add stacking framework

decompiler/IR2/Form.cpp

@@ -20,6 +20,18 @@ FormPool::~FormPool() {
   }
 }
 
+///////////////////
+// FormElement
+///////////////////
+
+std::string FormElement::to_string(const Env& env) const {
+  return to_form(env).print();
+}
+
+void FormElement::push_to_stack(const Env& env, FormStack&) {
+  throw std::runtime_error("push_to_stack not implemented for " + to_string(env));
+}
+
 ///////////////////
 // Form
 //////////////////
@@ -38,6 +50,10 @@ goos::Object Form::to_form(const Env& env) const {
   }
 }
 
+std::string Form::to_string(const Env& env) const {
+  return to_form(env).print();
+}
+
 void Form::inline_forms(std::vector<goos::Object>& forms, const Env& env) const {
   for (auto& x : m_elements) {
     forms.push_back(x->to_form(env));