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// 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-iterator-gen.h"
#include "src/factory-inl.h"
namespace v8 {
namespace internal {
using compiler::Node;
IteratorRecord IteratorBuiltinsAssembler::GetIterator(Node* context,
Node* object,
Label* if_exception,
Variable* exception) {
Node* method = GetProperty(context, object, factory()->iterator_symbol());
GotoIfException(method, if_exception, exception);
Callable callable = CodeFactory::Call(isolate());
Node* iterator = CallJS(callable, context, method, object);
GotoIfException(iterator, if_exception, exception);
Label get_next(this), if_notobject(this, Label::kDeferred);
GotoIf(TaggedIsSmi(iterator), &if_notobject);
Branch(IsJSReceiver(iterator), &get_next, &if_notobject);
BIND(&if_notobject);
{
Node* ret =
CallRuntime(Runtime::kThrowTypeError, context,
SmiConstant(MessageTemplate::kNotAnIterator), iterator);
GotoIfException(ret, if_exception, exception);
Unreachable();
}
BIND(&get_next);
Node* const next = GetProperty(context, iterator, factory()->next_string());
GotoIfException(next, if_exception, exception);
return IteratorRecord{TNode<JSReceiver>::UncheckedCast(iterator),
TNode<Object>::UncheckedCast(next)};
}
Node* IteratorBuiltinsAssembler::IteratorStep(
Node* context, const IteratorRecord& iterator, Label* if_done,
Node* fast_iterator_result_map, Label* if_exception, Variable* exception) {
DCHECK_NOT_NULL(if_done);
// 1. a. Let result be ? Invoke(iterator, "next", « »).
Callable callable = CodeFactory::Call(isolate());
Node* result = CallJS(callable, context, iterator.next, iterator.object);
GotoIfException(result, if_exception, exception);
// 3. If Type(result) is not Object, throw a TypeError exception.
Label if_notobject(this, Label::kDeferred), return_result(this);
GotoIf(TaggedIsSmi(result), &if_notobject);
Node* result_map = LoadMap(result);
if (fast_iterator_result_map != nullptr) {
// Fast iterator result case:
Label if_generic(this);
// 4. Return result.
GotoIfNot(WordEqual(result_map, fast_iterator_result_map), &if_generic);
// IteratorComplete
// 2. Return ToBoolean(? Get(iterResult, "done")).
Node* done = LoadObjectField(result, JSIteratorResult::kDoneOffset);
BranchIfToBooleanIsTrue(done, if_done, &return_result);
BIND(&if_generic);
}
// Generic iterator result case:
{
// 3. If Type(result) is not Object, throw a TypeError exception.
GotoIfNot(IsJSReceiverMap(result_map), &if_notobject);
// IteratorComplete
// 2. Return ToBoolean(? Get(iterResult, "done")).
Node* done = GetProperty(context, result, factory()->done_string());
GotoIfException(done, if_exception, exception);
BranchIfToBooleanIsTrue(done, if_done, &return_result);
}
BIND(&if_notobject);
{
Node* ret =
CallRuntime(Runtime::kThrowIteratorResultNotAnObject, context, result);
GotoIfException(ret, if_exception, exception);
Unreachable();
}
BIND(&return_result);
return result;
}
Node* IteratorBuiltinsAssembler::IteratorValue(Node* context, Node* result,
Node* fast_iterator_result_map,
Label* if_exception,
Variable* exception) {
CSA_ASSERT(this, IsJSReceiver(result));
Label exit(this);
VARIABLE(var_value, MachineRepresentation::kTagged);
if (fast_iterator_result_map != nullptr) {
// Fast iterator result case:
Label if_generic(this);
Node* map = LoadMap(result);
GotoIfNot(WordEqual(map, fast_iterator_result_map), &if_generic);
var_value.Bind(LoadObjectField(result, JSIteratorResult::kValueOffset));
Goto(&exit);
BIND(&if_generic);
}
// Generic iterator result case:
{
Node* value = GetProperty(context, result, factory()->value_string());
GotoIfException(value, if_exception, exception);
var_value.Bind(value);
Goto(&exit);
}
BIND(&exit);
return var_value.value();
}
void IteratorBuiltinsAssembler::IteratorCloseOnException(
Node* context, const IteratorRecord& iterator, Label* if_exception,
Variable* exception) {
// Perform ES #sec-iteratorclose when an exception occurs. This simpler
// algorithm does not include redundant steps which are never reachable from
// the spec IteratorClose algorithm.
DCHECK_NOT_NULL(if_exception);
DCHECK_NOT_NULL(exception);
CSA_ASSERT(this, IsNotTheHole(exception->value()));
CSA_ASSERT(this, IsJSReceiver(iterator.object));
// Let return be ? GetMethod(iterator, "return").
Node* method =
GetProperty(context, iterator.object, factory()->return_string());
GotoIfException(method, if_exception, exception);
// If return is undefined, return Completion(completion).
GotoIf(Word32Or(IsUndefined(method), IsNull(method)), if_exception);
{
// Let innerResult be Call(return, iterator, « »).
// If an exception occurs, the original exception remains bound
Node* inner_result =
CallJS(CodeFactory::Call(isolate()), context, method, iterator.object);
GotoIfException(inner_result, if_exception, nullptr);
// (If completion.[[Type]] is throw) return Completion(completion).
Goto(if_exception);
}
}
void IteratorBuiltinsAssembler::IteratorCloseOnException(
Node* context, const IteratorRecord& iterator, Variable* exception) {
Label rethrow(this, Label::kDeferred);
IteratorCloseOnException(context, iterator, &rethrow, exception);
BIND(&rethrow);
CallRuntime(Runtime::kReThrow, context, exception->value());
Unreachable();
}
} // namespace internal
} // namespace v8
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