[runtime] DHCECK terminating exception in Microtasks

Check that we don't accidentally end up entering a microtask if we have
a pending terminating exception.

Bug: chromium:1319267
Change-Id: Id1ec7e3deb39aa18f08c363e17bb8df599379d66
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3610624Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80230}

src/builtins/builtins-microtask-queue-gen.cc

@@ -118,6 +118,7 @@ void MicrotaskQueueBuiltinsAssembler::PrepareForContext(
 void MicrotaskQueueBuiltinsAssembler::RunSingleMicrotask(
     TNode<Context> current_context, TNode<Microtask> microtask) {
   CSA_DCHECK(this, TaggedIsNotSmi(microtask));
+  CSA_DCHECK(this, Word32BinaryNot(IsExecutionTerminating()));
 
   StoreRoot(RootIndex::kCurrentMicrotask, microtask);
   TNode<IntPtrT> saved_entered_context_count = GetEnteredContextCount();

src/codegen/code-stub-assembler.cc

@@ -6170,6 +6170,12 @@ void CodeStubAssembler::SetPendingMessage(TNode<HeapObject> message) {
   StoreFullTaggedNoWriteBarrier(pending_message, message);
 }
 
+TNode<BoolT> CodeStubAssembler::IsExecutionTerminating() {
+  TNode<HeapObject> pending_message = GetPendingMessage();
+  return TaggedEqual(pending_message,
+                     LoadRoot(RootIndex::kTerminationException));
+}
+
 TNode<BoolT> CodeStubAssembler::InstanceTypeEqual(TNode<Int32T> instance_type,
                                                   int type) {
   return Word32Equal(instance_type, Int32Constant(type));

src/codegen/code-stub-assembler.h

@@ -2522,6 +2522,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
 
   TNode<HeapObject> GetPendingMessage();
   void SetPendingMessage(TNode<HeapObject> message);
+  TNode<BoolT> IsExecutionTerminating();
 
   // Type checks.
   // Check whether the map is for an object with special properties, such as a

src/execution/microtask-queue.cc

@@ -179,6 +179,8 @@ 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()) {
     delete[] ring_buffer_;