Move SetObjectPrototype to JSObject

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 3308 matching lines @@
   }
 
   // Careful: Don't allocate here!
   // For some callers of this method, |object| might be in an inconsistent
   // state now: the new map might have a new elements_kind, but the object's
   // elements pointer hasn't been updated yet. Callers will fix this, but in
   // the meantime, (indirectly) calling JSObjectVerify() must be avoided.
   // When adding code here, add a DisallowHeapAllocation too.
 }
 
+void JSObject::ForceSetPrototype(Handle<JSObject> object,
+                                 Handle<Object> proto) {
+  // object.__proto__ = proto;
+  Handle<Map> old_map = Handle<Map>(object->map());
+  Handle<Map> new_map = Map::Copy(old_map, "ForceSetPrototype");
+  Map::SetPrototype(new_map, proto, FAST_PROTOTYPE);
+  JSObject::MigrateToMap(object, new_map);
+}
+
 int Map::NumberOfFields() {
   DescriptorArray* descriptors = instance_descriptors();
   int result = 0;
   for (int i = 0; i < NumberOfOwnDescriptors(); i++) {
     if (descriptors->GetDetails(i).location() == kField) result++;
   }
   return result;
 }
 
 Handle<Map> Map::CopyGeneralizeAllRepresentations(
@@ skipping 15596 matching lines @@
 
   Object* data_obj =
       constructor->shared()->get_api_func_data()->access_check_info();
   if (data_obj->IsUndefined(isolate)) return nullptr;
 
   return AccessCheckInfo::cast(data_obj);
 }
 
 }  // namespace internal
 }  // namespace v8