Revert "[explicit-resource-management] Avoid unnecessary awaits"

This reverts commit f054729.

Reason for revert: https://issues.chromium.org/u/1/issues/365060988

Original change's description:
> [explicit-resource-management] Avoid unnecessary awaits
>
> This CL reduces unnecessary Awaits for nullish values in blocks containing `await using` and in `AsyncDisposableStack`
> tc39/proposal-explicit-resource-management#219
>
>
> Bug: 42203814
> Change-Id: Ia94755bd19a217512d308b5b4f524471b8321d63
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5819755
> Reviewed-by: Shu-yu Guo <[email protected]>
> Commit-Queue: Rezvan Mahdavi Hezaveh <[email protected]>
> Cr-Commit-Position: refs/heads/main@{#95982}

Bug: 42203814
Change-Id: I932341e117fd02299bda224ab5ff694372006ac0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5840443
Bot-Commit: Rubber Stamper <[email protected]>
Owners-Override: Rezvan Mahdavi Hezaveh <[email protected]>
Commit-Queue: Rezvan Mahdavi Hezaveh <[email protected]>
Cr-Commit-Position: refs/heads/main@{#95998}

src/builtins/promise-abstract-operations.tq

@@ -488,18 +488,6 @@ transitioning macro PerformPromiseThenImpl(
   promise.SetHasHandler();
 }
 
-transitioning javascript builtin PerformPromiseThenFunction(
-    js-implicit context: NativeContext, receiver: JSAny)(onFulfilled: JSAny,
-    onRejected: JSAny): JSAny {
-  const jsPromise = Cast<JSPromise>(receiver) otherwise unreachable;
-  const callableOnFulfilled = Cast<Callable>(onFulfilled) otherwise unreachable;
-  const callableOnRejected = Cast<Callable>(onRejected) otherwise unreachable;
-
-  PerformPromiseThenImpl(
-      jsPromise, callableOnFulfilled, callableOnRejected, Undefined);
-  return Undefined;
-}
-
 // https://tc39.es/ecma262/#sec-performpromisethen
 transitioning builtin PerformPromiseThen(
     implicit context: Context)(promise: JSPromise,

src/diagnostics/objects-printer.cc

@@ -1977,8 +1977,6 @@ void JSDisposableStackBase::JSDisposableStackBasePrint(std::ostream& os) {
   os << "\n - stack: " << Brief(stack());
   os << "\n - length: " << length();
   os << "\n - state: " << state();
-  os << "\n - needsAwait: " << needsAwait();
-  os << "\n - hasAwaited: " << hasAwaited();
   os << "\n - error: " << error();
   JSObjectPrintBody(os, *this);
 }
@@ -1988,8 +1986,6 @@ void JSAsyncDisposableStack::JSAsyncDisposableStackPrint(std::ostream& os) {
   os << "\n - stack: " << Brief(stack());
   os << "\n - length: " << length();
   os << "\n - state: " << state();
-  os << "\n - needsAwait: " << needsAwait();
-  os << "\n - hasAwaited: " << hasAwaited();
   os << "\n - error: " << error();
   JSObjectPrintBody(os, *this);
 }

src/init/bootstrapper.cc

@@ -3272,12 +3272,6 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         isolate_, prototype, "then", Builtin::kPromisePrototypeThen, 2, kAdapt);
     native_context()->set_promise_then(*promise_then);
 
-    DirectHandle<JSFunction> perform_promise_then =
-        InstallFunctionWithBuiltinId(isolate_, prototype, "performPromiseThen",
-                                     Builtin::kPerformPromiseThenFunction, 2,
-                                     kAdapt);
-    native_context()->set_perform_promise_then(*perform_promise_then);
-
     InstallFunctionWithBuiltinId(isolate_, prototype, "catch",
                                  Builtin::kPromisePrototypeCatch, 1, kAdapt);
 

src/interpreter/bytecode-generator.cc

@@ -2732,7 +2732,7 @@ void BytecodeGenerator::BuildDisposeScope(WrappedFunc wrapped_func,
 
           builder()
               ->StoreAccumulatorInRegister(result_register)
-              .LoadTrue()
+              .LoadUndefined()
               .CompareReference(result_register);
 
           loop_builder.BreakIfTrue(ToBooleanMode::kConvertToBoolean);

src/objects/contexts.h

@@ -54,7 +54,6 @@ enum ContextLookupFlags {
     async_module_evaluate_internal)                                            \
   V(REFLECT_APPLY_INDEX, JSFunction, reflect_apply)                            \
   V(REFLECT_CONSTRUCT_INDEX, JSFunction, reflect_construct)                    \
-  V(PERFORM_PROMISE_THEN_INDEX, JSFunction, perform_promise_then)              \
   V(PROMISE_THEN_INDEX, JSFunction, promise_then)                              \
   V(PROMISE_RESOLVE_INDEX, JSFunction, promise_resolve)                        \
   V(FUNCTION_PROTOTYPE_APPLY_INDEX, JSFunction, function_prototype_apply)      \

src/objects/js-disposable-stack.cc

@@ -70,93 +70,65 @@ MaybeHandle<Object> JSDisposableStackBase::DisposeResources(
         DisposeCallTypeBit::decode(stack_type_case);
     DisposeMethodHint hint = DisposeHintBit::decode(stack_type_case);
 
