ladybird/Libraries/LibJS/Interpreter.cpp
Andreas Kling 363c40e3f3 LibJS: Make sure we mark everything reachable from the scope stack
This ensures that local variables survive GC.
2020-03-09 21:49:20 +01:00

116 lines
3.3 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Badge.h>
#include <LibJS/AST.h>
#include <LibJS/Interpreter.h>
#include <LibJS/Object.h>
#include <LibJS/Value.h>
namespace JS {
Interpreter::Interpreter()
: m_heap(*this)
{
m_global_object = heap().allocate<Object>();
}
Interpreter::~Interpreter()
{
}
Value Interpreter::run(const ScopeNode& scope_node)
{
enter_scope(scope_node);
Value last_value = js_undefined();
for (auto& node : scope_node.children()) {
last_value = node.execute(*this);
}
exit_scope(scope_node);
return last_value;
}
void Interpreter::enter_scope(const ScopeNode& scope_node)
{
m_scope_stack.append({ scope_node, {} });
}
void Interpreter::exit_scope(const ScopeNode& scope_node)
{
ASSERT(&m_scope_stack.last().scope_node == &scope_node);
m_scope_stack.take_last();
}
void Interpreter::do_return()
{
dbg() << "FIXME: Implement Interpreter::do_return()";
}
void Interpreter::declare_variable(String name)
{
m_scope_stack.last().variables.set(move(name), js_undefined());
}
void Interpreter::set_variable(String name, Value value)
{
for (ssize_t i = m_scope_stack.size() - 1; i >= 0; --i) {
auto& scope = m_scope_stack.at(i);
if (scope.variables.contains(name)) {
scope.variables.set(move(name), move(value));
return;
}
}
global_object().put(move(name), move(value));
}
Value Interpreter::get_variable(const String& name)
{
for (ssize_t i = m_scope_stack.size() - 1; i >= 0; --i) {
auto& scope = m_scope_stack.at(i);
auto value = scope.variables.get(name);
if (value.has_value())
return value.value();
}
return global_object().get(name);
}
void Interpreter::collect_roots(Badge<Heap>, HashTable<Cell*>& roots)
{
roots.set(m_global_object);
for (auto& scope : m_scope_stack) {
for (auto& it : scope.variables) {
if (it.value.is_object())
roots.set(it.value.as_object());
}
}
}
}