How to control subdirectory compiling order of cmake?

Question

This is my CMakeLists.txt:

ADD_SUBDIRECTORY(third)
ADD_SUBDIRECTORY(utils)
ADD_SUBDIRECTORY(rpc)

But the directory 'rpc' will be compiled before directory 'utils', actually the 'rpc' is depends on 'utils', so I will get a link error.

How can I make the 'rpc' compiling after 'utils'?

Thanks.

Answer 1

When you use target_link_libraries() function and pass it other target name, CMake automatically sets this target as a dependency. You can also use add_dependencies() to specify dependencies manually.

Also note that order of sources compilation have nothing to do with your problem. Link errors (i guess, you are seeing "undefined reference" ones) are because you aren't linking your targets properly.

Answer 2

if the 'rpc' is depends on 'utils':

utils CMAKELISTS.txt

project(utils)
add_library (utils SHARED ${PROJECT_SOURCE_LIST})

rpc CMAKELISTS.txt

project(rpc)
add_library (rpc SHARED ${PROJECT_SOURCE_LIST})
# must add this command to scan dependencies of target rpc
add_dependencies (rpc utils)
target_link_libraries (${TEST_SOURCE_FILE_NAME} libutils.so)