+/* options */
+extern vector<string> dump_header_fieldnames_global;
+extern string output_backend_global;
+extern string output_name_global;
+extern bool be_safe_global;
+extern bool be_verbose_global;
+extern bool do_internal_type_checking_global;
+extern bool is_pango_format_global;
+extern bool is_TeX_format_global;
+extern bool point_and_click_global;
+extern string prefix_directory;
+extern bool use_object_keys;
+extern bool strict_infinity_checking;
+/*
+ todo: collect in Output_option struct?
+*/
+extern string output_format_global;