--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/Object/Minidump.cpp	Wed Aug 14 19:46:37 2019 +0900
@@ -0,0 +1,137 @@
+//===- Minidump.cpp - Minidump object file 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/Object/Minidump.h"
+#include "llvm/Object/Error.h"
+#include "llvm/Support/ConvertUTF.h"
+
+using namespace llvm;
+using namespace llvm::object;
+using namespace llvm::minidump;
+
+Optional<ArrayRef<uint8_t>>
+MinidumpFile::getRawStream(minidump::StreamType Type) const {
+  auto It = StreamMap.find(Type);
+  if (It != StreamMap.end())
+    return getRawStream(Streams[It->second]);
+  return None;
+}
+
+Expected<std::string> MinidumpFile::getString(size_t Offset) const {
+  // Minidump strings consist of a 32-bit length field, which gives the size of
+  // the string in *bytes*. This is followed by the actual string encoded in
+  // UTF16.
+  auto ExpectedSize =
+      getDataSliceAs<support::ulittle32_t>(getData(), Offset, 1);
+  if (!ExpectedSize)
+    return ExpectedSize.takeError();
+  size_t Size = (*ExpectedSize)[0];
+  if (Size % 2 != 0)
+    return createError("String size not even");
+  Size /= 2;
+  if (Size == 0)
+    return "";
+
+  Offset += sizeof(support::ulittle32_t);
+  auto ExpectedData =
+      getDataSliceAs<support::ulittle16_t>(getData(), Offset, Size);
+  if (!ExpectedData)
+    return ExpectedData.takeError();
+
+  SmallVector<UTF16, 32> WStr(Size);
+  copy(*ExpectedData, WStr.begin());
+
+  std::string Result;
+  if (!convertUTF16ToUTF8String(WStr, Result))
+    return createError("String decoding failed");
+
+  return Result;
+}
+
+template <typename T>
+Expected<ArrayRef<T>> MinidumpFile::getListStream(StreamType Stream) const {
+  auto OptionalStream = getRawStream(Stream);
+  if (!OptionalStream)
+    return createError("No such stream");
+  auto ExpectedSize =
+      getDataSliceAs<support::ulittle32_t>(*OptionalStream, 0, 1);
+  if (!ExpectedSize)
+    return ExpectedSize.takeError();
+
+  size_t ListSize = ExpectedSize.get()[0];
+
+  size_t ListOffset = 4;
+  // Some producers insert additional padding bytes to align the list to an
+  // 8-byte boundary. Check for that by comparing the list size with the overall
+  // stream size.
+  if (ListOffset + sizeof(T) * ListSize < OptionalStream->size())
+    ListOffset = 8;
+
+  return getDataSliceAs<T>(*OptionalStream, ListOffset, ListSize);
+}
+template Expected<ArrayRef<Module>>
+    MinidumpFile::getListStream(StreamType) const;
+template Expected<ArrayRef<Thread>>
+    MinidumpFile::getListStream(StreamType) const;
+template Expected<ArrayRef<MemoryDescriptor>>
+    MinidumpFile::getListStream(StreamType) const;
+
+Expected<ArrayRef<uint8_t>>
+MinidumpFile::getDataSlice(ArrayRef<uint8_t> Data, size_t Offset, size_t Size) {
+  // Check for overflow.
+  if (Offset + Size < Offset || Offset + Size < Size ||
+      Offset + Size > Data.size())
+    return createEOFError();
+  return Data.slice(Offset, Size);
+}
+
+Expected<std::unique_ptr<MinidumpFile>>
+MinidumpFile::create(MemoryBufferRef Source) {
+  ArrayRef<uint8_t> Data = arrayRefFromStringRef(Source.getBuffer());
+  auto ExpectedHeader = getDataSliceAs<minidump::Header>(Data, 0, 1);
+  if (!ExpectedHeader)
+    return ExpectedHeader.takeError();
+
+  const minidump::Header &Hdr = (*ExpectedHeader)[0];
+  if (Hdr.Signature != Header::MagicSignature)
+    return createError("Invalid signature");
+  if ((Hdr.Version & 0xffff) != Header::MagicVersion)
+    return createError("Invalid version");
+
+  auto ExpectedStreams = getDataSliceAs<Directory>(Data, Hdr.StreamDirectoryRVA,
+                                                   Hdr.NumberOfStreams);
+  if (!ExpectedStreams)
+    return ExpectedStreams.takeError();
+
+  DenseMap<StreamType, std::size_t> StreamMap;
+  for (const auto &Stream : llvm::enumerate(*ExpectedStreams)) {
+    StreamType Type = Stream.value().Type;
+    const LocationDescriptor &Loc = Stream.value().Location;
+
+    auto ExpectedStream = getDataSlice(Data, Loc.RVA, Loc.DataSize);
+    if (!ExpectedStream)
+      return ExpectedStream.takeError();
+
+    if (Type == StreamType::Unused && Loc.DataSize == 0) {
+      // Ignore dummy streams. This is technically ill-formed, but a number of
+      // existing minidumps seem to contain such streams.
+      continue;
+    }
+
+    if (Type == DenseMapInfo<StreamType>::getEmptyKey() ||
+        Type == DenseMapInfo<StreamType>::getTombstoneKey())
+      return createError("Cannot handle one of the minidump streams");
+
+    // Update the directory map, checking for duplicate stream types.
+    if (!StreamMap.try_emplace(Type, Stream.index()).second)
+      return createError("Duplicate stream type");
+  }
+
+  return std::unique_ptr<MinidumpFile>(
+      new MinidumpFile(Source, Hdr, *ExpectedStreams, std::move(StreamMap)));
+}