Custom target as target library in cmake

Question

I have a custom target, which is actually a library created externally that I want to integrate into my assembly.

add_custom_command( OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/liblib2.a COMMAND make -f ${CMAKE_CURRENT_SOURCE_DIR}/makefile liblib2.a) add_custom_target(lib2 DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/liblib2.a) 

How can I tell cmake that this target is actually a library , where it can be found, and where the headers are ?

To be clear: I do not want the top CMakeList, using this library, to manually specify the incoming folders and the library location folder . This should be done automatically (from the target properties).

In the standard cmake library, I just need to add the INTERFACE_INCLUDE_DIRECTORIES property to the CMakeLists library to force cmake to link my application with the corresponding -I and -L gcc parameters:

 set_target_properties(lib1 PROPERTIES INTERFACE_INCLUDE_DIRECTORIES ${CMAKE_CURRENT_SOURCE_DIR}) 

But in the case of a custom goal, I don’t know how to go about it.

Any clue?

Thank you for your help.

---

Thanks zaufi it works!

For others who may be interested in a built-in external target implementation inside cmake, here is what I did:

 cmake_minimum_required(VERSION 2.8) SET(LIB_FILE ${CMAKE_CURRENT_SOURCE_DIR}/bin/liblib2.a) SET(LIB_HEADER_FOLDER ${CMAKE_CURRENT_SOURCE_DIR}/include) # how to build the result of the library add_custom_command(OUTPUT ${LIB_FILE} COMMAND make WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}) # create a target out of the library compilation result add_custom_target(lib2_target DEPENDS ${LIB_FILE}) # create an library target out of the library compilation result add_library(lib2 STATIC IMPORTED GLOBAL) add_dependencies(lib2 lib2_target) # specify where the library is and where to find the headers set_target_properties(lib2 PROPERTIES IMPORTED_LOCATION ${LIB_FILE} INTERFACE_INCLUDE_DIRECTORIES ${LIB_HEADER_FOLDER}) 

Now in CMakeLists.txt I can do something like

 add_subdirectory(${ROOT_DIR}/lib1 bin/lib1) add_subdirectory(${ROOT_DIR}/lib2 bin/lib2) add_executable(app app.c ) target_link_libraries(app lib1 lib2) 

No need to indicate where .a and .h are located.

Answer 1

You can use add_library() and say that it is actually imported . Then, using set_target_properties() , you can set the necessary INTERFACE_XXX properties for it. After that, you can use it as a regular target, like all others created by your project.