cmake / CMakeLists.txt中 判断操作系统平台

camke 中判断操作系统平台有两种方法：

1. 判断变量CMAKE_SYSTEM_NAME

MESSAGE(STATUS "operation system is ${CMAKE_SYSTEM}")
IF (CMAKE_SYSTEM_NAME MATCHES "Linux")
    MESSAGE(STATUS "current platform: Linux ")
ELSEIF (CMAKE_SYSTEM_NAME MATCHES "Windows")
    MESSAGE(STATUS "current platform: Windows")
ELSEIF (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
    MESSAGE(STATUS "current platform: FreeBSD")
ELSE ()
    MESSAGE(STATUS "other platform: ${CMAKE_SYSTEM_NAME}")
ENDIF (CMAKE_SYSTEM_NAME MATCHES "Linux")

注意：上面的代码必须在指定了project之后，否则CMAKE_SYSTEM_NAME就是空的

1. 通过宏定义

IF (WIN32)
    MESSAGE(STATUS "Now is windows")
ELSEIF (APPLE)
    MESSAGE(STATUS "Now is Apple systens.")
ELSEIF (UNIX)
    MESSAGE(STATUS "Now is UNIX-like OS's.")
ENDIF ()

https://blog.csdn.net/sean_8180/article/details/81189996