def gen_function_decl(func_attrs: Dict[str, Any]) -> str:
    """
    Parameters
    ----------
    func_attrs : dict
        Attributes from Operator
    backend_spec : class
        specifies backend configs

    Returns
    -------
    str
        Function declaration
    """

    func_name = func_attrs["name"]
    x = func_attrs["inputs"][0]
    rank = x._rank()
    return FUNC_DECL_TEMPLATE.render(
        func_name=func_name,
        input_rank=rank,
    )

    Parameters
    ----------
    func_attrs : dict
        Attributes from Operator
    backend_spec : class
        specifies backend configs

    Returns
    -------
    str
        Function declaration
    
python/aitemplate/backend/cuda/tensor/permute.py