# File lib/rake/extensiontask.rb, line 39
    def binary(platform = nil)
      if platform == "java"
        warn_once "Compiling a native C extension on JRuby. This is discouraged and a\nJava extension should be preferred.\n"
        "#{name}.#{RbConfig::MAKEFILE_CONFIG['DLEXT']}"
      else
        super
      end
    end