C语言宏展开程序及其在教学中的应用

常用于定义符号常量的C语言宏使程序清晰、易读，便于修改；可代替简单函数的C语言带参数宏，比函数调用具有更高的时间效率。宏使用时容易出错且不容易发现，其根本原因是编译器不提供宏展开后的代码，这给编程和教学带来了许多不便。笔者编制了一个实用的宏展开程序对源程序中的宏进行分析、处理，将源程序中的宏调用展开，产生宏展开后的源代码。根据展开的代码可以容易地发现宏使用中的问题，学生也更容易掌握宏的使用。

C Language Macro Expansion Program and Its Application in Teaching

The C language macro,which is often used in defining the symbolic constants makes the programs clear,easy to read and convenient to change. The C language macro with parameters,which can replace the simple functions,is more efficient in time-spending than the function call. When it is used,macro is apt to break down and it is difficult to find the causes. The reason is that compiler doesn't provide macro expansion codes,which brings inconvenience to programming and teaching. This paper gives a practical macro expansion program,which can analyze and process the macro in the source program and expand the macro call in the source program and produce the source codes after macro expansion. According to the expansion codes,we can easily find the problems in using macro,and the students can grasp macro more easily.