How to get CMake to link an executable to an external shared library that is not build within the same CMake project?
Just doing target_link_libraries(GLBall ${CMAKE_BINARY_DIR}/res/mylib.so) gives the error
make[2]: *** No rule to make target `res/mylib.so', needed by `GLBall'. Stop.
make[1]: *** [CMakeFiles/GLBall.dir/all] Error 2
make: *** [all] Error 2
(GLBall is the executable)
after I copied the library into the binary dir bin/res.
I tried using find_library(RESULT mylib.so PATHS ${CMAKE_BINARY_DIR}/res)
Which fails with RESULT-NOTFOUND.
Answer
arrowdodger's answer is correct and preferred on many occasions. I would simply like to add an alternative to his answer:
You could add an "imported" library target, instead of a link-directory. Something like:
# Your-external "mylib", add GLOBAL if the imported library is located in directories above the current.
add_library( mylib SHARED IMPORTED )
# You can define two import-locations: one for debug and one for release.
set_target_properties( mylib PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/res/mylib.so )
And then link as if this library was built by your project:
TARGET_LINK_LIBRARIES(GLBall mylib)
Such an approach would give you a little more flexibility: Take a look at the add_library( ) command and the many target-properties related to imported libraries.
I do not know if this will solve your problem with "updated versions of libs".