1 files changed, 126 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp b/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp
new file mode 100644
index 000000000000..4a88391494cd
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Native/NamedStreamMap.cpp
@@ -0,0 +1,126 @@
+//===- NamedStreamMap.cpp - PDB Named Stream Map --------------------------===//
+//
+// 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/NamedStreamMap.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/DebugInfo/PDB/Native/Hash.h"
+#include "llvm/DebugInfo/PDB/Native/HashTable.h"
+#include "llvm/DebugInfo/PDB/Native/RawError.h"
+#include "llvm/Support/BinaryStreamReader.h"
+#include "llvm/Support/BinaryStreamRef.h"
+#include "llvm/Support/BinaryStreamWriter.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <tuple>
+
+using namespace llvm;
+using namespace llvm::pdb;
+
+NamedStreamMapTraits::NamedStreamMapTraits(NamedStreamMap &NS) : NS(&NS) {}
+
+uint16_t NamedStreamMapTraits::hashLookupKey(StringRef S) const {
+  // In the reference implementation, this uses
+  // HASH Hasher<ULONG*, USHORT*>::hashPbCb(PB pb, size_t cb, ULONG ulMod).
+  // Here, the type HASH is a typedef of unsigned short.
+  // ** It is not a bug that we truncate the result of hashStringV1, in fact
+  //    it is a bug if we do not! **
+  // See NMTNI::hash() in the reference implementation.
+  return static_cast<uint16_t>(hashStringV1(S));
+}
+
+StringRef NamedStreamMapTraits::storageKeyToLookupKey(uint32_t Offset) const {
+  return NS->getString(Offset);
+}
+
+uint32_t NamedStreamMapTraits::lookupKeyToStorageKey(StringRef S) {
+  return NS->appendStringData(S);
+}
+
+NamedStreamMap::NamedStreamMap() : HashTraits(*this), OffsetIndexMap(1) {}
+
+Error NamedStreamMap::load(BinaryStreamReader &Stream) {
+  uint32_t StringBufferSize;
+  if (auto EC = Stream.readInteger(StringBufferSize))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Expected string buffer size"));
+
+  StringRef Buffer;
+  if (auto EC = Stream.readFixedString(Buffer, StringBufferSize))
+    return EC;
+  NamesBuffer.assign(Buffer.begin(), Buffer.end());
+
+  return OffsetIndexMap.load(Stream);
+}
+
+Error NamedStreamMap::commit(BinaryStreamWriter &Writer) const {
+  // The first field is the number of bytes of string data.
+  if (auto EC = Writer.writeInteger<uint32_t>(NamesBuffer.size()))
+    return EC;
+
+  // Then the actual string data.
+  StringRef Data(NamesBuffer.data(), NamesBuffer.size());
+  if (auto EC = Writer.writeFixedString(Data))
+    return EC;
+
+  // And finally the Offset Index map.
+  if (auto EC = OffsetIndexMap.commit(Writer))
+    return EC;
+
+  return Error::success();
+}
+
+uint32_t NamedStreamMap::calculateSerializedLength() const {
+  return sizeof(uint32_t)                              // String data size
+         + NamesBuffer.size()                          // String data
+         + OffsetIndexMap.calculateSerializedLength(); // Offset Index Map
+}
+
+uint32_t NamedStreamMap::size() const { return OffsetIndexMap.size(); }
+
+StringRef NamedStreamMap::getString(uint32_t Offset) const {
+  assert(NamesBuffer.size() > Offset);
+  return StringRef(NamesBuffer.data() + Offset);
+}
+
+uint32_t NamedStreamMap::hashString(uint32_t Offset) const {
+  return hashStringV1(getString(Offset));
+}
+
+bool NamedStreamMap::get(StringRef Stream, uint32_t &StreamNo) const {
+  auto Iter = OffsetIndexMap.find_as(Stream, HashTraits);
+  if (Iter == OffsetIndexMap.end())
+    return false;
+  StreamNo = (*Iter).second;
+  return true;
+}
+
+StringMap<uint32_t> NamedStreamMap::entries() const {
+  StringMap<uint32_t> Result;
+  for (const auto &Entry : OffsetIndexMap) {
+    StringRef Stream(NamesBuffer.data() + Entry.first);
+    Result.try_emplace(Stream, Entry.second);
+  }
+  return Result;
+}
+
+uint32_t NamedStreamMap::appendStringData(StringRef S) {
+  uint32_t Offset = NamesBuffer.size();
+  NamesBuffer.insert(NamesBuffer.end(), S.begin(), S.end());
+  NamesBuffer.push_back('\0');
+  return Offset;
+}
+
+void NamedStreamMap::set(StringRef Stream, uint32_t StreamNo) {
+  OffsetIndexMap.set_as(Stream, support::ulittle32_t(StreamNo), HashTraits);
+}