CMake target_link_libraries Interface Dependencies

问题:

I am new to CMAKE and a bit confused with the PUBLIC, PRIVATE and INTERFACE keywords related to target_link_libraries. Documentation mentions that they can be used to specify both the link dependencies and the link interface in one command.

What does link dependencies and link interface actually mean?

回答1:

If you are creating a shared library and your source cpp files #include the headers of another library (Say, QtNetwork for example), but your header files don't include QtNetwork headers, then QtNetwork is a PRIVATE dependency.

If your source files and your headers include the headers of another library, then it is a PUBLIC dependency.

If your header files but not your source files include the headers of another library, then it is an INTERFACE dependency.

Other build properties of PUBLIC and INTERFACE dependencies are propagated to consuming libraries. http://www.cmake.org/cmake/help/v3.0/manual/cmake-buildsystem.7.html#transitive-usage-requirements