- Add extra checking when validating objects.

vm/raw_object.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/raw_object.h"
 
+#include "vm/class_table.h"
 #include "vm/freelist.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/visitor.h"
 
 
 namespace dart {
 
-void RawObject::Validate() const {
+void RawObject::Validate(Isolate* isolate) const {
+  // Validation only happens in DEBUG builds.
+#if defined(DEBUG)
   if (Object::null_class_ == reinterpret_cast<RawClass*>(kHeapObjectTag)) {
     // Validation relies on properly initialized class classes. Skip if the
     // VM is still being initialized.
     return;
   }
   // All Smi values are valid.
   if (!IsHeapObject()) {
     return;
   }
   // Validate that the class_ field is sensible.
   RawClass* raw_class = ptr()->class_;
   ASSERT(raw_class->IsHeapObject());
   RawClass* raw_class_class = raw_class->ptr()->class_;
   ASSERT(raw_class_class->IsHeapObject());
   ASSERT(raw_class_class->ptr()->instance_kind_ == kClass);
 
   // Validate that the tags_ field is sensible.
-  intptr_t tags = ptr()->tags_;
+  uword tags = ptr()->tags_;
   ASSERT((tags & 0x000000f0) == 0);
+  intptr_t cid = ClassTag::decode(tags);
+  RawClass* tag_class = isolate->class_table()->At(cid);
+  ASSERT(tag_class == raw_class);
+#endif
 }
 
 
 intptr_t RawObject::SizeFromClass() const {
   NoHandleScope no_handles(Isolate::Current());
 
   // Only reasonable to be called on heap objects.
   ASSERT(IsHeapObject());
 
   RawClass* raw_class = ptr()->class_;
@@ skipping 125 matching lines @@
         FreeListElement* element = reinterpret_cast<FreeListElement*>(addr);
         instance_size = element->Size();
         break;
       }
       default:
         UNREACHABLE();
         break;
     }
   }
   ASSERT(instance_size != 0);
-  intptr_t tags = ptr()->tags_;
+  uword tags = ptr()->tags_;
   ASSERT((instance_size == SizeTag::decode(tags)) ||
          (SizeTag::decode(tags) == 0) ||
          FreeBit::decode(tags));
   return instance_size;
 }
 
 
 intptr_t RawObject::VisitPointers(ObjectPointerVisitor* visitor) {
   intptr_t size = 0;
   NoHandleScope no_handles(Isolate::Current());
@@ skipping 502 matching lines @@
 intptr_t RawJSRegExp::VisitJSRegExpPointers(RawJSRegExp* raw_obj,
                                             ObjectPointerVisitor* visitor) {
   // Make sure that we got here with the tagged pointer as this.
   ASSERT(raw_obj->IsHeapObject());
   intptr_t length = Smi::Value(raw_obj->ptr()->data_length_);
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return JSRegExp::InstanceSize(length);
 }
 
 }  // namespace dart