[CMake] CMake: using dlopen

[Eric Noulard]

Explanations on PRIVATE, PUBLIC, INTERFACE has already been discussed in
those ML threads:
https://cmake.org/pipermail/cmake/2017-April/065340.html
https://cmake.org/pipermail/cmake/2016-May/063400.html

I guess we need some doc update.
I did promess contribution and I didn't do it.
I'll try again.


2018-01-08 10:45 GMT+01:00 J Decker <d3ck0r at gmail.com>:

>
> On Mon, Jan 8, 2018 at 1:41 AM, Franck Houssen <franck.houssen at inria.fr>
> wrote:
>
>>
>>
>> ----- Mail original -----
>> > De: "Rainer Poisel" <rainer.poisel at gmail.com>
>> > À: "Franck Houssen" <franck.houssen at inria.fr>
>> > Envoyé: Dimanche 7 Janvier 2018 19:34:21
>> > Objet: Re: [CMake] CMake: using dlopen
>> >
>> > Hi,
>> >
>> > On Sun, Jan 7, 2018 at 7:13 PM, Franck Houssen <franck.houssen at inria.fr
>> >
>> > wrote:
>> > > Difference between PUBLIC/PRIVATE has never been clear to me (usually
>> I
>> > > always use PUBLIC).
>> > > main.cpp includes dlfcn.h and uses it: not sure to get what you meant
>> > > (PRIVATE is for templates ? when a header include headers ?)
>> >
>> > you are looking for the "Transitive Dependencies" feature of CMake:
>>
>> OK, I didn't get that. It's more clear to me now. Thanks !
>>
>> >   *
>> >   https://cmake.org/cmake/help/v3.0/manual/cmake-buildsystem.
>> 7.html#transitive-usage-requirements
>> >
>> > Generally speaking and from my personal experience, use the
>> > target_-commands as much as possible because properties are bound to
>> > targets and their dependencies rather than a file/directory structure.
>> >
>> > So, that means, use target_include_directories(),
>> > target_compile_options(), target_compile_definitions(),
>> > target_sources(), ... for your targets. The magic keyword to propagate
>> > the properties of your targets is target_link_libraries(). Depending
>> > on what scope (PRIVATE, PUBLIC, INTERFACE) the properties have been
>> > defined using the other target_-commands, the target_link_libraries()
>> > command propagates these properties to other targets. E. g.
>> >
>> > add_library(otherlib SHARED
>> >   foo.c
>> > )
>> >
>> > target_include_directories(otherlib PRIVATE
>> >   dirPrivate
>> > )
>> >
>> > target_include_directories(otherlib PUBLIC
>> >   dirPublic
>> > )
>> >
>> > add_library(mylib SHARED
>> >   bar.c
>> > )
>> >
>> > target_link_libraries(mylib PRIVATE
>>
>> Is this a typo ?
>> For the example to work I would have done: target_link_libraries(mylib
>> PUBLIC otherLib), no ? (mylib needs only PUBLIC stuff's from otherLib but
>> not PRIVATE one's). Correct ?
>>
>>
> Public is whether it propagates outside of the current target to things
> that then require 'mylib'
> private keeps it within that target, has nothing to do with what it's
> pulling from any linked library.
>
>
>>
>> >   otherlib
>> > )
>> >
>> > In this case, mylib will use all PUBLIC or INTERFACE properties of
>> > otherlib for its build. Thus, dirPublic will be added to the include
>> > directory search path for the compilation of bar.c of mylib. PRIVATE
>> > properties will not be propagated. In the above mentioned example,
>> > dirPrivate will NOT be added to the include directory search path for
>> > the compilation of bar.c of mylib.
>> >
>>
>> The example is illustrative (transitivity - PRIVATE is not propagated)
>>
>> > This is a very short summary, but I hope it is of help to you. There
>> > are other ressources on the Internet. E. g.
>> >   *
>> >   https://stackoverflow.com/questions/26037954/cmake-target-
>> link-libraries-interface-dependencies
>> >   * https://rix0r.nl/blog/2015/08/13/cmake-guide/
>> >
>> > Regards,
>> >   Rainer
>> >
>> --
>>
>> Powered by www.kitware.com
>>
>> Please keep messages on-topic and check the CMake FAQ at:
>> http://www.cmake.org/Wiki/CMake_FAQ
>>
>> Kitware offers various services to support the CMake community. For more
>> information on each offering, please visit:
>>
>> CMake Support: http://cmake.org/cmake/help/support.html
>> CMake Consulting: http://cmake.org/cmake/help/consulting.html
>> CMake Training Courses: http://cmake.org/cmake/help/training.html
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Follow this link to subscribe/unsubscribe:
>> https://cmake.org/mailman/listinfo/cmake
>>
>
>
> --
>
> Powered by www.kitware.com
>
> Please keep messages on-topic and check the CMake FAQ at:
> http://www.cmake.org/Wiki/CMake_FAQ
>
> Kitware offers various services to support the CMake community. For more
> information on each offering, please visit:
>
> CMake Support: http://cmake.org/cmake/help/support.html
> CMake Consulting: http://cmake.org/cmake/help/consulting.html
> CMake Training Courses: http://cmake.org/cmake/help/training.html
>
> Visit other Kitware open-source projects at http://www.kitware.com/
> opensource/opensource.html
>
> Follow this link to subscribe/unsubscribe:
> https://cmake.org/mailman/listinfo/cmake
>
>


-- 
Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://cmake.org/pipermail/cmake/attachments/20180108/3ee6c723/attachment.html>