register_flag_optional(CMAKE_CXX_COMPILER
        "Any CXX compiler that is supported by CMake detection, this is used for host compilation"
        "c++")

register_flag_optional(MEM "Device memory mode:
        DEFAULT   - allocate host and device memory pointers.
        MANAGED   - use CUDA Managed Memory.
        PAGEFAULT - shared memory, only host pointers allocated."
        "DEFAULT")

register_flag_required(CMAKE_CUDA_COMPILER
        "Path to the CUDA nvcc compiler")

# XXX CMake 3.18 supports CMAKE_CUDA_ARCHITECTURES/CUDA_ARCHITECTURES but we support older CMakes
register_flag_required(CUDA_ARCH
        "Nvidia architecture, will be passed in via `-arch=` (e.g `sm_70`) for nvcc")

register_flag_optional(CUDA_EXTRA_FLAGS
        "Additional CUDA flags passed to nvcc, this is appended after `CUDA_ARCH`"
        "")


macro(setup)
    enable_language(CUDA)
    register_definitions(MEM=${MEM})
    set(CMAKE_CUDA_FLAGS ${CMAKE_CUDA_FLAGS} -arch=${CUDA_ARCH} ${CUDA_EXTRA_FLAGS})
    message(STATUS "NVCC flags: ${CMAKE_CUDA_FLAGS}")
endmacro()