Ensure that scanner state is correctly reset when an error is encountered.

src/scanner.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 40 matching lines @@
   void StartLiteral() {
     buffer_.StartSequence();
   }
 
   Vector<const char> EndLiteral() {
     buffer_.Add(kEndMarker);
     Vector<char> sequence = buffer_.EndSequence();
     return Vector<const char>(sequence.start(), sequence.length());
   }
 
+  void DropLiteral() {
+    buffer_.DropSequence();
+  }
+
+  void Reset() {
+    buffer_.Reset();
+  }
+
   // The end marker added after a parsed literal.
   // Using zero allows the usage of strlen and similar functions on
   // identifiers and numbers (but not strings, since they may contain zero
   // bytes).
   // TODO(lrn): Use '\xff' as end marker, since it cannot occur inside
   // an utf-8 string. This requires changes in all places that uses
   // str-functions on the literals, but allows a single pointer to represent
   // the literal, even if it contains embedded zeros.
   static const char kEndMarker = '\x00';
  private:
@@ skipping 184 matching lines @@
 
 
 enum ParserMode { PARSE, PREPARSE };
 enum ParserLanguage { JAVASCRIPT, JSON };
 
 
 class Scanner {
  public:
   typedef unibrow::Utf8InputBuffer<1024> Utf8Decoder;
 
+  class LiteralScope {
+   public:
+    explicit LiteralScope(Scanner* self);
+
+    ~LiteralScope();
+
+    void Complete();
+   private:

[Mads Ager (chromium), 2010/08/24 12:19:32]

Strange spacing going on here. Please add blank line before private: and
consider removing the blanks between the function declarations.

[Lasse Reichstein, 2010/08/24 12:30:21]

Done.

+    Scanner* scanner_;
+    bool complete_;
+  };
+
   // Construction
   explicit Scanner(ParserMode parse_mode);
 
   // Initialize the Scanner to scan source.
   void Initialize(Handle<String> source,
                   ParserLanguage language);
   void Initialize(Handle<String> source,
                   unibrow::CharacterStream* stream,
                   ParserLanguage language);
   void Initialize(Handle<String> source,
@@ skipping 100 matching lines @@
   void Init(Handle<String> source,
             unibrow::CharacterStream* stream,
             int start_position, int end_position,
             ParserLanguage language);
 
   // Literal buffer support
   inline void StartLiteral();
   inline void AddChar(uc32 ch);
   inline void AddCharAdvance();
   inline void TerminateLiteral();
+  // Stops scanning of a literal, e.g., due to an encountered error.
+  inline void DropLiteral();
 
   // Low-level scanning support.
   void Advance() { c0_ = source_->Advance(); }
   void PushBack(uc32 ch) {
     source_->PushBack(ch);
     c0_ = ch;
   }
 
   bool SkipWhiteSpace() {
     if (is_parsing_json_) {
@@ skipping 96 matching lines @@
   bool stack_overflow_;
   static StaticResource<Utf8Decoder> utf8_decoder_;
 
   // One Unicode character look-ahead; c0_ < 0 at the end of the input.
   uc32 c0_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_H_