Trigger exception debug events on Promise reject.

R=rossberg@chromium.org, aandrey@chromium.org
BUG=393913
LOG=Y

Review URL: https://codereview.chromium.org/440773004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22913 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/debug.cc

@@ -855,8 +855,8 @@ void Debug::Unload() {
   ClearAllBreakPoints();
   ClearStepping();
 
-  // Match unmatched PromiseHandlePrologue calls.
-  while (thread_local_.promise_on_stack_) PromiseHandleEpilogue();
+  // Match unmatched PopPromise calls.
+  while (thread_local_.promise_on_stack_) PopPromise();
 
   // Return debugger is not loaded.
   if (!is_loaded()) return;
@@ -1272,30 +1272,29 @@ bool Debug::IsBreakOnException(ExceptionBreakType type) {
 }
 
 
-PromiseOnStack::PromiseOnStack(Isolate* isolate,
-                                      PromiseOnStack* prev,
-                                      Handle<JSFunction> getter)
+PromiseOnStack::PromiseOnStack(Isolate* isolate, PromiseOnStack* prev,
+                               Handle<JSObject> promise)
     : isolate_(isolate), prev_(prev) {
   handler_ = StackHandler::FromAddress(
       Isolate::handler(isolate->thread_local_top()));
-  getter_ = Handle<JSFunction>::cast(
-      isolate->global_handles()->Create(*getter));
+  promise_ =
+      Handle<JSObject>::cast(isolate->global_handles()->Create(*promise));
 }
 
 
 PromiseOnStack::~PromiseOnStack() {
-  isolate_->global_handles()->Destroy(Handle<Object>::cast(getter_).location());
+  isolate_->global_handles()->Destroy(
+      Handle<Object>::cast(promise_).location());
 }
 
 
-void Debug::PromiseHandlePrologue(Handle<JSFunction> promise_getter) {
+void Debug::PushPromise(Handle<JSObject> promise) {
   PromiseOnStack* prev = thread_local_.promise_on_stack_;
-  thread_local_.promise_on_stack_ =
-      new PromiseOnStack(isolate_, prev, promise_getter);
+  thread_local_.promise_on_stack_ = new PromiseOnStack(isolate_, prev, promise);
 }
 
 
-void Debug::PromiseHandleEpilogue() {
+void Debug::PopPromise() {
   if (thread_local_.promise_on_stack_ == NULL) return;
   PromiseOnStack* prev = thread_local_.promise_on_stack_->prev();
   delete thread_local_.promise_on_stack_;
@@ -1303,35 +1302,40 @@ void Debug::PromiseHandleEpilogue() {
 }
 
 
-Handle<Object> Debug::GetPromiseForUncaughtException() {
+Handle<Object> Debug::GetPromiseOnStackOnThrow() {
   Handle<Object> undefined = isolate_->factory()->undefined_value();
   if (thread_local_.promise_on_stack_ == NULL) return undefined;
-  Handle<JSFunction> promise_getter = thread_local_.promise_on_stack_->getter();
-  StackHandler* promise_catch = thread_local_.promise_on_stack_->handler();
+  StackHandler* promise_try = thread_local_.promise_on_stack_->handler();
   // Find the top-most try-catch handler.
   StackHandler* handler = StackHandler::FromAddress(
       Isolate::handler(isolate_->thread_local_top()));
-  while (handler != NULL && !handler->is_catch()) {
-    handler = handler->next();
-  }
-#ifdef DEBUG
-  // Make sure that our promise catch handler is in the list of handlers,
-  // even if it's not the top-most try-catch handler.
-  StackHandler* temp = handler;
-  while (temp != promise_catch && !temp->is_catch()) {
-    temp = temp->next();
-    CHECK(temp != NULL);
-  }
-#endif  // DEBUG
-
-  if (handler == promise_catch) {
-    return Execution::Call(
-        isolate_, promise_getter, undefined, 0, NULL).ToHandleChecked();
+  do {
+    if (handler == promise_try) {
+      // Mark the pushed try-catch handler to prevent a later duplicate event
+      // triggered with the following reject.
+      return thread_local_.promise_on_stack_->promise();
     }
+    handler = handler->next();
+    // There must be a try-catch handler if a promise is on stack.
+    DCHECK_NE(NULL, handler);
+    // Throwing inside a Promise can be intercepted by an inner try-catch, so
+    // we stop at the first try-catch handler.
+  } while (!handler->is_catch());
   return undefined;
 }
 
 
+bool Debug::PromiseHasRejectHandler(Handle<JSObject> promise) {
+  Handle<JSFunction> fun = Handle<JSFunction>::cast(
+      JSObject::GetDataProperty(isolate_->js_builtins_object(),
+                                isolate_->factory()->NewStringFromStaticAscii(
+                                    "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) {
@@ -2562,13 +2566,25 @@ MaybeHandle<Object> Debug::MakeAsyncTaskEvent(Handle<JSObject> task_event) {
 }
 
 
-void Debug::OnException(Handle<Object> exception, bool uncaught) {
+void Debug::OnThrow(Handle<Object> exception, bool uncaught) {
   if (in_debug_scope() || ignore_events()) return;
+  HandleScope scope(isolate_);
+  OnException(exception, uncaught, GetPromiseOnStackOnThrow());
+}
+
 
