Allow uncacheable identifiers to go generic.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index f629d9f19f52b122f9f71c838c787ab91314df5f..fb8f7ce974777f8f884cad4159f2a1d9c4dfc480 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -2649,6 +2649,32 @@ bool Name::Equals(Name* other) {
 }
 
 
+static bool IsIdentifier(UnicodeCache* cache, Name* name) {

[Jakob Kummerow, 2013/09/02 13:28:59]

This seems a little large for -inl.h. Please move it to objects.cc (and
Name::IsCacheable with it). You could also consider making it a method of Name.

+  // Checks whether the buffer contains an identifier (no escape).
+  if (!name->IsString()) return false;
+  String* string = String::cast(name);
+  if (string->length() == 0) return false;
+  ConsStringIteratorOp op;
+  StringCharacterStream stream(string, &op);
+  if (!cache->IsIdentifierStart(stream.GetNext())) {
+    return false;
+  }
+  while (stream.HasMore()) {
+    if (!cache->IsIdentifierPart(stream.GetNext())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+
+bool Name::IsCacheable(Isolate* isolate) {
+  return IsSymbol() ||
+      IsIdentifier(isolate->unicode_cache(), this) ||
+      this == isolate->heap()->hidden_string();
+}
+
+
 ACCESSORS(Symbol, name, Object, kNameOffset)