return llvm::formatv("requires attribute '{0}'", attribute).str();
}

// Populates a TPUCompileMetadataProto with StepMarkerLocation from a
// `tf_device::ClusterFuncOp`.
LogicalResult SetMetadataProtoStepMarkerLocation(
    tf_device::ClusterFuncOp op,
    tensorflow::tpu::TPUCompileMetadataProto* metadata) {
  auto step_marker_location =
      op->getAttrOfType<StringAttr>(kStepMarkerLocationAttr);

}

void TPUResourceReadsWritesPartitioningPass::runOnOperation() {
  llvm::SmallVector<tf_device::ClusterFuncOp, 4> cluster_funcs;
  getOperation()->walk([&cluster_funcs](tf_device::ClusterFuncOp cluster_func) {
    cluster_funcs.push_back(cluster_func);
  });
  for (tf_device::ClusterFuncOp cluster_func : cluster_funcs)
    if (failed(PartitionResourceReadsWrites(cluster_func)))
      return signalPassFailure();
}

}

void TPUSpaceToDepthPass::runOnOperation() {
  std::optional<tf_device::ClusterFuncOp> cluster_func;
  // Space to depth only supports training loop.
  auto func_result = getOperation().walk([&](tf_device::ClusterFuncOp cluster) {
    cluster_func = cluster;
    return WalkResult::interrupt();
  });

  // Return if there is no tf_device::ClusterFuncOp in training loop.
  if (!func_result.wasInterrupted() || !cluster_func.has_value()) {

    return WalkResult::advance();
  });
  if (result_init.wasInterrupted()) return signalPassFailure();
  llvm::SmallVector<tf_device::ClusterFuncOp> to_be_erased;
  OpBuilder builder(&getContext());
  auto result = getOperation().walk([&](tf_device::ClusterFuncOp op) {
    if (failed(TF::HasValidCompilationAndReplicationAttributes(*op)))
      return WalkResult::interrupt();
    // Skip non-tpu device cluster_func.

// XlaSharding op.
void IdentifyXlaShardingForComputationInputs(
    const llvm::SmallVector<std::string>& logical_device_vec,
    bool infer_from_computation, mlir::tf_device::ClusterFuncOp cluster_func,
    mlir::func::FuncOp func, Builder* builder,
    OptionalOpShardingVector& sharding_for_args) {
  // Look up function definition from module.
  Block& function_block = func.front();

              mlir::StringAttr::get(op->getContext(), hlosharding->ToString()));
}

mlir::LogicalResult ExtractInputsForLogicalDevices(
    const int num_cores_per_replica,
    mlir::tf_device::ClusterFuncOp cluster_func, mlir::OpBuilder* builder,
    llvm::SmallVectorImpl<llvm::SmallVector<mlir::Value, 4>>* input_list) {
  // Initialize the input list for each logical devices.
  input_list->reserve(num_cores_per_replica);

  // Returns whether it's legal to inline a call to a function.
  bool isLegalToInline(Operation* call, Operation* callable,
                       bool wouldBeCloned) const final {
    if (isa<ClusterFuncOp>(call)) return false;
    return true;
  }

  // Returns if its legal to inline 'src' region into the 'dest' region
  // attached to a TF Device operation.