Remove assumption from the heap verifier that objects occupy a narrow range of the address space.

runtime/vm/pages.cc

 // 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.
 
 #include "vm/pages.h"
 
 #include "platform/assert.h"
 #include "vm/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
 #include "vm/lockers.h"
 #include "vm/object.h"
+#include "vm/object_set.h"
 #include "vm/os_thread.h"
 #include "vm/safepoint.h"
 #include "vm/virtual_memory.h"
 
 namespace dart {
 
 DEFINE_FLAG(int, heap_growth_rate, 0,
             "The max number of pages the heap can grow at a time");
 DEFINE_FLAG(int, old_gen_growth_space_ratio, 20,
             "The desired maximum percentage of free space after old gen GC");
@@ skipping 558 matching lines @@
   }
   for (ExclusivePageIterator it(this); !it.Done(); it.Advance()) {
     if ((it.page()->type() == type) && it.page()->Contains(addr)) {
       return true;
     }
   }
   return false;
 }
 
 
-void PageSpace::StartEndAddress(uword* start, uword* end) const {
+void PageSpace::AddRegionsToObjectSet(ObjectSet* set) const {
   ASSERT((pages_ != NULL) || (exec_pages_ != NULL) || (large_pages_ != NULL));
-  *start = static_cast<uword>(~0);
-  *end = 0;
   for (ExclusivePageIterator it(this); !it.Done(); it.Advance()) {
-    *start = Utils::Minimum(*start, it.page()->object_start());
-    *end = Utils::Maximum(*end, it.page()->object_end());
+    set->AddRegion(it.page()->object_start(), it.page()->object_end());
   }
-  ASSERT(*start != static_cast<uword>(~0));
-  ASSERT(*end != 0);
 }
 
 
 void PageSpace::VisitObjects(ObjectVisitor* visitor) const {
   for (ExclusivePageIterator it(this); !it.Done(); it.Advance()) {
     it.page()->VisitObjects(visitor);
   }
 }
 
 
@@ skipping 609 matching lines @@
     return 0;
   } else {
     ASSERT(total_time >= gc_time);
     int result = static_cast<int>((static_cast<double>(gc_time) /
                                    static_cast<double>(total_time)) * 100);
     return result;
   }
 }
 
 }  // namespace dart