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/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Interpreter.h>
#include <LibJS/Runtime/Completion.h>
#include <LibJS/Runtime/FunctionEnvironment.h>
#include <LibJS/Runtime/GlobalObject.h>
namespace JS {
FunctionEnvironment::FunctionEnvironment(Environment* parent_environment)
: DeclarativeEnvironment(parent_environment)
{
}
void FunctionEnvironment::visit_edges(Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_this_value);
visitor.visit(m_new_target);
visitor.visit(m_function_object);
}
// 9.1.1.3.5 GetSuperBase ( ), https://tc39.es/ecma262/#sec-getsuperbase
ThrowCompletionOr<Value> FunctionEnvironment::get_super_base() const
{
VERIFY(m_function_object);
// 1. Let home be envRec.[[FunctionObject]].[[HomeObject]].
auto home_object = m_function_object->home_object();
// 2. If home is undefined, return undefined.
if (!home_object)
return js_undefined();
// 3. Assert: Type(home) is Object.
// 4. Return ? home.[[GetPrototypeOf]]().
return TRY(home_object->internal_get_prototype_of());
}
// 9.1.1.3.2 HasThisBinding ( ), https://tc39.es/ecma262/#sec-function-environment-records-hasthisbinding
bool FunctionEnvironment::has_this_binding() const
{
if (this_binding_status() == ThisBindingStatus::Lexical)
return false;
return true;
}
// 9.1.1.3.3 HasSuperBinding ( ), https://tc39.es/ecma262/#sec-function-environment-records-hassuperbinding
bool FunctionEnvironment::has_super_binding() const
{
if (this_binding_status() == ThisBindingStatus::Lexical)
return false;
if (!function_object().home_object())
return false;
return true;
}
// 9.1.1.3.4 GetThisBinding ( ), https://tc39.es/ecma262/#sec-function-environment-records-getthisbinding
ThrowCompletionOr<Value> FunctionEnvironment::get_this_binding(GlobalObject& global_object) const
{
// 1. Assert: envRec.[[ThisBindingStatus]] is not lexical.
VERIFY(m_this_binding_status != ThisBindingStatus::Lexical);
// 2. If envRec.[[ThisBindingStatus]] is uninitialized, throw a ReferenceError exception.
if (m_this_binding_status == ThisBindingStatus::Uninitialized)
return vm().throw_completion<ReferenceError>(global_object, ErrorType::ThisHasNotBeenInitialized);
// 3. Return envRec.[[ThisValue]].
return m_this_value;
}
// 9.1.1.3.1 BindThisValue ( V ), https://tc39.es/ecma262/#sec-bindthisvalue
ThrowCompletionOr<Value> FunctionEnvironment::bind_this_value(GlobalObject& global_object, Value this_value)
{
VERIFY(!this_value.is_empty());
// 1. Assert: envRec.[[ThisBindingStatus]] is not lexical.
VERIFY(m_this_binding_status != ThisBindingStatus::Lexical);
// 2. If envRec.[[ThisBindingStatus]] is initialized, throw a ReferenceError exception.
if (m_this_binding_status == ThisBindingStatus::Initialized)
return vm().throw_completion<ReferenceError>(global_object, ErrorType::ThisIsAlreadyInitialized);
// 3. Set envRec.[[ThisValue]] to V.
m_this_value = this_value;
// 4. Set envRec.[[ThisBindingStatus]] to initialized.
m_this_binding_status = ThisBindingStatus::Initialized;
// 5. Return V.
return this_value;
}
}
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