宏定义 重复了会如何？

lam2

so in other words, it won't turn out to be this file `define is one thing and `define is another thing in the other file.
Instead, redefinition of macro means different guy is expecting different things, assuming there're more than 1 people on your project.  This should be solved once spotted.  VCS warns about it.  lint tools would warn about it too.