Convert Unicode code points outside the basic multilingual plane to the replacement character.

src/heap.cc

 // Copyright 2009 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 2848 matching lines @@
   SeqAsciiString* string_result = SeqAsciiString::cast(result);
   for (int i = 0; i < string.length(); i++) {
     string_result->SeqAsciiStringSet(i, string[i]);
   }
   return result;
 }
 
 
 Object* Heap::AllocateStringFromUtf8(Vector<const char> string,
                                      PretenureFlag pretenure) {
+  // V8 only supports characters in the Basic Multilingual Plane.
+  const uc32 kMaxSupportedChar = 0xFFFF;
   // Count the number of characters in the UTF-8 string and check if
   // it is an ASCII string.
   Access<Scanner::Utf8Decoder> decoder(Scanner::utf8_decoder());
   decoder->Reset(string.start(), string.length());
   int chars = 0;
   bool is_ascii = true;
   while (decoder->has_more()) {
     uc32 r = decoder->GetNext();
     if (r > String::kMaxAsciiCharCode) is_ascii = false;
     chars++;
   }
 
   // If the string is ascii, we do not need to convert the characters
   // since UTF8 is backwards compatible with ascii.
   if (is_ascii) return AllocateStringFromAscii(string, pretenure);
 
   Object* result = AllocateRawTwoByteString(chars, pretenure);
   if (result->IsFailure()) return result;
 
   // Convert and copy the characters into the new object.
   String* string_result = String::cast(result);
   decoder->Reset(string.start(), string.length());
   for (int i = 0; i < chars; i++) {
     uc32 r = decoder->GetNext();
+    if (r > kMaxSupportedChar) { r = unibrow::Utf8::kBadChar; }
     string_result->Set(i, r);
   }
   return result;
 }
 
 
 Object* Heap::AllocateStringFromTwoByte(Vector<const uc16> string,
                                         PretenureFlag pretenure) {
   // Check if the string is an ASCII string.
   int i = 0;
@@ skipping 1919 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal