[CMake] how to inherit includes from other directories

[Victor Yankee]

Raymond,

I appreciate your detailed reply.

But apparently include_directories do not propagate UP, only down into
subdirectories.
The project has many such subdirectories each with its own headers. I think
my example
was therefore misleading and too simple :(

There may 3 or 4 levels. At the top level, I would very much like to avoid
needing to know all the dependencies at all the lower levels and
exhaustively listing each one in an  'include_directories()' command.

If utils/B.h needs utils/A.h which needs foo/Z.h, then in my top-level
directory (that only needs to know about B.h)  what does its CMakeLists.txt
look like? I would like to just be add_includes(utils/B) and have cmake
figure out it also needs utils/A and foo.

I have somewhat succeeded by using a global variable called "my_includes"
and using PARENT_SCOPE in all the low-level cmakelist files. But then I
basically end up including all of the subdirectories all of the time.


-Victor




On Sun, Sep 4, 2011 at 8:15 AM, Raymond Wan <r.wan at aist.go.jp> wrote:

> Hi Victor,
>
>
> On Sat, Sep 3, 2011 at 02:27, Victor Yankee
> <victor.whiskey.yankee at gmail.com> wrote:
> > build/
> > src/
> >       utils
> >               a
> >                      A.h
> >                      unittest_a.cpp
> >
> >               b
> >                      B.h   // needs a.h
> >
> >                      unittest_b.cpp
> >
> >       common
> >               c
> >                     C.h      // needs A.h and B.h
> >                     testit.cpp   // needs C.h, B.h and A.h
> >
> >
> > The directory src/utils/a has a header file A.h. Likewise src/utils/b has
> a
> >
> > header file B.h that #includes a.h.
> > Finally, c has a header file C.h that #includes a.h and b.h.
> >
> >
> > This is just a short example of my large project. In reality there are
> other
> > directories and levels of subdirectories.
> >
> >
> > What can I do in the local CMakeLists.txt files so that the directories
> > where the header files live are automatically made part of the others as
> > needed,
> > so I do not have to keep remembering all of them for every header-only
> >
> > library all the way down the dependency chain?
>
>
>
> I'm not much of a CMake expert, but it sounds like something I've done
> and I think the INCLUDE_DIRECTORIES command is all you need:
>
>
> http://www.cmake.org/cmake/help/cmake-2-8-docs.html#command:include_directories
>
> So in each of:
>
> src/utils/a
> src/utils/b
> src/common/c
> src/
>
> you would have a CMakeLists.txt .  The first 3 performs the unit
> testing.  And the top-level one in src/ is the one that builds your
> executable.  In the CMakeLists.txt that refers to the header file in
> another directory, you would put INCLUDE_DIRECTORIES.
>
> You would then tie up their dependencies using ADD_DEPENDENCIES so
> that an executable is made once something else is made:
>
>
> http://www.cmake.org/cmake/help/cmake-2-8-docs.html#command:add_dependencies
>
> I *think* that is all you need.  I've also used ADD_SUBDIRECTORY but
> I'm not too sure if you need it too in your situation.
>
> Hope this helps!
>
> Ray
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.cmake.org/pipermail/cmake/attachments/20110906/bdc781fd/attachment.htm>