说明：  Gcc编程中makefile文件的使用手册，本文比较完整的讲述 GNU make 工具，涵盖 GNU make 的用法、语法。同时重点讨论如何 为一个工程编写 Makefile
(Gcc documentation makefile programming user manual, this article about the complete GNU make tools, GNU make to cover the use of grammar. At the same time focus on how to prepare a project Makefile)