Upgrade V8 to version 4.9.385.28

https://chromium.googlesource.com/v8/v8/+/4.9.385.28

FPIIM-449

Change-Id: I4b2e74289d4bf3667f2f3dc8aa2e541f63e26eb4
diff --git a/src/parsing/scanner-character-streams.h b/src/parsing/scanner-character-streams.h
new file mode 100644
index 0000000..603db93
--- /dev/null
+++ b/src/parsing/scanner-character-streams.h
@@ -0,0 +1,189 @@
+// Copyright 2011 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_PARSING_SCANNER_CHARACTER_STREAMS_H_
+#define V8_PARSING_SCANNER_CHARACTER_STREAMS_H_
+
+#include "src/handles.h"
+#include "src/parsing/scanner.h"
+#include "src/vector.h"
+
+namespace v8 {
+namespace internal {
+
+// Forward declarations.
+class ExternalTwoByteString;
+
+// A buffered character stream based on a random access character
+// source (ReadBlock can be called with pos_ pointing to any position,
+// even positions before the current).
+class BufferedUtf16CharacterStream: public Utf16CharacterStream {
+ public:
+  BufferedUtf16CharacterStream();
+  ~BufferedUtf16CharacterStream() override;
+
+  void PushBack(uc32 character) override;
+
+ protected:
+  static const size_t kBufferSize = 512;
+  static const size_t kPushBackStepSize = 16;
+
+  size_t SlowSeekForward(size_t delta) override;
+  bool ReadBlock() override;
+  virtual void SlowPushBack(uc16 character);
+
+  virtual size_t BufferSeekForward(size_t delta) = 0;
+  virtual size_t FillBuffer(size_t position) = 0;
+
+  const uc16* pushback_limit_;
+  uc16 buffer_[kBufferSize];
+};
+
+
+// Generic string stream.
+class GenericStringUtf16CharacterStream: public BufferedUtf16CharacterStream {
+ public:
+  GenericStringUtf16CharacterStream(Handle<String> data, size_t start_position,
+                                    size_t end_position);
+  ~GenericStringUtf16CharacterStream() override;
+
+  bool SetBookmark() override;
+  void ResetToBookmark() override;
+
+ protected:
+  static const size_t kNoBookmark = -1;
+
+  size_t BufferSeekForward(size_t delta) override;
+  size_t FillBuffer(size_t position) override;
+
+  Handle<String> string_;
+  size_t length_;
+  size_t bookmark_;
+};
+
+
+// Utf16 stream based on a literal UTF-8 string.
+class Utf8ToUtf16CharacterStream: public BufferedUtf16CharacterStream {
+ public:
+  Utf8ToUtf16CharacterStream(const byte* data, size_t length);
+  ~Utf8ToUtf16CharacterStream() override;
+
+  static size_t CopyChars(uint16_t* dest, size_t length, const byte* src,
+                          size_t* src_pos, size_t src_length);
+
+ protected:
+  size_t BufferSeekForward(size_t delta) override;
+  size_t FillBuffer(size_t char_position) override;
+  void SetRawPosition(size_t char_position);
+
+  const byte* raw_data_;
+  size_t raw_data_length_;  // Measured in bytes, not characters.
+  size_t raw_data_pos_;
+  // The character position of the character at raw_data[raw_data_pos_].
+  // Not necessarily the same as pos_.
+  size_t raw_character_position_;
+};
+
+
+// ExternalStreamingStream is a wrapper around an ExternalSourceStream (see
+// include/v8.h) subclass implemented by the embedder.
+class ExternalStreamingStream : public BufferedUtf16CharacterStream {
+ public:
+  ExternalStreamingStream(ScriptCompiler::ExternalSourceStream* source_stream,
+                          v8::ScriptCompiler::StreamedSource::Encoding encoding)
+      : source_stream_(source_stream),
+        encoding_(encoding),
+        current_data_(NULL),
+        current_data_offset_(0),
+        current_data_length_(0),
+        utf8_split_char_buffer_length_(0),
+        bookmark_(0),
+        bookmark_data_is_from_current_data_(false),
+        bookmark_data_offset_(0),
+        bookmark_utf8_split_char_buffer_length_(0) {}
+
+  ~ExternalStreamingStream() override {
+    delete[] current_data_;
+    bookmark_buffer_.Dispose();
+    bookmark_data_.Dispose();
+  }
+
+  size_t BufferSeekForward(size_t delta) override {
+    // We never need to seek forward when streaming scripts. We only seek
+    // forward when we want to parse a function whose location we already know,
+    // and when streaming, we don't know the locations of anything we haven't
+    // seen yet.
+    UNREACHABLE();
+    return 0;
+  }
+
+  size_t FillBuffer(size_t position) override;
+
+  bool SetBookmark() override;
+  void ResetToBookmark() override;
+
+ private:
+  void HandleUtf8SplitCharacters(size_t* data_in_buffer);
+  void FlushCurrent();
+
+  ScriptCompiler::ExternalSourceStream* source_stream_;
+  v8::ScriptCompiler::StreamedSource::Encoding encoding_;
+  const uint8_t* current_data_;
+  size_t current_data_offset_;
+  size_t current_data_length_;
+  // For converting UTF-8 characters which are split across two data chunks.
+  uint8_t utf8_split_char_buffer_[4];
+  size_t utf8_split_char_buffer_length_;
+
+  // Bookmark support. See comments in ExternalStreamingStream::SetBookmark
+  // for additional details.
+  size_t bookmark_;
+  Vector<uint16_t> bookmark_buffer_;
+  Vector<uint8_t> bookmark_data_;
+  bool bookmark_data_is_from_current_data_;
+  size_t bookmark_data_offset_;
+  uint8_t bookmark_utf8_split_char_buffer_[4];
+  size_t bookmark_utf8_split_char_buffer_length_;
+};
+
+
+// UTF16 buffer to read characters from an external string.
+class ExternalTwoByteStringUtf16CharacterStream: public Utf16CharacterStream {
+ public:
+  ExternalTwoByteStringUtf16CharacterStream(Handle<ExternalTwoByteString> data,
+                                            int start_position,
+                                            int end_position);
+  ~ExternalTwoByteStringUtf16CharacterStream() override;
+
+  void PushBack(uc32 character) override {
+    DCHECK(buffer_cursor_ > raw_data_);
+    buffer_cursor_--;
+    pos_--;
+  }
+
+  bool SetBookmark() override;
+  void ResetToBookmark() override;
+
+ protected:
+  size_t SlowSeekForward(size_t delta) override {
+    // Fast case always handles seeking.
+    return 0;
+  }
+  bool ReadBlock() override {
+    // Entire string is read at start.
+    return false;
+  }
+  Handle<ExternalTwoByteString> source_;
+  const uc16* raw_data_;  // Pointer to the actual array of characters.
+
+ private:
+  static const size_t kNoBookmark = -1;
+
+  size_t bookmark_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_PARSING_SCANNER_CHARACTER_STREAMS_H_