+void Debug::OnPromiseReject(Handle<JSObject> promise, Handle<Object> value) {
+  if (in_debug_scope() || ignore_events()) return;
   HandleScope scope(isolate_);
-  Handle<Object> promise = GetPromiseForUncaughtException();
-  uncaught |= !promise->IsUndefined();
+  OnException(value, false, promise);
+}
+
 
+void Debug::OnException(Handle<Object> exception, bool uncaught,
+                        Handle<Object> promise) {
+  if (promise->IsJSObject()) {
+    uncaught |= !PromiseHasRejectHandler(Handle<JSObject>::cast(promise));
+  }
   // Bail out if exception breaks are not active
   if (uncaught) {
     // Uncaught exceptions are reported by either flags.

src/debug.h

@@ -335,17 +335,16 @@ class LockingCommandMessageQueue BASE_EMBEDDED {
 
 class PromiseOnStack {
  public:
-  PromiseOnStack(Isolate* isolate,
-                 PromiseOnStack* prev,
-                 Handle<JSFunction> getter);
+  PromiseOnStack(Isolate* isolate, PromiseOnStack* prev,
+                 Handle<JSObject> getter);
   ~PromiseOnStack();
   StackHandler* handler() { return handler_; }
-  Handle<JSFunction> getter() { return getter_; }
+  Handle<JSObject> promise() { return promise_; }
   PromiseOnStack* prev() { return prev_; }
  private:
   Isolate* isolate_;
   StackHandler* handler_;
-  Handle<JSFunction> getter_;
+  Handle<JSObject> promise_;
   PromiseOnStack* prev_;
 };
 
@@ -361,7 +360,9 @@ class Debug {
  public:
   // Debug event triggers.
   void OnDebugBreak(Handle<Object> break_points_hit, bool auto_continue);
-  void OnException(Handle<Object> exception, bool uncaught);
+
+  void OnThrow(Handle<Object> exception, bool uncaught);
+  void OnPromiseReject(Handle<JSObject> promise, Handle<Object> value);
   void OnCompileError(Handle<Script> script);
   void OnBeforeCompile(Handle<Script> script);
   void OnAfterCompile(Handle<Script> script);
@@ -452,8 +453,9 @@ class Debug {
   bool IsBreakAtReturn(JavaScriptFrame* frame);
 
   // Promise handling.
-  void PromiseHandlePrologue(Handle<JSFunction> promise_getter);
-  void PromiseHandleEpilogue();
+  // Push and pop a promise and the current try-catch handler.
+  void PushPromise(Handle<JSObject> promise);
+  void PopPromise();
 
   // Support for LiveEdit
   void FramesHaveBeenDropped(StackFrame::Id new_break_frame_id,
@@ -523,6 +525,9 @@ class Debug {
   inline bool has_commands() const { return !command_queue_.IsEmpty(); }
   inline bool ignore_events() const { return is_suppressed_ || !is_active_; }
 
+  void OnException(Handle<Object> exception, bool uncaught,
+                   Handle<Object> promise);
+
   // Constructors for debug event objects.
   MUST_USE_RESULT MaybeHandle<Object> MakeJSObject(
       const char* constructor_name,
@@ -545,8 +550,9 @@ class Debug {
   // Mirror cache handling.
   void ClearMirrorCache();
 
-  // Returns a promise if it does not have a reject handler.
-  Handle<Object> GetPromiseForUncaughtException();
+  // Returns a promise if the pushed try-catch handler matches the current one.
+  Handle<Object> GetPromiseOnStackOnThrow();
+  bool PromiseHasRejectHandler(Handle<JSObject> promise);
 
   void CallEventCallback(v8::DebugEvent event,
                          Handle<Object> exec_state,

src/isolate.cc

@@ -1026,7 +1026,7 @@ void Isolate::DoThrow(Object* exception, MessageLocation* location) {
 
   // Notify debugger of exception.
   if (catchable_by_javascript) {
-    debug()->OnException(exception_handle, report_exception);
+    debug()->OnThrow(exception_handle, report_exception);
   }
 
   // Generate the message if required.

src/promise.js

@@ -18,6 +18,7 @@ var PromiseReject;
 var PromiseChain;
 var PromiseCatch;
 var PromiseThen;
+var PromiseHasRejectHandler;
 
 // mirror-debugger.js currently uses builtins.promiseStatus. It would be nice
 // if we could move these property names into the closure below.
@@ -29,6 +30,7 @@ var promiseValue = GLOBAL_PRIVATE("Promise#value");
 var promiseOnResolve = GLOBAL_PRIVATE("Promise#onResolve");
 var promiseOnReject = GLOBAL_PRIVATE("Promise#onReject");
 var promiseRaw = GLOBAL_PRIVATE("Promise#raw");
+var promiseDebug = GLOBAL_PRIVATE("Promise#debug");
 var lastMicrotaskId = 0;
 
 (function() {
@@ -40,13 +42,13 @@ var lastMicrotaskId = 0;
       throw MakeTypeError('resolver_not_a_function', [resolver]);
     var promise = PromiseInit(this);
     try {
-      %DebugPromiseHandlePrologue(function() { return promise });
+      %DebugPushPromise(promise);
       resolver(function(x) { PromiseResolve(promise, x) },
                function(r) { PromiseReject(promise, r) });
     } catch (e) {
       PromiseReject(promise, e);
     } finally {
-      %DebugPromiseHandleEpilogue();
+      %DebugPopPromise();
     }
   }
 
