[CMake] Executable and library dependencies

[Andreas Pakulat]

On 05.05.09 14:29:03, eblotml at free.fr wrote:
> Hi,
> 
> I have a question about CMake and dependency management when an executable is built, and linked with static libraries which are built within the same project.
> 
> I use a top CMakeLists.txt which looks like:
>   PROJECT (proj)
>   SET (subprojects mylib myapp)
>   FOREACH (prj ${subprojects})
>     ADD_SUBDIRECTORY (${prj} ${prj})
>   ENDFOREACH (prj)
> 
> mylib/ contains a CMakeList.txt file that contains something like
>   ADD_LIBRARY (mylib src/mylib.c)
> 
> myapp/ contains a CMakeList.txt file that contains something like
>   ADD_EXECUTABLE (myapp src/myapp.c)
>   TARGET_LINK_LIBRARIES (myapp -L${PATH_TO_MYLIB} -Wl,--start-group -lmylib -lsomeotherlib -Wl,--end-group) 
> 
> 
> I don't think I can use the FIND_LIBRARY command, because the actual link command requires the start-group/end-group linker directives, and the actual application is linked against several other libraries.

Ideally you wouldn't use linker flags, but just use the target you've
created via add_library. But I guess that doesn't work with the start-group
stuff. So...
 
> There is no explicit dependencies between myapp and mylib, which I guess explain why CMake allows myapp to be built before mylib is built.
> 
> What would be the best way to add a dependency to solve this issue?
> In other word, I'll go for ADD_DEPENDENCY(myapp x), but I'm not sure how to define 'x' here.

This would be the right way and "x" should simply be "mylib" in your
example, which creates a dependency between the myapp target and the mylib
target in your project.

Andreas

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