# Problems when trying to make out of tree modules **URL:** \ **Category:** GNU Radio\ **Created:** [May 13, 2015, 6:39pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934 "2015-05-13T18:39:22Z")\ **Posts on this page:** 8\ **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:** [May 13, 2015, 6:39pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/1 "2015-05-13T18:39:22Z")
Dear All, I am trying to make an out of tree module by following the tutorial on Gnu radio website. I can write simple blocks in C++, compile it and install it to it usable in Gnuradio company. But for some complex block, I want to implement them based on the gnuradio build-in blocks, for example, clock\_recovery\_mm\_ff. So I make a new block in my out-of-tree module and try to first “copy” the build-in block into my out-of-tree module. I changed the following 4 files in my OOT module to match the corresponding files of the build-in block: lib/my\_block\_impl.cc lib/my\_block\_impl.h include/my\_block.h grc/my\_block.xml In each file, I changed all the “clock\_recovery\_mm\_ff” into “my\_block”. I can successfully make and install the block without error and warring. But when I try to run the grc graph, an error happens. AttributeError: ‘module’ object has no attribute ‘my\_block’. Anyone can tell me what I should do to correct this error? Is there any other files I should change? When I make simple blocks by myself, I only change this 4 files and it works. Best regards, Su Li ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 13, 2015, 6:48pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/2 "2015-05-13T18:48:08Z")
Hi Su Li, have you added the new source files to the CMakeLists.txt in lib, include and grc? Do these block have the YOURMODULE\_API property? Best regards, Marcus ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 13, 2015, 7:12pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/3 "2015-05-13T19:12:40Z")
Hi Marcus, Thank you for your reply. The source files are added to the CMakeLists.text files. But they are not added by my self, they are added when I use “gr\_modtool add -t general my\_block” and “gr\_modtool makexml my\_block” to make a new block and xml file. Only the my\_block.h file in include directory contains API class MY\_MODULE\_API my\_block : virtual public gr::block { … } Could you please tell me how to check the API property for the block? Thanks in advance. Best regards, Su 2015-05-13 18:47 GMT+02:00 Marcus Müller [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 14, 2015, 2:34pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/4 "2015-05-14T14:34:01Z")
Hi Peter, Thanks for your reply and suggestions. I checked all the 4 files. I changed the original module and block names of build-in block into my module and block names. But unfortunately, the error still exists. Could it be possibly because the build-in block, in my case “clock\_recovery\_mm\_ff” block, has some special dependency which is included in the code of the module but not in the code of the block. The type of “clock\_recovery\_mm\_ff” block is abnormal. It is just block, not gr::block nor gr::sync\_block as mentioned in the OOT tutorial . Here is the code of declaration of this block in \*.h file in “include” folder. class DIGITAL\_API clock\_recovery\_mm\_ff : virtual public block In my code, I change it into class MY\_MODULE\_API my\_block : virtual public block Thank you for your reply again. Best regards, Su Li 2015-05-13 20:36 GMT+02:00 Peter M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 13, 2015, 8:38pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/5 "2015-05-13T20:38:33Z")
I’ve had a similar problem when I generated files for my own module using the gr\_modtool and then copied some existing code by replacing the file(s) that gr\_modtool generates. It turns out I had overlooked that the new “my\_block” name needs to be changed in several places, like the namespace declaration, the #include compiler directive, and the conditional #ifndef INCLUDED … directives. Once I updated that correctly the AttributeError got resolved. -Peter- ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 15, 2015, 11:48am UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/6 "2015-05-15T11:48:45Z")
Hi all, I found the problem. In my OOT block, I try to use mmse\_fir\_interpolator. Thus, in the my\_block\_impl.h file I use the following code to include the fir interpolator: _#include \_ But when I run ctest for my block, I got the following error: _ImportError: /home/suli/gr-ctia802\_15\_4/build/lib/libgnuradio-ctia802\_15\_4.so: undefined symbol: \_ZN2gr6filter24mmse\_fir\_interpolator\_ffC1Ev_ where ctia802\_15\_4 is my OOT module name. It seems that this fir filter is not correctly included. Anyone can tell me how to fix it? Thanks in advance. Best regards, Su Li 2015-05-14 14:33 GMT+02:00 Su Li [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 15, 2015, 2:50pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/7 "2015-05-15T14:50:26Z")
There’s a GR\_REQUIRED\_COMPONENTS CMake variable[e.g. 1]; add FILTER. Best regards, Marcus [1] > Am 15. Mai 2015 11:47:51 MESZ, schrieb Su Li [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): ---
**Author:** ![Su\_Li](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/b9e5f3/32.png) [@Su\_Li](https://www.ruby-forum.com/u/Su_Li)\ **Post date:** [May 16, 2015, 8:12pm UTC](https://www.ruby-forum.com/t/problems-when-trying-to-make-out-of-tree-modules/241934/8 "2015-05-16T20:12:19Z")
Hi Marcus, Thanks a lot. It works now. Best regards, Su 2015-05-15 14:49 GMT+02:00 Marcus Müller [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):