1 files changed, 178 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/Native/TpiStreamBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/TpiStreamBuilder.cpp
new file mode 100644
index 000000000000..4f10f8524a9b
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Native/TpiStreamBuilder.cpp
@@ -0,0 +1,178 @@
+//===- TpiStreamBuilder.cpp -   -------------------------------------------===//
+//
+// 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/DebugInfo/PDB/Native/TpiStreamBuilder.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/DebugInfo/CodeView/TypeIndex.h"
+#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/MSF/MSFBuilder.h"
+#include "llvm/DebugInfo/MSF/MappedBlockStream.h"
+#include "llvm/DebugInfo/PDB/Native/PDBFile.h"
+#include "llvm/DebugInfo/PDB/Native/RawError.h"
+#include "llvm/DebugInfo/PDB/Native/RawTypes.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/BinaryByteStream.h"
+#include "llvm/Support/BinaryStreamArray.h"
+#include "llvm/Support/BinaryStreamReader.h"
+#include "llvm/Support/BinaryStreamWriter.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+#include <algorithm>
+#include <cstdint>
+
+using namespace llvm;
+using namespace llvm::msf;
+using namespace llvm::pdb;
+using namespace llvm::support;
+
+TpiStreamBuilder::TpiStreamBuilder(MSFBuilder &Msf, uint32_t StreamIdx)
+    : Msf(Msf), Allocator(Msf.getAllocator()), Header(nullptr), Idx(StreamIdx) {
+}
+
+TpiStreamBuilder::~TpiStreamBuilder() = default;
+
+void TpiStreamBuilder::setVersionHeader(PdbRaw_TpiVer Version) {
+  VerHeader = Version;
+}
+
+void TpiStreamBuilder::addTypeRecord(ArrayRef<uint8_t> Record,
+                                     Optional<uint32_t> Hash) {
+  // If we just crossed an 8KB threshold, add a type index offset.
+  size_t NewSize = TypeRecordBytes + Record.size();
+  constexpr size_t EightKB = 8 * 1024;
+  if (NewSize / EightKB > TypeRecordBytes / EightKB || TypeRecords.empty()) {
+    TypeIndexOffsets.push_back(
+        {codeview::TypeIndex(codeview::TypeIndex::FirstNonSimpleIndex +
+                             TypeRecords.size()),
+         ulittle32_t(TypeRecordBytes)});
+  }
+  TypeRecordBytes = NewSize;
+
+  TypeRecords.push_back(Record);
+  if (Hash)
+    TypeHashes.push_back(*Hash);
+}
+
+Error TpiStreamBuilder::finalize() {
+  if (Header)
+    return Error::success();
+
+  TpiStreamHeader *H = Allocator.Allocate<TpiStreamHeader>();
+
+  uint32_t Count = TypeRecords.size();
+
+  H->Version = VerHeader;
+  H->HeaderSize = sizeof(TpiStreamHeader);
+  H->TypeIndexBegin = codeview::TypeIndex::FirstNonSimpleIndex;
+  H->TypeIndexEnd = H->TypeIndexBegin + Count;
+  H->TypeRecordBytes = TypeRecordBytes;
+
+  H->HashStreamIndex = HashStreamIndex;
+  H->HashAuxStreamIndex = kInvalidStreamIndex;
+  H->HashKeySize = sizeof(ulittle32_t);
+  H->NumHashBuckets = MaxTpiHashBuckets - 1;
+
+  // Recall that hash values go into a completely different stream identified by
+  // the `HashStreamIndex` field of the `TpiStreamHeader`.  Therefore, the data
+  // begins at offset 0 of this independent stream.
+  H->HashValueBuffer.Off = 0;
+  H->HashValueBuffer.Length = calculateHashBufferSize();
+
+  // We never write any adjustments into our PDBs, so this is usually some
+  // offset with zero length.
+  H->HashAdjBuffer.Off = H->HashValueBuffer.Off + H->HashValueBuffer.Length;
+  H->HashAdjBuffer.Length = 0;
+
+  H->IndexOffsetBuffer.Off = H->HashAdjBuffer.Off + H->HashAdjBuffer.Length;
+  H->IndexOffsetBuffer.Length = calculateIndexOffsetSize();
+
+  Header = H;
+  return Error::success();
+}
+
+uint32_t TpiStreamBuilder::calculateSerializedLength() {
+  return sizeof(TpiStreamHeader) + TypeRecordBytes;
+}
+
+uint32_t TpiStreamBuilder::calculateHashBufferSize() const {
+  assert((TypeRecords.size() == TypeHashes.size() || TypeHashes.empty()) &&
+         "either all or no type records should have hashes");
+  return TypeHashes.size() * sizeof(ulittle32_t);
+}
+
+uint32_t TpiStreamBuilder::calculateIndexOffsetSize() const {
+  return TypeIndexOffsets.size() * sizeof(codeview::TypeIndexOffset);
+}
+
+Error TpiStreamBuilder::finalizeMsfLayout() {
+  uint32_t Length = calculateSerializedLength();
+  if (auto EC = Msf.setStreamSize(Idx, Length))
+    return EC;
+
+  uint32_t HashStreamSize =
+      calculateHashBufferSize() + calculateIndexOffsetSize();
+
+  if (HashStreamSize == 0)
+    return Error::success();
+
+  auto ExpectedIndex = Msf.addStream(HashStreamSize);
+  if (!ExpectedIndex)
+    return ExpectedIndex.takeError();
+  HashStreamIndex = *ExpectedIndex;
+  if (!TypeHashes.empty()) {
+    ulittle32_t *H = Allocator.Allocate<ulittle32_t>(TypeHashes.size());
+    MutableArrayRef<ulittle32_t> HashBuffer(H, TypeHashes.size());
+    for (uint32_t I = 0; I < TypeHashes.size(); ++I) {
+      HashBuffer[I] = TypeHashes[I] % (MaxTpiHashBuckets - 1);
+    }
+    ArrayRef<uint8_t> Bytes(
+        reinterpret_cast<const uint8_t *>(HashBuffer.data()),
+        calculateHashBufferSize());
+    HashValueStream =
+        std::make_unique<BinaryByteStream>(Bytes, llvm::support::little);
+  }
+  return Error::success();
+}
+
+Error TpiStreamBuilder::commit(const msf::MSFLayout &Layout,
+                               WritableBinaryStreamRef Buffer) {
+  if (auto EC = finalize())
+    return EC;
+
+  auto InfoS = WritableMappedBlockStream::createIndexedStream(Layout, Buffer,
+                                                              Idx, Allocator);
+
+  BinaryStreamWriter Writer(*InfoS);
+  if (auto EC = Writer.writeObject(*Header))
+    return EC;
+
+  for (auto Rec : TypeRecords) {
+    assert(!Rec.empty()); // An empty record will not write anything, but it
+                          // would shift all offsets from here on.
+    if (auto EC = Writer.writeBytes(Rec))
+      return EC;
+  }
+
+  if (HashStreamIndex != kInvalidStreamIndex) {
+    auto HVS = WritableMappedBlockStream::createIndexedStream(
+        Layout, Buffer, HashStreamIndex, Allocator);
+    BinaryStreamWriter HW(*HVS);
+    if (HashValueStream) {
+      if (auto EC = HW.writeStreamRef(*HashValueStream))
+        return EC;
+    }
+
+    for (auto &IndexOffset : TypeIndexOffsets) {
+      if (auto EC = HW.writeObject(IndexOffset))
+        return EC;
+    }
+  }
+
+  return Error::success();
+}