@@ -98,11 +100,7 @@ var lastMicrotaskId = 0;
 
   function PromiseHandle(value, handler, deferred) {
     try {
-      %DebugPromiseHandlePrologue(
-          function() {
-            var queue = GET_PRIVATE(deferred.promise, promiseOnReject);
-            return (queue && queue.length == 0) ? deferred.promise : UNDEFINED;
-          });
+      %DebugPushPromise(deferred.promise);
       var result = handler(value);
       if (result === deferred.promise)
         throw MakeTypeError('promise_cyclic', [result]);
@@ -111,14 +109,9 @@ var lastMicrotaskId = 0;
       else
         deferred.resolve(result);
     } catch (exception) {
-      try {
-        %DebugPromiseHandlePrologue(function() { return deferred.promise });
-        deferred.reject(exception);
-      } catch (e) { } finally {
-        %DebugPromiseHandleEpilogue();
-      }
+      try { deferred.reject(exception); } catch (e) { }
     } finally {
-      %DebugPromiseHandleEpilogue();
+      %DebugPopPromise();
     }
   }
 
@@ -165,6 +158,13 @@ var lastMicrotaskId = 0;
   }
 
   PromiseReject = function PromiseReject(promise, r) {
+    // Check promise status to confirm that this reject has an effect.
+    // Check promiseDebug property to avoid duplicate event.
+    if (DEBUG_IS_ACTIVE &&
+        GET_PRIVATE(promise, promiseStatus) == 0 &&
+        !HAS_PRIVATE(promise, promiseDebug)) {
+      %DebugPromiseRejectEvent(promise, r);
+    }
     PromiseDone(promise, -1, r, promiseOnReject)
   }
 
@@ -322,6 +322,16 @@ var lastMicrotaskId = 0;
     return deferred.promise;
   }
 
+
+  // Utility for debugger
+
+  PromiseHasRejectHandler = function PromiseHasRejectHandler() {
+    // Mark promise as already having triggered a reject event.
+    SET_PRIVATE(this, promiseDebug, true);
+    var queue = GET_PRIVATE(this, promiseOnReject);
+    return !IS_UNDEFINED(queue) && queue.length > 0;
+  };
+
   // -------------------------------------------------------------------
   // Install exported functions.
 

src/runtime.cc

@@ -5465,22 +5465,19 @@ RUNTIME_FUNCTION(Runtime_DebugPrepareStepInIfStepping) {
 }
 
 
-// The argument is a closure that is kept until the epilogue is called.
-// On exception, the closure is called, which returns the promise if the
-// exception is considered uncaught, or undefined otherwise.
-RUNTIME_FUNCTION(Runtime_DebugPromiseHandlePrologue) {
+RUNTIME_FUNCTION(Runtime_DebugPushPromise) {
   DCHECK(args.length() == 1);
   HandleScope scope(isolate);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, promise_getter, 0);
-  isolate->debug()->PromiseHandlePrologue(promise_getter);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
+  isolate->debug()->PushPromise(promise);
   return isolate->heap()->undefined_value();
 }
 
 
-RUNTIME_FUNCTION(Runtime_DebugPromiseHandleEpilogue) {
+RUNTIME_FUNCTION(Runtime_DebugPopPromise) {
   DCHECK(args.length() == 0);
   SealHandleScope shs(isolate);
-  isolate->debug()->PromiseHandleEpilogue();
+  isolate->debug()->PopPromise();
   return isolate->heap()->undefined_value();
 }
 
@@ -5494,6 +5491,16 @@ RUNTIME_FUNCTION(Runtime_DebugPromiseEvent) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_DebugPromiseRejectEvent) {
+  DCHECK(args.length() == 2);
+  HandleScope scope(isolate);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
+  isolate->debug()->OnPromiseReject(promise, value);
+  return isolate->heap()->undefined_value();
+}
+
+
 RUNTIME_FUNCTION(Runtime_DebugAsyncTaskEvent) {
   DCHECK(args.length() == 1);
   HandleScope scope(isolate);

src/runtime.h

@@ -76,9 +76,10 @@ namespace internal {
   F(SetInlineBuiltinFlag, 1, 1)                             \
   F(StoreArrayLiteralElement, 5, 1)                         \
   F(DebugPrepareStepInIfStepping, 1, 1)                     \
-  F(DebugPromiseHandlePrologue, 1, 1)                       \
-  F(DebugPromiseHandleEpilogue, 0, 1)                       \
+  F(DebugPushPromise, 1, 1)                                 \
+  F(DebugPopPromise, 0, 1)                                  \
   F(DebugPromiseEvent, 1, 1)                                \
+  F(DebugPromiseRejectEvent, 2, 1)                          \
   F(DebugAsyncTaskEvent, 1, 1)                              \
   F(FlattenString, 1, 1)                                    \
   F(LoadMutableDouble, 2, 1)                                \