+    // (TODO:rezvan):
+    // https://github.com/tc39/proposal-explicit-resource-management/pull/219
     //  d. If hint is sync-dispose and needsAwait is true and hasAwaited is
     //  false, then
     //    i. Perform ! Await(undefined).
     //    ii. Set needsAwait to false.
 
-    if (hint == DisposeMethodHint::kSyncDispose &&
-        disposable_stack->needsAwait() == true &&
-        disposable_stack->hasAwaited() == false) {
-      //  i. Perform ! Await(undefined).
-      //  ii. Set needsAwait to false.
-      disposable_stack->set_needsAwait(false);
-
-      return ResolveAPromiseWithValueAndReturnIt(
-          isolate, ReadOnlyRoots(isolate).undefined_value_handle());
+    //  e. If method is not undefined, then
+    //    i. Let result be Completion(Call(method, value)).
+    //    ii. If result is a normal completion and hint is async-dispose, then
+    //      1. Set result to Completion(Await(result.[[Value]])).
+    //      2. Set hasAwaited to true.
+    //    iii. If result is a throw completion, then
+    //  Else,
+    //    i. Assert: hint is async-dispose.
+    //    ii. Set needsAwait to true.
+    //    iii. NOTE: This can only indicate a case where either null or
+    //    undefined was the initialized value of an await using declaration.
+    // 4. If needsAwait is true and hasAwaited is false, then
+    //   a. Perform ! Await(undefined).
+    v8::TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));
+    try_catch.SetVerbose(false);
+    try_catch.SetCaptureMessage(false);
+
+    if (call_type == DisposeMethodCallType::kValueIsReceiver) {
+      result = Execution::Call(isolate, method, value, 0, nullptr);
+    } else if (call_type == DisposeMethodCallType::kValueIsArgument) {
+      result = Execution::Call(isolate, method,
+                               ReadOnlyRoots(isolate).undefined_value_handle(),
+                               1, argv);
     }
 
-    //  e. If method is not undefined, then
-    if (!IsUndefined(*method)) {
-      //    i. Let result be Completion(Call(method, value)).
-      v8::TryCatch try_catch(reinterpret_cast<v8::Isolate*>(isolate));
-      try_catch.SetVerbose(false);
-      try_catch.SetCaptureMessage(false);
-
-      if (call_type == DisposeMethodCallType::kValueIsReceiver) {
-        result = Execution::Call(isolate, method, value, 0, nullptr);
-      } else if (call_type == DisposeMethodCallType::kValueIsArgument) {
-        result = Execution::Call(
-            isolate, method, ReadOnlyRoots(isolate).undefined_value_handle(), 1,
-            argv);
-      }
+    Handle<Object> result_handle;
 
-      Handle<Object> result_handle;
-      //    ii. If result is a normal completion and hint is async-dispose, then
-      //      1. Set result to Completion(Await(result.[[Value]])).
-      //      2. Set hasAwaited to true.
-      if (result.ToHandle(&result_handle)) {
-        if (hint == DisposeMethodHint::kAsyncDispose) {
-          DCHECK_NE(resources_type, DisposableStackResourcesType::kAllSync);
-          disposable_stack->set_length(length);
-
-          disposable_stack->set_hasAwaited(true);
-
-          return ResolveAPromiseWithValueAndReturnIt(isolate, result_handle);
-        }
-      } else {
-        //    iii. If result is a throw completion, then
-        //      1. If completion is a throw completion, then
-        //        a. Set result to result.[[Value]].
-        //        b. Let suppressed be completion.[[Value]].
-        //        c. Let error be a newly created SuppressedError object.
-        //        d. Perform CreateNonEnumerableDataPropertyOrThrow(error,
-        //        "error", result). e. Perform
-        //        CreateNonEnumerableDataPropertyOrThrow(error, "suppressed",
-        //        suppressed). f. Set completion to ThrowCompletion(error).
-        //      2. Else,
-        //        a. Set completion to result.
-        DCHECK(isolate->has_exception());
-        DCHECK(try_catch.HasCaught());
-        Handle<Object> current_error(isolate->exception(), isolate);
-        if (!isolate->is_catchable_by_javascript(*current_error)) {
-          return {};
-        }
-        HandleErrorInDisposal(isolate, disposable_stack, current_error);
+    if (result.ToHandle(&result_handle)) {
+      if (hint == DisposeMethodHint::kAsyncDispose) {
+        DCHECK_NE(resources_type, DisposableStackResourcesType::kAllSync);
+        disposable_stack->set_length(length);
+
+        Handle<JSFunction> promise_function = isolate->promise_function();
+        Handle<Object> argv[] = {result_handle};
+        Handle<Object> resolve_result =
+            Execution::CallBuiltin(isolate, isolate->promise_resolve(),
+                                   promise_function, arraysize(argv), argv)
+                .ToHandleChecked();
+        return Cast<JSReceiver>(resolve_result);
       }
     } else {
-      //  Else,
-      //    i. Assert: hint is async-dispose.
-      DCHECK_EQ(hint, DisposeMethodHint::kAsyncDispose);
-      //    ii. Set needsAwait to true.
-      //    iii. NOTE: This can only indicate a case where either null or
-      //    undefined was the initialized value of an await using declaration.
-      disposable_stack->set_length(length);
-      disposable_stack->set_needsAwait(true);
+      // b. If result is a throw completion, then
+      DCHECK(isolate->has_exception());
+      DCHECK(try_catch.HasCaught());
+      Handle<Object> current_error(isolate->exception(), isolate);
+      if (!isolate->is_catchable_by_javascript(*current_error)) {
+        return {};
+      }
+      HandleErrorInDisposal(isolate, disposable_stack, current_error);
     }
   }
 
