Retaining path in Observatory.

runtime/vm/object_graph.cc

 // Copyright (c) 2014, 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/object_graph.h"
 
 #include "vm/dart.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 205 matching lines @@
     ASSERT(Isolate::Current()->no_gc_scope_depth() != 0);
   }
 
   intptr_t length() const { return length_; }
 
   virtual Direction VisitObject(ObjectGraph::StackIterator* it) {
     if (it->Get() != obj_) {
       return kProceed;
     } else {
       HANDLESCOPE(Isolate::Current());
-      Object& parent = Object::Handle();
-      for (length_ = 0; it->MoveToParent(); ++length_) {
+      Object& current = Object::Handle();
+      do {
         if (!path_.IsNull() && length_ < path_.Length()) {
-          parent = it->Get();
-          path_.SetAt(length_, parent);
+          current = it->Get();
+          path_.SetAt(length_, current);
         }
-      }
+        ++length_;
+      } while (it->MoveToParent());
       return kAbort;
     }
   }
 
  private:
   RawObject* obj_;
   const Array& path_;
   intptr_t length_;
 };
 
 
 intptr_t ObjectGraph::RetainingPath(Object* obj, const Array& path) {
   NoGCScope no_gc_scope_;
   // To break the trivial path, the handle 'obj' is temporarily cleared during
   // the search, but restored before returning.
   RawObject* raw = obj->raw();
   *obj = Object::null();
   RetainingPathVisitor visitor(raw, path);
   IterateObjects(&visitor);
   *obj = raw;
   return visitor.length();
 }
 
 }  // namespace dart