hacky work to get backend registration

Author: JacobSzwejbka

backends/cuda/runtime/cuda_backend.cpp

@@ -376,4 +376,17 @@ executorch::runtime::Backend backend{"CudaBackend", &cls};
 static executorch::runtime::Error success_with_compiler =
     register_backend(backend);
 } // namespace
+
+// Export an initialization function to ensure static initializers run on Windows
+#ifdef _WIN32
+#define CUDA_BACKEND_INIT_EXPORT __declspec(dllexport)
+#else
+#define CUDA_BACKEND_INIT_EXPORT __attribute__((visibility("default")))
+#endif
+
+extern "C" CUDA_BACKEND_INIT_EXPORT void InitCudaBackend() {
+  // Force the static initializer to run by referencing it
+  (void)success_with_compiler;
+}
+
 } // namespace executorch::backends

examples/models/voxtral/CMakeLists.txt

@@ -84,17 +84,6 @@ list(
   extension_flat_tensor
 )
 
-# Link CUDA backend
-if(EXECUTORCH_BUILD_CUDA)
-  find_package(CUDAToolkit REQUIRED)
-  list(APPEND link_libraries aoti_cuda)
-  # CMake will automatically use the import library on Windows
-  if(NOT MSVC)
-    # Only apply shared lib linking options on non-Windows platforms
-    executorch_target_link_options_shared_lib(aoti_cuda)
-  endif()
-endif()
-
 if(EXECUTORCH_BUILD_METAL)
   list(APPEND link_libraries metal_backend)
   executorch_target_link_options_shared_lib(metal_backend)
@@ -111,6 +100,17 @@ if(NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
   endif()
 endif()
 
+# Link CUDA backend
+if(EXECUTORCH_BUILD_CUDA AND NOT MSVC)
+  find_package(CUDAToolkit REQUIRED)
+  list(APPEND link_libraries aoti_cuda)
+  executorch_target_link_options_shared_lib(aoti_cuda)
+elseif(EXECUTORCH_BUILD_CUDA AND MSVC)
+  find_package(CUDAToolkit REQUIRED)
+  target_link_libraries(voxtral_runner PRIVATE aoti_cuda)
+  executorch_target_link_options_shared_lib(aoti_cuda)
+endif()
+
 target_include_directories(voxtral_runner PUBLIC ${_common_include_directories})
 target_link_libraries(voxtral_runner PUBLIC ${link_libraries})
 target_compile_options(voxtral_runner PUBLIC ${_common_compile_options})

examples/models/voxtral/multimodal.cpp

@@ -282,7 +282,16 @@ MultimodalInput processAudioFile(
 
 } // namespace
 
+// Forward declare the initialization function from aoti_cuda
+extern "C" void InitCudaBackend();
+
 int32_t main(int32_t argc, char** argv) {
+#ifdef _WIN32
+  // On Windows, explicitly initialize the CUDA backend to ensure
+  // static initializers in the DLL run
+  InitCudaBackend();
+#endif
+  
   gflags::ParseCommandLineFlags(&argc, &argv, true);
 
   const char* model_path = FLAGS_model_path.c_str();