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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Interpreter.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/Function.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/LexicalEnvironment.h>
#include <LibJS/Runtime/Value.h>
namespace JS {
LexicalEnvironment::LexicalEnvironment()
: ScopeObject(nullptr)
{
}
LexicalEnvironment::LexicalEnvironment(EnvironmentRecordType environment_record_type)
: ScopeObject(nullptr)
, m_environment_record_type(environment_record_type)
{
}
LexicalEnvironment::LexicalEnvironment(HashMap<FlyString, Variable> variables, ScopeObject* parent_scope)
: ScopeObject(parent_scope)
, m_variables(move(variables))
{
}
LexicalEnvironment::LexicalEnvironment(HashMap<FlyString, Variable> variables, ScopeObject* parent_scope, EnvironmentRecordType environment_record_type)
: ScopeObject(parent_scope)
, m_environment_record_type(environment_record_type)
, m_variables(move(variables))
{
}
LexicalEnvironment::~LexicalEnvironment()
{
}
void LexicalEnvironment::visit_edges(Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_this_value);
visitor.visit(m_home_object);
visitor.visit(m_new_target);
visitor.visit(m_current_function);
for (auto& it : m_variables)
visitor.visit(it.value.value);
}
Optional<Variable> LexicalEnvironment::get_from_scope(const FlyString& name) const
{
return m_variables.get(name);
}
void LexicalEnvironment::put_to_scope(const FlyString& name, Variable variable)
{
m_variables.set(name, variable);
}
bool LexicalEnvironment::delete_from_scope(FlyString const& name)
{
return m_variables.remove(name);
}
bool LexicalEnvironment::has_super_binding() const
{
return m_environment_record_type == EnvironmentRecordType::Function && this_binding_status() != ThisBindingStatus::Lexical && m_home_object.is_object();
}
Value LexicalEnvironment::get_super_base()
{
VERIFY(has_super_binding());
if (m_home_object.is_object())
return m_home_object.as_object().prototype();
return {};
}
bool LexicalEnvironment::has_this_binding() const
{
// More like "is_capable_of_having_a_this_binding".
switch (m_environment_record_type) {
case EnvironmentRecordType::Declarative:
case EnvironmentRecordType::Object:
return false;
case EnvironmentRecordType::Function:
return this_binding_status() != ThisBindingStatus::Lexical;
case EnvironmentRecordType::Module:
return true;
}
VERIFY_NOT_REACHED();
}
Value LexicalEnvironment::get_this_binding(GlobalObject& global_object) const
{
VERIFY(has_this_binding());
if (this_binding_status() == ThisBindingStatus::Uninitialized) {
vm().throw_exception<ReferenceError>(global_object, ErrorType::ThisHasNotBeenInitialized);
return {};
}
return m_this_value;
}
void LexicalEnvironment::bind_this_value(GlobalObject& global_object, Value this_value)
{
VERIFY(has_this_binding());
if (m_this_binding_status == ThisBindingStatus::Initialized) {
vm().throw_exception<ReferenceError>(global_object, ErrorType::ThisIsAlreadyInitialized);
return;
}
m_this_value = this_value;
m_this_binding_status = ThisBindingStatus::Initialized;
}
}
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