Re: [Discuss-gnuradio] Link libraries to a OOT block

[Tom Rondeau]

On Mon, Dec 9, 2013 at 9:53 AM, James Austin <address@hidden> wrote:
> Hi Martin,
>
> I did look through the CMake documentation and was trying different things
> with the target_link_libraries tag, with no success.
>
> What I am trying to do is (and this may be a solved problem already) build a
> gnuradio block for the RFSpaces SDR-IQ receiver. This is mostly for me to
> become more familiar with Linux programming and to learn more about Python.
>
> I wrote a library that is able to retrieve data from the SDR-IQ and it is
> called libsdriq.a, now I want to use that library with gnuradio. Following
> the gnuradio tutorial on out of tree blocks, I created a block called
> gr-sdriq and it works fine with dummy data, has a complex output port and
> outputs a cosine and sine to the real and imaginary parts and I can see the
> data as expected in gnuradio. My problem is getting the gnuradio block  to
> use my libsdriq.a library and that is where things are breaking. Compiling
> is not a problem, but linking is not producing a gnuradio block that
> includes my libsdriq.a.
>
> I've looked through some gnuradio blocks to see if I could find something
> similar and through CMake documentation. This is likely solved through
> CMake, but haven't figured it out yet.
>
> Jim

Jim,

You're on the right track with using the target_link_libraries. I
think your mail problem is using an archive library (the libsdriq.a).
While it's possible, you don't really want to use a static archive
like that. Look into building that into a shared object library (.so)
instead. That will be easier to use with the cmake tools.

Also, when asking questions about a problem you're having, providing
us with the error results you're seeing would help us help you better.

Tom



> On Sun, Dec 8, 2013 at 9:24 AM, Martin Braun (CEL) <address@hidden>
> wrote:
>>
>> On Sat, Dec 07, 2013 at 08:40:45PM -0500, James Austin wrote:
>> > I'm a long time Windows programmer trying to write a gnuradio module to
>> > improve
>> > my Linux development skills.
>> >
>> > I created a gnuradio module following the tutorial that just sends dummy
>> > data
>> > back to gnuradio. That works fine, I can plot the dummy data in my
>> > flowgraph
>> > and it works and displays as expected.
>> >
>> > I also created a static library that produces data, no reason I can't
>> > make it a
>> > shared library if that is the solution.
>> >
>> > My problem is trying to get the gnuradio module to link against the
>> > static
>> > library, so that the data produced by this library can be fed into
>> > gnuradio. I
>> > haven't been able to figure out the cmake magic to make this happen. I
>> > get a
>> > variety of error messages on everything I try.
>> >
>> > Does anyone have any hints to get me past this?
>>
>> Hey Jim,
>>
>> you're not giving us much to work on here. You might want to specify
>> what exactly you're linking to, and what you've tried.
>>
>> What you're trying to do seems like a cmake problem, so checking cmake
>> tutorials (unrelated to GNU Radio) might help.
>>
>> Most often, you want your C++ blocks to access some library. This would
>> mean editing the lib/CMakeLists.txt file to make sure you're linking to
>> the right libs.
>>
>> MB
>>
>> --
>> Karlsruhe Institute of Technology (KIT)
>> Communications Engineering Lab (CEL)
>>
>> Dipl.-Ing. Martin Braun
>> Research Associate
>>
>> Kaiserstraße 12
>> Building 05.01
>> 76131 Karlsruhe
>>
>> Phone: +49 721 608-43790
>> Fax: +49 721 608-46071
>> www.cel.kit.edu
>>
>> KIT -- University of the State of Baden-Württemberg and
>> National Laboratory of the Helmholtz Association