CMake - Different Include Directories For Different Targets?

Question

I'm developing a C++ project in Linux using CMake.

I am creating two libraries, LibA and LibB. I do not want LibA and LibB to have the same include directories. Is there any way I can set only LibA to include DirectoryA and set only LibB to include DirectoryB?

Edit:

Both LibA and LibB will be used in an executable, MyExe. When I #include LibA.h and LibB.h in MyExe's source code, I cannot have the included header files from DirectoryA and DirectoryBcoexisting in MyExe, as this will create namespace conflicts.

Is this possible?

Edit 2 : Here is my CMakeLists.txt include_directories(include)

add_library(LibA src/LibA.cpp include/LibA.h)
set_property(TARGET LibA PROPERTY INCLUDE_DIRECTORIES /opt/SomeLibrary2.0/include/)
target_link_libraries(LibA /opt/SomeLibrary2.0/lib/a.so /opt/SomeLibrary2.0/lib/b.so /opt/SomeLibrary2.0/lib/c.so)

add_library(LibB src/LibB.cpp include/LibB.h)
set_property(TARGET LibB PROPERTY INCLUDE_DIRECTORIES ${LIB_B_INCLUDE_DIRS})
target_link_libraries(LibB ${LIB_B_LIBRARIES})

add_executable(MyExe src/myexe.cpp)
target_link_libraries(MyExe LibA LibB)

But I'm still getting errors. LibA.h says that SomeLibrary's header files cannot be found?

Thank you for your comment. My original question was updated to better reflect my issue. — trianta2, Dec 17 '13 at 20:07
`I cannot have the included header files from DirectoryA and DirectoryB coexisting in MyExe, as this will create namespace conflicts` IMHO it is design issue, if you solve include conflicts you may have strange linker errors and unexpected runtime behaviour — , Dec 17 '13 at 21:07

Fraser · Accepted Answer · 2013-12-17T20:06:50.800

13

If you can specify CMake version 2.8.12 as the minimum, you can use target_include_directories. This was introduced in version 2.8.11, but I think it was a bit buggy until 2.8.12.

So you can do:

target_include_directories(LibA PRIVATE DirectoryA)
target_include_directories(LibB PRIVATE DirectoryB)

If you have to support older versions of CMake, you can set the INCLUDE_DIRECTORIES property on the targets appropriately:

set_property(TARGET LibA
             PROPERTY INCLUDE_DIRECTORIES ${CMAKE_SOURCE_DIR}/DirectoryA)
set_property(TARGET LibB
             PROPERTY INCLUDE_DIRECTORIES ${CMAKE_SOURCE_DIR}/DirectoryB)

edited Dec 17 '13 at 20:06

answered Dec 17 '13 at 19:57

Fraser

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Thank you for your answer. My original question was updated to better reflect my issue. – trianta2 Dec 17 '13 at 20:08
I'm currently using 2.8.7, so not as of now. If 2.8.12 has features which will solve my problem then I will update CMake. – trianta2 Dec 17 '13 at 20:11
1

I updated my answer to show libs rather than exes. There should be no need to upgrade CMake - using either method should not cause the include directories of the libraries to become include dirs of the exe. – Fraser Dec 17 '13 at 20:14
So I unwittingly installed the one of the libraries "DirectoryA" to my /usr/local/ directory, so the entire project already sees it. I'm reinstalling the library to /opt/DirectoryA/ and giving this a shot. Rebuilding this library could be process however. – trianta2 Dec 17 '13 at 20:23
1

I think this is now a design issue. I'm guessing that `LibA` builds OK on its own, but when you try to build `MyExe` the failure happens. If `LibA.h` includes a header from `/opt/SomeLibrary2.0/include/` (directly or indirectly via one of its other include files), and `MyExe` includes `LibA.h`, then `/opt/SomeLibrary2.0/include/` *must* be available as a search path for `MyExe` too. Off the top of my head, you can maybe consider using the [pimpl idiom](http://stackoverflow.com/q/3597693/2556117) to avoid having to expose `SomeLibrary2.0`'s headers to `MyExe`. – Fraser Dec 17 '13 at 22:10

CMake - Different Include Directories For Different Targets?

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