[debugger] Ensure debug listeners do not throw

This exposes a couple of broken tests that used to silently throw within
the listener. Mark these as failing for now

BUG=v8:5330, v8:5581

Review-Url: https://codereview.chromium.org/2460833002
Cr-Commit-Position: refs/heads/master@{#40672}

src/d8.cc

@@ -1808,11 +1808,9 @@ class InspectorFrontend final : public v8_inspector::V8Inspector::Channel {
     if (callback->IsFunction()) {
       v8::TryCatch try_catch(isolate_);
       Local<Value> args[] = {message};
-      if (Local<Function>::Cast(callback)
-              ->Call(context, Undefined(isolate_), 1, args)
-              .IsEmpty()) {
-        try_catch.ReThrow();
-      }
+      MaybeLocal<Value> result = Local<Function>::Cast(callback)->Call(
+          context, Undefined(isolate_), 1, args);
+      CHECK(!result.IsEmpty());  // Listeners may not throw.
     }
   }
 

src/debug/debug.cc

@@ -1850,7 +1850,7 @@ void Debug::CallEventCallback(v8::DebugEvent event,
                                    event_listener_data_,
                                    client_data);
     callback(event_details);
-    DCHECK(!isolate_->has_scheduled_exception());
+    CHECK(!isolate_->has_scheduled_exception());
   } else {
     // Invoke the JavaScript debug event listener.
     DCHECK(event_listener_->IsJSFunction());
@@ -1859,8 +1859,10 @@ void Debug::CallEventCallback(v8::DebugEvent event,
                               event_data,
                               event_listener_data_ };
     Handle<JSReceiver> global = isolate_->global_proxy();
-    Execution::TryCall(isolate_, Handle<JSFunction>::cast(event_listener_),
-                       global, arraysize(argv), argv);
+    MaybeHandle<Object> result =
+        Execution::Call(isolate_, Handle<JSFunction>::cast(event_listener_),
+                        global, arraysize(argv), argv);
+    CHECK(!result.is_null());  // Listeners may not throw.
   }
   in_debug_event_listener_ = previous;
 }

test/mjsunit/mjsunit.status

@@ -69,7 +69,6 @@
 
   ##############################################################################
   # Too slow in debug mode with --stress-opt mode.
-  'regress/regress-2318': [PASS, ['mode == debug', SKIP]],
   'regress/regress-create-exception': [PASS, ['mode == debug', SKIP]],
 
   ##############################################################################
@@ -135,6 +134,17 @@
   'verify-check-false': [FAIL, NO_VARIANTS],
   'verify-assert-false': [NO_VARIANTS, ['mode == release and dcheck_always_on == False', PASS], ['mode == debug or dcheck_always_on == True', FAIL]],
 
+  ##############################################################################
+  # BUG(5581): Broken tests with exceptions thrown in debug listener.
+  'es6/debug-step-into-constructor': [FAIL],
+  'es6/default-parameters-debug': [FAIL],
+  'regress/regress-2296': [FAIL],
+  'regress/regress-2318': [FAIL],
+  'regress/regress-4703': [FAIL],
+  'regress/regress-5071': [FAIL],
+  'regress/regress-998565': [FAIL],
+  'regress/regress-crbug-107996': [FAIL],
+
   ##############################################################################
   # Tests with different versions for release and debug.
   'compiler/alloc-number': [PASS, ['mode == debug', SKIP]],