Streaming API: detect UTF-8 BOM.

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/scanner.h"
 
 namespace v8 {
@@ skipping 69 matching lines @@
 // 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) {}
+        utf8_split_char_buffer_length_(0),
+        first_chunk_(true) {}
 
   virtual ~ExternalStreamingStream() { delete[] current_data_; }
 
   virtual unsigned BufferSeekForward(unsigned 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;
   }
 
   virtual unsigned FillBuffer(unsigned position) OVERRIDE;
 
  private:
   void HandleUtf8SplitCharacters(unsigned* data_in_buffer);
 
   ScriptCompiler::ExternalSourceStream* source_stream_;
   v8::ScriptCompiler::StreamedSource::Encoding encoding_;
   const uint8_t* current_data_;
   unsigned current_data_offset_;
   unsigned current_data_length_;
   // For converting UTF-8 characters which are split across two data chunks.
   uint8_t utf8_split_char_buffer_[4];
   unsigned utf8_split_char_buffer_length_;
+  bool first_chunk_;
 };
 
 
 // UTF16 buffer to read characters from an external string.
 class ExternalTwoByteStringUtf16CharacterStream: public Utf16CharacterStream {
  public:
   ExternalTwoByteStringUtf16CharacterStream(Handle<ExternalTwoByteString> data,
                                             int start_position,
                                             int end_position);
   virtual ~ExternalTwoByteStringUtf16CharacterStream();
@@ skipping 13 matching lines @@
     // Entire string is read at start.
     return false;
   }
   Handle<ExternalTwoByteString> source_;
   const uc16* raw_data_;  // Pointer to the actual array of characters.
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_CHARACTER_STREAMS_H_