def define
if RUBY_PLATFORM == 'java' || (defined?(RUBY_ENGINE) && RUBY_ENGINE == 'ironruby')
warn_once "WARNING: You're attempting to (cross-)compile C extensions from a platform\n(\#{RUBY_ENGINE}) that does not support native extensions or mkmf.rb.\nRerun `rake` under MRI Ruby 1.8.x/1.9.x to cross/native compile.\n"
return
end
super
define_native_tasks if !@no_native && (@gem_spec && @gem_spec.platform == 'ruby')
return unless @cross_compile
if cross_platform.is_a?(Array) then
cross_platform.each { |platf| define_cross_platform_tasks(platf) }
else
define_cross_platform_tasks(cross_platform)
end
end