Implemented schema change for the isolate reload operation.

runtime/vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1139 matching lines @@
                     bound_error,
                     bound_trail,
                     space);
   }
 
   // Check if this is the top level class.
   bool IsTopLevel() const;
 
   bool IsPrivate() const;
 
+  // Returns an array of instance and static fields defined by this class.
   RawArray* fields() const { return raw_ptr()->fields_; }
   void SetFields(const Array& value) const;
   void AddField(const Field& field) const;
   void AddFields(const GrowableArray<const Field*>& fields) const;
 
-  // Returns an array of all fields of this class and its superclasses indexed
-  // by offset in words.
+  // Returns an array of all instance fields of this class and its superclasses
+  // indexed by offset in words.
   RawArray* OffsetToFieldMap() const;
 
   // Returns true if non-static fields are defined.
   bool HasInstanceFields() const;
 
   // TODO(koda): Unite w/ hash table.
   RawArray* functions() const { return raw_ptr()->functions_; }
   void SetFunctions(const Array& value) const;
   void AddFunction(const Function& function) const;
   void RemoveFunction(const Function& function) const;
@@ skipping 218 matching lines @@
 
   bool TraceAllocation(Isolate* isolate) const;
   void SetTraceAllocation(bool trace_allocation) const;
 
   bool ValidatePostFinalizePatch(const Class& orig_class, Error* error) const;
   void ReplaceEnum(const Class& old_enum) const;
   void CopyStaticFieldValues(const Class& old_cls) const;
   void PatchFieldsAndFunctions() const;
   void CopyCanonicalConstants(const Class& old_cls) const;
   void CopyCanonicalType(const Class& old_cls) const;
-  bool CanReload(const Class& replacement) const;
+  void CheckReload(const Class& replacement,
+                   IsolateReloadContext* context) const;
 
  private:
+  bool CanReloadFinalized(const Class& replacement,
+                          IsolateReloadContext* context) const;
+  bool CanReloadPreFinalized(const Class& replacement,
+                             IsolateReloadContext* context) const;
+
+  // Tells whether instances need morphing for reload.
+  bool RequiresInstanceMorphing(const Class& replacement) const;
+
   template <class FakeObject> static RawClass* NewCommon(intptr_t index);
 
   enum MemberKind {
     kAny = 0,
     kStatic,
     kInstance,
     kInstanceAllowAbstract,
     kConstructor,
     kFactory,
   };
@@ skipping 1545 matching lines @@
 
   // Returns a field cloned from 'this'. 'this' is set as the
   // original field of result.
   RawField* CloneFromOriginal() const;
 
   RawString* name() const { return raw_ptr()->name_; }
   RawString* UserVisibleName() const;  // Same as scrubbed name.
   virtual RawString* DictionaryName() const { return name(); }
 
   bool is_static() const { return StaticBit::decode(raw_ptr()->kind_bits_); }
+  bool is_instance() const { return !is_static(); }
   bool is_final() const { return FinalBit::decode(raw_ptr()->kind_bits_); }
   bool is_const() const { return ConstBit::decode(raw_ptr()->kind_bits_); }
   bool is_reflectable() const {
     return ReflectableBit::decode(raw_ptr()->kind_bits_);
   }
   void set_is_reflectable(bool value) const {
     ASSERT(IsOriginal());
     set_kind_bits(ReflectableBit::update(value, raw_ptr()->kind_bits_));
   }
   bool is_double_initialized() const {
@@ skipping 745 matching lines @@
                                   const char* class_name,
                                   const char* function_name);
 
   // Character used to indicate a private identifier.
   static const char kPrivateIdentifierStart  = '_';
 
   // Character used to separate private identifiers from
   // the library-specific key.
   static const char kPrivateKeySeparator = '@';
 
