Index: llvm/trunk/include/llvm/XRay/RecordPrinter.h
===================================================================
--- llvm/trunk/include/llvm/XRay/RecordPrinter.h
+++ llvm/trunk/include/llvm/XRay/RecordPrinter.h
@@ -0,0 +1,48 @@
+//===- RecordPrinter.h - FDR Record Printer -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// An implementation of the RecordVisitor which prints an individual record's
+// data in an adhoc format, suitable for human inspection.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_INCLUDE_LLVM_XRAY_RECORDPRINTER_H_
+#define LLVM_INCLUDE_LLVM_XRAY_RECORDPRINTER_H_
+
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/XRay/FDRRecords.h"
+
+namespace llvm {
+namespace xray {
+
+class RecordPrinter : public RecordVisitor {
+  raw_ostream &OS;
+  std::string Delim;
+
+public:
+  explicit RecordPrinter(raw_ostream &O, std::string D)
+      : RecordVisitor(), OS(O), Delim(std::move(D)) {}
+
+  explicit RecordPrinter(raw_ostream &O) : RecordPrinter(O, ""){};
+
+  Error visit(BufferExtents &) override;
+  Error visit(WallclockRecord &) override;
+  Error visit(NewCPUIDRecord &) override;
+  Error visit(TSCWrapRecord &) override;
+  Error visit(CustomEventRecord &) override;
+  Error visit(CallArgRecord &) override;
+  Error visit(PIDRecord &) override;
+  Error visit(NewBufferRecord &) override;
+  Error visit(EndBufferRecord &) override;
+  Error visit(FunctionRecord &) override;
+};
+
+} // namespace xray
+} // namespace llvm
+
+#endif // LLVM_INCLUDE_LLVM_XRAY_RECORDPRINTER_H
Index: llvm/trunk/lib/XRay/CMakeLists.txt
===================================================================
--- llvm/trunk/lib/XRay/CMakeLists.txt
+++ llvm/trunk/lib/XRay/CMakeLists.txt
@@ -7,6 +7,7 @@
   LogBuilderConsumer.cpp
   Profile.cpp
   RecordInitializer.cpp
+  RecordPrinter.cpp
   Trace.cpp
 
   ADDITIONAL_HEADER_DIRS
Index: llvm/trunk/lib/XRay/RecordPrinter.cpp
===================================================================
--- llvm/trunk/lib/XRay/RecordPrinter.cpp
+++ llvm/trunk/lib/XRay/RecordPrinter.cpp
@@ -0,0 +1,89 @@
+//===- RecordPrinter.cpp - FDR Record Printer -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/XRay/RecordPrinter.h"
+
+#include "llvm/Support/FormatVariadic.h"
+
+namespace llvm {
+namespace xray {
+
+Error RecordPrinter::visit(BufferExtents &R) {
+  OS << formatv("<Buffer: size = {0} bytes>", R.size()) << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(WallclockRecord &R) {
+  OS << formatv("<Wall Time: seconds = {0}.{1,0+6}>", R.seconds(), R.nanos())
+     << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(NewCPUIDRecord &R) {
+  OS << formatv("<CPU ID: {0}>", R.cpuid()) << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(TSCWrapRecord &R) {
+  OS << formatv("<TSC Wrap: base = {0}>", R.tsc()) << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(CustomEventRecord &R) {
+  OS << formatv("<Custom Event: tsc = {0}, size = {1}, data = '{2}'>", R.tsc(),
+                R.size(), R.data())
+     << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(CallArgRecord &R) {
+  OS << formatv("<Call Argument: data = {0} (hex = {0:x})>", R.arg()) << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(PIDRecord &R) {
+  OS << formatv("<PID: {0}>", R.pid()) << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(NewBufferRecord &R) {
+  OS << formatv("<Thread ID: {0}>", R.tid()) << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(EndBufferRecord &R) {
+  OS << "<End of Buffer>" << Delim;
+  return Error::success();
+}
+
+Error RecordPrinter::visit(FunctionRecord &R) {
+  // FIXME: Support symbolization here?
