To give certain use options a presence at run-time.

§1. A relatively late addition to the design of use options was to make them values at run-time, of the kind "use option". We need to provide two routines: one to test them, one to print them.

void RTUseOptions::TestUseOption_routine(void) {
    inter_name *iname = Hierarchy::find(NO_USE_OPTIONS_HL);
    Emit::named_numeric_constant(iname, (inter_ti) NUMBER_CREATED(use_option));
    Compile the TestUseOption routine1.1;
    Compile the PrintUseOption routine1.2;
}

§1.1. Compile the TestUseOption routine1.1 =

    packaging_state save = Routines::begin(Hierarchy::find(TESTUSEOPTION_HL));
    inter_symbol *UO_s = LocalVariables::add_named_call_as_symbol(I"UO");
    use_option *uo;
    LOOP_OVER(uo, use_option)
        if ((uo->option_used) || (uo->minimum_setting_value >= 0)) {
            Produce::inv_primitive(Emit::tree(), IF_BIP);
            Produce::down(Emit::tree());
                Produce::inv_primitive(Emit::tree(), EQ_BIP);
                Produce::down(Emit::tree());
                    Produce::val_symbol(Emit::tree(), K_value, UO_s);
                    Produce::val(Emit::tree(), K_number, LITERAL_IVAL,
                        (inter_ti) uo->allocation_id);
                Produce::up(Emit::tree());
                Produce::code(Emit::tree());
                Produce::down(Emit::tree());
                    Produce::rtrue(Emit::tree());
                Produce::up(Emit::tree());
            Produce::up(Emit::tree());
        }
    Produce::rfalse(Emit::tree());
    Routines::end(save);

• This code is used in §1.

§1.2. Compile the PrintUseOption routine1.2 =

    inter_name *iname = Kinds::Behaviour::get_iname(K_use_option);
    packaging_state save = Routines::begin(iname);
    inter_symbol *UO_s = LocalVariables::add_named_call_as_symbol(I"UO");
    Produce::inv_primitive(Emit::tree(), SWITCH_BIP);
    Produce::down(Emit::tree());
        Produce::val_symbol(Emit::tree(), K_value, UO_s);
        Produce::code(Emit::tree());
        Produce::down(Emit::tree());
            use_option *uo;
            LOOP_OVER(uo, use_option) {
                Produce::inv_primitive(Emit::tree(), CASE_BIP);
                Produce::down(Emit::tree());
                    Produce::val(Emit::tree(), K_number, LITERAL_IVAL,
                        (inter_ti) uo->allocation_id);
                    Produce::code(Emit::tree());
                    Produce::down(Emit::tree());
                        Produce::inv_primitive(Emit::tree(), PRINT_BIP);
                        Produce::down(Emit::tree());
                            TEMPORARY_TEXT(N)
                            WRITE_TO(N, "%W option", uo->name);
                            if (uo->minimum_setting_value > 0)
                                WRITE_TO(N, " [%d]", uo->minimum_setting_value);
                            Produce::val_text(Emit::tree(), N);
                            DISCARD_TEXT(N)
                        Produce::up(Emit::tree());
                    Produce::up(Emit::tree());
                Produce::up(Emit::tree());
            }
        Produce::up(Emit::tree());
    Produce::up(Emit::tree());
    Routines::end(save);

• This code is used in §1.

§2. And we also compile constants. The aim of all of this is to enable Inter kits for the model world to operate without conditional compilation, which would make them harder to precompile.

void RTUseOptions::configure_template(void) {
    int bitmap = 0;
    if (global_compilation_settings.scoring_option_set == TRUE) bitmap += 1;
    if (global_compilation_settings.undo_prevention) bitmap += 2;
    if (global_compilation_settings.serial_comma) bitmap += 4;
    if (global_compilation_settings.predictable_randomisation) bitmap += 16;
    if (global_compilation_settings.command_line_echoing) bitmap += 32;
    if (global_compilation_settings.no_verb_verb_exists) bitmap += 64;
    if (global_compilation_settings.American_dialect) bitmap += 128;
    if (global_compilation_settings.story_author_given) bitmap += 256;
    if (global_compilation_settings.ranking_table_given) bitmap += 512;

    inter_name *iname = Hierarchy::find(TEMPLATE_CONFIGURATION_BITMAP_HL);
    Emit::named_numeric_constant(iname, (inter_ti) bitmap);
    Hierarchy::make_available(Emit::tree(), iname);

    iname = Hierarchy::find(TEMPLATE_CONFIGURATION_LOOKMODE_HL);
    Emit::named_numeric_constant(iname, (inter_ti) global_compilation_settings.room_description_level);
    Hierarchy::make_available(Emit::tree(), iname);
}

§3. Most use options take effect by causing a constant to be defined:

void RTUseOptions::compile(void) {
    use_option *uo;
    LOOP_OVER(uo, use_option)
        if ((uo->option_used) || (uo->minimum_setting_value >= 0)) {
            text_stream *UO = Str::new();
            I6T::interpret_i6t(UO,
                Lexer::word_raw_text(Wordings::first_wn(uo->expansion) + 1),
                uo->minimum_setting_value);
            WRITE_TO(UO, "\n");
            Emit::intervention(EARLY_LINK_STAGE, NULL, NULL, UO, NULL);
        }
}

§4. I6 memory settings need to be issued as ICL commands at the top of the I6 source code: see the DM4 for details.

void RTUseOptions::compile_pragmas(void) {
    Emit::pragma(I"-s");
    i6_memory_setting *ms;
    LOOP_OVER(ms, i6_memory_setting) {
        if ((Str::eq_wide_string(ms->ICL_identifier, L"MAX_LOCAL_VARIABLES")) &&
            (TargetVMs::allow_MAX_LOCAL_VARIABLES(Task::vm()) == FALSE))
            continue;
        TEMPORARY_TEXT(prag)
        WRITE_TO(prag, "$%S=%d", ms->ICL_identifier, ms->number);
        Emit::pragma(prag);
        DISCARD_TEXT(prag)
    }
}