Global variables translated to C.

• §1. Setting up the model

§1. Setting up the model.

void CGlobals::initialise?Usage of CGlobals::initialise:
Final C - §1(code_generator *cgt) {
    METHOD_ADD(cgt, DECLARE_VARIABLES_MTID, CGlobals::declare_variables);
    METHOD_ADD(cgt, EVALUATE_VARIABLE_MTID, CGlobals::evaluate_variable);
}

int C_var_count = 1;
text_stream *C_var_vals = NULL;

void CGlobals::initialise_data?Usage of CGlobals::initialise_data:
Final C - §4(code_generation *gen) {
    C_var_count = 1;
    C_var_vals = Str::new();
}

void CGlobals::begin?Usage of CGlobals::begin:
Final C - §5(code_generation *gen) {
}

void CGlobals::end?Usage of CGlobals::end:
Final C - §6(code_generation *gen) {
    segmentation_pos saved = CodeGen::select(gen, c_ids_and_maxima_I7CGS);
    text_stream *OUT = CodeGen::current(gen);

    WRITE("#define i7_no_variables %d\n", C_var_count);
    WRITE("#define i7_var_self 0\n");
    WRITE("i7word_t i7_initial_variable_values[];\n");
    CodeGen::deselect(gen, saved);

    saved = CodeGen::select(gen, c_globals_array_I7CGS);
    OUT = CodeGen::current(gen);
    WRITE("i7word_t i7_initial_variable_values[] = { 0 %S };\n", C_var_vals);
    CodeGen::deselect(gen, saved);
}

§2.

void CGlobals::declare_variables?Usage of CGlobals::declare_variables:
§1(code_generator *cgt, code_generation *gen, linked_list *L) {
    inter_symbol *var_name;
    LOOP_OVER_LINKED_LIST(var_name, inter_symbol, L) {
        inter_tree_node *P = var_name->definition;
        CGlobals::declare_variable_by_name(gen, Inter::Symbols::name(var_name), P);
        text_stream *name = Metadata::read_optional_textual(Inter::Packages::container(var_name->definition), I"^name");
        if (name)
            CObjectModel::define_header_constant_for_variable(gen, name, C_var_count - 1);
        else
            CObjectModel::define_header_constant_for_variable(gen,  Inter::Symbols::name(var_name), C_var_count - 1);
    }
}

void CGlobals::declare_variable_by_name(code_generation *gen, text_stream *name,
    inter_tree_node *P) {
    segmentation_pos saved = CodeGen::select(gen, c_predeclarations_I7CGS);
    text_stream *OUT = CodeGen::current(gen);
    WRITE("#define i7_var_%S %d\n", name, C_var_count);
    CodeGen::deselect(gen, saved);

    C_var_count++;
    CodeGen::select_temporary(gen, C_var_vals);
    WRITE_TO(C_var_vals, ", ");
    if (P) CodeGen::pair(gen, P, P->W.data[VAL1_VAR_IFLD], P->W.data[VAL2_VAR_IFLD]);
    else WRITE_TO(C_var_vals, "0");
    CodeGen::deselect_temporary(gen);
    WRITE_TO(C_var_vals, " /* %S */\n", name);
}

void CGlobals::evaluate_variable?Usage of CGlobals::evaluate_variable:
§1(code_generator *cgt, code_generation *gen, inter_symbol *var_name, int as_reference) {
    text_stream *OUT = CodeGen::current(gen);
    WRITE("proc->state.variables[i7_var_%S]", Inter::Symbols::name(var_name));
}

§3.

i7word_t i7_read_variable(i7process_t *proc, i7word_t var_id);
void i7_write_variable(i7process_t *proc, i7word_t var_id, i7word_t val);

• This is part of the extract file inform7_clib.h.

i7word_t i7_read_variable(i7process_t *proc, i7word_t var_id) {
    return proc->state.variables[var_id];
}
void i7_write_variable(i7process_t *proc, i7word_t var_id, i7word_t val) {
    proc->state.variables[var_id] = val;
}

• This is part of the extract file inform7_clib.c.