1 files changed, 79 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/Msf/ByteStream.cpp b/llvm/lib/DebugInfo/Msf/ByteStream.cpp
new file mode 100644
index 00000000000..32fcbccaacc
--- /dev/null
+++ b/llvm/lib/DebugInfo/Msf/ByteStream.cpp
@@ -0,0 +1,79 @@
+//===- ByteStream.cpp - Reads stream data from a byte sequence ------------===//
+//
+//                     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/ByteStream.h"
+#include "llvm/DebugInfo/Msf/MsfError.h"
+#include "llvm/DebugInfo/Msf/StreamReader.h"
+#include <cstring>
+
+using namespace llvm;
+using namespace llvm::msf;
+
+static Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Src,
+                        ArrayRef<uint8_t> Dest) {
+  return make_error<MsfError>(msf_error_code::not_writable,
+                              "ByteStream is immutable.");
+}
+
+static Error writeBytes(uint32_t Offset, ArrayRef<uint8_t> Src,
+                        MutableArrayRef<uint8_t> Dest) {
+  if (Dest.size() < Src.size())
+    return make_error<MsfError>(msf_error_code::insufficient_buffer);
+  if (Offset > Src.size() - Dest.size())
+    return make_error<MsfError>(msf_error_code::insufficient_buffer);
+
+  ::memcpy(Dest.data() + Offset, Src.data(), Src.size());
+  return Error::success();
+}
+
+template <bool Writable>
+Error ByteStream<Writable>::readBytes(uint32_t Offset, uint32_t Size,
+                                      ArrayRef<uint8_t> &Buffer) const {
+  if (Offset > Data.size())
+    return make_error<MsfError>(msf_error_code::insufficient_buffer);
+  if (Data.size() < Size + Offset)
+    return make_error<MsfError>(msf_error_code::insufficient_buffer);
+  Buffer = Data.slice(Offset, Size);
+  return Error::success();
+}
+
+template <bool Writable>
+Error ByteStream<Writable>::readLongestContiguousChunk(
+    uint32_t Offset, ArrayRef<uint8_t> &Buffer) const {
+  if (Offset >= Data.size())
+    return make_error<MsfError>(msf_error_code::insufficient_buffer);
+  Buffer = Data.slice(Offset);
+  return Error::success();
+}
+
+template <bool Writable>
+Error ByteStream<Writable>::writeBytes(uint32_t Offset,
+                                       ArrayRef<uint8_t> Buffer) const {
+  return ::writeBytes(Offset, Buffer, Data);
+}
+
+template <bool Writable> uint32_t ByteStream<Writable>::getLength() const {
+  return Data.size();
+}
+
+template <bool Writable> Error ByteStream<Writable>::commit() const {
+  return Error::success();
+}
+
+template <bool Writable> StringRef ByteStream<Writable>::str() const {
+  const char *CharData = reinterpret_cast<const char *>(Data.data());
+  return StringRef(CharData, Data.size());
+}
+
+namespace llvm {
+namespace msf {
+template class ByteStream<true>;
+template class ByteStream<false>;
+}
+}