Fix WeakMap processing for evacuation candidates.

test/cctest/test-weakmaps.cc

Index: test/cctest/test-weakmaps.cc
diff --git a/test/cctest/test-weakmaps.cc b/test/cctest/test-weakmaps.cc
index 56d593628af6a6fe67eef6cc465bcfe81b10e801..4c37145119489d56af47978411c12c244c7e5ef1 100644
--- a/test/cctest/test-weakmaps.cc
+++ b/test/cctest/test-weakmaps.cc
@@ -48,11 +48,11 @@ static Handle<JSWeakMap> AllocateJSWeakMap() {
 
 static void PutIntoWeakMap(Handle<JSWeakMap> weakmap,
                            Handle<JSObject> key,
-                           int value) {
+                           Handle<Object> value) {
   Handle<ObjectHashTable> table = PutIntoObjectHashTable(
       Handle<ObjectHashTable>(ObjectHashTable::cast(weakmap->table())),
       Handle<JSObject>(JSObject::cast(*key)),
-      Handle<Smi>(Smi::FromInt(value)));
+      value);
   weakmap->set_table(*table);
 }
 
@@ -83,7 +83,9 @@ TEST(Weakness) {
   // Put entry into weak map.
   {
     v8::HandleScope scope;
-    PutIntoWeakMap(weakmap, Handle<JSObject>(JSObject::cast(*key)), 23);
+    PutIntoWeakMap(weakmap,
+                   Handle<JSObject>(JSObject::cast(*key)),
+                   Handle<Smi>(Smi::FromInt(23)));
   }
   CHECK_EQ(1, ObjectHashTable::cast(weakmap->table())->NumberOfElements());
 
@@ -133,7 +135,7 @@ TEST(Shrinking) {
     Handle<Map> map = FACTORY->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
     for (int i = 0; i < 32; i++) {
       Handle<JSObject> object = FACTORY->NewJSObjectFromMap(map);
-      PutIntoWeakMap(weakmap, object, i);
+      PutIntoWeakMap(weakmap, object, Handle<Smi>(Smi::FromInt(i)));
     }
   }
 
@@ -152,3 +154,36 @@ TEST(Shrinking) {
   // Check shrunk capacity.
   CHECK_EQ(32, ObjectHashTable::cast(weakmap->table())->Capacity());
 }
+
+
+// Test that weak map values on an evacuation candidate which are not reachable
+// by other paths are correctly recorded in in the slots buffer.
+TEST(Regress2060) {
+  FLAG_always_compact = true;
+  LocalContext context;
+  v8::HandleScope scope;
+  Handle<JSFunction> function =
+      FACTORY->NewFunction(FACTORY->function_symbol(), FACTORY->null_value());
+  Handle<JSObject> key = FACTORY->NewJSObject(function);
+  Handle<JSWeakMap> weakmap = AllocateJSWeakMap();
+
+  // Start second old-space page so that values land on evacuation candidate.
+  Page* first_page = HEAP->old_pointer_space()->anchor()->next_page();
+  FACTORY->NewFixedArray(900 * KB / kPointerSize, TENURED);
+
+  // Fill up weak map with values on an evacuation candidate.
+  {
+    v8::HandleScope scope;
+    for (int i = 0; i < 32; i++) {
+      Handle<JSObject> object = FACTORY->NewJSObject(function, TENURED);
+      CHECK(!HEAP->InNewSpace(object->address()));
+      CHECK(!first_page->Contains(object->address()));
+      PutIntoWeakMap(weakmap, key, object);
+      printf("o%d = %p (!= %p)\n", i, (void*)*object, (void*)first_page);
+    }
+  }
+
+  // Force compacting garbage collection.
+  CHECK(FLAG_always_compact);
+  HEAP->CollectAllGarbage(Heap::kNoGCFlags);
+}