class RbSys::CargoBuilder

def maybe_resolve_ldflag_variable(input_arg, dest_dir)
  var_matches = input_arg.match(/\$\((\w+)\)/)
  return input_arg unless var_matches
  var_name = var_matches[1]
  return input_arg if var_name.nil? || var_name.chomp.empty?
  case var_name
  when "DEFFILE"
    # DEFFILE already generated by cargo
  else
    RbConfig::CONFIG[var_name]
  end
end