- Ensure that BaseIsolate is only used to break the header include cycles.

runtime/vm/zone.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_ZONE_H_
 #define VM_ZONE_H_
 
 #include "platform/utils.h"
 #include "vm/allocation.h"
 #include "vm/handles.h"
@@ skipping 139 matching lines @@
   friend class StackZone;
   friend class ApiZone;
   template<typename T, typename B> friend class BaseGrowableArray;
   DISALLOW_COPY_AND_ASSIGN(Zone);
 };
 
 
 class StackZone : public StackResource {
  public:
   // Create an empty zone and set is at the current zone for the Isolate.
-  explicit StackZone(BaseIsolate* isolate)
+  explicit StackZone(Isolate* isolate)
     : StackResource(isolate),
       zone_() {
 #ifdef DEBUG
     if (FLAG_trace_zones) {
       OS::PrintErr("*** Starting a new Stack zone 0x%" Px "(0x%" Px ")\n",
                    reinterpret_cast<intptr_t>(this),
                    reinterpret_cast<intptr_t>(&zone_));
     }
 #endif
-    zone_.Link(isolate->current_zone());
-    isolate->set_current_zone(&zone_);
+    BaseIsolate* base_isolate = reinterpret_cast<BaseIsolate*>(isolate);
+    zone_.Link(base_isolate->current_zone());
+    base_isolate->set_current_zone(&zone_);
   }
 
   // Delete all memory associated with the zone.
   ~StackZone() {
-    ASSERT(isolate()->current_zone() == &zone_);
-    isolate()->set_current_zone(zone_.previous_);
+    BaseIsolate* base_isolate = reinterpret_cast<BaseIsolate*>(isolate());
+    ASSERT(base_isolate->current_zone() == &zone_);
+    base_isolate->set_current_zone(zone_.previous_);
 #ifdef DEBUG
     if (FLAG_trace_zones) {
       OS::PrintErr("*** Deleting Stack zone 0x%" Px "(0x%" Px ")\n",
                    reinterpret_cast<intptr_t>(this),
                    reinterpret_cast<intptr_t>(&zone_));
     }
 #endif
   }
 
   // Compute the total size of this zone. This includes wasted space that is
@@ skipping 55 matching lines @@
             reinterpret_cast<void*>(old_data),
             Utils::Minimum(old_len * sizeof(ElementType),
                            new_len * sizeof(ElementType)));
   }
   return new_data;
 }
 
 }  // namespace dart
 
 #endif  // VM_ZONE_H_