void foo()
{
int error = 0;
#if defined(SUPPORT_FEATURE)
error = feature_bar();
#else // feature not supported
// we call bar otherwise
error = bar();
#endif // SUPPORT_FEATURE
// continue with function logic
if (error != 0)
{
#if 0 // TODO: this is disabled
// call final bar
error_bar(error);
#endif
}
}