Implement a 2-pass heap verification algorithm.

runtime/vm/heap.h

Index: runtime/vm/heap.h
diff --git a/runtime/vm/heap.h b/runtime/vm/heap.h
index 4e59ff0f64591ab0118a626afb99c7bfed666e99..f54ad77c9975ec94a60dfdb83acddd129b03dba9 100644
--- a/runtime/vm/heap.h
+++ b/runtime/vm/heap.h
@@ -17,6 +17,7 @@ namespace dart {
 // Forward declarations.
 class Isolate;
 class ObjectPointerVisitor;
+class ObjectSet;
 class VirtualMemory;
 
 DECLARE_FLAG(bool, verbose_gc);
@@ -80,6 +81,10 @@ class Heap {
   bool CodeContains(uword addr) const;
   bool StubCodeContains(uword addr) const;
 
+  void VisitObjects(ObjectVisitor* visitor);

[Ivan Posva, 2012/06/29 22:20:41]

It is unclear why these are named different. We already have IterateXObjects and
IterateXPointers. We should move these down next to them and name them
consistently.

[cshapiro, 2012/07/10 21:48:17]

VisitObjects -> IterateObjects
VisitObjectPointers -> IteratePointers

Each signature is above the space-specific iterators for the sake of
consistency.

Done.

+
+  void VisitObjectPointers(ObjectPointerVisitor* visitor);
+
   // Visit all pointers in the space.
   void IterateNewPointers(ObjectPointerVisitor* visitor);
   void IterateOldPointers(ObjectPointerVisitor* visitor);
@@ -122,6 +127,10 @@ class Heap {
   // Print heap sizes.
   void PrintSizes() const;
 
+  void StartEndAddress(uword* start, uword* end) const;
+
+  ObjectSet* GetAllocatedObjects() const;
+
   // Generates a profile of the current and VM isolate heaps.
   void Profile(Dart_HeapProfileWriteCallback callback, void* stream) const;