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// Copyright 2020 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.
namespace function {
extern macro OrdinaryHasInstance(Context, Object, Object): JSAny;
// ES6 section 19.2.3.6 Function.prototype[@@hasInstance]
javascript builtin FunctionPrototypeHasInstance(
js-implicit context: NativeContext, receiver: JSAny)(value: JSAny): JSAny {
return OrdinaryHasInstance(context, receiver, value);
}
extern transitioning builtin
FunctionPrototypeBind(implicit context: Context)(
JSFunction, JSAny, int32): JSAny;
const kLengthDescriptorIndex:
constexpr int32 generates 'JSFunction::kLengthDescriptorIndex';
const kNameDescriptorIndex:
constexpr int32 generates 'JSFunction::kNameDescriptorIndex';
const kMinDescriptorsForFastBind:
constexpr int31 generates 'JSFunction::kMinDescriptorsForFastBind';
macro CheckAccessor(implicit context: Context)(
array: DescriptorArray, index: constexpr int32, name: Name) labels Slow {
const descriptor: DescriptorEntry = array.descriptors[index];
const key: Name|Undefined = descriptor.key;
if (!TaggedEqual(key, name)) goto Slow;
// The descriptor value must be an AccessorInfo.
Cast<AccessorInfo>(descriptor.value) otherwise goto Slow;
}
// ES6 section 19.2.3.2 Function.prototype.bind
transitioning javascript builtin
FastFunctionPrototypeBind(
js-implicit context: NativeContext, receiver: JSAny, newTarget: JSAny,
target: JSFunction)(...arguments): JSAny {
const argc: intptr = arguments.length;
try {
typeswitch (receiver) {
case (fn: JSFunction|JSBoundFunction): {
// Disallow binding of slow-mode functions. We need to figure out
// whether the length and name property are in the original state.
Comment('Disallow binding of slow-mode functions');
if (IsDictionaryMap(fn.map)) goto Slow;
// Check whether the length and name properties are still present as
// AccessorInfo objects. If so, their value can be recomputed even if
// the actual value on the object changes.
if (fn.map.bit_field3.number_of_own_descriptors <
kMinDescriptorsForFastBind) {
goto Slow;
}
const descriptors: DescriptorArray = fn.map.instance_descriptors;
CheckAccessor(
descriptors, kLengthDescriptorIndex, LengthStringConstant())
otherwise Slow;
CheckAccessor(descriptors, kNameDescriptorIndex, NameStringConstant())
otherwise Slow;
// Choose the right bound function map based on whether the target is
// constructable.
const boundFunctionMap: Map = UnsafeCast<Map>(
IsConstructor(fn) ?
context[NativeContextSlot::
BOUND_FUNCTION_WITH_CONSTRUCTOR_MAP_INDEX] :
context[NativeContextSlot::
BOUND_FUNCTION_WITHOUT_CONSTRUCTOR_MAP_INDEX]);
// Verify that prototype matches that of the target bound function.
if (fn.map.prototype != boundFunctionMap.prototype) goto Slow;
// Allocate the arguments array.
const argumentsArray = arguments.length <= 1 ?
kEmptyFixedArray :
NewFixedArray(
arguments.length - 1, ArgumentsIterator{arguments, current: 1});
const boundReceiver: JSAny = arguments[0];
const result = new JSBoundFunction{
map: boundFunctionMap,
properties_or_hash: kEmptyFixedArray,
elements: kEmptyFixedArray,
bound_target_function: fn,
bound_this: boundReceiver,
bound_arguments: argumentsArray
};
return result;
}
case (JSAny): {
goto Slow;
}
}
} label Slow {
tail FunctionPrototypeBind(
LoadTargetFromFrame(), newTarget, Convert<int32>(argc));
}
}
} // namespace function
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