Provide accessor for object internal properties that doesn't require debugger to be active

src/objects.cc

 // Copyright 2013 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 <iomanip>
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 94 matching lines @@
   const Object* fun = this;
   while (fun->IsJSFunctionProxy()) {
     fun = JSFunctionProxy::cast(fun)->call_trap();
   }
   return fun->IsJSFunction() ||
          (fun->IsHeapObject() &&
           HeapObject::cast(fun)->map()->has_instance_call_handler());
 }
 
 
+bool Object::IsPromise(Handle<Object> object) {
+  if (!object->IsJSObject()) return false;
+  auto js_object = Handle<JSObject>::cast(object);
+  // Promises can't have access checks.
+  if (js_object->map()->is_access_check_needed()) return false;
+  auto isolate = js_object->GetIsolate();
+  // TODO(dcarney): this should just be read from the symbol registry so as not
+  // to be context dependent.
+  auto key = isolate->promise_status();
+  // Shouldn't be possible to throw here.
+  return JSObject::HasRealNamedProperty(js_object, key).FromJust();
+}
+
+
 MaybeHandle<Object> Object::GetProperty(LookupIterator* it) {
   for (; it->IsFound(); it->Next()) {
     switch (it->state()) {
       case LookupIterator::NOT_FOUND:
       case LookupIterator::TRANSITION:
         UNREACHABLE();
       case LookupIterator::JSPROXY:
         return JSProxy::GetPropertyWithHandler(it->GetHolder<JSProxy>(),
                                                it->GetReceiver(), it->name());
       case LookupIterator::INTERCEPTOR: {
@@ skipping 17113 matching lines @@
 void PropertyCell::SetValueWithInvalidation(Handle<PropertyCell> cell,
                                             Handle<Object> new_value) {
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 } }  // namespace v8::internal