[promises] Move PromiseReject to c++

This patch refactors most of FulfillPromise runtime call out to a separate
function so that we can to it from PromiseReject runtime call.

This patch adds a PromiseStatus enum.

BUG=v8:5343

Review-Url: https://codereview.chromium.org/2451163003
Cr-Commit-Position: refs/heads/master@{#40615}

src/globals.h

@@ -603,6 +603,14 @@ enum ParseRestriction {
   ONLY_SINGLE_FUNCTION_LITERAL  // Only a single FunctionLiteral expression.
 };
 
+// TODO(gsathya): Move this to JSPromise once we create it.
+// This should be in sync with the constants in promise.js
+enum PromiseStatus {
+  kPromisePending,
+  kPromiseFulfilled,
+  kPromiseRejected,
+};
+
 // A CodeDesc describes a buffer holding instructions and relocation
 // information. The instructions start at the beginning of the buffer
 // and grow forward, the relocation information starts at the end of

src/js/async-await.js

@@ -130,7 +130,7 @@ function AsyncFunctionAwaitCaught(generator, awaited, outerPromise) {
 
 // How the parser rejects promises from async/await desugaring
 function RejectPromiseNoDebugEvent(promise, reason) {
-  return RejectPromise(promise, reason, false);
+  return RejectPromise(promise, reason);
 }
 
 function AsyncFunctionPromiseCreate() {

src/js/promise.js

@@ -44,9 +44,10 @@ utils.Import(function(from) {
 // -------------------------------------------------------------------
 
 // [[PromiseState]] values:
+// These values should be kept in sync with PromiseStatus in globals.h
 const kPending = 0;
 const kFulfilled = +1;
-const kRejected = -1;
+const kRejected = +2;
 
 // ES#sec-createresolvingfunctions
 // CreateResolvingFunctions ( promise )
@@ -66,7 +67,8 @@ function CreateResolvingFunctions(promise, debugEvent) {
   var reject = reason => {
     if (alreadyResolved === true) return;
     alreadyResolved = true;
-    RejectPromise(promise, reason, debugEvent);
+    %PromiseReject(promise, reason, debugEvent);
+    PromiseSet(promise, kRejected, reason);
   };
 
   return {
@@ -157,7 +159,8 @@ function PromiseHandle(value, handler, deferred) {
       if (IS_UNDEFINED(deferred.reject)) {
         // Pass false for debugEvent so .then chaining does not trigger
         // redundant ExceptionEvents.
-        RejectPromise(deferred.promise, exception, false);
+        %PromiseReject(deferred.promise, exception, false);
+        PromiseSet(deferred.promise, kRejected, exception);
       } else {
         %_Call(deferred.reject, UNDEFINED, exception);
       }
@@ -243,16 +246,19 @@ function PromiseCreate() {
 // Promise Resolve Functions, steps 6-13
 function ResolvePromise(promise, resolution) {
   if (resolution === promise) {
-    return RejectPromise(promise,
-                         %make_type_error(kPromiseCyclic, resolution),
-                         true);
+    var exception = %make_type_error(kPromiseCyclic, resolution);
+    %PromiseReject(promise, exception, true);
+    PromiseSet(promise, kRejected, exception);
+    return;
   }
   if (IS_RECEIVER(resolution)) {
     // 25.4.1.3.2 steps 8-12
     try {
       var then = resolution.then;
     } catch (e) {
-      return RejectPromise(promise, e, true);
+      %PromiseReject(promise, e, true);
+      PromiseSet(promise, kRejected, e);
+      return;
     }
 
     // Resolution is a native promise and if it's already resolved or
@@ -277,7 +283,8 @@ function ResolvePromise(promise, resolution) {
           %PromiseRevokeReject(resolution);
         }
         // Don't cause a debug event as this case is forwarding a rejection
-        RejectPromise(promise, thenableValue, false);
+        %PromiseReject(promise, thenableValue, false);
+        PromiseSet(promise, kRejected, thenableValue);
         SET_PRIVATE(resolution, promiseHasHandlerSymbol, true);
         return;
       }
@@ -299,26 +306,16 @@ function ResolvePromise(promise, resolution) {
   PromiseSet(promise, kFulfilled, resolution);
 }
 
