CMake交叉编译：CMAKE_SYSROOT与CMAKE_FIND_ROOT_PATH区别详解

1. CMAKE_FIND_ROOT_PATH用来控制find_*命令搜索路径的前缀。

   # adjust the default behavior of the FIND_XXX() commands:
   # search programs in the host environment
   set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
    
   # search headers and libraries in the target environment
   set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
   set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

2. CMAKE_SYSROOT的参数会被find_*命令用作搜索路径的前缀。并且会传递给编译器的 —sysroot 参数，那么此时究竟作用是什么就取决于编译器了。并且这一参数还有细分：
   1. CMAKE_SYSROOT_COMPILE: used only for compiling sources and not linking.
   2. CMAKE_SYSROOT_LINK: used only for linking and not compiling sources.

参考资料

1. CMAKE_SYSROOT
2. CMAKE_FIND_ROOT_PATH
3. Cross Compiling With CMake