# "make" error while making detector (howto\_detect\_ff) block **URL:** \ **Category:** GNU Radio\ **Created:** [March 29, 2015, 3:17pm UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321 "2015-03-29T15:17:32Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Post date:** [March 29, 2015, 3:17pm UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321/1 "2015-03-29T15:17:32Z")
hey, I am working to make a detector block in gnuradio 3.7.1 using gr-how “out-of-tree module”. I am stuck with an error during make command abhishek@abhishek-Inspiron-N5110:~/gr-howto/build$ make Scanning dependencies of target gnuradio-howto [5%] Building CXX object lib/CMakeFiles/gnuradio-howto.dir/howto\_detect\_ff\_impl.cc.o /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:37:5: error: ‘howto\_detect\_ff\_sptr’ does not name a type howto\_detect\_ff\_sptr ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc: In constructor ‘gr::howto::howto\_detect\_ff\_impl::howto\_detect\_ff\_impl(float, int, int)’: /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:59:17: error: expression cannot be used as a function d\_pfa(pfa), d\_L(L), d\_samples(samples) ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:59:25: error: expression cannot be used as a function d\_pfa(pfa), d\_L(L), d\_samples(samples) ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:59:45: error: expression cannot be used as a function d\_pfa(pfa), d\_L(L), d\_samples(samples) ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:185:1: error: expected ‘{’ before ‘}’ token } /\* namespace howto \*/ ^ make[2]: \*\*\* [lib/CMakeFiles/gnuradio-howto.dir/howto\_detect\_ff\_impl.cc.o] Error 1 make[1]: \*\*\* [lib/CMakeFiles/gnuradio-howto.dir/all] Error 2 make: \*\*\* [all] Error 2 Os is ubuntu 14.04. Even i have attached howto\_detect\_ff\_impl.h, howto\_detect\_ff\_impl.cc and howto\_swig.i file. It seems that some mistake is there in howto\_detect\_ff.h file whose path is gr-howto/include/howto. But i am not getting what exactly it is Any solution to sort an error will be appreciated. Thanks in advance, Abhishek. ---
**Author:** ![abhishek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7ba0ec/32.png) [@abhishek](https://www.ruby-forum.com/u/abhishek)\ **Post date:** [March 29, 2015, 3:28pm UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321/2 "2015-03-29T15:28:05Z")
Hi Abhishek, your \_impl.cc is using old-style naming in out-of-tree-modules and their components, whilst your detect\_ff.h uses the consistent new way. I think this could be the result of using gr\_modtool to generate the module skeleton, and then copy/pasting over lines from a pre-3.7 code example. Is that possible? Also, I already pointed you to the newer guided tutorials[1], which don’t build on the unmaintained gr-howto example. Please use these to get used to GNU Radio. Greetings, Marcus [1] [https://gnuradio.org/redmine/projects/gnuradio/wiki/Guided\_Tutorials](https://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorials) ---
**Author:** ![abhishek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7ba0ec/32.png) [@abhishek](https://www.ruby-forum.com/u/abhishek)\ **Post date:** [April 1, 2015, 6:30am UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321/3 "2015-04-01T06:30:33Z")
hey marcus, here error given is, could not insert function, but we can according to “[http://gnuradio.org/redmine/projects/gnuradio/wiki/BlocksCodingGuide#Public-Header-Files](http://gnuradio.org/redmine/projects/gnuradio/wiki/BlocksCodingGuide#Public-Header-Files)”. Even i am not able to get last and second last error of expected “(” and “{”, but in the code all brackets are up to the mark and used properly. abhishek@abhishek-Inspiron-N5110:~/gr-howto/build$ make Scanning dependencies of target gnuradio-howto [5%] Building CXX object lib/CMakeFiles/gnuradio-howto.dir/howto\_detect\_ff\_impl.cc.o In file included from /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:27:0: /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.h:40:7: error: ???gr::howto::howto\_detect\_ff\_impl::howto\_detect\_ff\_impl(float, int, int)??? cannot be overloaded