ladybird/Libraries/LibJS/Interpreter.h
0xtechnobabble 7aad10d984 LibJS: Fix assignment of const variable on declaration
We were previously assuming that we were reassigning a variable even
when we were not, oops, my bad. :/
2020-03-16 13:42:13 +01:00

105 lines
3.1 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.
*/
#pragma once
#include <AK/HashMap.h>
#include <AK/String.h>
#include <AK/Vector.h>
#include <LibJS/Forward.h>
#include <LibJS/Heap.h>
#include <LibJS/Value.h>
namespace JS {
enum class ScopeType {
Function,
Block,
};
struct Variable {
Value value;
DeclarationType declaration_type;
};
struct ScopeFrame {
ScopeType type;
const ScopeNode& scope_node;
HashMap<String, Variable> variables;
};
struct Argument {
String name;
Value value;
};
class Interpreter {
public:
Interpreter();
~Interpreter();
Value run(const ScopeNode&, Vector<Argument> = {}, ScopeType = ScopeType::Block);
Object& global_object() { return *m_global_object; }
const Object& global_object() const { return *m_global_object; }
Heap& heap() { return m_heap; }
void do_return();
Value get_variable(const String& name);
void set_variable(String name, Value, bool first_assignment = false);
void declare_variable(String name, DeclarationType);
void gather_roots(Badge<Heap>, HashTable<Cell*>&);
void enter_scope(const ScopeNode&, Vector<Argument>, ScopeType);
void exit_scope(const ScopeNode&);
void push_this_value(Value value) { m_this_stack.append(move(value)); }
void pop_this_value() { m_this_stack.take_last(); }
Value this_value() const
{
if (m_this_stack.is_empty())
return m_global_object;
return m_this_stack.last();
}
Object* string_prototype() { return m_string_prototype; }
Object* object_prototype() { return m_object_prototype; }
private:
Heap m_heap;
Vector<ScopeFrame> m_scope_stack;
Vector<Value> m_this_stack;
Object* m_global_object { nullptr };
Object* m_string_prototype { nullptr };
Object* m_object_prototype { nullptr };
};
}