从别人的博客学习

链接：

http://www.cppblog.com/ownwaterloo/archive/2009/04/20/predefined_macro___cplusplus.html

http://www.cnblogs.com/ggjucheng/archive/2011/12/14/2287738.html

http://www.cnblogs.com/ggjucheng/archive/2012/01/08/2316692.html

http://wangjunle23.blog.163.com/blog/static/117838171201211832935169/

http://jincv.blog.163.com/blog/static/24905510201042741115721/

http://www.cnblogs.com/gaojun/archive/2012/08/22/2650229.html

http://crifan.com/files/doc/docbook/embedded_soft_dev/release/html/embedded_soft_dev.html

http://blog.chinaunix.net/uid-21633169-id-4437868.html