Index: src/builtins/builtins-async-iterator.cc |
diff --git a/src/builtins/builtins-async-iterator.cc b/src/builtins/builtins-async-iterator.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..baa2982e9f5fa3200b9f441896ac08e545db56a0 |
--- /dev/null |
+++ b/src/builtins/builtins-async-iterator.cc |
@@ -0,0 +1,440 @@ |
+// Copyright 2017 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/builtins-async.h" |
+#include "src/builtins/builtins-utils.h" |
+#include "src/builtins/builtins.h" |
+#include "src/code-factory.h" |
+#include "src/code-stub-assembler.h" |
+#include "src/frames-inl.h" |
+ |
+namespace v8 { |
+namespace internal { |
+ |
+// Describe fields of Context associated with the AsyncIterator unwrap closure. |
+class ValueUnwrapContext { |
Benedikt Meurer
2017/02/16 05:16:38
Can we wrap these helpers into an anonymous namesp
caitp
2017/02/16 14:25:11
Done.
|
+ public: |
+ enum Fields { kDoneSlot = Context::MIN_CONTEXT_SLOTS, kLength }; |
+}; |
+ |
+class AsyncFromSyncBuiltinsAssembler : public AsyncBuiltinsAssembler { |
+ public: |
+ explicit AsyncFromSyncBuiltinsAssembler(CodeAssemblerState* state) |
+ : AsyncBuiltinsAssembler(state) {} |
+ |
+ std::pair<Node*, Node*> LoadIteratorResult(Node* const context, |
+ Node* const native_context, |
+ Node* const iter_result, |
+ Label* if_exception, |
+ Variable* var_exception); |
+ |
+ Node* CreateUnwrapClosure(Node* native_context, Node* done); |
+}; |
+ |
+std::pair<Node*, Node*> AsyncFromSyncBuiltinsAssembler::LoadIteratorResult( |
+ Node* const context, Node* const native_context, Node* const iter_result, |
+ Label* if_exception, Variable* var_exception) { |
+ Label if_fastpath(this), if_slowpath(this), merge(this), to_boolean(this), |
+ done(this); |
+ GotoIf(TaggedIsSmi(iter_result), &if_slowpath); |
+ |
+ Node* const fast_iter_result_map = |
+ LoadContextElement(native_context, Context::ITERATOR_RESULT_MAP_INDEX); |
+ Node* const iter_result_map = LoadMap(iter_result); |
+ |
+ Variable var_value(this, MachineRepresentation::kTagged); |
+ Variable var_done(this, MachineRepresentation::kTagged); |
+ Branch(WordEqual(iter_result_map, fast_iter_result_map), &if_fastpath, |
+ &if_slowpath); |
+ |
+ Bind(&if_fastpath); |
+ { |
+ var_value.Bind( |
+ LoadObjectField(iter_result, JSIteratorResult::kValueOffset)); |
+ var_done.Bind(LoadObjectField(iter_result, JSIteratorResult::kDoneOffset)); |
+ Goto(&merge); |
+ } |
+ |
+ Bind(&if_slowpath); |
+ { |
+ // Let nextValue be IteratorValue(nextResult). |
+ // IfAbruptRejectPromise(nextValue, promiseCapability). |
+ Node* const value = |
+ CallStub(CodeFactory::GetProperty(isolate()), context, iter_result, |
+ HeapConstant(factory()->value_string())); |
+ GotoIfException(value, if_exception, var_exception); |
+ |
+ // Let nextDone be IteratorComplete(nextResult). |
+ // IfAbruptRejectPromise(nextDone, promiseCapability). |
+ Node* const done = |
+ CallStub(CodeFactory::GetProperty(isolate()), context, iter_result, |
+ HeapConstant(factory()->done_string())); |
+ GotoIfException(done, if_exception, var_exception); |
+ |
+ var_value.Bind(value); |
+ var_done.Bind(done); |
+ Goto(&merge); |
+ } |
+ |
+ Bind(&merge); |
+ // Ensure `iterResult.done` is a Boolean. |
+ GotoIf(TaggedIsSmi(var_done.value()), &to_boolean); |
+ Branch(IsBooleanMap(LoadMap(var_done.value())), &done, &to_boolean); |
+ |
+ Bind(&to_boolean); |
+ { |
+ Node* const result = |
+ CallStub(CodeFactory::ToBoolean(isolate()), context, var_done.value()); |
+ var_done.Bind(result); |
