Support intriscDefaultProto for Error functions

src/isolate.cc

 // Copyright 2012 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/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 1338 matching lines @@
       int pos = PositionFromStackTrace(elements, i);
       Handle<Script> casted_script(Script::cast(script));
       *target = MessageLocation(casted_script, pos, pos + 1);
       return true;
     }
   }
   return false;
 }
 
 
-// Traverse prototype chain to find out whether the object is derived from
-// the Error object.
-bool Isolate::IsErrorObject(Handle<Object> obj) {
-  if (!obj->IsJSObject()) return false;
-  Handle<Object> error_constructor = error_function();
-  DisallowHeapAllocation no_gc;
-  for (PrototypeIterator iter(this, *obj, PrototypeIterator::START_AT_RECEIVER);
-       !iter.IsAtEnd(); iter.Advance()) {
-    if (iter.GetCurrent()->IsJSProxy()) return false;
-    if (iter.GetCurrent<JSObject>()->map()->GetConstructor() ==
-        *error_constructor) {
-      return true;
-    }
-  }
-  return false;
+// Use stack_trace_symbol as proxy for [[ErrorData]].
+bool Isolate::IsErrorObject(Handle<Object> object) {
+  Handle<Name> symbol = factory()->stack_trace_symbol();
+  if (!object->IsJSObject()) return false;
+  Maybe<bool> has_stack_trace =
+      JSReceiver::HasOwnProperty(Handle<JSReceiver>::cast(object), symbol);
+  DCHECK(!has_stack_trace.IsNothing());
+  return has_stack_trace.FromJust();
 }
 
 
 Handle<JSMessageObject> Isolate::CreateMessage(Handle<Object> exception,
                                                MessageLocation* location) {
   Handle<JSArray> stack_trace_object;
   if (capture_stack_trace_for_uncaught_exceptions_) {
     if (IsErrorObject(exception)) {
       // We fetch the stack trace that corresponds to this error object.
       // If the lookup fails, the exception is probably not a valid Error
@@ skipping 1454 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8