howto\_detect\_ff\_impl(float pfa, int L, int samples); ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.h:37:6: error: with ???gr::howto::howto\_detect\_ff\_impl::howto\_detect\_ff\_impl(float, int, int)??? howto\_detect\_ff\_impl (float pfa, int L, int samples); ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:37:27: error: prototype for ???gr::howto::howto\_detect\_ff::sptr gr::howto::howto\_detect\_ff::make(float, int, int)??? does not match any in class ???gr::howto::howto\_detect\_ff??? howto\_detect\_ff::sptr howto\_detect\_ff::make(float pfa, int L, int samples) ^ In file included from /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.h:24:0, from /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:27: /home/abhishek/gr-howto/include/howto/howto\_detect\_ff.h:49:19: error: candidate is: static gr::howto::howto\_detect\_ff::sptr gr::howto::howto\_detect\_ff::make() static sptr make(); ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc: In constructor ???gr::howto::howto\_detect\_ff\_impl::howto\_detect\_ff\_impl(float, int, int)???: /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:57:71: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11 [enabled by default] gr::io\_signature::make (MIN\_OUT, MAX\_OUT, sizeof(float)), ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:66:5: error: expected ???)??? before ???(??? token (howto\_detect\_ff\_impl()::~howto\_detect\_ff\_impl()) ^ /home/abhishek/gr-howto/lib/howto\_detect\_ff\_impl.cc:187:1: error: expected ???{??? before ???}??? token } /\* namespace howto \*/ ^ make[2]: \*\*\* [lib/CMakeFiles/gnuradio-howto.dir/howto\_detect\_ff\_impl.cc.o] Error 1 make[1]: \*\*\* [lib/CMakeFiles/gnuradio-howto.dir/all] Error 2 make: \*\*\* [all] Error 2 Could you please help me out with all individual errors. Attachment of al the 3 files are provided. Thanks in advance, Abhishek. ---
**Author:** ![abhishek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7ba0ec/32.png) [@abhishek](https://www.ruby-forum.com/u/abhishek)\ **Post date:** [April 5, 2015, 5:27pm UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321/4 "2015-04-05T17:27:19Z")
hey Marcus, Now, I am able to import detect\_ff block. But while running an example using that block, i am stuck with a runtime error File “/usr/local/lib/python2.7/dist-packages/howto/howto\_swig.py”, line 24, in swig\_import\_helper \_mod = imp.load\_module(‘\_howto\_swig’, fp, pathname, description) ImportError: /usr/local/lib/libgnuradio-howto.so: undefined symbol: gsl\_matrix\_alloc > > > Done Hence not able to generate flow graph. Screen shot of given example is attached. Also i have attached .cc file of detect\_ff block. Would you please help me out with this error. Thanks in advance, Abhishek On Wed, Apr 1, 2015 at 1:44 PM, Marcus Müller [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![abhishek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7ba0ec/32.png) [@abhishek](https://www.ruby-forum.com/u/abhishek)\ **Post date:** [April 5, 2015, 7:17pm UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321/5 "2015-04-05T19:17:55Z")
Hey Abishek, happy easter. How did you you generate your module? gr\_modtool? Does it use any matrix methods from GSL? Greetings, Marcus ---
**Author:** ![abhishek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7ba0ec/32.png) [@abhishek](https://www.ruby-forum.com/u/abhishek)\ **Post date:** [April 1, 2015, 10:15am UTC](https://www.ruby-forum.com/t/make-error-while-making-detector-howto-detect-ff-block/241321/6 "2015-04-01T10:15:55Z")
Hi Abhishek, that guide refers to a somewhat outdated API, so it doesn’t apply to your case (that guide refers to an architecture where there was no separate \_impl class). Have you read the guided tutorials and their chapter on C++ blocks? It’s explaining how you can add functions to blocks. I’d personally recommend just starting anew, sticking to the guided tutorials; wherever you got your guidance from, it mixes things that apply to different versions of GNU Radio, and debugging this is really not worth it when you could as well just start with a clean slate and learn things _right_. Best regards, Marcus