test/mjsunit/es6/debug-promises/reject-after-resolve.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we listen to uncaught exceptions and
+// the Promise is rejected in a chained closure after it has been resolved.
+// We expect no Exception debug event to be triggered.
+
+Debug = debug.Debug;
+
+var log = [];
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve(reject);
+});
+
+var q = p.chain(
+  function(value) {
+    assertEquals(["resolve", "end main"], log);
+    value(new Error("reject"));
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    assertTrue(event != Debug.DebugEvent.Exception);
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnException();
+Debug.setListener(listener);
+
+log.push("end main");

test/mjsunit/es6/debug-promises/reject-caught-all.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we listen to all exceptions and
+// there is a catch handler for the to-be-rejected Promise.
+// We expect a normal Exception debug event to be triggered.
+
+Debug = debug.Debug;
+
+var log = [];
+var expected_events = 1;
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+var q = p.chain(
+  function(value) {
+    log.push("reject");
+    return Promise.reject(new Error("reject"));
+  });
+
+q.catch(
+  function(e) {
+    assertEquals("reject", e.message);
+  });
+
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      assertEquals("reject", event_data.exception().message);
+      assertEquals(q, event_data.promise());
+      assertFalse(event_data.uncaught());
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnException();
+Debug.setListener(listener);
+
+log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "end main", "reject"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/reject-caught-late.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we only listen to uncaught exceptions, the Promise
+// is rejected, and a catch handler is installed right before the rejection.
+// We expect no debug event to be triggered.
+
+Debug = debug.Debug;
+
+var p = new Promise(function(resolve, reject) {
+  resolve();
+});
+
+var q = p.chain(
+  function() {
+    q.catch(function(e) {
+      assertEquals("caught", e.message);
+    });
+    return Promise.reject(Error("caught"));
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    assertTrue(event != Debug.DebugEvent.Exception);
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);

test/mjsunit/es6/debug-promises/reject-caught-uncaught.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we only listen to uncaught exceptions and
+// there is a catch handler for the to-be-rejected Promise.
+// We expect no debug event to be triggered.
+
+Debug = debug.Debug;
+
+var p = new Promise(function(resolve, reject) {
+  resolve();
+});
+
+var q = p.chain(
+  function() {
+    return Promise.reject(Error("caught reject"));
+  });
+
+q.catch(
+  function(e) {
+    assertEquals("caught reject", e.message);
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    assertTrue(event != Debug.DebugEvent.Exception);
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);

test/mjsunit/es6/debug-promises/reject-in-constructor.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug
+
+// Test debug events when we only listen to uncaught exceptions and
+// the Promise is rejected in the Promise constructor.
+// We expect an Exception debug event with a promise to be triggered.
+
+Debug = debug.Debug;
+
+var steps = 0;
+var exception = null;
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      steps++;
+      assertEquals("uncaught", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertTrue(event_data.uncaught());
+      // Assert that the debug event is triggered at the throw site.
+      assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
+    }
+  } catch (e) {
+    exception = e;
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+var p = new Promise(function(resolve, reject) {
+  reject(new Error("uncaught"));  // event
+});
+
+assertEquals(1, steps);
+assertNull(exception);

test/mjsunit/es6/debug-promises/reject-uncaught-all.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we listen to all exceptions and
+// there is a catch handler for the to-be-rejected Promise.
+// We expect an Exception debug event with a promise to be triggered.
+
+Debug = debug.Debug;
+
+var expected_events = 1;
+var log = [];
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+var q = p.chain(
+  function() {
+    log.push("reject");
+    return Promise.reject(new Error("uncaught reject"));
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      assertEquals("uncaught reject", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertEquals(q, event_data.promise());
+      assertTrue(event_data.uncaught());
+      // All of the frames on the stack are from native Javascript.
+      assertEquals(0, exec_state.frameCount());
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnException();
+Debug.setListener(listener);
+
+log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "end main", "reject"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/reject-uncaught-late.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we only listen to uncaught exceptions and
+// there is a catch handler for the to-be-rejected Promise.
+// We expect an Exception debug event with a promise to be triggered.
+
+Debug = debug.Debug;
+
+var expected_events = 1;
+var log = [];
+
+var reject_closure;
+
+var p = new Promise(function(resolve, reject) {
+  log.push("postpone p");
+  reject_closure = reject;
+});
+
+var q = new Promise(function(resolve, reject) {
+  log.push("resolve q");
+  resolve();
+});
+
+q.then(function() {
+  log.push("reject p");
+  reject_closure(new Error("uncaught reject p"));  // event
+})
+
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      assertEquals("uncaught reject p", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertEquals(p, event_data.promise());
+      assertTrue(event_data.uncaught());
+      // Assert that the debug event is triggered at the throw site.
+      assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["postpone p", "resolve q", "end main", "reject p"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/reject-uncaught-uncaught.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when we only listen to uncaught exceptions and
+// there is no catch handler for the to-be-rejected Promise.
+// We expect an Exception debug event with a promise to be triggered.
+
+Debug = debug.Debug;
+
+var expected_events = 1;
+var log = [];
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+var q = p.chain(
+  function() {
+    log.push("reject");
+    return Promise.reject(Error("uncaught reject"));  // event
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      assertEquals("uncaught reject", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertEquals(q, event_data.promise());
+      assertTrue(event_data.uncaught());
+      // All of the frames on the stack are from native Javascript.
+      assertEquals(0, exec_state.frameCount());
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "end main", "reject"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/reject-with-invalid-reject.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when a Promise is rejected, which is caught by a custom
+// promise, which has a number for reject closure.  We expect an Exception debug
+// events trying to call the invalid reject closure.
+
+Debug = debug.Debug;
+
+var expected_events = 1;
+var log = [];
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+function MyPromise(resolver) {
+  var reject = 1;
+  var resolve = function() { };
+  log.push("construct");
+  resolver(resolve, reject);
+};
+
+MyPromise.prototype = new Promise(function() {});
+p.constructor = MyPromise;
+
+var q = p.chain(
+  function() {
+    log.push("reject caught");
+    return Promise.reject(new Error("caught"));
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      assertEquals("number is not a function", event_data.exception().message);
+      // All of the frames on the stack are from native Javascript.
+      assertEquals(0, exec_state.frameCount());
+      assertEquals(q, event_data.promise());
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "construct", "end main", "reject caught"],
+                     log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);
+
+log.push("end main");

