Function ConvertToTensor

tensorflow/python/eager/pywrap_tfe_src.cc:2696–2726

Supports 3 cases at the moment: i) input is an EagerTensor. ii) input is a ResourceVariable - in this case, the is_variable param is set to true. iii) input is an arbitrary python list/tuple (note, this handling doesn't support packing). NOTE: dtype_hint_getter must *always* return a PyObject that can be decref'd. So if no hint is found, Py_RETURN_NONE (which correctly increfs Py_None). NOTE: Th

//  NOTE: This function sets a python error directly, and returns false.
//  TF_Status is only passed since we don't want to have to reallocate it.
bool ConvertToTensor(
    const FastPathOpExecInfo& op_exec_info, PyObject* input,
    tensorflow::Safe_PyObjectPtr* output_handle,
    // This gets a hint for this particular input.
    const std::function<tensorflow::DataType()>& dtype_hint_getter,
    // This sets the dtype after conversion is complete.
    const std::function<void(const tensorflow::DataType dtype)>& dtype_setter,
    TF_Status* status) {
  if (EagerTensor_CheckExact(input)) {
    Py_INCREF(input);
    output_handle->reset(input);
    return true;
  } else if (CheckResourceVariable(input)) {
    return ReadVariableOp(op_exec_info, input, output_handle, status);
  }

  // The hint comes from a supposedly similarly typed tensor.
  tensorflow::DataType dtype_hint = dtype_hint_getter();

  TFE_TensorHandle* handle = tensorflow::ConvertToEagerTensor(
      op_exec_info.ctx, input, dtype_hint, op_exec_info.device_name);
  if (handle == nullptr) {
    return MaybeRaiseExceptionFromTFStatus(status, nullptr);
  }

  output_handle->reset(EagerTensorFromHandle(handle));
  dtype_setter(
      static_cast<tensorflow::DataType>(TFE_TensorHandleDataType(handle)));

  return true;
}

// Adds input and type attr to the op, and to the list of flattened
// inputs/attrs.