Allow uncacheable identifiers to go generic.

src/objects-inl.h

 // Copyright 2012 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 2631 matching lines @@
 bool Name::Equals(Name* other) {
   if (other == this) return true;
   if ((this->IsInternalizedString() && other->IsInternalizedString()) ||
       this->IsSymbol() || other->IsSymbol()) {
     return false;
   }
   return String::cast(this)->SlowEquals(String::cast(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)
 
 
 bool String::Equals(String* other) {
   if (other == this) return true;
   if (this->IsInternalizedString() && other->IsInternalizedString()) {
     return false;
   }
   return SlowEquals(other);
 }
@@ skipping 3623 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_