Const constructor must have const super initializer

runtime/vm/class_finalizer.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/class_finalizer.h"
 
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/longjump.h"
@@ skipping 1791 matching lines @@
     }
     interface_class.set_is_implemented();
     // Now resolve the super interfaces.
     ResolveSuperTypeAndInterfaces(interface_class, visited);
   }
   visited->RemoveLast();
 }
 
 
 // A class is marked as constant if it has one constant constructor.
-// A constant class:
-// - may extend only const classes.
-// - has only const instance fields.
+// A constant class can only have final instance fields.
 // Note: we must check for cycles before checking for const properties.
 void ClassFinalizer::CheckForLegalConstClass(const Class& cls) {
   ASSERT(cls.is_const());
-  const Class& super = Class::Handle(cls.SuperClass());
-  if (!super.IsNull() && !super.is_const()) {
-    String& name = String::Handle(super.Name());
-    const Script& script = Script::Handle(cls.script());
-    ReportError(script, cls.token_pos(),
-                "superclass '%s' must be const", name.ToCString());
-  }
   const Array& fields_array = Array::Handle(cls.fields());
   intptr_t len = fields_array.Length();
   Field& field = Field::Handle();
   for (intptr_t i = 0; i < len; i++) {
     field ^= fields_array.At(i);
     if (!field.is_static() && !field.is_final()) {
       const String& class_name = String::Handle(cls.Name());
       const String& field_name = String::Handle(field.name());
       const Script& script = Script::Handle(cls.script());
       ReportError(script, field.token_pos(),
@@ skipping 210 matching lines @@
   expected_name ^= String::New("_offset");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
   field ^= fields_array.At(2);
   ASSERT(field.Offset() == TypedDataView::length_offset());
   name ^= field.name();
   ASSERT(name.Equals("length"));
 #endif
 }
 
 }  // namespace dart