test/mjsunit/es6/debug-promises-throw-in-reject.js → test/mjsunit/es6/debug-promises/reject-with-throw-in-reject.js

@@ -2,16 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
-// Test debug events when an exception is thrown inside a Promise, which is
-// caught by a custom promise, which throws a new exception in its reject
-// handler.  We expect an Exception debug event with a promise to be triggered.
+// Test debug events when a Promise is rejected, which is caught by a
+// custom promise, which throws a new exception in its reject handler.
+// We expect two Exception debug events:
+//  1) when promise q is rejected.
+//  2) when the custom reject closure in MyPromise throws an exception.
 
 Debug = debug.Debug;
 
+var expected_events = 1;
 var log = [];
-var step = 0;
 
 var p = new Promise(function(resolve, reject) {
   log.push("resolve");
@@ -20,7 +22,7 @@ var p = new Promise(function(resolve, reject) {
 
 function MyPromise(resolver) {
   var reject = function() {
-    log.push("throw reject");
+    log.push("throw in reject");
     throw new Error("reject");  // event
   };
   var resolve = function() { };
@@ -28,23 +30,24 @@ function MyPromise(resolver) {
   resolver(resolve, reject);
 };
 
-MyPromise.prototype = p;
+MyPromise.prototype = new Promise(function() {});
 p.constructor = MyPromise;
 
 var q = p.chain(
   function() {
-    log.push("throw caught");
-    throw new Error("caught");
+    log.push("reject caught");
+    return Promise.reject(new Error("caught"));
   });
 
 function listener(event, exec_state, event_data, data) {
   try {
     if (event == Debug.DebugEvent.Exception) {
-      assertEquals(["resolve", "construct", "end main",
-                    "throw caught", "throw reject"], log);
+      expected_events--;
+      assertTrue(expected_events >= 0);
       assertEquals("reject", event_data.exception().message);
-      assertEquals(q, event_data.promise());
-      assertTrue(exec_state.frame(0).sourceLineText().indexOf('// event') > 0);
+      // Assert that the debug event is triggered at the throw site.
+      assertTrue(
+          exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
     }
   } catch (e) {
     // Signal a failure with exit code 1.  This is necessary since the
@@ -59,3 +62,26 @@ Debug.setBreakOnUncaughtException();
 Debug.setListener(listener);
 
 log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "construct", "end main",
+                      "reject caught", "throw in reject"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/reject-with-undefined-reject.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when a Promise is rejected, which is caught by a custom
+// promise, which has undefined for reject closure.  We expect an Exception
+// debug even calling the (undefined) custom rejected closure.
+
+Debug = debug.Debug;
+
+var expected_events = 1;
+var log = [];
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+function MyPromise(resolver) {
+  var reject = undefined;
+  var resolve = function() { };
+  log.push("construct");
+  resolver(resolve, reject);
+};
+
+MyPromise.prototype = new Promise(function() {});
+p.constructor = MyPromise;
+
+var q = p.chain(
+  function() {
+    log.push("reject caught");
+    return Promise.reject(new Error("caught"));
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      assertEquals("caught", event_data.exception().message);
+      // All of the frames on the stack are from native Javascript.
+      assertEquals(0, exec_state.frameCount());
+      assertEquals(q, event_data.promise());
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "construct", "end main", "reject caught"],
+                     log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);
+
+log.push("end main");

test/mjsunit/es6/debug-promises-caught-all.js → test/mjsunit/es6/debug-promises/throw-caught-all.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we listen to all exceptions and
 // there is a catch handler for the exception thrown in a Promise.
@@ -10,8 +10,8 @@
 
 Debug = debug.Debug;
 
+var expected_events = 1;
 var log = [];
-var step = 0;
 
 var p = new Promise(function(resolve, reject) {
   log.push("resolve");
@@ -30,23 +30,16 @@ q.catch(
   });
 
 function listener(event, exec_state, event_data, data) {
-  if (event == Debug.DebugEvent.AsyncTaskEvent) return;
   try {
-    // Ignore exceptions during startup in stress runs.
-    if (step >= 1) return;
-    assertEquals(["resolve", "end main", "throw"], log);
     if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
       assertEquals("caught", event_data.exception().message);
-      assertEquals(undefined, event_data.promise());
+      assertEquals(q, event_data.promise());
       assertFalse(event_data.uncaught());
-      step++;
     }
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
-    quit(1);
+    %AbortJS(e + "\n" + e.stack);
   }
 }
 