+  switch (R.recordType()) {
+  case RecordTypes::ENTER:
+    OS << formatv("<Function Enter: #{0} delta = +{0}>", R.functionId(),
+                  R.delta());
+    break;
+  case RecordTypes::ENTER_ARG:
+    OS << formatv("<Function Enter With Arg: #{0} delta = +{0}>",
+                  R.functionId(), R.delta());
+    break;
+  case RecordTypes::EXIT:
+    OS << formatv("<Function Exit: #{0} delta = +{0}>", R.functionId(),
+                  R.delta());
+    break;
+  case RecordTypes::TAIL_EXIT:
+    OS << formatv("<Function Tail Exit: #{0} delta = +{0}>", R.functionId(),
+                  R.delta());
+    break;
+  }
+  OS << Delim;
+  return Error::success();
+}
+
+} // namespace xray
+} // namespace llvm
Index: llvm/trunk/unittests/XRay/CMakeLists.txt
===================================================================
--- llvm/trunk/unittests/XRay/CMakeLists.txt
+++ llvm/trunk/unittests/XRay/CMakeLists.txt
@@ -4,10 +4,11 @@
   )
 
 add_llvm_unittest(XRayTests
+  ProfileTest.cpp
   FDRProducerConsumerTest.cpp
+  FDRRecordPrinterTest.cpp
   FDRTraceWriterTest.cpp
   GraphTest.cpp
-	ProfileTest.cpp
   )
 
 add_dependencies(XRayTests intrinsics_gen)
Index: llvm/trunk/unittests/XRay/FDRRecordPrinterTest.cpp
===================================================================
--- llvm/trunk/unittests/XRay/FDRRecordPrinterTest.cpp
+++ llvm/trunk/unittests/XRay/FDRRecordPrinterTest.cpp
@@ -0,0 +1,176 @@
+//===- llvm/unittest/XRay/FDRRecordPrinterTest.cpp --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/XRay/FDRRecords.h"
+#include "llvm/XRay/RecordPrinter.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include <string>
+
+namespace llvm {
+namespace xray {
+namespace {
+
+using ::testing::Eq;
+
+template <class RecordType> struct Helper {};
+
+template <> struct Helper<BufferExtents> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<BufferExtents>(1);
+  }
+
+  static constexpr char Expected[] = "<Buffer: size = 1 bytes>";
+};
+constexpr char Helper<BufferExtents>::Expected[];
+
+template <> struct Helper<WallclockRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<WallclockRecord>(1, 2);
+  }
+
+  static constexpr char Expected[] = "<Wall Time: seconds = 1.000002>";
+};
+constexpr char Helper<WallclockRecord>::Expected[];
+
+template <> struct Helper<NewCPUIDRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<NewCPUIDRecord>(1);
+  }
+
+  static constexpr char Expected[] = "<CPU ID: 1>";
+};
+constexpr char Helper<NewCPUIDRecord>::Expected[];
+
+template <> struct Helper<TSCWrapRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<TSCWrapRecord>(1);
+  }
+
+  static constexpr char Expected[] = "<TSC Wrap: base = 1>";
+};
+constexpr char Helper<TSCWrapRecord>::Expected[];
+
+template <> struct Helper<CustomEventRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<CustomEventRecord>(4, 1, "data");
+  }
+
+  static constexpr char Expected[] =
+      "<Custom Event: tsc = 1, size = 4, data = 'data'>";
+};
+constexpr char Helper<CustomEventRecord>::Expected[];
+
+template <> struct Helper<CallArgRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<CallArgRecord>(1);
