[execution] Fix microtask error reporting DCHECKs

Previously we've added has_scheduled_exception DCHECKs that were a bit
too strict in some cases.

- Remove unused exception_out param for TryRunMicrotasks
- Simplify overzealous DCHECK and clean up MicrotaskQueue::RunMicrotasks

Change-Id: I3a945a731573b6b3e44e17487fb8bf871b9a6793
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3789504
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82131}

src/execution/execution.cc

@@ -49,8 +49,7 @@ struct InvokeParams {
       MaybeHandle<Object>* exception_out, bool reschedule_terminate);
 
   static InvokeParams SetUpForRunMicrotasks(Isolate* isolate,
-                                            MicrotaskQueue* microtask_queue,
-                                            MaybeHandle<Object>* exception_out);
+                                            MicrotaskQueue* microtask_queue);
 
   bool IsScript() const {
     if (!target->IsJSFunction()) return false;
@@ -152,8 +151,7 @@ InvokeParams InvokeParams::SetUpForTryCall(
 
 // static
 InvokeParams InvokeParams::SetUpForRunMicrotasks(
-    Isolate* isolate, MicrotaskQueue* microtask_queue,
-    MaybeHandle<Object>* exception_out) {
+    Isolate* isolate, MicrotaskQueue* microtask_queue) {
   auto undefined = isolate->factory()->undefined_value();
   InvokeParams params;
   params.target = undefined;
@@ -163,7 +161,7 @@ InvokeParams InvokeParams::SetUpForRunMicrotasks(
   params.new_target = undefined;
   params.microtask_queue = microtask_queue;
   params.message_handling = Execution::MessageHandling::kReport;
-  params.exception_out = exception_out;
+  params.exception_out = nullptr;
   params.is_construct = false;
   params.execution_target = Execution::Target::kRunMicrotasks;
   params.reschedule_terminate = true;
@@ -503,6 +501,8 @@ MaybeHandle<Object> InvokeWithTryCatch(Isolate* isolate,
           isolate->OptionalRescheduleException(true);
         }
       }
+    } else {
+      DCHECK(!isolate->has_pending_exception());
     }
   }
 
@@ -594,11 +594,9 @@ MaybeHandle<Object> Execution::TryCall(
 
 // static
 MaybeHandle<Object> Execution::TryRunMicrotasks(
-    Isolate* isolate, MicrotaskQueue* microtask_queue,
-    MaybeHandle<Object>* exception_out) {
+    Isolate* isolate, MicrotaskQueue* microtask_queue) {
   return InvokeWithTryCatch(
-      isolate, InvokeParams::SetUpForRunMicrotasks(isolate, microtask_queue,
-                                                   exception_out));
+      isolate, InvokeParams::SetUpForRunMicrotasks(isolate, microtask_queue));
 }
 
 struct StackHandlerMarker {

src/execution/execution.h

@@ -68,9 +68,8 @@ class Execution final : public AllStatic {
       bool reschedule_terminate = true);
 
   // Convenience method for performing RunMicrotasks
-  static MaybeHandle<Object> TryRunMicrotasks(
-      Isolate* isolate, MicrotaskQueue* microtask_queue,
-      MaybeHandle<Object>* exception_out);
+  static MaybeHandle<Object> TryRunMicrotasks(Isolate* isolate,
+                                              MicrotaskQueue* microtask_queue);
 
 #if V8_ENABLE_WEBASSEMBLY
   // Call a Wasm function identified by {wasm_call_target} through the

src/execution/microtask-queue.cc

@@ -156,7 +156,6 @@ int MicrotaskQueue::RunMicrotasks(Isolate* isolate) {
   intptr_t base_count = finished_microtask_count_;
 
   HandleScope handle_scope(isolate);
-  MaybeHandle<Object> maybe_exception;
 
   MaybeHandle<Object> maybe_result;
 
@@ -170,8 +169,7 @@ int MicrotaskQueue::RunMicrotasks(Isolate* isolate) {
     TRACE_EVENT_BEGIN0("v8.execute", "RunMicrotasks");
     {
       TRACE_EVENT_CALL_STATS_SCOPED(isolate, "v8", "V8.RunMicrotasks");
-      maybe_result = Execution::TryRunMicrotasks(isolate, this,
-                                                 &maybe_exception);
+      maybe_result = Execution::TryRunMicrotasks(isolate, this);
       processed_microtask_count =
           static_cast<int>(finished_microtask_count_ - base_count);
     }
@@ -179,16 +177,14 @@ int MicrotaskQueue::RunMicrotasks(Isolate* isolate) {
                      processed_microtask_count);
   }
 
-  DCHECK_IMPLIES(isolate->has_scheduled_exception(),
-                 maybe_result.is_null() && maybe_exception.is_null());
-  // If execution is terminating, clean up and propagate that to TryCatch scope.
-  if (maybe_result.is_null() && maybe_exception.is_null()) {
+  if (isolate->is_execution_terminating()) {
+    DCHECK(isolate->has_scheduled_exception());
+    DCHECK(maybe_result.is_null());
     delete[] ring_buffer_;
     ring_buffer_ = nullptr;
     capacity_ = 0;
     size_ = 0;
     start_ = 0;
-    DCHECK(isolate->has_scheduled_exception());
     isolate->OnTerminationDuringRunMicrotasks();
     OnCompleted(isolate);
     return -1;