、makefile文件的作用是什么，makefile文件中有一种变量，其值是根据具体的规则来确定的，称为自动变量，其中代表所有依赖文件列表的是哪个；举例说明make命令的工作流程。-What is the role of, makefile file, there is a variable in the makefile file, its value is based on the specific rules, known as automatic variables, which rep