@@ -54,3 +47,25 @@ Debug.setBreakOnException();
 Debug.setListener(listener);
 
 log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "end main", "throw"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises-caught-late.js → test/mjsunit/es6/debug-promises/throw-caught-late.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we only listen to uncaught exceptions, the Promise
 // throws, and a catch handler is installed right before throwing.
@@ -26,11 +26,7 @@ function listener(event, exec_state, event_data, data) {
   try {
     assertTrue(event != Debug.DebugEvent.Exception);
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
-    quit(1);
+    %AbortJS(e + "\n" + e.stack);
   }
 }
 

test/mjsunit/es6/debug-promises-caught-uncaught.js → test/mjsunit/es6/debug-promises/throw-caught-uncaught.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we only listen to uncaught exceptions and
 // there is a catch handler for the exception thrown in a Promise.
@@ -16,23 +16,19 @@ var p = new Promise(function(resolve, reject) {
 
 var q = p.chain(
   function() {
-    throw new Error("caught");
+    throw new Error("caught throw");
   });
 
 q.catch(
   function(e) {
-    assertEquals("caught", e.message);
+    assertEquals("caught throw", e.message);
   });
 
 function listener(event, exec_state, event_data, data) {
   try {
     assertTrue(event != Debug.DebugEvent.Exception);
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
-    quit(1);
+    %AbortJS(e + "\n" + e.stack);
   }
 }
 

test/mjsunit/es6/debug-promises-throw-in-constructor.js → test/mjsunit/es6/debug-promises/throw-in-constructor.js

@@ -5,7 +5,7 @@
 // Flags: --expose-debug-as debug
 
 // Test debug events when we only listen to uncaught exceptions and
-// an exception is thrown in the the Promise constructor.
+// an exception is thrown in the Promise constructor.
 // We expect an Exception debug event with a promise to be triggered.
 
 Debug = debug.Debug;
@@ -15,8 +15,6 @@ var exception = null;
 
 function listener(event, exec_state, event_data, data) {
   try {
-    // Ignore exceptions during startup in stress runs.
-    if (step >= 1) return;
     if (event == Debug.DebugEvent.Exception) {
       assertEquals(0, step);
       assertEquals("uncaught", event_data.exception().message);
@@ -27,10 +25,6 @@ function listener(event, exec_state, event_data, data) {
       step++;
     }
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
     exception = e;
   }
 }

test/mjsunit/es6/debug-promises-uncaught-all.js → test/mjsunit/es6/debug-promises/throw-uncaught-all.js

@@ -2,17 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we listen to all exceptions and
-// there is a catch handler for the exception thrown in a Promise.
+// there is no catch handler for the exception thrown in a Promise.
 // We expect an Exception debug event with a promise to be triggered.
 
 Debug = debug.Debug;
 
+var expected_events = 1;
 var log = [];
-var step = 0;
-var exception = undefined;
 
 var p = new Promise(function(resolve, reject) {
   log.push("resolve");
@@ -26,27 +25,20 @@ var q = p.chain(
   });
 
 function listener(event, exec_state, event_data, data) {
-  if (event == Debug.DebugEvent.AsyncTaskEvent) return;
   try {
     // Ignore exceptions during startup in stress runs.
-    if (step >= 1) return;
-    assertEquals(["resolve", "end main", "throw"], log);
     if (event == Debug.DebugEvent.Exception) {
-      assertEquals(0, step);
+      expected_events--;
+      assertTrue(expected_events >= 0);
       assertEquals("uncaught", event_data.exception().message);
       assertTrue(event_data.promise() instanceof Promise);
       assertEquals(q, event_data.promise());
       assertTrue(event_data.uncaught());
       // Assert that the debug event is triggered at the throw site.
       assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
-      step++;
     }
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
-    quit(1);
+    %AbortJS(e + "\n" + e.stack);
   }
 }
 
@@ -54,3 +46,25 @@ Debug.setBreakOnException();
 Debug.setListener(listener);
 
 log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "end main", "throw"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Rerun testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises-uncaught-uncaught.js → test/mjsunit/es6/debug-promises/throw-uncaught-uncaught.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when we only listen to uncaught exceptions and
 // there is a catch handler for the exception thrown in a Promise.
@@ -10,8 +10,8 @@
 
 Debug = debug.Debug;
 
+var expected_events = 1;
 var log = [];
-var step = 0;
 
 var p = new Promise(function(resolve, reject) {
   log.push("resolve");
@@ -27,25 +27,18 @@ var q = p.chain(
 function listener(event, exec_state, event_data, data) {
   if (event == Debug.DebugEvent.AsyncTaskEvent) return;
   try {
-    // Ignore exceptions during startup in stress runs.
-    if (step >= 1) return;
-    assertEquals(["resolve", "end main", "throw"], log);
     if (event == Debug.DebugEvent.Exception) {
-      assertEquals(0, step);
+      expected_events--;
+      assertTrue(expected_events >= 0);
       assertEquals("uncaught", event_data.exception().message);
       assertTrue(event_data.promise() instanceof Promise);
       assertEquals(q, event_data.promise());
       assertTrue(event_data.uncaught());
       // Assert that the debug event is triggered at the throw site.
       assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
-      step++;
     }
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
-    quit(1);
+    %AbortJS(e + "\n" + e.stack);
   }
 }
 