+ Goto(&done); |
+ } |
+ |
+ Bind(&done); |
+ return std::make_pair(var_value.value(), var_done.value()); |
+} |
+ |
+Node* AsyncFromSyncBuiltinsAssembler::CreateUnwrapClosure(Node* native_context, |
+ Node* done) { |
+ Node* const map = LoadContextElement( |
+ native_context, Context::STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX); |
+ Node* const on_resolve_shared = LoadContextElement( |
+ native_context, Context::ASYNC_ITERATOR_VALUE_UNWRAP_SHARED_FUN); |
+ CSA_ASSERT(this, |
+ HasInstanceType(on_resolve_shared, SHARED_FUNCTION_INFO_TYPE)); |
+ Node* const closure_context = |
+ AllocateAsyncIteratorValueUnwrapContext(native_context, done); |
+ return AllocateFunctionWithMapAndContext(map, on_resolve_shared, |
+ closure_context); |
+} |
+ |
+// https://tc39.github.io/proposal-async-iteration/ |
+// Section #sec-%asyncfromsynciteratorprototype%.next |
+TF_BUILTIN(AsyncFromSyncIteratorPrototypeNext, AsyncFromSyncBuiltinsAssembler) { |
+ const char* method_name = "[Async-from-Sync Iterator].prototype.next"; |
+ |
+ Node* const iterator = Parameter(0); |
+ Node* const parameter = Parameter(1); |
+ Node* const context = Parameter(4); |
+ |
+ Node* const native_context = LoadNativeContext(context); |
+ Node* const promise = AllocateAndInitJSPromise(context); |
+ |
+ Variable var_parent(this, MachineRepresentation::kTagged); |
+ Variable var_exception(this, MachineRepresentation::kTagged); |
+ var_exception.Bind(UndefinedConstant()); |
+ Label reject_promise(this, Label::kDeferred); |
+ Label if_receiverisincompatible(this, Label::kDeferred); |
+ |
+ GotoIf(TaggedIsSmi(iterator), &if_receiverisincompatible); |
+ GotoUnless(HasInstanceType(iterator, JS_ASYNC_FROM_SYNC_ITERATOR_TYPE), |
+ &if_receiverisincompatible); |
+ |
+ Node* const sync_iterator = |
+ LoadObjectField(iterator, JSAsyncFromSyncIterator::kSyncIteratorOffset); |
+ |
+ // Let nextResult be IteratorNext(syncIterator, value). |
+ // IfAbruptRejectPromise(nextResult, promiseCapability). |
+ Node* next_method = |
+ CallStub(CodeFactory::GetProperty(isolate()), context, sync_iterator, |
+ HeapConstant(factory()->next_string())); |
+ Node* const iter_result = CallJS(CodeFactory::Call(isolate()), context, |
+ next_method, sync_iterator, parameter); |
+ GotoIfException(iter_result, &reject_promise, &var_exception); |
+ |
+ Node* value; |
+ Node* done; |
+ std::tie(value, done) = LoadIteratorResult( |
+ context, native_context, iter_result, &reject_promise, &var_exception); |
+ |
+ // Let valueWrapperCapability be ! NewPromiseCapability(%Promise%). |
+ Node* const wrapper = AllocateAndInitJSPromise(context); |
+ |
+ // Perform ! Call(valueWrapperCapability.[[Resolve]], undefined, |
+ // « nextValue »). |
+ InternalResolvePromise(context, wrapper, value); |
+ |
+ // Let onFulfilled be a new built-in function object as defined in |
+ // Async Iterator Value Unwrap Functions. |
+ // Set onFulfilled.[[Done]] to nextDone. |
+ Node* const on_resolve = CreateUnwrapClosure(native_context, done); |
+ |
+ // Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]], |
+ // onFulfilled, undefined, promiseCapability). |
+ Node* const undefined = UndefinedConstant(); |
+ InternalPerformPromiseThen(context, wrapper, on_resolve, undefined, promise, |
+ undefined, undefined); |
+ |
+ // TODO(caitp): Use TailCallStub once it's possible for a JS-linkage builtin |
Benedikt Meurer
2017/02/16 05:16:38
Is the TailCall required by the specification? Bec
caitp
2017/02/16 14:25:11
Not required by the spec. My reasoning is, it shou
