Confusion on changing data property callback attributes

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 12f2ee0e5ce980e9009a80d944bb30a92a2b3828..43f2d6e2d975634aac49caeba8e956a7658c2061 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2129,14 +2129,6 @@ class JSObject: public JSReceiver {
       Handle<Object> structure,
       Handle<Name> name);
 
-  MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithCallback(
-      Handle<JSObject> object,
-      Handle<Object> structure,
-      Handle<Name> name,
-      Handle<Object> value,
-      Handle<JSObject> holder,
-      StrictMode strict_mode);
-
   MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithInterceptor(
       Handle<JSObject> object,
       Handle<Name> name,
@@ -2153,6 +2145,13 @@ class JSObject: public JSReceiver {
       StrictMode strict_mode,
       StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
 
+  // SetLocalPropertyIgnoreAttributes converts callbacks to fields. We need to
+  // grant an exemption to ExecutableAccessor callbacks in some cases.
+  enum ExecutableAccessorInfoHandling {
+    DEFAULT_HANDLING,
+    DONT_FORCE_FIELD
+  };
+
   MUST_USE_RESULT static MaybeHandle<Object> SetLocalPropertyIgnoreAttributes(
       Handle<JSObject> object,
       Handle<Name> key,
@@ -2161,7 +2160,8 @@ class JSObject: public JSReceiver {
       ValueType value_type = OPTIMAL_REPRESENTATION,
       StoreMode mode = ALLOW_AS_CONSTANT,
       ExtensibilityCheck extensibility_check = PERFORM_EXTENSIBILITY_CHECK,
-      StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
+      StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED,
+      ExecutableAccessorInfoHandling handling = DEFAULT_HANDLING);
 
   static inline Handle<String> ExpectedTransitionKey(Handle<Map> map);
   static inline Handle<Map> ExpectedTransitionTarget(Handle<Map> map);
@@ -2667,6 +2667,14 @@ class JSObject: public JSReceiver {
   static void UpdateAllocationSite(Handle<JSObject> object,
                                    ElementsKind to_kind);
 
+  MUST_USE_RESULT static MaybeHandle<Object> SetPropertyWithCallback(
+      Handle<JSObject> object,
+      Handle<Object> structure,
+      Handle<Name> name,
+      Handle<Object> value,
+      Handle<JSObject> holder,
+      StrictMode strict_mode);
+
   // Used from Object::GetProperty().
   MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithFailedAccessCheck(
       Handle<JSObject> object,
@@ -10591,6 +10599,8 @@ class ExecutableAccessorInfo: public AccessorInfo {
   static const int kDataOffset = kSetterOffset + kPointerSize;
   static const int kSize = kDataOffset + kPointerSize;
 
+  inline void clear_setter();
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ExecutableAccessorInfo);
 };