+  }
+
+  static constexpr char Expected[] = "<Call Argument: data = 1 (hex = 0x1)>";
+};
+constexpr char Helper<CallArgRecord>::Expected[];
+
+template <> struct Helper<PIDRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<PIDRecord>(1);
+  }
+
+  static constexpr char Expected[] = "<PID: 1>";
+};
+constexpr char Helper<PIDRecord>::Expected[];
+
+template <> struct Helper<NewBufferRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<NewBufferRecord>(1);
+  }
+
+  static constexpr char Expected[] = "<Thread ID: 1>";
+};
+constexpr char Helper<NewBufferRecord>::Expected[];
+
+template <> struct Helper<EndBufferRecord> {
+  static std::unique_ptr<Record> construct() {
+    return make_unique<EndBufferRecord>();
+  }
+
+  static constexpr char Expected[] = "<End of Buffer>";
+};
+constexpr char Helper<EndBufferRecord>::Expected[];
+
+template <class T> class PrinterTest : public ::testing::Test {
+protected:
+  std::string Data;
+  raw_string_ostream OS;
+  RecordPrinter P;
+  std::unique_ptr<Record> R;
+
+public:
+  PrinterTest() : Data(), OS(Data), P(OS), R(Helper<T>::construct()) {}
+};
+
+TYPED_TEST_CASE_P(PrinterTest);
+
+TYPED_TEST_P(PrinterTest, PrintsRecord) {
+  ASSERT_NE(nullptr, this->R);
+  ASSERT_FALSE(errorToBool(this->R->apply(this->P)));
+  this->OS.flush();
+  EXPECT_THAT(this->Data, Eq(Helper<TypeParam>::Expected));
+}
+
+REGISTER_TYPED_TEST_CASE_P(PrinterTest, PrintsRecord);
+using FDRRecordTypes =
+    ::testing::Types<BufferExtents, NewBufferRecord, EndBufferRecord,
+                     NewCPUIDRecord, TSCWrapRecord, WallclockRecord,
+                     CustomEventRecord, CallArgRecord, BufferExtents,
+                     PIDRecord>;
+INSTANTIATE_TYPED_TEST_CASE_P(Records, PrinterTest, FDRRecordTypes);
+
+TEST(FDRRecordPrinterTest, WriteFunctionRecordEnter) {
+  std::string Data;
+  raw_string_ostream OS(Data);
+  RecordPrinter P(OS);
+  FunctionRecord R(RecordTypes::ENTER, 1, 2);
+  ASSERT_FALSE(errorToBool(R.apply(P)));
+  OS.flush();
+  EXPECT_THAT(Data, Eq("<Function Enter: #1 delta = +1>"));
+}
+
+TEST(FDRRecordPrinterTest, WriteFunctionRecordExit) {
+  std::string Data;
+  raw_string_ostream OS(Data);
+  RecordPrinter P(OS);
+  FunctionRecord R(RecordTypes::EXIT, 1, 2);
+  ASSERT_FALSE(errorToBool(R.apply(P)));
+  OS.flush();
+  EXPECT_THAT(Data, Eq("<Function Exit: #1 delta = +1>"));
+}
+
+TEST(FDRRecordPrinterTest, WriteFunctionRecordTailExit) {
+  std::string Data;
+  raw_string_ostream OS(Data);
+  RecordPrinter P(OS);
+  FunctionRecord R(RecordTypes::TAIL_EXIT, 1, 2);
+  ASSERT_FALSE(errorToBool(R.apply(P)));
+  OS.flush();
+  EXPECT_THAT(Data, Eq("<Function Tail Exit: #1 delta = +1>"));
+}
+
+TEST(FDRRecordPrinterTest, WriteFunctionRecordEnterArg) {
+  std::string Data;
+  raw_string_ostream OS(Data);
+  RecordPrinter P(OS);
+  FunctionRecord R(RecordTypes::ENTER_ARG, 1, 2);
+  ASSERT_FALSE(errorToBool(R.apply(P)));
+  OS.flush();
+  EXPECT_THAT(Data, Eq("<Function Enter With Arg: #1 delta = +1>"));
+}
+
+} // namespace
+} // namespace xray
+} // namespace llvm