|
+ // to tailcall a CS-linkage builtin when an arguments adaptor frame is used. |
+ Return(promise); |
+ |
+ Bind(&if_receiverisincompatible); |
+ { |
+ // If Type(O) is not Object, or if O does not have a [[SyncIterator]] |
+ // internal slot, then |
+ |
+ // Let badIteratorError be a new TypeError exception. |
+ Node* const error = |
+ MakeTypeError(MessageTemplate::kIncompatibleMethodReceiver, context, |
+ CStringConstant(method_name), iterator); |
+ |
+ // Perform ! Call(promiseCapability.[[Reject]], undefined, |
+ // « badIteratorError »). |
+ var_exception.Bind(error); |
+ Goto(&reject_promise); |
+ } |
+ |
+ Bind(&reject_promise); |
+ { |
+ Node* const promise = AllocateAndInitJSPromise(context); |
+ Node* const exception = var_exception.value(); |
+ InternalPromiseReject(context, promise, exception, TrueConstant()); |
+ |
+ // Return promiseCapability.[[Promise]]. |
+ Return(promise); |
+ } |
+} |
+ |
+// https://tc39.github.io/proposal-async-iteration/ |
+// Section #sec-%asyncfromsynciteratorprototype%.return |
+TF_BUILTIN(AsyncFromSyncIteratorPrototypeReturn, |
+ AsyncFromSyncBuiltinsAssembler) { |
+ const char* method_name = "[Async-from-Sync Iterator].prototype.return"; |
+ |
+ Node* const iterator = Parameter(0); |
+ Node* const parameter = Parameter(1); |
+ Node* const context = Parameter(4); |
+ |
+ Node* const native_context = LoadNativeContext(context); |
+ Node* const promise = AllocateAndInitJSPromise(context); |
+ |
+ Variable var_exception(this, MachineRepresentation::kTagged); |
+ var_exception.Bind(UndefinedConstant()); |
+ Label reject_promise(this, Label::kDeferred); |
+ Label if_receiverisincompatible(this, Label::kDeferred); |
+ |
+ GotoIf(TaggedIsSmi(iterator), &if_receiverisincompatible); |
+ GotoUnless(HasInstanceType(iterator, JS_ASYNC_FROM_SYNC_ITERATOR_TYPE), |
+ &if_receiverisincompatible); |
+ |
+ Node* const sync_iterator = |
+ LoadObjectField(iterator, JSAsyncFromSyncIterator::kSyncIteratorOffset); |
+ |
+ // Let return be GetMethod(syncIterator, "return"). |
+ // IfAbruptRejectPromise(return, promiseCapability). |
+ Node* const return_method = |
+ CallStub(CodeFactory::GetProperty(isolate()), context, sync_iterator, |
+ HeapConstant(factory()->return_string())); |
+ GotoIfException(return_method, &reject_promise, &var_exception); |
+ |
+ Variable var_value(this, MachineRepresentation::kTagged); |
+ Variable var_done(this, MachineRepresentation::kTagged); |
+ |
+ Label if_isundefined(this), if_isnotundefined(this), resolve_promise(this); |
+ |
+ Branch(IsUndefined(return_method), &if_isundefined, &if_isnotundefined); |
+ Bind(&if_isundefined); |
+ { |
+ // If return is undefined, then |
+ // Let iterResult be ! CreateIterResultObject(value, true) |
+ Node* const iter_result = |
+ CallStub(CodeFactory::CreateIterResultObject(isolate()), context, |
+ parameter, TrueConstant()); |
+ |
+ // Perform ! Call(promiseCapability.[[Resolve]], undefined, « iterResult »). |
+ // IfAbruptRejectPromise(nextDone, promiseCapability). |
+ // Return promiseCapability.[[Promise]]. |
+ PromiseFulfill(context, promise, iter_result, v8::Promise::kFulfilled); |
+ Return(promise); |
+ } |
+ |
+ Bind(&if_isnotundefined); |
+ { |
+ // Let returnResult be Call(return, syncIterator, « value »). |
+ Node* const iter_result = CallJS(CodeFactory::Call(isolate()), context, |
+ return_method, sync_iterator, parameter); |
+ // IfAbruptRejectPromise(returnResult, promiseCapability). |
+ GotoIfException(iter_result, &reject_promise, &var_exception); |
