Use output parameter to distinguish error from absent result

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 119 matching lines @@
 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->GetName());
       case LookupIterator::INTERCEPTOR: {
-        MaybeHandle<Object> maybe_result =
-            JSObject::GetPropertyWithInterceptor(it);
-        if (!maybe_result.is_null()) return maybe_result;
-        if (it->isolate()->has_pending_exception()) return maybe_result;
+        bool done;
+        Handle<Object> result;
+        ASSIGN_RETURN_ON_EXCEPTION(
+            it->isolate(), result,
+            JSObject::GetPropertyWithInterceptor(it, &done), Object);
+        if (done) return result;
         break;
       }
       case LookupIterator::ACCESS_CHECK:
         if (it->HasAccess()) break;
         return JSObject::GetPropertyWithFailedAccessCheck(it);
       case LookupIterator::ACCESSOR:
         return GetPropertyWithAccessor(it);
       case LookupIterator::INTEGER_INDEXED_EXOTIC:
         return it->factory()->undefined_value();
       case LookupIterator::DATA:
@@ skipping 332 matching lines @@
 
 
 MaybeHandle<Object> JSObject::GetPropertyWithFailedAccessCheck(
     LookupIterator* it) {
   Handle<JSObject> checked = it->GetHolder<JSObject>();
   while (FindAllCanReadHolder(it)) {
     if (it->state() == LookupIterator::ACCESSOR) {
       return GetPropertyWithAccessor(it);
     }
     DCHECK_EQ(LookupIterator::INTERCEPTOR, it->state());
-    auto result = GetPropertyWithInterceptor(it);
-    if (it->isolate()->has_scheduled_exception()) break;
-    if (!result.is_null()) return result;
+    bool done;
+    Handle<Object> result;
+    ASSIGN_RETURN_ON_EXCEPTION(it->isolate(), result,
+                               GetPropertyWithInterceptor(it, &done), Object);
+    if (done) return result;
   }
   it->isolate()->ReportFailedAccessCheck(checked);
   RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(it->isolate(), Object);
   return it->factory()->undefined_value();
 }
 
 
 Maybe<PropertyAttributes> JSObject::GetPropertyAttributesWithFailedAccessCheck(
     LookupIterator* it) {
   Handle<JSObject> checked = it->GetHolder<JSObject>();
@@ skipping 12798 matching lines @@
 InterceptorInfo* JSObject::GetIndexedInterceptor() {
   DCHECK(map()->has_indexed_interceptor());
   JSFunction* constructor = JSFunction::cast(map()->GetConstructor());
   DCHECK(constructor->shared()->IsApiFunction());
   Object* result =
       constructor->shared()->get_api_func_data()->indexed_property_handler();
   return InterceptorInfo::cast(result);
 }
 
 
-MaybeHandle<Object> JSObject::GetPropertyWithInterceptor(LookupIterator* it) {
+MaybeHandle<Object> JSObject::GetPropertyWithInterceptor(LookupIterator* it,
+                                                         bool* done) {
+  *done = false;
   Isolate* isolate = it->isolate();
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
   AssertNoContextChange ncc(isolate);
 
   DCHECK_EQ(LookupIterator::INTERCEPTOR, it->state());
   Handle<InterceptorInfo> interceptor = it->GetInterceptor();
-  if (interceptor->getter()->IsUndefined()) return MaybeHandle<Object>();
+  if (interceptor->getter()->IsUndefined()) {
+    return isolate->factory()->undefined_value();
+  }
 
   Handle<JSObject> holder = it->GetHolder<JSObject>();
   v8::Handle<v8::Value> result;
   PropertyCallbackArguments args(isolate, interceptor->data(),
                                  *it->GetReceiver(), *holder);
 
   if (it->IsElement()) {
     uint32_t index = it->index();
     v8::IndexedPropertyGetterCallback getter =
         v8::ToCData<v8::IndexedPropertyGetterCallback>(interceptor->getter());
     LOG(isolate,
         ApiIndexedPropertyAccess("interceptor-indexed-get", *holder, index));
     result = args.Call(getter, index);
   } else {
     Handle<Name> name = it->name();
 
     if (name->IsSymbol() && !interceptor->can_intercept_symbols()) {
-      return MaybeHandle<Object>();
+      return isolate->factory()->undefined_value();
     }
 
     v8::GenericNamedPropertyGetterCallback getter =
         v8::ToCData<v8::GenericNamedPropertyGetterCallback>(
             interceptor->getter());
     LOG(isolate,
         ApiNamedPropertyAccess("interceptor-named-get", *holder, *name));
     result = args.Call(getter, v8::Utils::ToLocal(name));
   }
 
   RETURN_EXCEPTION_IF_SCHEDULED_EXCEPTION(isolate, Object);
-  if (result.IsEmpty()) return MaybeHandle<Object>();
+  if (result.IsEmpty()) return isolate->factory()->undefined_value();
   Handle<Object> result_internal = v8::Utils::OpenHandle(*result);
   result_internal->VerifyApiCallResultType();
+  *done = true;
   // Rebox handle before return
   return handle(*result_internal, isolate);
 }
 
 
 // Compute the property keys from the interceptor.
 MaybeHandle<JSObject> JSObject::GetKeysForNamedInterceptor(
     Handle<JSObject> object, Handle<JSReceiver> receiver) {
   Isolate* isolate = receiver->GetIsolate();
   Handle<InterceptorInfo> interceptor(object->GetNamedInterceptor());
@@ skipping 3264 matching lines @@
                                             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 internal
 }  // namespace v8