gcc有一个选项来提醒你一下：

gcc has an option to warn you about this:

gcc -Wmissing-prototypes

您可以关闭该警告变成了错误，停止编译和力量的人来解决它：

You can turn this warning into an error to stop compilation and force people to fix it:

gcc -Werror=missing-prototypes

如果你只是想列出它，你可以用 GCC 选项 -Wmissing的原型和grep的编译否previous原型在日志中。

If you just want to list it you can compile with the gcc option -Wmissing-prototypes and grep for no previous prototype for in the log.

基于编辑更新

既然你现在提到，你不能用gcc，你必须找到你当前的编译器的类似选项。大多数编译器有这样一个选项。先从手册页或内置的帮助输出。

Since you now mention that you can't use gcc, you'll have to find a similar option for your current compiler. Most compilers have such an option. Start with the man page or the built in help output.