Create ast/ and parsing/ subdirectories and move appropriate files

src/scanner-character-streams.h

-// 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_SCANNER_CHARACTER_STREAMS_H_
-#define V8_SCANNER_CHARACTER_STREAMS_H_
-
-#include "src/handles.h"
-#include "src/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_SCANNER_CHARACTER_STREAMS_H_