Re: [Discuss-gnuradio] Linking gr-digital in OOT Module (Success on OSX, fails on Linux)

[Garver, Paul W]

The module library builds without linker errors. The block which calls viterbi_algorithm_combined() is rfid_decode.

[12%] Linking CXX shared library libgnuradio-pwg-1.0.0git.so
/usr/bin/c++  -fPIC -O3 -DNDEBUG  -shared -Wl,-soname,libgnuradio-pwg-1.0.0git.so.0.0.0 -o libgnuradio-pwg-1.0.0git.so.0.0.0 CMakeFiles/gnuradio-pwg.dir/rfid_decode_impl.cc.o CMakeFiles/gnuradio-pwg.dir/rfid_channel_switch_impl.cc.o -lboost_filesystem -lboost_system /usr/local/lib/libgnuradio-runtime.so /usr/local/lib/libgnuradio-pmt.so /usr/local/lib/libgnuradio-digital.so /usr/local/lib/libgnuradio-trellis.so -Wl,-rpath,/usr/local/lib:
[ 12%] Built target gnuradio-pwg

But the pure C++ test harness fails to link properly:

[ 95%] Building CXX object examples/c++/CMakeFiles/rfid_dec_harness.dir/rfid_dec_harness.cc.o
[100%] Linking CXX executable rfid_dec_harness
/usr/bin/c++   -O3 -DNDEBUG   CMakeFiles/rfid_dec_harness.dir/rfid_dec_harness.cc.o  -o rfid_dec_harness -rdynamic ../../lib/libgnuradio-pwg-1.0.0git.so.0.0.0 -lgnuradio-blocks -lboost_filesystem -lboost_system /usr/local/lib/libgnuradio-runtime.so /usr/local/lib/libgnuradio-pmt.so /usr/local/lib/libgnuradio-digital.so /usr/local/lib/libgnuradio-trellis.so -Wl,-rpath,/home/paul/git_repos/gr-pwg/build/lib:/usr/local/lib:
../../lib/libgnuradio-pwg-1.0.0git.so.0.0.0: undefined reference to `void gr::trellis::viterbi_algorithm_combined<float, unsigned char>(int, int, int, std::vector<int, std::allocator<int> > const&, std::vector<int, std::allocator<int> > const&, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > const&, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > const&, int, int, int, int, std::vector<float, std::allocator<float> > const&, gr::digital::trellis_metric_type_t, float const*, unsigned char*)'
collect2: error: ld returned 1 exit status

The symbol exists in libgnuradio-trellis!

nm /usr/local/lib/libgnuradio-trellis.so | grep -i viterbi_algorithm_combined | c++filt

000000000007df30 t void gr::trellis::viterbi_algorithm_combined<float, unsigned char>(int, int, int, std::vector<int, std::allocator<int> > const&, std::vector<int, std::allocator<int> > const&, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > const&, std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > > const&, int, int, int, int, std::vector<float, std::allocator<float> > const&, gr::digital::trellis_metric_type_t, float const*, unsigned char*)

Now, I know order matters into g++. I've tried various linking orders to no avail. I just do not understand why g++ can't find the symbol.

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From: Michael Dickens <address@hidden>
Sent: Thursday, November 17, 2016 11:04:09 AM
To: Garver, Paul W
Cc: address@hidden
Subject: Re: [Discuss-gnuradio] Linking gr-digital in OOT Module (Success on OSX, fails on Linux)

 

The lib/ and swig/ libraries used inside cmake are generally the same. I'll be very curious how this issue pans out! Cheers! - MLD

On Thu, Nov 17, 2016, at 08:13 AM, Garver, Paul W wrote:

I’m thinking I should write a simple C++ harness to call the block. That way, I can isolate a SWIG problem from a block/C++ issue. Should the SWIG link libraries (GR_SWIG_LIBRARIES) be different from the libraries used in the lib directory?