-void run_frontend(std::string filename, std::string command, std::string *backend_command, std::string *from_to_label = nullptr, RTLIL::Design *design = nullptr);
-void run_frontend(std::string filename, std::string command, RTLIL::Design *design = nullptr);
+bool run_frontend(std::string filename, std::string command, RTLIL::Design *design = nullptr, std::string *from_to_label = nullptr);