+ |
+ Node* value; |
+ Node* done; |
+ std::tie(value, done) = LoadIteratorResult( |
+ context, native_context, iter_result, &reject_promise, &var_exception); |
+ |
+ var_value.Bind(value); |
+ var_done.Bind(done); |
+ Goto(&resolve_promise); |
+ } |
+ |
+ Bind(&resolve_promise); |
+ { |
+ // Let valueWrapperCapability be ! NewPromiseCapability(%Promise%). |
+ Node* const wrapper = AllocateAndInitJSPromise(context); |
+ Node* const value = var_value.value(); |
+ Node* const done = var_done.value(); |
+ |
+ // Perform ! Call(valueWrapperCapability.[[Resolve]], undefined, |
+ // « nextValue »). |
+ InternalResolvePromise(context, wrapper, value); |
+ |
+ // Let onFulfilled be a new built-in function object as defined in |
+ // Async Iterator Value Unwrap Functions. |
+ // Set onFulfilled.[[Done]] to nextDone. |
+ Node* const on_resolve = CreateUnwrapClosure(native_context, done); |
+ |
+ // Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]], |
+ // onFulfilled, undefined, promiseCapability). |
+ Node* const undefined = UndefinedConstant(); |
+ InternalPerformPromiseThen(context, wrapper, on_resolve, undefined, promise, |
+ undefined, undefined); |
+ Return(promise); |
+ } |
+ |
+ Bind(&if_receiverisincompatible); |
+ { |
+ // If Type(O) is not Object, or if O does not have a [[SyncIterator]] |
+ // internal slot, then |
+ |
+ // Let badIteratorError be a new TypeError exception. |
+ Node* const error = |
+ MakeTypeError(MessageTemplate::kIncompatibleMethodReceiver, context, |
+ CStringConstant(method_name), iterator); |
+ |
+ // Perform ! Call(promiseCapability.[[Reject]], undefined, |
+ // « badIteratorError »). |
+ var_exception.Bind(error); |
+ Goto(&reject_promise); |
+ } |
+ |
+ Bind(&reject_promise); |
+ { |
+ Node* const exception = var_exception.value(); |
+ InternalPromiseReject(context, promise, exception, TrueConstant()); |
+ |
+ // Return promiseCapability.[[Promise]]. |
+ Return(promise); |
+ } |
+} |
+ |
+// https://tc39.github.io/proposal-async-iteration/ |
+// Section #sec-%asyncfromsynciteratorprototype%.throw |
+TF_BUILTIN(AsyncFromSyncIteratorPrototypeThrow, |
+ AsyncFromSyncBuiltinsAssembler) { |
+ const char* method_name = "[Async-from-Sync Iterator].prototype.throw"; |
+ |
+ Node* const iterator = Parameter(0); |
+ Node* const parameter = Parameter(1); |
+ Node* const context = Parameter(4); |
+ |
+ Node* const native_context = LoadNativeContext(context); |
+ Node* const promise = AllocateAndInitJSPromise(context); |
+ |
+ Variable var_exception(this, MachineRepresentation::kTagged); |
+ var_exception.Bind(parameter); |
+ Variable var_value(this, MachineRepresentation::kTagged); |
+ Variable var_done(this, MachineRepresentation::kTagged); |
+ Label reject_promise(this, Label::kDeferred); |
+ Label if_receiverisincompatible(this, Label::kDeferred); |
+ |
+ GotoIf(TaggedIsSmi(iterator), &if_receiverisincompatible); |
+ GotoUnless(HasInstanceType(iterator, JS_ASYNC_FROM_SYNC_ITERATOR_TYPE), |
+ &if_receiverisincompatible); |
+ |
+ Node* const sync_iterator = |
+ LoadObjectField(iterator, JSAsyncFromSyncIterator::kSyncIteratorOffset); |
+ |
+ // Let throw be GetMethod(syncIterator, "throw"). |
+ // IfAbruptRejectPromise(nextResult, promiseCapability). |
+ // IfAbruptRejectPromise(throw, promiseCapability). |
+ Node* const throw_method = |
+ CallStub(CodeFactory::GetProperty(isolate()), context, sync_iterator, |
Benedikt Meurer
2017/02/16 05:16:38
How about introducing a helper method on the CSA f
caitp
2017/02/16 14:25:11
Done.
