[promises] Remove one runtime call to create_resolving_functions

src/promise-utils.cc

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/promise-utils.h"
+
+#include "src/factory.h"
+#include "src/isolate.h"
+#include "src/objects-inl.h"
+
+namespace v8 {
+namespace internal {
+
+enum PromiseResolvingFunctionContextSlot {
+  kAlreadyVisitedSlot = Context::MIN_CONTEXT_SLOTS,
+  kPromiseSlot,
+  kDebugEventSlot,
+  kPromiseContextLength,
+};
+
+JSObject* PromiseUtils::GetPromise(Handle<Context> context) {
+  return JSObject::cast(context->get(kPromiseSlot));
+}
+
+Object* PromiseUtils::GetDebugEvent(Handle<Context> context) {
+  return context->get(kDebugEventSlot);
+}
+
+bool PromiseUtils::HasAlreadyVisited(Handle<Context> context) {
+  return Smi::cast(context->get(kAlreadyVisitedSlot))->value() != 0;
+}
+
+void PromiseUtils::SetAlreadyVisited(Handle<Context> context) {
+  context->set(kAlreadyVisitedSlot, Smi::FromInt(1));
+}
+
+void PromiseUtils::CreateResolvingFunctions(Isolate* isolate,
+                                            Handle<JSObject> promise,
+                                            Handle<Object> debug_event,
+                                            Handle<JSFunction>* resolve,
+                                            Handle<JSFunction>* reject) {
+  DCHECK(debug_event->IsTrue(isolate) || debug_event->IsFalse(isolate));
+  Handle<Context> context =
+      isolate->factory()->NewPromiseResolvingFunctionContext(
+          kPromiseContextLength);
+  context->set_native_context(*isolate->native_context());
+  context->set(kAlreadyVisitedSlot, Smi::kZero);
+  context->set(kPromiseSlot, *promise);
+  context->set(kDebugEventSlot, *debug_event);
+
+  Handle<SharedFunctionInfo> resolve_shared_fun(
+      isolate->native_context()->promise_resolve_shared_fun(), isolate);
+  Handle<JSFunction> resolve_fun =
+      isolate->factory()->NewFunctionFromSharedFunctionInfo(
+          isolate->sloppy_function_without_prototype_map(), resolve_shared_fun,
+          isolate->native_context(), TENURED);
+
+  Handle<SharedFunctionInfo> reject_shared_fun(
+      isolate->native_context()->promise_reject_shared_fun(), isolate);
+  Handle<JSFunction> reject_fun =
+      isolate->factory()->NewFunctionFromSharedFunctionInfo(
+          isolate->sloppy_function_without_prototype_map(), reject_shared_fun,
+          isolate->native_context(), TENURED);
+
+  resolve_fun->set_context(*context);
+  reject_fun->set_context(*context);
+
+  *resolve = resolve_fun;
+  *reject = reject_fun;
+}
+
+}  // namespace internal
+}  // namespace v8