Fix bug with guarded fields and deserialization.

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 845 matching lines @@
                     other_type_arguments,
                     bound_error);
   }
 
   // Check if this is the top level class.
   bool IsTopLevel() const;
 
   RawArray* fields() const { return raw_ptr()->fields_; }
   void SetFields(const Array& value) const;
 
+  // Returns an array of all 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;
 
   RawArray* functions() const { return raw_ptr()->functions_; }
   void SetFunctions(const Array& value) const;
   void AddFunction(const Function& function) const;
 
   RawGrowableObjectArray* closures() const {
     return raw_ptr()->closure_functions_;
   }
@@ skipping 1241 matching lines @@
   bool is_nullable() const {
     return raw_ptr()->is_nullable_ == kNullCid;
   }
   void set_is_nullable(bool val) const {
     raw_ptr()->is_nullable_ = val ? kNullCid : kIllegalCid;
   }
   static intptr_t is_nullable_offset() {
     return OFFSET_OF(RawField, is_nullable_);
   }
 
-  // Update guarded class id and nullability of the field to reflect assignment
-  // of the value with the given class id to this field. May trigger
-  // deoptimization of dependent code.
-  void UpdateCid(intptr_t cid) const;
-  // Update guarded class length of the field to reflect assignment of the
-  // value with the given length. May trigger deoptimization of dependent code.
-  void UpdateLength(intptr_t length) const;
+  // Update guarded cid and guarded length for this field. May trigger
+  // deoptimization of dependent optimized code.
+  bool UpdateGuardedCidAndLength(const Object& value) const;
 
   // Return the list of optimized code objects that were optimized under
   // assumptions about guarded class id and nullability of this field.
   // These code objects must be deoptimized when field's properties change.
   // Code objects are held weakly via an indirection through WeakProperty.
   RawArray* dependent_code() const;
   void set_dependent_code(const Array& array) const;
 
   // Add the given code object to the list of dependent ones.
   void RegisterDependentCode(const Code& code) const;
@@ skipping 18 matching lines @@
     kConstBit = 1,
     kStaticBit,
     kFinalBit,
     kHasInitializerBit,
   };
   class ConstBit : public BitField<bool, kConstBit, 1> {};
   class StaticBit : public BitField<bool, kStaticBit, 1> {};
   class FinalBit : public BitField<bool, kFinalBit, 1> {};
   class HasInitializerBit : public BitField<bool, kHasInitializerBit, 1> {};
 
+  // Update guarded class id and nullability of the field to reflect assignment
+  // of the value with the given class id to this field. Returns true, if
+  // deoptimization of dependent code is required.
+  bool UpdateCid(intptr_t cid) const;
+
+  // Update guarded class length of the field to reflect assignment of the
+  // value with the given length. Returns true if deoptimization of dependent
+  // code is required.
+  bool UpdateLength(intptr_t length) const;
+
   void set_name(const String& value) const;
   void set_is_static(bool is_static) const {
     set_kind_bits(StaticBit::update(is_static, raw_ptr()->kind_bits_));
   }
   void set_is_final(bool is_final) const {
     set_kind_bits(FinalBit::update(is_final, raw_ptr()->kind_bits_));
   }
   void set_is_const(bool value) const {
     set_kind_bits(ConstBit::update(value, raw_ptr()->kind_bits_));
   }
@@ skipping 1639 matching lines @@
   virtual RawInstance* CheckAndCanonicalize(const char** error_str) const;
 
   // Returns true if all fields are OK for canonicalization.
   virtual bool CheckAndCanonicalizeFields(const char** error_str) const;
 
   RawObject* GetField(const Field& field) const {
     return *FieldAddr(field);
   }
 
   void SetField(const Field& field, const Object& value) const {
+    field.UpdateGuardedCidAndLength(value);
     StorePointer(FieldAddr(field), value.raw());
   }
 
   RawType* GetType() const;
 
   virtual RawAbstractTypeArguments* GetTypeArguments() const;
   virtual void SetTypeArguments(const AbstractTypeArguments& value) const;
 
   // Check if the type of this instance is a subtype of the given type.
   bool IsInstanceOf(const AbstractType& type,
@@ skipping 2453 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_