namespace parallel_device {
namespace {

class OpDeleter {
 public:
  void operator()(TFE_Op* to_delete) const { TFE_DeleteOp(to_delete); }
};

using OpPtr = std::unique_ptr<TFE_Op, OpDeleter>;

using MaybeParallelTensorOwned =
    absl::variant<std::unique_ptr<ParallelTensor>, TensorHandlePtr>;

using MaybeParallelTensorUnowned =
    absl::variant<ParallelTensor*, TFE_TensorHandle*>;

// deleted by TF_DeleteTensor.
using Safe_TF_TensorPtr = std::unique_ptr<TF_Tensor, detail::TFTensorDeleter>;
Safe_TF_TensorPtr make_safe(TF_Tensor* tensor);

// Safe containers for an owned TFE_TensorHandle. On destruction, the handle
// will be deleted by TFE_DeleteTensorHandle.
using Safe_TFE_TensorHandlePtr =
    std::unique_ptr<TFE_TensorHandle, detail::TFETensorHandleDeleter>;

  // Create instances of all registered hardwares.
  std::vector<std::unique_ptr<tac::TargetHardware>> InstantiateBackends();

  std::unique_ptr<TacImporter> importer_;
  std::unique_ptr<TacExporter> exporter_;
  // Owned list of all target hardware backends.
  std::vector<std::unique_ptr<tac::TargetHardware>> backends_;
  // Holder for const pointers for the data in 'backends_'

  auto ret3 = ops::_Retval(s.WithOpName("ret3"), while_op.output[1], 3);
  std::unique_ptr<Graph> g(new Graph(OpRegistry::Global()));
  TF_CHECK_OK(s.ToGraph(g.get()));

  std::vector<std::unique_ptr<FunctionBody>> fbodies;
  TF_CHECK_OK(RearrangeFunctionArguments(
      [&](const NameAttrList &function, const FunctionBody **fbody) {
        std::unique_ptr<FunctionBody> new_fbody;

// ops.
std::unique_ptr<OperationPass<ModuleOp>> CreateLegalizeTFCommunicationPass();

// Legalizes TF/XLA collective ops (TF dialect) to HLO dialect collective
// ops.
std::unique_ptr<OperationPass<ModuleOp>> CreateLegalizeTFCollectivePass();

// Verifies that the TF/XLA ops have all been lowered to MHLO.
std::unique_ptr<OperationPass<func::FuncOp>> CreateVerifyTFXLALegalizationPass(

std::function<std::unique_ptr<TargetHardware>()> GetTargetHardwareFactory(
    const std::string& hardware_name);

namespace internal {

void RegisterTargetHardwareFactory(
    const std::string& unique_name, const std::string& description,
    mlir::TypeID type_id,
    std::function<std::unique_ptr<TargetHardware>()> target_hardware_factory);

  using TFE_MonitoringGauge::TFE_MonitoringGauge;
};

struct TFE_MonitoringBuckets {
  explicit TFE_MonitoringBuckets(
      std::function<std::unique_ptr<tensorflow::monitoring::Buckets>(void)>
          fn) {
    create_buckets = fn;
  }

  std::function<std::unique_ptr<tensorflow::monitoring::Buckets>(void)>
      create_buckets;
};

struct TFE_MonitoringSamplerCell {
  tensorflow::monitoring::SamplerCell cell;

  static absl::StatusOr<std::unique_ptr<WritableFileWrapper>> Create(
      const std::string& filepath) {
    std::unique_ptr<tsl::WritableFile> file;
    TF_RETURN_IF_ERROR(tsl::Env::Default()->NewWritableFile(filepath, &file));
    return absl::WrapUnique(new WritableFileWrapper(std::move(file)));
  }

 private:
  explicit WritableFileWrapper(std::unique_ptr<tsl::WritableFile> file)
      : file_(std::move(file)) {

        func_name_attrs, new_func_name, host_graph_func_name, host_compute_core,
        flr, fld, shape_inference_graphs, has_outside_compilation);
  }

 private:
  std::unique_ptr<DeviceMgr> device_mgr_;
  std::unique_ptr<ProcessFunctionLibraryRuntime> pflr_;
};

TEST_F(ExtractOutsideCompilationForFunctionTest, Basic) {
  // Build the XLA computation func.
  // "const0"

// qint types to int types and surround TF UniformQuantized ops with qint <->
// int casts.
std::unique_ptr<OperationPass<func::FuncOp>> CreateConvertTFQuantTypesPass();

// Creates an instance of the VerifyQuantLegalization pass, which verifies all
// quant ops and types are lowered.
std::unique_ptr<OperationPass<func::FuncOp>>
CreateVerifyQuantLegalizationPass();