1 files changed, 92 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/MSF/BinaryStreamReader.cpp b/llvm/lib/DebugInfo/MSF/BinaryStreamReader.cpp
new file mode 100644
index 00000000000..567e6b1270e
--- /dev/null
+++ b/llvm/lib/DebugInfo/MSF/BinaryStreamReader.cpp
@@ -0,0 +1,92 @@
+//===- StreamReader.cpp - Reads bytes and objects from a stream -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/MSF/BinaryStreamReader.h"
+
+#include "llvm/DebugInfo/MSF/BinaryStreamRef.h"
+#include "llvm/DebugInfo/MSF/MSFError.h"
+
+using namespace llvm;
+using namespace llvm::msf;
+
+StreamReader::StreamReader(ReadableStreamRef S) : Stream(S), Offset(0) {}
+
+Error StreamReader::readLongestContiguousChunk(ArrayRef<uint8_t> &Buffer) {
+  if (auto EC = Stream.readLongestContiguousChunk(Offset, Buffer))
+    return EC;
+  Offset += Buffer.size();
+  return Error::success();
+}
+
+Error StreamReader::readBytes(ArrayRef<uint8_t> &Buffer, uint32_t Size) {
+  if (auto EC = Stream.readBytes(Offset, Size, Buffer))
+    return EC;
+  Offset += Size;
+  return Error::success();
+}
+
+Error StreamReader::readZeroString(StringRef &Dest) {
+  uint32_t Length = 0;
+  // First compute the length of the string by reading 1 byte at a time.
+  uint32_t OriginalOffset = getOffset();
+  const char *C;
+  do {
+    if (auto EC = readObject(C))
+      return EC;
+    if (*C != '\0')
+      ++Length;
+  } while (*C != '\0');
+  // Now go back and request a reference for that many bytes.
+  uint32_t NewOffset = getOffset();
+  setOffset(OriginalOffset);
+
+  ArrayRef<uint8_t> Data;
+  if (auto EC = readBytes(Data, Length))
+    return EC;
+  Dest = StringRef(reinterpret_cast<const char *>(Data.begin()), Data.size());
+
+  // Now set the offset back to where it was after we calculated the length.
+  setOffset(NewOffset);
+  return Error::success();
+}
+
+Error StreamReader::readFixedString(StringRef &Dest, uint32_t Length) {
+  ArrayRef<uint8_t> Bytes;
+  if (auto EC = readBytes(Bytes, Length))
+    return EC;
+  Dest = StringRef(reinterpret_cast<const char *>(Bytes.begin()), Bytes.size());
+  return Error::success();
+}
+
+Error StreamReader::readStreamRef(ReadableStreamRef &Ref) {
+  return readStreamRef(Ref, bytesRemaining());
+}
+
+Error StreamReader::readStreamRef(ReadableStreamRef &Ref, uint32_t Length) {
+  if (bytesRemaining() < Length)
+    return make_error<MSFError>(msf_error_code::insufficient_buffer);
+  Ref = Stream.slice(Offset, Length);
+  Offset += Length;
+  return Error::success();
+}
+
+Error StreamReader::skip(uint32_t Amount) {
+  if (Amount > bytesRemaining())
+    return make_error<MSFError>(msf_error_code::insufficient_buffer);
+  Offset += Amount;
+  return Error::success();
+}
+
+uint8_t StreamReader::peek() const {
+  ArrayRef<uint8_t> Buffer;
+  auto EC = Stream.readBytes(Offset, 1, Buffer);
+  assert(!EC && "Cannot peek an empty buffer!");
+  llvm::consumeError(std::move(EC));
+  return Buffer[0];
+}