--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/XRay/BlockPrinter.cpp	Wed Aug 14 19:46:37 2019 +0900
@@ -0,0 +1,113 @@
+//===- BlockPrinter.cpp - FDR Block Pretty Printer Implementation --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/XRay/BlockPrinter.h"
+
+namespace llvm {
+namespace xray {
+
+Error BlockPrinter::visit(BufferExtents &R) {
+  OS << "\n[New Block]\n";
+  CurrentState = State::Preamble;
+  return RP.visit(R);
+}
+
+// Preamble printing.
+Error BlockPrinter::visit(NewBufferRecord &R) {
+  if (CurrentState == State::Start)
+    OS << "\n[New Block]\n";
+
+  OS << "Preamble: \n";
+  CurrentState = State::Preamble;
+  return RP.visit(R);
+}
+
+Error BlockPrinter::visit(WallclockRecord &R) {
+  CurrentState = State::Preamble;
+  return RP.visit(R);
+}
+
+Error BlockPrinter::visit(PIDRecord &R) {
+  CurrentState = State::Preamble;
+  return RP.visit(R);
+}
+
+// Metadata printing.
+Error BlockPrinter::visit(NewCPUIDRecord &R) {
+  if (CurrentState == State::Preamble)
+    OS << "\nBody:\n";
+  if (CurrentState == State::Function)
+    OS << "\nMetadata: ";
+  CurrentState = State::Metadata;
+  OS << " ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+Error BlockPrinter::visit(TSCWrapRecord &R) {
+  if (CurrentState == State::Function)
+    OS << "\nMetadata:";
+  CurrentState = State::Metadata;
+  OS << " ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+// Custom events will be rendered like "function" events.
+Error BlockPrinter::visit(CustomEventRecord &R) {
+  if (CurrentState == State::Metadata)
+    OS << "\n";
+  CurrentState = State::CustomEvent;
+  OS << "*  ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+Error BlockPrinter::visit(CustomEventRecordV5 &R) {
+  if (CurrentState == State::Metadata)
+    OS << "\n";
+  CurrentState = State::CustomEvent;
+  OS << "*  ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+Error BlockPrinter::visit(TypedEventRecord &R) {
+  if (CurrentState == State::Metadata)
+    OS << "\n";
+  CurrentState = State::CustomEvent;
+  OS << "*  ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+// Function call printing.
+Error BlockPrinter::visit(FunctionRecord &R) {
+  if (CurrentState == State::Metadata)
+    OS << "\n";
+  CurrentState = State::Function;
+  OS << "-  ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+Error BlockPrinter::visit(CallArgRecord &R) {
+  CurrentState = State::Arg;
+  OS << " : ";
+  auto E = RP.visit(R);
+  return E;
+}
+
+Error BlockPrinter::visit(EndBufferRecord &R) {
+    CurrentState = State::End;
+    OS << " *** ";
+    auto E = RP.visit(R);
+    return E;
+}
+
+} // namespace xray
+} // namespace llvm