Changed scavenge GC to collect unmodified references

src/global-handles.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/global-handles.h"
 
 #include "src/api.h"
 #include "src/v8.h"
 #include "src/vm-state-inl.h"
 
@@ skipping 669 matching lines @@
         node->CollectPhantomCallbackData(isolate(),
                                          &pending_phantom_callbacks_);
       } else {
         v->VisitPointer(node->location());
       }
     }
   }
 }
 
 
+void GlobalHandles::IterateNewSpaceWeakRoots(ObjectVisitor* v,
+                                             WeakSlotCallback can_skip) {
+  for (int i = 0; i < new_space_nodes_.length(); ++i) {
+    Node* node = new_space_nodes_[i];
+    Object* object = node->object();
+    // If node->location is used instead of &object, import-expando-gc.html
+    // fails
+    if (node->IsWeak() && !can_skip(node->location()))
+      v->VisitPointer(&object);  // node->location());
+  }
+}
+
+
 bool GlobalHandles::IterateObjectGroups(ObjectVisitor* v,
                                         WeakSlotCallbackWithHeap can_skip) {
   ComputeObjectGroupsAndImplicitReferences();
   int last = 0;
   bool any_group_was_visited = false;
   for (int i = 0; i < object_groups_.length(); i++) {
     ObjectGroup* entry = object_groups_.at(i);
     DCHECK(entry != NULL);
 
     Object*** objects = entry->objects;
@@ skipping 11 matching lines @@
     if (!group_should_be_visited) {
       object_groups_[last++] = entry;
       continue;
     }
 
     // An object in the group requires visiting, so iterate over all
     // objects in the group.
     for (size_t j = 0; j < entry->length; ++j) {
       Object* object = *objects[j];
       if (object->IsHeapObject()) {
-        v->VisitPointer(&object);
+        // v->VisitPointer(&object);
+        v->VisitPointer(objects[j]);

[mythria, 2015/09/22 10:57:00]

If I pass objects[j] instead of &object for the visitor the test fails when I
use object groups for minor gc. I am not sure which one of these correct, but I
just tried to get more insight to debug the earlier problem

         any_group_was_visited = true;
       }
     }
 
     // Once the entire group has been iterated over, set the object
     // group to NULL so it won't be processed again.
     delete entry;
     object_groups_.at(i) = NULL;
   }
   object_groups_.Rewind(last);
@@ skipping 542 matching lines @@
   blocks_[block][offset] = object;
   if (isolate->heap()->InNewSpace(object)) {
     new_space_indices_.Add(size_);
   }
   *index = size_++;
 }
 
 
 }  // namespace internal
 }  // namespace v8