@@ -53,3 +46,25 @@ Debug.setBreakOnUncaughtException();
 Debug.setListener(listener);
 
 log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "end main", "throw"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/throw-with-throw-in-reject.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug --allow-natives-syntax
+
+// Test debug events when an exception is thrown inside a Promise, which is
+// caught by a custom promise, which throws a new exception in its reject
+// handler. We expect two Exception debug events:
+//  1) when the exception is thrown in the promise q.
+//  2) when the custom reject closure in MyPromise throws an exception.
+
+Debug = debug.Debug;
+
+var expected_events = 2;
+var log = [];
+
+var p = new Promise(function(resolve, reject) {
+  log.push("resolve");
+  resolve();
+});
+
+function MyPromise(resolver) {
+  var reject = function() {
+    log.push("throw in reject");
+    throw new Error("reject");  // event
+  };
+  var resolve = function() { };
+  log.push("construct");
+  resolver(resolve, reject);
+};
+
+MyPromise.prototype = new Promise(function() {});
+p.constructor = MyPromise;
+
+var q = p.chain(
+  function() {
+    log.push("throw caught");
+    throw new Error("caught");  // event
+  });
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      if (expected_events == 1) {
+        assertEquals(["resolve", "construct", "end main",
+                      "throw caught"], log);
+        assertEquals("caught", event_data.exception().message);
+      } else if (expected_events == 0) {
+        assertEquals("reject", event_data.exception().message);
+      } else {
+        assertUnreachable();
+      }
+      assertEquals(q, event_data.promise());
+      assertTrue(exec_state.frame(0).sourceLineText().indexOf('// event') > 0);
+    }
+  } catch (e) {
+    %AbortJS(e + "\n" + e.stack);
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "construct", "end main",
+                      "throw caught", "throw in reject"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises-undefined-reject.js → test/mjsunit/es6/debug-promises/throw-with-undefined-reject.js

@@ -2,16 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --expose-debug-as debug
+// Flags: --expose-debug-as debug --allow-natives-syntax
 
 // Test debug events when an exception is thrown inside a Promise, which is
 // caught by a custom promise, which has no reject handler.
-// We expect an Exception event with a promise to be triggered.
+// We expect two Exception debug events:
+//  1) when the exception is thrown in the promise q.
+//  2) when calling the undefined custom reject closure in MyPromise throws.
 
 Debug = debug.Debug;
 
+var expected_events = 2;
 var log = [];
-var step = 0;
 
 var p = new Promise(function(resolve, reject) {
   log.push("resolve");
@@ -25,7 +27,7 @@ function MyPromise(resolver) {
   resolver(resolve, reject);
 };
 
-MyPromise.prototype = p;
+MyPromise.prototype = new Promise(function() {});
 p.constructor = MyPromise;
 
 var q = p.chain(
@@ -37,17 +39,24 @@ var q = p.chain(
 function listener(event, exec_state, event_data, data) {
   try {
     if (event == Debug.DebugEvent.Exception) {
-      assertEquals(["resolve", "construct", "end main", "throw caught"], log);
+      expected_events--;
+      assertTrue(expected_events >= 0);
+      if (expected_events == 1) {
+        assertTrue(
+            exec_state.frame(0).sourceLineText().indexOf('// event') > 0);
+        assertEquals("caught", event_data.exception().message);
+      } else if (expected_events == 0) {
+        // All of the frames on the stack are from native Javascript.
+        assertEquals(0, exec_state.frameCount());
         assertEquals("undefined is not a function",
                      event_data.exception().message);
+      } else {
+        assertUnreachable();
+      }
       assertEquals(q, event_data.promise());
     }
   } catch (e) {
-    // Signal a failure with exit code 1.  This is necessary since the
-    // debugger swallows exceptions and we expect the chained function
-    // and this listener to be executed after the main script is finished.
-    print("Unexpected exception: " + e + "\n" + e.stack);
-    quit(1);
+    %AbortJS(e + "\n" + e.stack);
   }
 }
 
@@ -55,3 +64,25 @@ Debug.setBreakOnUncaughtException();
 Debug.setListener(listener);
 
 log.push("end main");
+
+function testDone(iteration) {
+  function checkResult() {
+    try {
+      assertTrue(iteration < 10);
+      if (expected_events === 0) {
+        assertEquals(["resolve", "construct", "end main", "throw caught"], log);
+      } else {
+        testDone(iteration + 1);
+      }
+    } catch (e) {
+      %AbortJS(e + "\n" + e.stack);
+    }
+  }
+
+  // Run testDone through the Object.observe processing loop.
+  var dummy = {};
+  Object.observe(dummy, checkResult);
+  dummy.dummy = dummy;
+}
+
+testDone(0);

