cmake - Path to target output file

Question

I have a .so library target created by add_library, and need to pass an absolute path to this library to an external script. Now I have ${LIBRARY_OUTPUT_PATH}/${CMAKE_SHARED_LIBRARY_PREFIX}LangShared${CMAKE_SHARED_LIBRARY_SUFFIX} for that (LIBRARY_OUTPUT_PATH is defined in my CMakeLists.txt). This looks like hard-coding to me, because it will break as soon as the target is renamed or some of its properties are changed. Is there a way to get an absolute path to add_library's output?

Answer 1

You should use a generator expression for this.

From the docs for add_custom_command and the docs for generator expressions:

Arguments to COMMAND may use "generator expressions"...

Generator expressions are evaluted during build system generation to produce information specific to each build configuration.

In this case, assuming your library target is called "MyLib", the generator expression representing the full path to the built library would be:

$<TARGET_FILE:MyLib>