|
+ HeapConstant(factory()->throw_string())); |
+ GotoIfException(throw_method, &reject_promise, &var_exception); |
+ |
+ Label if_isnotundefined(this), resolve_promise(this); |
+ |
+ // If throw is undefined, then |
+ // Perform ! Call(promiseCapability.[[Reject]], undefined, « value »). |
+ Branch(IsUndefined(throw_method), &reject_promise, &if_isnotundefined); |
+ |
+ Bind(&if_isnotundefined); |
+ { |
+ // Let throwResult be Call(throw, syncIterator, « value »). |
+ Node* const iter_result = CallJS(CodeFactory::Call(isolate()), context, |
+ throw_method, sync_iterator, parameter); |
+ GotoIfException(iter_result, &reject_promise, &var_exception); |
+ |
+ Node* value; |
+ Node* done; |
+ std::tie(value, done) = LoadIteratorResult( |
+ context, native_context, iter_result, &reject_promise, &var_exception); |
+ |
+ // Let valueWrapperCapability be ! NewPromiseCapability(%Promise%). |
+ Node* const wrapper = AllocateAndInitJSPromise(context); |
+ |
+ // Perform ! Call(valueWrapperCapability.[[Resolve]], undefined, « |
+ // throwValue »). |
+ InternalResolvePromise(context, wrapper, value); |
+ |
+ // Let onFulfilled be a new built-in function object as defined in |
+ // Async Iterator Value Unwrap Functions. |
+ // Set onFulfilled.[[Done]] to throwDone. |
+ Node* const on_resolve = CreateUnwrapClosure(native_context, done); |
+ |
+ // Perform ! PerformPromiseThen(valueWrapperCapability.[[Promise]], |
+ // onFulfilled, undefined, promiseCapability). |
+ Node* const undefined = UndefinedConstant(); |
+ InternalPerformPromiseThen(context, wrapper, on_resolve, undefined, promise, |
+ undefined, undefined); |
+ Return(promise); |
+ } |
+ |
+ Bind(&if_receiverisincompatible); |
+ { |
+ // If Type(O) is not Object, or if O does not have a [[SyncIterator]] |
+ // internal slot, then |
+ |
+ // Let badIteratorError be a new TypeError exception. |
+ Node* const error = |
+ MakeTypeError(MessageTemplate::kIncompatibleMethodReceiver, context, |
+ CStringConstant(method_name), iterator); |
+ |
+ // Perform ! Call(promiseCapability.[[Reject]], undefined, |
+ // « badIteratorError »). |
+ var_exception.Bind(error); |
+ Goto(&reject_promise); |
+ } |
+ |
+ Bind(&reject_promise); |
+ { |
+ Node* const exception = var_exception.value(); |
+ InternalPromiseReject(context, promise, exception, TrueConstant()); |
+ |
+ // Return promiseCapability.[[Promise]]. |
+ Return(promise); |
+ } |
+} |
+ |
+TF_BUILTIN(AsyncIteratorValueUnwrap, AsyncBuiltinsAssembler) { |
+ Node* const value = Parameter(1); |
+ Node* const context = Parameter(4); |
+ |
+ Node* const done = LoadContextElement(context, ValueUnwrapContext::kDoneSlot); |
+ Node* const unwrapped_value = CallStub( |
+ CodeFactory::CreateIterResultObject(isolate()), context, value, done); |
+ |
+ Return(unwrapped_value); |
+} |
+ |
+Node* AsyncBuiltinsAssembler::AllocateAsyncIteratorValueUnwrapContext( |
+ Node* native_context, Node* done) { |
+ Node* const context = |
+ CreatePromiseContext(native_context, ValueUnwrapContext::kLength); |
+ StoreContextElementNoWriteBarrier(context, ValueUnwrapContext::kDoneSlot, |
+ done); |
+ return context; |
+} |
+ |
+} // namespace internal |
+} // namespace v8 |