LibJS: Add Interpreter::create<GlobalObjectType>()

Force Interpreter construction to go via a create() helper that takes
the global object type as a template parameter.

Libraries/LibJS/Interpreter.h

@@ -68,16 +68,16 @@ struct Argument {
 
 class Interpreter {
 public:
-    Interpreter();
-    ~Interpreter();
-
-    template<typename T, typename... Args>
-    void initialize_global_object(Args&&... args)
+    template<typename GlobalObjectType, typename... Args>
+    static NonnullOwnPtr<Interpreter> create(Args&&... args)
     {
-        ASSERT(!m_global_object);
-        m_global_object = heap().allocate<T>(forward<Args>(args)...);
+        auto interpreter = adopt_own(*new Interpreter);
+        interpreter->m_global_object = interpreter->heap().allocate<GlobalObjectType>(forward<Args>(args)...);
+        return interpreter;
     }
 
+    ~Interpreter();
+
     Value run(const Statement&, Vector<Argument> = {}, ScopeType = ScopeType::Block);
 
     Object& global_object() { return *m_global_object; }
@@ -136,6 +136,8 @@ public:
     }
 
 private:
+    Interpreter();
+
     Heap m_heap;
 
     Vector<ScopeFrame> m_scope_stack;

Libraries/LibWeb/DOM/Document.cpp

@@ -360,10 +360,8 @@ Color Document::visited_link_color() const
 
 JS::Interpreter& Document::interpreter()
 {
-    if (!m_interpreter) {
-        m_interpreter = make<JS::Interpreter>();
-        m_interpreter->initialize_global_object<Bindings::WindowObject>(*m_window);
-    }
+    if (!m_interpreter)
+        m_interpreter = JS::Interpreter::create<Bindings::WindowObject>(*m_window);
     return *m_interpreter;
 }
 

Userland/js.cpp

@@ -198,16 +198,15 @@ int main(int argc, char** argv)
     args_parser.add_positional_argument(script_path, "Path to script file", "script", Core::ArgsParser::Required::No);
     args_parser.parse(argc, argv);
 
-    JS::Interpreter interpreter;
-    interpreter.initialize_global_object<JS::GlobalObject>();
-    interpreter.heap().set_should_collect_on_every_allocation(gc_on_every_allocation);
+    auto interpreter = JS::Interpreter::create<JS::GlobalObject>();
+    interpreter->heap().set_should_collect_on_every_allocation(gc_on_every_allocation);
 
-    interpreter.global_object().put("global", &interpreter.global_object());
+    interpreter->global_object().put("global", &interpreter->global_object());
 
     if (script_path == nullptr) {
         editor = make<Line::Editor>();
         editor->initialize();
-        repl(interpreter);
+        repl(*interpreter);
     } else {
         auto file = Core::File::construct(script_path);
         if (!file->open(Core::IODevice::ReadOnly)) {
@@ -232,7 +231,7 @@ int main(int argc, char** argv)
         if (dump_ast)
             program->dump(0);
 
-        auto result = interpreter.run(*program);
+        auto result = interpreter->run(*program);
 
         if (print_last_result)
             printf("%s\n", result.to_string().characters());