[CMake] dependency in custom command?

[King, Steven R]

Hello List,
I'm new to cmake and liking it a lot.  I'm using cmake 2.6.3 on Linux.

I'm building a dynamically loadable module and an executable to test it.  Each lives in a different directory.  My test program needs to know the location of the dll when calling dlopen().   To solve this, I created a custom command to copy the dll to the binary directory of the test program.   This works, but I have an annoying dependency problem.  Specifically, if the dll gets rebuilt, the copy command does not execute.  The copy command only executes if the test program gets rebuilt.  I do not understand how to make this copy depend on the dll being rebuilt.  I want all test programs to "pull" the rebuilt dll as needed.  I do not want the CMakeLists.txt for the dll to have any knowledge of the test programs.

In CMakeLists.txt for the test program:


add_executable            (
                          test_my_module
                          test_main.cpp
                          )

add_dependencies          (
                          test_my_module
                          my_module		# not needed?
                          )

# Loadable modules are never listed at link time.
target_link_libraries     (
                          test_my_module
                          dl
                          )

# Put the location of the .so library we need in the SO_LOCATION variable.
# We then use this location in the copy command below.
get_target_property       (
                          SO_LOCATION
                          my_module        # .so library target
                          LOCATION
                          )

# Create a custom build step to copy the dynamically loaded .so file
# into the this directory so our test executable can find it.
add_custom_command        (
                          TARGET test_my_module
                          POST_BUILD
                          DEPENDS my_module  # no effect?
                          COMMAND ${CMAKE_COMMAND} -E copy ${SO_LOCATION} ${CMAKE_CURRENT_BINARY_DIR}
                          COMMENT "CUSTOM COMMAND: Copy my_module to build directory"
                          )


What should I do make the copy happen if the dll is rebuilt?

Thanks for any advice,
-steve