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// 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/builtins/builtins.h"
#include "src/builtins/builtins-utils.h"
#include "src/code-factory.h"
namespace v8 {
namespace internal {
namespace {
void Generate_GeneratorPrototypeResume(
CodeStubAssembler* assembler, JSGeneratorObject::ResumeMode resume_mode,
char const* const method_name) {
typedef CodeStubAssembler::Label Label;
typedef compiler::Node Node;
Node* receiver = assembler->Parameter(0);
Node* value = assembler->Parameter(1);
Node* context = assembler->Parameter(4);
Node* closed =
assembler->SmiConstant(Smi::FromInt(JSGeneratorObject::kGeneratorClosed));
// Check if the {receiver} is actually a JSGeneratorObject.
Label if_receiverisincompatible(assembler, Label::kDeferred);
assembler->GotoIf(assembler->TaggedIsSmi(receiver),
&if_receiverisincompatible);
Node* receiver_instance_type = assembler->LoadInstanceType(receiver);
assembler->GotoUnless(assembler->Word32Equal(
receiver_instance_type,
assembler->Int32Constant(JS_GENERATOR_OBJECT_TYPE)),
&if_receiverisincompatible);
// Check if the {receiver} is running or already closed.
Node* receiver_continuation = assembler->LoadObjectField(
receiver, JSGeneratorObject::kContinuationOffset);
Label if_receiverisclosed(assembler, Label::kDeferred),
if_receiverisrunning(assembler, Label::kDeferred);
assembler->GotoIf(assembler->SmiEqual(receiver_continuation, closed),
&if_receiverisclosed);
DCHECK_LT(JSGeneratorObject::kGeneratorExecuting,
JSGeneratorObject::kGeneratorClosed);
assembler->GotoIf(assembler->SmiLessThan(receiver_continuation, closed),
&if_receiverisrunning);
// Resume the {receiver} using our trampoline.
Node* result = assembler->CallStub(
CodeFactory::ResumeGenerator(assembler->isolate()), context, value,
receiver, assembler->SmiConstant(Smi::FromInt(resume_mode)));
assembler->Return(result);
assembler->Bind(&if_receiverisincompatible);
{
// The {receiver} is not a valid JSGeneratorObject.
Node* result = assembler->CallRuntime(
Runtime::kThrowIncompatibleMethodReceiver, context,
assembler->HeapConstant(assembler->factory()->NewStringFromAsciiChecked(
method_name, TENURED)),
receiver);
assembler->Return(result); // Never reached.
}
assembler->Bind(&if_receiverisclosed);
{
// The {receiver} is closed already.
Node* result = nullptr;
switch (resume_mode) {
case JSGeneratorObject::kNext:
result = assembler->CallRuntime(Runtime::kCreateIterResultObject,
context, assembler->UndefinedConstant(),
assembler->BooleanConstant(true));
break;
case JSGeneratorObject::kReturn:
result =
assembler->CallRuntime(Runtime::kCreateIterResultObject, context,
value, assembler->BooleanConstant(true));
break;
case JSGeneratorObject::kThrow:
result = assembler->CallRuntime(Runtime::kThrow, context, value);
break;
}
assembler->Return(result);
}
assembler->Bind(&if_receiverisrunning);
{
Node* result =
assembler->CallRuntime(Runtime::kThrowGeneratorRunning, context);
assembler->Return(result); // Never reached.
}
}
} // anonymous namespace
// ES6 section 25.3.1.2 Generator.prototype.next ( value )
void Builtins::Generate_GeneratorPrototypeNext(CodeStubAssembler* assembler) {
Generate_GeneratorPrototypeResume(assembler, JSGeneratorObject::kNext,
"[Generator].prototype.next");
}
// ES6 section 25.3.1.3 Generator.prototype.return ( value )
void Builtins::Generate_GeneratorPrototypeReturn(CodeStubAssembler* assembler) {
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");
}
} // namespace internal
} // namespace v8
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