.cmake 文件谁用
.cmake 文件 是给cmake执行用的：
cmake -P /path/of/xxx.cmake
cmake 参数-P的解释
-P <file>
Process script mode.Process the given cmake file as a script written in the CMake language. No configure or generate step is performed and the cache is not modified. If variables are defined using -D, this must be done before the -P argument.
原文链接：https://blog.csdn.net/xiaowang1379214245/article/details/78191917
.cmake 文件的作用
就像CMakeList.txt的库一样，加载后可以在CMakeList.txt中使用它的一些函数和定义？
提供最小可用配置？
其他：
https://stackoverflow.com/questions/34795816/hinting-findname-cmake-files-with-a-custom-directory