-  bool CanReload(const Library& replacement) const;
+  void CheckReload(const Library& replacement,
+                   IsolateReloadContext* context) const;
 
  private:
   static const int kInitialImportsCapacity = 4;
   static const int kImportsCapacityIncrement = 8;
 
   static RawLibrary* New();
 
   void set_num_imports(intptr_t value) const;
   bool HasExports() const;
   RawArray* loaded_scripts() const { return raw_ptr()->loaded_scripts_; }
@@ skipping 1569 matching lines @@
   RawObject** FieldAddrAtOffset(intptr_t offset) const {
     ASSERT(IsValidFieldOffset(offset));
     return reinterpret_cast<RawObject**>(raw_value() - kHeapObjectTag + offset);
   }
   RawObject** FieldAddr(const Field& field) const {
     return FieldAddrAtOffset(field.Offset());
   }
   RawObject** NativeFieldsAddr() const {
     return FieldAddrAtOffset(sizeof(RawObject));
   }
-
   void SetFieldAtOffset(intptr_t offset, const Object& value) const {
     StorePointer(FieldAddrAtOffset(offset), value.raw());
   }
   bool IsValidFieldOffset(intptr_t offset) const;
 
   static intptr_t NextFieldOffset() {
     return sizeof(RawInstance);
   }
 
+  // The follwoing raw methods are used for morphing.
+  // They are needed due to the extraction of the class in IsValidFieldOffset.
+  RawObject** RawFieldAddrAtOffset(intptr_t offset) const {
+    return reinterpret_cast<RawObject**>(raw_value() - kHeapObjectTag + offset);
+  }
+  RawObject* RawGetFieldAtOffset(intptr_t offset) const {
+    return *RawFieldAddrAtOffset(offset);
+  }
+  void RawSetFieldAtOffset(intptr_t offset, const Object& value) const {
+    StorePointer(RawFieldAddrAtOffset(offset), value.raw());
+  }
+
   // TODO(iposva): Determine if this gets in the way of Smi.
   HEAP_OBJECT_IMPLEMENTATION(Instance, Object);
   friend class ByteBuffer;
   friend class Class;
   friend class Closure;
   friend class DeferredObject;
   friend class RegExp;
   friend class SnapshotWriter;
   friend class StubCode;
   friend class TypedDataView;
   friend class InstanceSerializationCluster;
   friend class InstanceDeserializationCluster;
   friend class ClassDeserializationCluster;  // vtable
+  friend class InstanceMorpher;
 };
 
 
 class LibraryPrefix : public Instance {
  public:
   RawString* name() const { return raw_ptr()->name_; }
   virtual RawString* DictionaryName() const { return name(); }
 
   RawArray* imports() const { return raw_ptr()->imports_; }
   intptr_t num_imports() const { return raw_ptr()->num_imports_; }
@@ skipping 3117 matching lines @@
     Heap* isolate_heap = isolate->heap();
     Heap* vm_isolate_heap = Dart::vm_isolate()->heap();
     ASSERT(isolate_heap->Contains(RawObject::ToAddr(raw_)) ||
            vm_isolate_heap->Contains(RawObject::ToAddr(raw_)));
   }
 #endif
 }
 
 
 intptr_t Field::Offset() const {
-  ASSERT(!is_static());  // Valid only for dart instance fields.
+  ASSERT(is_instance());  // Valid only for dart instance fields.
   intptr_t value = Smi::Value(raw_ptr()->value_.offset_);
   return (value * kWordSize);
 }
 
 
 void Field::SetOffset(intptr_t offset_in_bytes) const {
-  ASSERT(!is_static());  // Valid only for dart instance fields.
+  ASSERT(is_instance());  // Valid only for dart instance fields.
   ASSERT(kWordSize != 0);
   StorePointer(&raw_ptr()->value_.offset_,
                Smi::New(offset_in_bytes / kWordSize));
 }
 
 
 RawInstance* Field::StaticValue() const {
   ASSERT(is_static());  // Valid only for static dart fields.
   return raw_ptr()->value_.static_value_;
 }
@@ skipping 152 matching lines @@
 
 inline void TypeArguments::SetHash(intptr_t value) const {
   // This is only safe because we create a new Smi, which does not cause
   // heap allocation.
   StoreSmi(&raw_ptr()->hash_, Smi::New(value));
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_