Make objects embedded in optimized code weak.

src/objects-debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 647 matching lines @@
     it.rinfo()->Verify();
     // Ensure that GC will not iterate twice over the same pointer.
     if (RelocInfo::IsGCRelocMode(it.rinfo()->rmode())) {
       CHECK(it.rinfo()->pc() != last_gc_pc);
       last_gc_pc = it.rinfo()->pc();
     }
   }
 }
 
 
-void Code::VerifyEmbeddedMapsDependency() {
+void Code::VerifyEmbeddedObjectsDependency() {
   int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
   for (RelocIterator it(this, mode_mask); !it.done(); it.next()) {
-    RelocInfo::Mode mode = it.rinfo()->rmode();
-    if (mode == RelocInfo::EMBEDDED_OBJECT &&
-      it.rinfo()->target_object()->IsMap()) {
-      Map* map = Map::cast(it.rinfo()->target_object());
-      if (map->CanTransition()) {
+    Object* obj = it.rinfo()->target_object();
+    if (IsWeakEmbeddedObject(kind(), obj)) {
+      if (obj->IsMap()) {
+        Map* map = Map::cast(obj);
         CHECK(map->dependent_code()->Contains(
             DependentCode::kWeaklyEmbeddedGroup, this));
+      } else if (obj->IsJSObject()) {
+        Object* raw_table = GetIsolate()->heap()->weak_object_to_code_table();
+        WeakHashTable* table = WeakHashTable::cast(raw_table);
+        CHECK(DependentCode::cast(table->Lookup(obj))->Contains(
+            DependentCode::kWeaklyEmbeddedGroup, this));
       }
     }
   }
 }
 
 
 void JSArray::JSArrayVerify() {
   JSObjectVerify();
   CHECK(length()->IsNumber() || length()->IsUndefined());
   // If a GC was caused while constructing this array, the elements
@@ skipping 496 matching lines @@
   for (int i = 0; i < number_of_transitions(); ++i) {
     if (!CheckOneBackPointer(current_map, GetTarget(i))) return false;
   }
   return true;
 }
 
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal