CMake Error at CMakeLists.txt:19 (add_subdirectory):
  The source directory

    /home/public/testProj/cmakeTest1/MathFunctions

  does not contain a CMakeLists.txt file.


-- Configuring incomplete, errors occurred!

说明 add_subdirectory是会查找子目录的CMakeLists.txt文件的
cmake手册中的add_subdirectory命令解释