- Add a size field to the header.

vm/raw_object.cc

 // Copyright (c) 2011, 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/freelist.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/visitor.h"
 
 
 namespace dart {
 
 void RawObject::Validate() const {
+  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_;
-  ASSERT((tags & 0xfffffff0) == 0);
+  ASSERT((tags & 0xffff00f0) == 0);
 }
 
 
-intptr_t RawObject::Size() const {
+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_;
   intptr_t instance_size = raw_class->ptr()->instance_size_;
   ObjectKind instance_kind = raw_class->ptr()->instance_kind_;
 
   if (instance_size == 0) {
@@ skipping 96 matching lines @@
         break;
       }
       case kJSRegExp: {
         const RawJSRegExp* raw_jsregexp =
             reinterpret_cast<const RawJSRegExp*>(this);
         intptr_t data_length = Smi::Value(raw_jsregexp->ptr()->data_length_);
         instance_size = JSRegExp::InstanceSize(data_length);
         break;
       }
       case kFreeListElement: {
+        ASSERT(FreeBit::decode(ptr()->tags_));
         uword addr = RawObject::ToAddr(const_cast<RawObject*>(this));
         FreeListElement* element = reinterpret_cast<FreeListElement*>(addr);
         instance_size = element->Size();
         break;
       }
       default:
         UNREACHABLE();
         break;
     }
   }
   ASSERT(instance_size != 0);
+  intptr_t 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());
 
   // Only reasonable to be called on heap objects.
   ASSERT(IsHeapObject());
 
   // Read the necessary data out of the class before visting the class itself.
   RawClass* raw_class = ptr()->class_;
   ObjectKind kind = raw_class->ptr()->instance_kind_;
 
   // Visit the class before visting the fields.
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&ptr()->class_));
 
   switch (kind) {
 #define RAW_VISITPOINTERS(clazz) \
     case clazz::kInstanceKind: { \
       Raw##clazz* raw_obj = reinterpret_cast<Raw##clazz*>(this); \
       size = Raw##clazz::Visit##clazz##Pointers(raw_obj, visitor); \
       break; \
     }
     CLASS_LIST_NO_OBJECT(RAW_VISITPOINTERS)
 #undef RAW_VISITPOINTERS
     case kFreeListElement: {
+      ASSERT(FreeBit::decode(ptr()->tags_));
       // Nothing to visit for free list elements.
       uword addr = RawObject::ToAddr(this);
       FreeListElement* element = reinterpret_cast<FreeListElement*>(addr);
       size = element->Size();
       break;
     }
     default:
       OS::Print("Kind: %d\n", kind);
       UNREACHABLE();
       break;
   }
 
   ASSERT(size != 0);
+  ASSERT(size == Size());
   return size;
 }
 
 
 intptr_t RawClass::VisitClassPointers(RawClass* raw_obj,
                                       ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());
   return Class::InstanceSize();
 }
 
@@ skipping 360 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