1 files changed, 97 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/Raw/PDBStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/PDBStream.cpp
new file mode 100644
index 0000000..310454d
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Raw/PDBStream.cpp
@@ -0,0 +1,97 @@
+//===- PDBStream.cpp - Low level interface to a PDB stream ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Raw/PDBStream.h"
+#include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
+
+using namespace llvm;
+
+static uint64_t bytesToBlocks(uint64_t NumBytes, uint64_t BlockSize) {
+  return alignTo(NumBytes, BlockSize) / BlockSize;
+}
+
+static uint64_t blockToOffset(uint64_t BlockNumber, uint64_t BlockSize) {
+  return BlockNumber * BlockSize;
+}
+
+PDBStream::PDBStream(uint32_t StreamIdx, const PDBFile &File) : Pdb(File) {
+  this->StreamLength = Pdb.getStreamByteSize(StreamIdx);
+  this->BlockList = Pdb.getStreamBlockList(StreamIdx);
+  this->Offset = 0;
+}
+
+std::error_code PDBStream::readInteger(uint32_t &Dest) {
+  support::detail::packed_endian_specific_integral<uint32_t, support::little,
+                                                   support::unaligned>
+      P;
+  if (std::error_code EC = readObject(&P))
+    return EC;
+  Dest = P;
+  return std::error_code();
+}
+
+std::error_code PDBStream::readZeroString(std::string &Dest) {
+  char C;
+  do {
+    readObject(&C);
+    if (C != '\0')
+      Dest.push_back(C);
+  } while (C != '\0');
+  return std::error_code();
+}
+
+std::error_code PDBStream::readBytes(void *Dest, uint32_t Length) {
+  uint32_t BlockNum = Offset / Pdb.getBlockSize();
+  uint32_t OffsetInBlock = Offset % Pdb.getBlockSize();
+
+  // Make sure we aren't trying to read beyond the end of the stream.
+  if (this->Offset + Length > this->StreamLength)
+    return std::make_error_code(std::errc::bad_address);
+
+  // Modify the passed in offset to point to the data after the object.
+  Offset += Length;
+
+  // Handle the contiguous case: the offset + size stays within a block.
+  if (OffsetInBlock + Length <= Pdb.getBlockSize()) {
+    uint32_t StreamBlockAddr = this->BlockList[BlockNum];
+
+    StringRef Data = Pdb.getBlockData(StreamBlockAddr, Pdb.getBlockSize());
+    ::memcpy(Dest, Data.data() + OffsetInBlock, Length);
+    return std::error_code();
+  }
+
+  // The non-contiguous case: we will stitch together non-contiguous chunks
+  uint32_t BytesLeft = Length;
+  uint32_t BytesWritten = 0;
+  char *WriteBuffer = static_cast<char *>(Dest);
+  while (BytesLeft > 0) {
+    uint32_t StreamBlockAddr = this->BlockList[BlockNum];
+    uint64_t StreamBlockOffset =
+        blockToOffset(StreamBlockAddr, Pdb.getBlockSize()) + OffsetInBlock;
+
+    StringRef Data = Pdb.getBlockData(StreamBlockAddr, Pdb.getBlockSize());
+
+    const char *ChunkStart = Data.data() + StreamBlockOffset;
+    uint32_t BytesInChunk =
+        std::min(BytesLeft, Pdb.getBlockSize() - OffsetInBlock);
+    ::memcpy(WriteBuffer + BytesWritten, ChunkStart, BytesInChunk);
+
+    BytesWritten += BytesInChunk;
+    BytesLeft -= BytesInChunk;
+    ++BlockNum;
+    OffsetInBlock = 0;
+  }
+  return std::error_code();
+}
+
+void PDBStream::setOffset(uint32_t O) { this->Offset = O; }
+
+uint32_t PDBStream::getOffset() const { return this->Offset; }
+
+uint32_t PDBStream::getLength() const { return this->StreamLength; }