Reapply "Fix the ScopeIterator reimplementation".

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index b79589160190cd4019428bf5cc4b2293ff3276a6..efffe5a4e68d92414118302a497b56502a2aa2e2 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -5541,7 +5541,7 @@ static ScriptDataImpl* DoPreParse(UC16CharacterStream* source,
 
 // Preparse, but only collect data that is immediately useful,
 // even if the preparser data is only used once.
-ScriptDataImpl* ParserApi::PartialPreParse(UC16CharacterStream* source,
+ScriptDataImpl* ParserApi::PartialPreParse(Handle<String> source,

[Lasse Reichstein, 2011/11/29 08:07:27]

For what it's worth, there is no longer any need for a PartialPreParse function,
or partial preparsing functionality.  
PartialPreParse was a smaller version of the offline preparser, used only for
preparsing just before parsing. That shouldn't be done any more. The
PartialParserRecorder can be deleted too, since the inline lazy function body
"preparsing" doesn't use it.

                                            v8::Extension* extension,
                                            int flags) {
   bool allow_lazy = FLAG_lazy && (extension == NULL);
@@ -5552,7 +5552,15 @@ ScriptDataImpl* ParserApi::PartialPreParse(UC16CharacterStream* source,
   }
   flags |= kAllowLazy;
   PartialParserRecorder recorder;
-  return DoPreParse(source, flags, &recorder);
+  int source_length = source->length();
+  if (source->IsExternalTwoByteString()) {
+    ExternalTwoByteStringUC16CharacterStream stream(
+        Handle<ExternalTwoByteString>::cast(source), 0, source_length);
+    return DoPreParse(&stream, flags, &recorder);
+  } else {
+    GenericStringUC16CharacterStream stream(source, 0, source_length);
+    return DoPreParse(&stream, flags, &recorder);
+  }
 }