Remove --supermixin flag from VM.

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/code_generator.h"
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/longjump.h"
 #include "vm/log.h"
 #include "vm/object_store.h"
 #include "vm/report.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, print_classes, false, "Prints details about loaded classes.");
 DEFINE_FLAG(bool, trace_class_finalization, false, "Trace class finalization.");
 DEFINE_FLAG(bool, trace_type_finalization, false, "Trace type finalization.");
-DECLARE_FLAG(bool, supermixin);
 DECLARE_FLAG(bool, use_cha_deopt);
 
 
 bool ClassFinalizer::AllClassesFinalized() {
   ObjectStore* object_store = Isolate::Current()->object_store();
   const GrowableObjectArray& classes =
       GrowableObjectArray::Handle(object_store->pending_classes());
   return classes.Length() == 0;
 }
 
@@ skipping 1992 matching lines @@
 
   // Check for illegal self references.
   GrowableArray<intptr_t> visited_mixins;
   if (!IsMixinCycleFree(mixin_class, &visited_mixins)) {
     const String& class_name = String::Handle(mixin_class.Name());
     ReportError(mixin_class, mixin_class.token_pos(),
                 "mixin class '%s' illegally refers to itself",
                 class_name.ToCString());
   }
 
-  if (!FLAG_supermixin) {
-    // Check that the super class of the mixin class is class Object.
-    Class& mixin_super_class = Class::Handle(mixin_class.SuperClass());
-    // Skip over mixin application alias classes, which are implemented as
-    // subclasses of the mixin application classes they name.
-    if (!mixin_super_class.IsNull() && mixin_class.is_mixin_app_alias()) {
-      while (mixin_super_class.is_mixin_app_alias()) {
-        mixin_super_class = mixin_super_class.SuperClass();
-      }
-      mixin_super_class = mixin_super_class.SuperClass();
-    }
-    if (mixin_super_class.IsNull() || !mixin_super_class.IsObjectClass()) {
-      const String& class_name = String::Handle(mixin_class.Name());
-      ReportError(mixin_app_class, mixin_app_class.token_pos(),
-                  "mixin class '%s' must extend class 'Object'",
-                  class_name.ToCString());
-    }
-  }
-
   // Copy type parameters to mixin application class.
   CloneMixinAppTypeParameters(mixin_app_class);
 
   // Verify that no restricted class is used as a mixin by checking the
   // interfaces of the mixin application class, which implements its mixin.
   GrowableArray<intptr_t> visited_interfaces;
   ResolveSuperTypeAndInterfaces(mixin_app_class, &visited_interfaces);
 
   if (FLAG_trace_class_finalization) {
     THR_Print("Done applying mixin type '%s' to class '%s' %s extending '%s'\n",
@@ skipping 1156 matching lines @@
   ASSERT(fields_array.Length() == ByteBuffer::NumberOfFields());
   field ^= fields_array.At(0);
   ASSERT(field.Offset() == ByteBuffer::data_offset());
   name ^= field.name();
   expected_name ^= String::New("_data");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
 #endif
 }
 
 }  // namespace dart