[SYCL][CUDA] Fix get_native interop for device

sycl/include/sycl/backend.hpp

@@ -101,6 +101,7 @@ struct BufferInterop<backend::opencl, DataT, Dimensions, AllocatorT> {
   }
 };
 
+#if SYCL_EXT_ONEAPI_BACKEND_LEVEL_ZERO
 template <backend BackendName, typename DataT, int Dimensions,
           typename AllocatorT>
 auto get_native_buffer(const buffer<DataT, Dimensions, AllocatorT, void> &Obj)
@@ -115,6 +116,7 @@ auto get_native_buffer(const buffer<DataT, Dimensions, AllocatorT, void> &Obj)
         PI_ERROR_INVALID_OPERATION);
   return Obj.template getNative<BackendName>();
 }
+#endif
 } // namespace detail
 
 template <backend BackendName, class SyclObjectT>
@@ -147,6 +149,7 @@ auto get_native(const buffer<DataT, Dimensions, AllocatorT> &Obj)
   return detail::get_native_buffer<BackendName>(Obj);
 }
 
+#if SYCL_BACKEND_OPENCL
 template <>
 inline backend_return_t<backend::opencl, event>
 get_native<backend::opencl, event>(const event &Obj) {
@@ -164,6 +167,23 @@ get_native<backend::opencl, event>(const event &Obj) {
   }
   return ReturnValue;
 }
+#endif
+
+#if SYCL_EXT_ONEAPI_BACKEND_CUDA
+template <>
+inline backend_return_t<backend::ext_oneapi_cuda, device>
+get_native<backend::ext_oneapi_cuda, device>(const device &Obj) {
+  // TODO use SYCL 2020 exception when implemented
+  if (Obj.get_backend() != backend::ext_oneapi_cuda) {
+    throw sycl::runtime_error(errc::backend_mismatch, "Backends mismatch",
+                              PI_ERROR_INVALID_OPERATION);
+  }
+  // CUDA uses a 32-bit int instead of an opaque pointer like other backends,
+  // so we need a specialization with static_cast instead of reinterpret_cast.
+  return static_cast<backend_return_t<backend::ext_oneapi_cuda, device>>(
+      Obj.getNative());
+}
+#endif
 
 // Native handle of an accessor should be accessed through interop_handler
 template <backend BackendName, typename DataT, int Dimensions,

sycl/include/sycl/ext/oneapi/experimental/backend/cuda.hpp

@@ -73,20 +73,6 @@ inline device make_device<backend::ext_oneapi_cuda>(
   return ext::oneapi::cuda::make_device(NativeHandle);
 }
 
-template <>
-backend_return_t<backend::ext_oneapi_cuda, device>
-get_native<backend::ext_oneapi_cuda, device>(const device &Obj) {
-  // TODO use SYCL 2020 exception when implemented
-  if (Obj.get_backend() != backend::ext_oneapi_cuda) {
-    throw sycl::runtime_error(errc::backend_mismatch, "Backends mismatch",
-                              PI_ERROR_INVALID_OPERATION);
-  }
-  // CUDA uses a 32-bit int instead of an opaque pointer like other backends,
-  // so we need a specialization with static_cast instead of reinterpret_cast.
-  return static_cast<backend_return_t<backend::ext_oneapi_cuda, device>>(
-      Obj.getNative());
-}
-
 // CUDA event specialization
 template <>
 inline event make_event<backend::ext_oneapi_cuda>(

sycl/test/basic_tests/interop-cuda-experimental.cpp → sycl/test/basic_tests/interop-cuda.cpp

@@ -1,12 +1,18 @@
 // REQUIRES: cuda
 // RUN: %clangxx %fsycl-host-only -fsyntax-only -Xclang -verify -Xclang -verify-ignore-unexpected=note %s -o %t.out
 // RUN: %clangxx %fsycl-host-only -fsyntax-only -Xclang -verify -Xclang -verify-ignore-unexpected=note -D__SYCL_INTERNAL_API %s -o %t.out
+//
+/// Also test the experimental CUDA interop interface
+// RUN: %clangxx %fsycl-host-only -fsyntax-only -Xclang -verify -Xclang -verify-ignore-unexpected=note -DSYCL_EXT_ONEAPI_BACKEND_CUDA_EXPERIMENTAL %s -o %t.out
+// RUN: %clangxx %fsycl-host-only -fsyntax-only -Xclang -verify -Xclang -verify-ignore-unexpected=note -D__SYCL_INTERNAL_API -DSYCL_EXT_ONEAPI_BACKEND_CUDA_EXPERIMENTAL %s -o %t.out
 // expected-no-diagnostics
 
-// Test for experimental CUDA interop API
+// Test for legacy and experimental CUDA interop API
 
-#define SYCL_EXT_ONEAPI_BACKEND_CUDA_EXPERIMENTAL 1
+#ifdef SYCL_EXT_ONEAPI_BACKEND_CUDA_EXPERIMENTAL
 #include <sycl/ext/oneapi/experimental/backend/cuda.hpp>
+#endif
+
 #include <sycl/sycl.hpp>
 
 using namespace sycl;
@@ -73,6 +79,7 @@ int main() {
   // behavior of these template functions is defined by the SYCL backend
   // specification document.
 
+#ifdef SYCL_EXT_ONEAPI_BACKEND_CUDA_EXPERIMENTAL
   backend_input_t<backend::ext_oneapi_cuda, device> InteropDeviceInput{
       cu_device};
   device InteropDevice =
@@ -85,6 +92,7 @@ int main() {
   event InteropEvent = make_event<backend::ext_oneapi_cuda>(cu_event, Context);
 
   queue InteropQueue = make_queue<backend::ext_oneapi_cuda>(cu_queue, Context);
+#endif
 
   return 0;
 }