-// ES#sec-rejectpromise
-// RejectPromise ( promise, reason )
-function RejectPromise(promise, reason, debugEvent) {
-  // Call runtime for callbacks to the debugger or for unhandled reject.
-  // The debugEvent parameter sets whether a debug ExceptionEvent should
-  // be triggered. It should be set to false when forwarding a rejection
-  // rather than creating a new one.
-  // This check is redundant with checks in the runtime, but it may help
-  // avoid unnecessary runtime calls.
-  if ((debugEvent && DEBUG_IS_ACTIVE) ||
-      !HAS_DEFINED_PRIVATE(promise, promiseHasHandlerSymbol)) {
-    %PromiseRejectEvent(promise, reason, debugEvent);
-  }
-  %PromiseFulfill(promise, kRejected, reason, promiseRejectReactionsSymbol)
+// Only used by async-await.js
+function RejectPromise(promise, reason) {
+  %PromiseReject(promise, reason, false);
   PromiseSet(promise, kRejected, reason);
 }
 
 // Export to bindings
 function DoRejectPromise(promise, reason) {
-  return RejectPromise(promise, reason, true);
+  %PromiseReject(promise, reason, true);
+  PromiseSet(promise, kRejected, reason);
 }
 
 // ES#sec-newpromisecapability

src/runtime/runtime-debug.cc

@@ -256,14 +256,14 @@ MaybeHandle<JSArray> Runtime::GetInternalProperties(Isolate* isolate,
     const char* status = "rejected";
     int status_val = Handle<Smi>::cast(status_obj)->value();
     switch (status_val) {
-      case +1:
+      case kPromiseFulfilled:
         status = "resolved";
         break;
-      case 0:
+      case kPromisePending:
         status = "pending";
         break;
       default:
-        DCHECK_EQ(-1, status_val);
+        DCHECK_EQ(kPromiseRejected, status_val);
     }
 
     Handle<FixedArray> result = factory->NewFixedArray(2 * 2);

src/runtime/runtime-internal.cc

@@ -601,8 +601,35 @@ void EnqueuePromiseReactionJob(Isolate* isolate, Handle<Object> value,
                                                     isolate->native_context());
   isolate->EnqueueMicrotask(info);
 }
+
+void PromiseFulfill(Isolate* isolate, Handle<JSReceiver> promise,
+                    Handle<Smi> status, Handle<Object> value,
+                    Handle<Symbol> reaction) {
+  Handle<Object> tasks = JSReceiver::GetDataProperty(promise, reaction);
+  if (!tasks->IsUndefined(isolate)) {
+    Handle<Object> deferred = JSReceiver::GetDataProperty(
+        promise, isolate->factory()->promise_deferred_reaction_symbol());
+    EnqueuePromiseReactionJob(isolate, value, tasks, deferred, status);
+  }
+}
 }  // namespace
 
+RUNTIME_FUNCTION(Runtime_PromiseReject) {
+  DCHECK(args.length() == 3);
+  HandleScope scope(isolate);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, reason, 1);
+  CONVERT_BOOLEAN_ARG_CHECKED(debug_event, 2);
+
+  PromiseRejectEvent(isolate, promise, promise, reason, debug_event);
+
+  Handle<Smi> status = handle(Smi::FromInt(kPromiseRejected), isolate);
+  Handle<Symbol> reaction =
+      isolate->factory()->promise_reject_reactions_symbol();
+  PromiseFulfill(isolate, promise, status, reason, reaction);
+  return isolate->heap()->undefined_value();
+}
+
 RUNTIME_FUNCTION(Runtime_PromiseFulfill) {
   DCHECK(args.length() == 4);
   HandleScope scope(isolate);
@@ -610,12 +637,7 @@ RUNTIME_FUNCTION(Runtime_PromiseFulfill) {
   CONVERT_ARG_HANDLE_CHECKED(Smi, status, 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 2);
   CONVERT_ARG_HANDLE_CHECKED(Symbol, reaction, 3);
-  Handle<Object> tasks = JSReceiver::GetDataProperty(promise, reaction);
-  if (!tasks->IsUndefined(isolate)) {
-    Handle<Object> deferred = JSReceiver::GetDataProperty(
-        promise, isolate->factory()->promise_deferred_reaction_symbol());
-    EnqueuePromiseReactionJob(isolate, value, tasks, deferred, status);
-  }
+  PromiseFulfill(isolate, promise, status, value, reaction);
   return isolate->heap()->undefined_value();
 }
 

src/runtime/runtime.h

@@ -304,6 +304,7 @@ namespace internal {
   F(NewSyntaxError, 2, 1)                           \
   F(NewTypeError, 2, 1)                             \
   F(OrdinaryHasInstance, 2, 1)                      \
+  F(PromiseReject, 3, 1)                            \
   F(PromiseFulfill, 4, 1)                           \
   F(PromiseRejectEvent, 3, 1)                       \
   F(PromiseRejectEventFromStack, 2, 1)              \