1 files changed, 111 insertions, 0 deletions
diff --git a/include/llvm/DebugInfo/CodeView/StreamReader.h b/include/llvm/DebugInfo/CodeView/StreamReader.h
new file mode 100644
index 000000000000..2f497c2c43f1
--- /dev/null
+++ b/include/llvm/DebugInfo/CodeView/StreamReader.h
@@ -0,0 +1,111 @@
+//===- StreamReader.h - Reads bytes and objects from a stream ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_CODEVIEW_STREAMREADER_H
+#define LLVM_DEBUGINFO_CODEVIEW_STREAMREADER_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/DebugInfo/CodeView/CodeViewError.h"
+#include "llvm/DebugInfo/CodeView/StreamArray.h"
+#include "llvm/DebugInfo/CodeView/StreamInterface.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+
+#include <string>
+
+namespace llvm {
+namespace codeview {
+
+class StreamRef;
+
+class StreamReader {
+public:
+  StreamReader(StreamRef Stream);
+
+  Error readLongestContiguousChunk(ArrayRef<uint8_t> &Buffer);
+  Error readBytes(ArrayRef<uint8_t> &Buffer, uint32_t Size);
+  Error readInteger(uint16_t &Dest);
+  Error readInteger(uint32_t &Dest);
+  Error readZeroString(StringRef &Dest);
+  Error readFixedString(StringRef &Dest, uint32_t Length);
+  Error readStreamRef(StreamRef &Ref);
+  Error readStreamRef(StreamRef &Ref, uint32_t Length);
+
+  template <typename T> Error readEnum(T &Dest) {
+    typename std::underlying_type<T>::type N;
+    if (auto EC = readInteger(N))
+      return EC;
+    Dest = static_cast<T>(N);
+    return Error::success();
+  }
+
+  template <typename T> Error readObject(const T *&Dest) {
+    ArrayRef<uint8_t> Buffer;
+    if (auto EC = readBytes(Buffer, sizeof(T)))
+      return EC;
+    Dest = reinterpret_cast<const T *>(Buffer.data());
+    return Error::success();
+  }
+
+  template <typename T>
+  Error readArray(ArrayRef<T> &Array, uint32_t NumElements) {
+    ArrayRef<uint8_t> Bytes;
+    if (NumElements == 0) {
+      Array = ArrayRef<T>();
+      return Error::success();
+    }
+
+    if (NumElements > UINT32_MAX/sizeof(T))
+      return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
+
+    if (auto EC = readBytes(Bytes, NumElements * sizeof(T)))
+      return EC;
+    Array = ArrayRef<T>(reinterpret_cast<const T *>(Bytes.data()), NumElements);
+    return Error::success();
+  }
+
+  template <typename T, typename U>
+  Error readArray(VarStreamArray<T, U> &Array, uint32_t Size) {
+    StreamRef S;
+    if (auto EC = readStreamRef(S, Size))
+      return EC;
+    Array = VarStreamArray<T, U>(S, Array.getExtractor());
+    return Error::success();
+  }
+
+  template <typename T>
+  Error readArray(FixedStreamArray<T> &Array, uint32_t NumItems) {
+    if (NumItems == 0) {
+      Array = FixedStreamArray<T>();
+      return Error::success();
+    }
+    uint32_t Length = NumItems * sizeof(T);
+    if (Length / sizeof(T) != NumItems)
+      return make_error<CodeViewError>(cv_error_code::corrupt_record);
+    if (Offset + Length > Stream.getLength())
+      return make_error<CodeViewError>(cv_error_code::insufficient_buffer);
+    StreamRef View = Stream.slice(Offset, Length);
+    Array = FixedStreamArray<T>(View);
+    Offset += Length;
+    return Error::success();
+  }
+
+  void setOffset(uint32_t Off) { Offset = Off; }
+  uint32_t getOffset() const { return Offset; }
+  uint32_t getLength() const { return Stream.getLength(); }
+  uint32_t bytesRemaining() const { return getLength() - getOffset(); }
+
+private:
+  StreamRef Stream;
+  uint32_t Offset;
+};
+} // namespace codeview
+} // namespace llvm
+
+#endif // LLVM_DEBUGINFO_CODEVIEW_STREAMREADER_H