uint16_t expr_evaluate(struct expr* e, uint16_t(*labelreplace)(bstring label), void(*errexit)(int code, void* data))
{
uint16_t t;
switch (e->type)
{
case EXPR_NUMBER:
return (uint16_t)(intptr_t)e->data;
case EXPR_LABEL:
if (labelreplace == NULL)
{
errexit(EXPR_EXIT_LABEL_NOT_FOUND, (bstring)e->data);
return 0;
}
else
return labelreplace((bstring)e->data);
case EXPR_EXPR:
switch (e->op)
{
case EXPR_OP_ADD:
return recursive_evaluate(e->a) + recursive_evaluate(e->b);
case EXPR_OP_SUBTRACT:
return recursive_evaluate(e->a) - recursive_evaluate(e->b);
case EXPR_OP_MULTIPLY:
return recursive_evaluate(e->a) * recursive_evaluate(e->b);
case EXPR_OP_DIVIDE:
t = recursive_evaluate(e->b);
if (t == 0)
errexit(EXPR_EXIT_DIVIDE_BY_ZERO, expr_representation(e->b));
return recursive_evaluate(e->a) / t;
case EXPR_OP_MODULUS:
t = recursive_evaluate(e->b);
if (t == 0)
errexit(EXPR_EXIT_DIVIDE_BY_ZERO, expr_representation(e->b));
return recursive_evaluate(e->a) % t;
case EXPR_OP_EQUALS:
return recursive_evaluate(e->a) == recursive_evaluate(e->b);
case EXPR_OP_NOT_EQUALS:
return recursive_evaluate(e->a) != recursive_evaluate(e->b);
case EXPR_OP_LESS_THAN:
return recursive_evaluate(e->a) < recursive_evaluate(e->b);
case EXPR_OP_LESS_EQUALS:
return recursive_evaluate(e->a) <= recursive_evaluate(e->b);
case EXPR_OP_GREATER_THAN:
return recursive_evaluate(e->a) > recursive_evaluate(e->b);
case EXPR_OP_GREATER_EQUALS:
return recursive_evaluate(e->a) >= recursive_evaluate(e->b);
case EXPR_OP_AND:
return recursive_evaluate(e->a) & recursive_evaluate(e->b);
case EXPR_OP_BOR:
return recursive_evaluate(e->a) | recursive_evaluate(e->b);
case EXPR_OP_XOR:
return recursive_evaluate(e->a) ^ recursive_evaluate(e->b);
default:
return 0;
}
default:
return 0;
}
}
struct process_parameter_results process_address(struct ast_node_address* param)
{
struct process_parameter_results result;
struct register_mapping* registr;
bstring btmp = NULL;
result.v_raw = NULL;
if (param->value != NULL)
btmp = expr_representation(param->value);
if (param->bracketed && param->added)
{
// This is of the form [0x1000+I].
registr = get_register_by_name_next(param->addcmpt);
if (registr == NULL)
{
// Attempt to use a label in brackets that can't be.
fprintf(stderr, "\n");
ahalt(ERR_NEXTED_LABEL_UNSUPPORTED, param->addcmpt);
}
else if (registr->value == VALUE_NEXT_UNSUPPORTED)
{
// Attempt to use a register in brackets that can't be.
fprintf(stderr, "\n");
ahalt(ERR_NEXTED_REGISTER_UNSUPPORTED, param->addcmpt);
}
fprintf(stderr, "[%s+%s]", btmp->data, registr->name);
result.v = registr->value;
result.v_extra = param->value;
result.v_extra_used = true;
result.v_label = NULL;
}
else
{
// This is either the form 0x1000 or [0x1000].
if (param->bracketed)
{
fprintf(stderr, "[%s]", btmp->data);
result.v = NXT;
}
else
{
fprintf(stderr, "%s", btmp->data);
result.v = NXT_LIT;
}
result.v_extra = param->value;
result.v_extra_used = true;
result.v_label = NULL;
}
if (btmp != NULL)
bdestroy(btmp);
return result;
}
struct process_parameter_results process_address(struct ast_node_address* param)
{
struct process_parameter_results result;
struct register_mapping* registr;
bstring btmp = NULL;
result.v_raw = NULL;
if (param->value != NULL)
btmp = expr_representation(param->value);
if (param->bracketed && param->added)
{
// This is of the form [0x1000+I].
registr = get_register_by_name_next(param->addcmpt);
if (registr == NULL)
{
// Attempt to use a label in square brackets. Convert this
// to an expression and then reinvoke ourselves with the
// evaluated value.
param->value = expr_new(expr_new_label(bautofree(bfromcstr(param->addcmpt))), EXPR_OP_ADD, param->value);
param->addcmpt = "";
param->added = 0;
param->bracketed = 0;
bdestroy(btmp);
return process_address(param);
}
else if (registr->value == VALUE_NEXT_UNSUPPORTED)
{
// Attempt to use a register in brackets that can't be.
printd(LEVEL_VERBOSE, "\n");
dhalt(ERR_NEXTED_REGISTER_UNSUPPORTED, param->addcmpt);
}
printd(LEVEL_VERBOSE, "[%s+%s]", btmp->data, registr->name);
result.v = registr->value;
result.v_extra = param->value;
result.v_extra_used = true;
result.v_label = NULL;
}
else
{
// This is either the form 0x1000 or [0x1000].
if (param->bracketed)
{
printd(LEVEL_VERBOSE, "[%s]", btmp->data);
result.v = NXT;
}
else
{
printd(LEVEL_VERBOSE, "%s", btmp->data);
result.v = NXT_LIT;
}
result.v_extra = param->value;
result.v_extra_used = true;
result.v_label = NULL;
}
if (btmp != NULL)
bdestroy(btmp);
return result;
}
bstring expr_representation(struct expr* e)
{
bstring a, b, op, result;
switch (e->type)
{
case EXPR_NUMBER:
return bformat("%u", (uint16_t)(intptr_t)e->data);
case EXPR_LABEL:
return bstrcpy((bstring)e->data);
case EXPR_EXPR:
a = expr_representation(e->a);
b = expr_representation(e->b);
switch (e->op)
{
case EXPR_OP_ADD:
op = bfromcstr("+");
break;
case EXPR_OP_SUBTRACT:
op = bfromcstr("-");
break;
case EXPR_OP_MULTIPLY:
op = bfromcstr("*");
break;
case EXPR_OP_DIVIDE:
op = bfromcstr("/");
break;
case EXPR_OP_MODULUS:
op = bfromcstr("%");
break;
case EXPR_OP_EQUALS:
op = bfromcstr("==");
break;
case EXPR_OP_NOT_EQUALS:
op = bfromcstr("!=");
break;
case EXPR_OP_LESS_THAN:
op = bfromcstr("<");
break;
case EXPR_OP_LESS_EQUALS:
op = bfromcstr("<=");
break;
case EXPR_OP_GREATER_THAN:
op = bfromcstr(">");
break;
case EXPR_OP_GREATER_EQUALS:
op = bfromcstr(">=");
break;
case EXPR_OP_AND:
op = bfromcstr("&");
break;
case EXPR_OP_BOR:
op = bfromcstr("|");
break;
case EXPR_OP_XOR:
op = bfromcstr("^");
break;
default:
op = bfromcstr("???");
break;
}
result = bfromcstr("");
bconchar(result, '(');
bconcat(result, a);
bconchar(result, ' ');
bconcat(result, op);
bconchar(result, ' ');
bconcat(result, b);
bconchar(result, ')');
bdestroy(a);
bdestroy(b);
bdestroy(op);
return result;
default:
return bfromcstr("???");
}
}