test/mjsunit/es6/debug-promises/try-reject-in-constructor.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug
+
+// Test debug events when we only listen to uncaught exceptions and
+// the Promise is rejected within a try-catch in the Promise constructor.
+// We expect an Exception debug event with a promise to be triggered.
+
+Debug = debug.Debug;
+
+var step = 0;
+var exception = null;
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      assertEquals(0, step);
+      assertEquals("uncaught", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertTrue(event_data.uncaught());
+      // Assert that the debug event is triggered at the throw site.
+      assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
+      step++;
+    }
+  } catch (e) {
+    exception = e;
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+var p = new Promise(function(resolve, reject) {
+  try {  // This try-catch must not prevent this uncaught reject event.
+    reject(new Error("uncaught"));  // event
+  } catch (e) { }
+});
+
+assertEquals(1, step);
+assertNull(exception);

test/mjsunit/es6/debug-promises/try-throw-reject-in-constructor.js

+// Copyright 2014 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.
+
+// Flags: --expose-debug-as debug
+
+// Test debug events when we only listen to uncaught exceptions and
+// an exception is thrown in the Promise constructor, but caught in an
+// inner try-catch.  The Promise is rejected afterwards.
+// We expect an Exception debug event with a promise to be triggered.
+
+Debug = debug.Debug;
+
+var step = 0;
+var exception = null;
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Exception) {
+      assertEquals(0, step);
+      assertEquals("uncaught", event_data.exception().message);
+      assertTrue(event_data.promise() instanceof Promise);
+      assertTrue(event_data.uncaught());
+      // Assert that the debug event is triggered at the throw site.
+      assertTrue(exec_state.frame(0).sourceLineText().indexOf("// event") > 0);
+      step++;
+    }
+  } catch (e) {
+    exception = e;
+  }
+}
+
+Debug.setBreakOnUncaughtException();
+Debug.setListener(listener);
+
+var p = new Promise(function(resolve, reject) {
+  try {  // This try-catch must not prevent this uncaught reject event.
+    throw new Error("caught");
+  } catch (e) { }
+  reject(new Error("uncaught"));  // event
+});
+
+assertEquals(1, step);
+assertNull(exception);

test/mjsunit/mjsunit.status

@@ -127,10 +127,14 @@
   'debug-stepout-scope-part3': [PASS, NO_VARIANTS],
   'debug-stepout-scope-part7': [PASS, NO_VARIANTS],
   'debug-stepout-to-builtin': [PASS, NO_VARIANTS],
-  'es6/debug-promises-throw-in-constructor': [PASS, NO_VARIANTS],
-  'es6/debug-promises-throw-in-reject': [PASS, NO_VARIANTS],
-  'es6/debug-promises-uncaught-all': [PASS, NO_VARIANTS],
-  'es6/debug-promises-uncaught-uncaught': [PASS, NO_VARIANTS],
+  'es6/debug-promises/throw-in-constructor': [PASS, NO_VARIANTS],
+  'es6/debug-promises/reject-in-constructor': [PASS, NO_VARIANTS],
+  'es6/debug-promises/throw-with-undefined-reject': [PASS, NO_VARIANTS],
+  'es6/debug-promises/throw-with-throw-in-reject': [PASS, NO_VARIANTS],
+  'es6/debug-promises/reject-with-throw-in-reject': [PASS, NO_VARIANTS],
+  'es6/debug-promises/throw-uncaught-all': [PASS, NO_VARIANTS],
+  'es6/debug-promises/throw-uncaught-uncaught': [PASS, NO_VARIANTS],
+  'es6/debug-promises/reject-uncaught-late': [PASS, NO_VARIANTS],
   'harmony/debug-blockscopes': [PASS, NO_VARIANTS],
   'harmony/generators-debug-scopes': [PASS, NO_VARIANTS],
   'regress/regress-1081309': [PASS, NO_VARIANTS],

test/mjsunit/runtime-gen/debugpromisehandleepilogue.js → test/mjsunit/runtime-gen/debugpoppromise.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
 // Flags: --allow-natives-syntax --harmony
-%DebugPromiseHandleEpilogue();
+%DebugPopPromise();

test/mjsunit/runtime-gen/debugpromiserejectevent.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
+// Flags: --allow-natives-syntax --harmony
+var _promise = new Object();
+var _value = new Object();
+%DebugPromiseRejectEvent(_promise, _value);

test/mjsunit/runtime-gen/debugpromisehandleprologue.js → test/mjsunit/runtime-gen/debugpushpromise.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
 // Flags: --allow-natives-syntax --harmony
-var _promise_getter = function() {};
-%DebugPromiseHandlePrologue(_promise_getter);
+var _promise = new Object();
+%DebugPushPromise(_promise);

tools/generate-runtime-tests.py

@@ -47,8 +47,8 @@ EXPAND_MACROS = [
 # that the parser doesn't bit-rot. Change the values as needed when you add,
 # remove or change runtime functions, but make sure we don't lose our ability
 # to parse them!
-EXPECTED_FUNCTION_COUNT = 425
-EXPECTED_FUZZABLE_COUNT = 328
+EXPECTED_FUNCTION_COUNT = 426
+EXPECTED_FUZZABLE_COUNT = 329
 EXPECTED_CCTEST_COUNT = 7
 EXPECTED_UNKNOWN_COUNT = 16
 EXPECTED_BUILTINS_COUNT = 813