[esnext] prototype runtime implementation for async functions

src/builtins.cc

 // Copyright 2012 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/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/once.h"
@@ skipping 2480 matching lines @@
   Generate_GeneratorPrototypeResume(assembler, JSGeneratorObject::kReturn,
                                     "[Generator].prototype.return");
 }
 
 // ES6 section 25.3.1.4 Generator.prototype.throw ( exception )
 void Builtins::Generate_GeneratorPrototypeThrow(CodeStubAssembler* assembler) {
   Generate_GeneratorPrototypeResume(assembler, JSGeneratorObject::kThrow,
                                     "[Generator].prototype.throw");
 }
 
+void Builtins::Generate_AsyncFunctionNext(CodeStubAssembler* assembler) {
+  Generate_GeneratorPrototypeResume(assembler, JSGeneratorObject::kNext,
+                                    "AsyncFunctionNext");
+}
+
+// ES6 section 25.3.1.4 Generator.prototype.throw ( exception )

[neis, 2016/05/12 16:34:22]

wrong comment

[caitp (gmail), 2016/05/12 16:38:39]

Acknowledged.

+void Builtins::Generate_AsyncFunctionThrow(CodeStubAssembler* assembler) {
+  Generate_GeneratorPrototypeResume(assembler, JSGeneratorObject::kThrow,
+                                    "AsyncFunctionThrow");
+}
+

[neis, 2016/05/12 16:34:22]

Can we get rid of these functions and just use GeneratorPrototypeNext/Throw
instead? The error case in which the difference would matter can't really
happen, right?

[caitp (gmail), 2016/05/12 16:38:39]

We mark these as native, which prevents them from being included in the stack
trace --- I believe for generators, you want them to appear in the stack trace.

 // -----------------------------------------------------------------------------
 // ES6 section 26.1 The Reflect Object
 
 // ES6 section 26.1.3 Reflect.defineProperty
 BUILTIN(ReflectDefineProperty) {
   HandleScope scope(isolate);
   DCHECK_EQ(4, args.length());
   Handle<Object> target = args.at<Object>(1);
   Handle<Object> key = args.at<Object>(2);
   Handle<Object> attributes = args.at<Object>(3);
@@ skipping 1705 matching lines @@
 
 // ES6 section 25.2.1.1 GeneratorFunction (p1, p2, ... , pn, body)
 BUILTIN(GeneratorFunctionConstructor) {
   HandleScope scope(isolate);
   Handle<JSFunction> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result, CreateDynamicFunction(isolate, args, "function*"));
   return *result;
 }
 
+BUILTIN(AsyncFunctionConstructor) {
+  HandleScope scope(isolate);
+  Handle<JSFunction> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result, CreateDynamicFunction(isolate, args, "async function"));
+  return *result;
+}
 
 // ES6 section 19.4.1.1 Symbol ( [ description ] ) for the [[Call]] case.
 BUILTIN(SymbolConstructor) {
   HandleScope scope(isolate);
   Handle<Symbol> result = isolate->factory()->NewSymbol();
   Handle<Object> description = args.atOrUndefined(isolate, 1);
   if (!description->IsUndefined()) {
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, description,
                                        Object::ToString(isolate, description));
     result->set_name(*description);
@@ skipping 1242 matching lines @@
 BUILTIN_LIST_T(DEFINE_BUILTIN_ACCESSOR_T)
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8