-  // 4. If needsAwait is true and hasAwaited is false, then
-  //   a. Perform ! Await(undefined).
-  if (disposable_stack->needsAwait() == true &&
-      disposable_stack->hasAwaited() == false) {
-    disposable_stack->set_length(length);
-    disposable_stack->set_hasAwaited(true);
-
-    return ResolveAPromiseWithValueAndReturnIt(
-        isolate, ReadOnlyRoots(isolate).undefined_value_handle());
-  }
-
   // 5. NOTE: After disposeCapability has been disposed, it will never be used
   // again. The contents of disposeCapability.[[DisposableResourceStack]] can be
   // discarded in implementations, such as by garbage collection, at this point.
@@ -174,18 +146,7 @@ MaybeHandle<Object> JSDisposableStackBase::DisposeResources(
     isolate->Throw(*existing_error_handle);
     return MaybeHandle<Object>();
   }
-  return isolate->factory()->true_value();
-}
-
-Handle<JSReceiver> JSDisposableStackBase::ResolveAPromiseWithValueAndReturnIt(
-    Isolate* isolate, Handle<Object> value) {
-  Handle<JSFunction> promise_function = isolate->promise_function();
-  Handle<Object> argv[] = {value};
-  Handle<Object> resolve_result =
-      Execution::CallBuiltin(isolate, isolate->promise_resolve(),
-                             promise_function, arraysize(argv), argv)
-          .ToHandleChecked();
-  return Cast<JSReceiver>(resolve_result);
+  return isolate->factory()->undefined_value();
 }
 
 Maybe<bool> JSAsyncDisposableStack::NextDisposeAsyncIteration(
@@ -208,7 +169,7 @@ Maybe<bool> JSAsyncDisposableStack::NextDisposeAsyncIteration(
   Handle<Object> result_handle;
 
   if (result.ToHandle(&result_handle)) {
-    if (!IsTrue(*result_handle)) {
+    if (!IsUndefined(*result_handle)) {
       Handle<Context> async_disposable_stack_context =
           isolate->factory()->NewBuiltinContext(
               isolate->native_context(),
@@ -240,8 +201,8 @@ Maybe<bool> JSAsyncDisposableStack::NextDisposeAsyncIteration(
               .Build();
 
       Handle<Object> argv[] = {on_fulfilled, on_rejected};
-
-      Execution::CallBuiltin(isolate, isolate->perform_promise_then(),
+      // (TODO:rezvan): Add a wrapper function for PerformPromiseThen.
+      Execution::CallBuiltin(isolate, isolate->promise_then(),
                              Cast<JSPromise>(result_handle), arraysize(argv),
                              argv)
           .ToHandleChecked();

src/objects/js-disposable-stack.h

@@ -80,8 +80,6 @@ class JSDisposableStackBase
       Isolate* isolate, DirectHandle<JSDisposableStackBase> disposable_stack,
       MaybeHandle<Object> maybe_continuation_error,
       DisposableStackResourcesType resources_type);
-  static Handle<JSReceiver> ResolveAPromiseWithValueAndReturnIt(
-      Isolate* isolate, Handle<Object> value);
   static void HandleErrorInDisposal(
       Isolate* isolate, DirectHandle<JSDisposableStackBase> disposable_stack,
       Handle<Object> current_error);