Report promise reject with no handler (behind a flag).

src/debug.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/v8.h"
 
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 750 matching lines @@
   MaybeHandle<Object> result = Execution::TryCall(
       function, handle(context->global_proxy()), 0, NULL, &maybe_exception);
 
   // Check for caught exceptions.
   if (result.is_null()) {
     DCHECK(!isolate->has_pending_exception());
     MessageLocation computed_location;
     isolate->ComputeLocation(&computed_location);
     Handle<Object> message = MessageHandler::MakeMessageObject(
         isolate, "error_loading_debugger", &computed_location,
-        Vector<Handle<Object> >::empty(), Handle<JSArray>());
+        Vector<Handle<Object> >::empty(), Handle<JSObject>(),
+        Handle<JSArray>());
     DCHECK(!isolate->has_pending_exception());
     Handle<Object> exception;
     if (maybe_exception.ToHandle(&exception)) {
       isolate->set_pending_exception(*exception);
       MessageHandler::ReportMessage(isolate, NULL, message);
       isolate->clear_pending_exception();
     }
     return false;
   }
 
@@ skipping 473 matching lines @@
 
 bool Debug::IsBreakOnException(ExceptionBreakType type) {
   if (type == BreakUncaughtException) {
     return break_on_uncaught_exception_;
   } else {
     return break_on_exception_;
   }
 }
 
 
-bool Debug::PromiseHasRejectHandler(Handle<JSObject> promise) {
-  Handle<JSFunction> fun = Handle<JSFunction>::cast(
-      JSObject::GetDataProperty(isolate_->js_builtins_object(),
-                                isolate_->factory()->NewStringFromStaticChars(
-                                    "PromiseHasRejectHandler")));
-  Handle<Object> result =
-      Execution::Call(isolate_, fun, promise, 0, NULL).ToHandleChecked();
-  return result->IsTrue();
-}
-
-
 void Debug::PrepareStep(StepAction step_action,
                         int step_count,
                         StackFrame::Id frame_id) {
   HandleScope scope(isolate_);
 
   PrepareForBreakPoints();
 
   DCHECK(in_debug_scope());
 
   // Remember this step action and count.
@@ skipping 1208 matching lines @@
 }
 
 
 MaybeHandle<Object> Debug::MakeAsyncTaskEvent(Handle<JSObject> task_event) {
   // Create the async task event object.
   Handle<Object> argv[] = { task_event };
   return MakeJSObject("MakeAsyncTaskEvent", arraysize(argv), argv);
 }
 
 
-void Debug::OnThrow(Handle<Object> exception, bool uncaught) {
+void Debug::OnThrow(Handle<Object> exception, Handle<Object> promise,
+                    bool uncaught) {
   if (in_debug_scope() || ignore_events()) return;
   // Temporarily clear any scheduled_exception to allow evaluating
   // JavaScript from the debug event handler.
   HandleScope scope(isolate_);
   Handle<Object> scheduled_exception;
   if (isolate_->has_scheduled_exception()) {
     scheduled_exception = handle(isolate_->scheduled_exception(), isolate_);
     isolate_->clear_scheduled_exception();
   }
-  OnException(exception, uncaught, isolate_->GetPromiseOnStackOnThrow());
+  OnException(exception, uncaught, promise);
   if (!scheduled_exception.is_null()) {
     isolate_->thread_local_top()->scheduled_exception_ = *scheduled_exception;
   }
 }
 
 
 void Debug::OnPromiseReject(Handle<JSObject> promise, Handle<Object> value) {
   if (in_debug_scope() || ignore_events()) return;
   HandleScope scope(isolate_);
   OnException(value, false, promise);
 }
 
 
 void Debug::OnException(Handle<Object> exception, bool uncaught,
                         Handle<Object> promise) {
   if (promise->IsJSObject()) {

[aandrey, 2014/09/26 14:58:46]

can it be "if (!uncaught && promise->IsJSObject())" ?
or Execution::PromiseHasRejectHandler() has side effects (marking a promise
reported)?

[Yang, 2014/09/26 15:04:42]

Done.

I agree. The side effect is now gone. We mark the promise as reported in
Isolate::DoThrow.

-    uncaught |= !PromiseHasRejectHandler(Handle<JSObject>::cast(promise));
+    Handle<Object> has_reject_handler;
+    ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+        isolate_, has_reject_handler,
+        Execution::PromiseHasRejectHandler(isolate_, promise), /* void */);
+    uncaught |= has_reject_handler->IsFalse();
   }
   // Bail out if exception breaks are not active
   if (uncaught) {
     // Uncaught exceptions are reported by either flags.
     if (!(break_on_uncaught_exception_ || break_on_exception_)) return;
   } else {
     // Caught exceptions are reported is activated.
     if (!break_on_exception_) return;
   }
 
@@ skipping 828 matching lines @@
   logger_->DebugEvent("Put", message.text());
 }
 
 
 void LockingCommandMessageQueue::Clear() {
   base::LockGuard<base::Mutex> lock_guard(&mutex_);
   queue_.Clear();
 }
 
 } }  // namespace v8::internal