Functions to create sets of shared variables.

§1. Shared variables are fleeting things: they come and go at runtime, and therefore they can't be set up statically by the compiler — they must be dynamically created by a function which is called at runtime each time they need to come into being.

Each set therefore has its own "creator function", and the following compiles it: 

void RTSharedVariables::compile_creator_fn(shared_variable_set *set, inter_name *iname) {
    if (set == NULL) internal_error("no shared variable set");

    packaging_state save = Functions::begin(iname);
    inter_symbol *pos_s = LocalVariables::new_other_as_symbol(I"pos");
    inter_symbol *state_s = LocalVariables::new_other_as_symbol(I"state");

    EmitCode::inv(IFELSE_BIP);
    EmitCode::down();
        EmitCode::inv(EQ_BIP);
        EmitCode::down();
            EmitCode::val_symbol(K_value, state_s);
            EmitCode::val_number(1);
        EmitCode::up();
        EmitCode::code();
        EmitCode::down();
            Compile frame creator if state is set1.1;
        EmitCode::up();
        EmitCode::code();
        EmitCode::down();
            Compile frame creator if state is clear1.2;
        EmitCode::up();
    EmitCode::up();

    EmitCode::inv(RETURN_BIP);
    EmitCode::down();
        EmitCode::val_number((inter_ti) LinkedLists::len(set->variables));
    EmitCode::up();

    Functions::end(save);
}

§1.1. Compile frame creator if state is set1.1 = 

    shared_variable *shv;
    LOOP_OVER_LINKED_LIST(shv, shared_variable, set->variables) {
        nonlocal_variable *q = SharedVariables::get_variable(shv);
        kind *K = NonlocalVariables::kind(q);
        EmitCode::inv(STORE_BIP);
        EmitCode::down();
            EmitCode::reference();
            EmitCode::down();
                EmitCode::inv(LOOKUP_BIP);
                EmitCode::down();
                    EmitCode::val_iname(K_value, Hierarchy::find(MSTACK_HL));
                    EmitCode::val_symbol(K_value, pos_s);
                EmitCode::up();
            EmitCode::up();
            if (Kinds::Behaviour::uses_block_values(K))
                TheHeap::emit_allocation(TheHeap::make_allocation(K, 1, -1));
            else
                RTVariables::initial_value_as_val(q);
        EmitCode::up();

        EmitCode::inv(POSTINCREMENT_BIP);
        EmitCode::down();
            EmitCode::ref_symbol(K_value, pos_s);
        EmitCode::up();
    }

§1.2. Compile frame creator if state is clear1.2 = 

    shared_variable *shv;
    LOOP_OVER_LINKED_LIST(shv, shared_variable, set->variables) {
        nonlocal_variable *q = SharedVariables::get_variable(shv);
        kind *K = NonlocalVariables::kind(q);
        if (Kinds::Behaviour::uses_block_values(K)) {
            EmitCode::call(Hierarchy::find(DESTROYPV_HL));
            EmitCode::down();
                EmitCode::inv(LOOKUP_BIP);
                EmitCode::down();
                    EmitCode::val_iname(K_value, Hierarchy::find(MSTACK_HL));
                    EmitCode::val_symbol(K_value, pos_s);
                EmitCode::up();
            EmitCode::up();
        }
        EmitCode::inv(POSTINCREMENT_BIP);
        EmitCode::down();
            EmitCode::ref_symbol(K_value, pos_s);
        EmitCode::up();
    }