How to include an additional CMakeLists.txt

Question

Say we have a command call foo in CMakeLists.txt which is in folder /A.

foo is defined in antother CMakeLists.txt which is in folder /B.

How can one reference to /B/CMakeLists.txt from within /A/CMakeLists.txt in order to call foo?

I tried to set search paths to /B/CMakeLists.txt via:

• CMAKE_INCLUDE_PATH
• CMAKE_MODULE_PATH
• CMAKE_SOURCE_DIR

but none of them worked.

CMake still complaines Unknown CMake command "foo".

Answer 1

That can be done with include, here's some simple example:

Content of A/CMakeLists.txt

function(foo)
    message(STATUS "heya")
endfunction()

Content of B/CMakeLists.txt

cmake_minimum_required(VERSION 2.8)
include(${CMAKE_CURRENT_SOURCE_DIR}/../A/CMakeLists.txt)
foo()

Now, including another CMakeLists.txt will also run everything in that file, so you may want to avoid doing that if there are targets in B/CMakeLists.txt

If you can modify your code, it would be better to define your functions in a "top level" CMakeLists.txt before calling add_subdirectory.