问题描述
当使用INTERFACE
选项调用target_include_directories
命令向IMPORTED
target添加include文件夹时会报如题的错误,过程描述:
# 创建一个imported target MyLib
add_library(MyLib SHARED IMPORTED)
set_property(TARGET MyLib PROPERTY IMPORTED_LOCATION mylib.dll)
set_property(TARGET MyLib PROPERTY IMPORTED_IMPLIB mylib.lib)
# 然后添加INTERFACE类型的include
target_include_directories(MyLib INTERFACE mylib/include)
# 就会报错:
# Cannot specify include directories for imported target "MyLib".
解决方案
这个问题严格来说不算是个bug,只能说是cmake的规则设计不合理,不允许对imported target调用target_include_directories
命令,在cmake 3.11之前所有版本中都存在。
很早就有报告:https://cmake.org/Bug/view.php?id=15689
解决的办法就是改用set_property
或set_target_properties
修改INTERFACE_INCLUDE_DIRECTORIES
属性,如下:
# set_property设置INTERFACE_INCLUDE_DIRECTORIES 是可以的
set_property(TARGET MyLib APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES mylib/include)
# 或者set_target_properties也是可以的:
set_target_properties(MyLib PROPERTIES INTERFACE_INCLUDE_DIRECTORIES mylib/include)
cmake 3.11
好消息是在最新的cmake 3.11版本中,这个问题被正式解决了,参见 CMake 3.11 Release Notes
就是说在3.11后续的版本中target_*
系列command可以对imported target
设置INTERFACE_*
系列属性了。target_include_directories(MyLib INTERFACE mylib/include)
这样的写法就不会报错了。