mode::write>(CGH);
 
     CGH.codeplay_host_task([=](interop_handle IH) {
-      auto NativeQ = IH.get_native_queue();
-      auto SrcMem = IH.get_native_mem(SrcA);
-      auto DstMem = IH.get_native_mem(DstA);
+      auto NativeQ = IH.get_native_queue<backend::opencl>();
+      auto SrcMem = IH.get_native_mem<backend::opencl>(SrcA);
+      auto DstMem = IH.get_native_mem<backend::opencl>(DstA);
       cl_event Event;
 
       int RC = clEnqueueCopyBuffer(NativeQ, SrcMem, DstMem, 0, 0,
@@ -221,13 +221,65 @@ void test5() {
   checkBufferValues(Buffer2, static_cast<int>(123));
 }
 
+// The test checks that placeholder accessors are correctly handled,
+// when properly registered in the command group.
+// It also checks that an exception is thrown if the placeholder accessor
+// is not registered.
+void test6() {
+  queue Queue([](sycl::exception_list ExceptionList) {
+    if (ExceptionList.size() != 1) {
+      std::cerr << "Should be one exception in exception list" << std::endl;
+      std::abort();
+    }
+    std::rethrow_exception(*ExceptionList.begin());
+  });
+
+  // Placeholder accessor that is properly registered in CGH.
+  try {
+    size_t size = 1;
+    buffer<int, 1> Buf{size};
+    accessor<int, 1, mode::write, target::global_buffer,
+             access::placeholder::true_t>
+        PHAcc(Buf);
+    Queue.submit([&](sycl::handler &CGH) {
+      CGH.require(PHAcc);
+      CGH.codeplay_host_task(
+          [=](interop_handle IH) { (void)IH.get_native_mem(PHAcc); });
+    });
+    Queue.wait_and_throw();
+  } catch (sycl::exception &E) {
+    std::cerr << "Unexpected exception caught: " << E.what();
+    assert(!"Unexpected exception caught");
+  }
+
+  // Placeholder accessor that is NOT registered in CGH.
+  try {
+    size_t size = 1;
+    buffer<int, 1> Buf{size};
+    accessor<int, 1, mode::write, target::global_buffer,
+             access::placeholder::true_t>
+        PHAcc(Buf);
+    Queue.submit([&](sycl::handler &CGH) {
+      CGH.codeplay_host_task(
+          [=](interop_handle IH) { (void)IH.get_native_mem(PHAcc); });
+    });
+    Queue.wait_and_throw();
+    assert(!"Expected exception was not caught");
+  } catch (sycl::exception &E) {
+    assert(std::string(E.what()).find("Invalid memory object") !=
+               std::string::npos &&
+           "Unexpected error was caught!");
+  }
+}
+
 int main() {
   test1();
   test2();
   test2_1();
   test3();
   test4();
   test5();
+  test6();
   std::cout << "Test PASSED" << std::endl;
   return 0;
 }