1 files changed, 154 insertions, 0 deletions
diff --git a/lib/XRay/FDRTraceWriter.cpp b/lib/XRay/FDRTraceWriter.cpp
new file mode 100644
index 000000000000..c5224f4be094
--- /dev/null
+++ b/lib/XRay/FDRTraceWriter.cpp
@@ -0,0 +1,154 @@
+//===- FDRTraceWriter.cpp - XRay FDR Trace Writer ---------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Test a utility that can write out XRay FDR Mode formatted trace files.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/XRay/FDRTraceWriter.h"
+#include <tuple>
+
+namespace llvm {
+namespace xray {
+
+namespace {
+
+template <size_t Index> struct IndexedWriter {
+  template <
+      class Tuple,
+      typename std::enable_if<
+          (Index <
+           std::tuple_size<typename std::remove_reference<Tuple>::type>::value),
+          int>::type = 0>
+  static size_t write(support::endian::Writer &OS, Tuple &&T) {
+    OS.write(std::get<Index>(T));
+    return sizeof(std::get<Index>(T)) + IndexedWriter<Index + 1>::write(OS, T);
+  }
+
+  template <
+      class Tuple,
+      typename std::enable_if<
+          (Index >=
+           std::tuple_size<typename std::remove_reference<Tuple>::type>::value),
+          int>::type = 0>
+  static size_t write(support::endian::Writer &OS, Tuple &&) {
+    return 0;
+  }
+};
+
+template <uint8_t Kind, class... Values>
+Error writeMetadata(support::endian::Writer &OS, Values &&... Ds) {
+  // The first bit in the first byte of metadata records is always set to 1, so
+  // we ensure this is the case when we write out the first byte of the record.
+  uint8_t FirstByte = (static_cast<uint8_t>(Kind) << 1) | uint8_t{0x01u};
+  auto T = std::make_tuple(std::forward<Values>(std::move(Ds))...);
+  // Write in field order.
+  OS.write(FirstByte);
+  auto Bytes = IndexedWriter<0>::write(OS, T);
+  assert(Bytes <= 15 && "Must only ever write at most 16 byte metadata!");
+  // Pad out with appropriate numbers of zero's.
+  for (; Bytes < 15; ++Bytes)
+    OS.write('\0');
+  return Error::success();
+}
+
+} // namespace
+
+FDRTraceWriter::FDRTraceWriter(raw_ostream &O, const XRayFileHeader &H)
+    : OS(O, support::endianness::native) {
+  // We need to re-construct a header, by writing the fields we care about for
+  // traces, in the format that the runtime would have written.
+  uint32_t BitField =
+      (H.ConstantTSC ? 0x01 : 0x0) | (H.NonstopTSC ? 0x02 : 0x0);
+
+  // For endian-correctness, we need to write these fields in the order they
+  // appear and that we expect, instead of blasting bytes of the struct through.
+  OS.write(H.Version);
+  OS.write(H.Type);
+  OS.write(BitField);
+  OS.write(H.CycleFrequency);
+  ArrayRef<char> FreeFormBytes(H.FreeFormData,
+                               sizeof(XRayFileHeader::FreeFormData));
+  OS.write(FreeFormBytes);
+}
+
+FDRTraceWriter::~FDRTraceWriter() {}
+
+Error FDRTraceWriter::visit(BufferExtents &R) {
+  return writeMetadata<7u>(OS, R.size());
+}
+
+Error FDRTraceWriter::visit(WallclockRecord &R) {
+  return writeMetadata<4u>(OS, R.seconds(), R.nanos());
+}
+
+Error FDRTraceWriter::visit(NewCPUIDRecord &R) {
+  return writeMetadata<2u>(OS, R.cpuid(), R.tsc());
+}
+
+Error FDRTraceWriter::visit(TSCWrapRecord &R) {
+  return writeMetadata<3u>(OS, R.tsc());
+}
+
+Error FDRTraceWriter::visit(CustomEventRecord &R) {
+  if (auto E = writeMetadata<5u>(OS, R.size(), R.tsc(), R.cpu()))
+    return E;
+  auto D = R.data();
+  ArrayRef<char> Bytes(D.data(), D.size());
+  OS.write(Bytes);
+  return Error::success();
+}
+
+Error FDRTraceWriter::visit(CustomEventRecordV5 &R) {
+  if (auto E = writeMetadata<5u>(OS, R.size(), R.delta()))
+    return E;
+  auto D = R.data();
+  ArrayRef<char> Bytes(D.data(), D.size());
+  OS.write(Bytes);
+  return Error::success();
+}
+
+Error FDRTraceWriter::visit(TypedEventRecord &R) {
+  if (auto E = writeMetadata<8u>(OS, R.size(), R.delta(), R.eventType()))
+    return E;
+  auto D = R.data();
+  ArrayRef<char> Bytes(D.data(), D.size());
+  OS.write(Bytes);
+  return Error::success();
+}
+
+Error FDRTraceWriter::visit(CallArgRecord &R) {
+  return writeMetadata<6u>(OS, R.arg());
+}
+
+Error FDRTraceWriter::visit(PIDRecord &R) {
+  return writeMetadata<9u>(OS, R.pid());
+}
+
+Error FDRTraceWriter::visit(NewBufferRecord &R) {
+  return writeMetadata<0u>(OS, R.tid());
+}
+
+Error FDRTraceWriter::visit(EndBufferRecord &R) {
+  return writeMetadata<1u>(OS, 0);
+}
+
+Error FDRTraceWriter::visit(FunctionRecord &R) {
+  // Write out the data in "field" order, to be endian-aware.
+  uint32_t TypeRecordFuncId = uint32_t{R.functionId() & ~uint32_t{0x0Fu << 28}};
+  TypeRecordFuncId <<= 3;
+  TypeRecordFuncId |= static_cast<uint32_t>(R.recordType());
+  TypeRecordFuncId <<= 1;
+  TypeRecordFuncId &= ~uint32_t{0x01};
+  OS.write(TypeRecordFuncId);
+  OS.write(R.delta());
+  return Error::success();
+}
+
+} // namespace xray
+} // namespace llvm