[BodyYarp] devices should be shared libraries

[jgvictores]

[BodyYarp] devices should be shared libraries (currently static).

[jgvictores]

Working on this in teo-main first: https://github.com/roboticslab-uc3m/teo-main/issues/60

[jgvictores]

Essentially https://github.com/jgvictores/example-yarp-plugin-gtest is a good example of a repository containing a YARP plugin compiled as a shared library. Important:

1. In root CMake of repo (maybe in teo-body could be elsewhere):
   option(BUILD_SHARED_LIBS "All shared libs" TRUE)
2. In reality, yarp_begin_plugin_library and yarp_end_plugin_library (line 9 and line 11 of the library parent directory) are not actually required for shared libraries.
3. Need new .ini file per plugin. Just imitate ExampleLibrary.ini.
4. Need to adapt CMakeLists.txt per plugin. Just imitate the CMakeLists.txt of ExampleLibrary.

[jgvictores]

Just in case, I would also recommend having YARP installed with CREATE_SHARED_LIBRARY activated.

[jgvictores]

PS: From https://github.com/asrob-uc3m/robotDevastation-robots I've just seen that https://github.com/jgvictores/example-yarp-plugin-gtest is not updated to the latest of YARP. Here are the two relevant fixes:

• update yarp_prepare_device -> yarp_prepare_plugin with CATEGORY device
• WRAPPER RobotServer -> EXTRA_CONFIG WRAPPER=RobotServer

[PeterBowman]

@jgvictores EXTRA_CONFIG is a recent addition to the yarp_prepare_plugin command, it won't work with pre-2.3.68 YARP.

[rsantos88]

I tried to do the first shared library with CanBusControlboard. Here is the commit but, when I've tried to do cmake .., it shows this:

-- The C compiler identification is GNU 5.2.1
-- The CXX compiler identification is GNU 5.2.1
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Libraries go to /home/teo/repos/rsantos88/teo-body/build/lib
-- Executables go to /home/teo/repos/rsantos88/teo-body/build/bin
-- Setting up installation of teo-body.ini to /usr/local/share/yarp/config/path.d folder.
--  +++ plugin CuiAbsolute, SKIP_CuiAbsolute is set
--  +++ plugin TechnosoftIpos, SKIP_TechnosoftIpos is set
--  +++ plugin LacqueyFetch, SKIP_LacqueyFetch is set
--  +++ plugin TextilesHand, SKIP_TextilesHand is set
--  +++ plugin FakeJoint, SKIP_FakeJoint is set
--  +++ plugin CanBusHico, SKIP_CanBusHico is set
--  +++ plugin CanBusControlboard, SKIP_CanBusControlboard is set
CMake Error at libraries/BodyYarp/CMakeLists.txt:32 (install):
  install TARGETS given target "BodyYarp" which does not exist in this
  directory.


CMake Error: Could not open file for write in copy operation /BodyYarp_yarpdev.cpp.tmp
CMake Error: : System Error: Permission denied
CMake Error at /usr/local/share/yarp/cmake/YarpPlugin.cmake:357 (configure_file):
  configure_file Problem configuring file
Call Stack (most recent call first):
  libraries/BodyYarp/CMakeLists.txt:36 (YARP_ADD_PLUGIN_YARPDEV_EXECUTABLE)


CMake Error at libraries/BodyYarp/CMakeLists.txt:37 (install):
  install TARGETS given target "launchBodyYarp" which does not exist in this
  directory.


-- Found PythonInterp: /usr/bin/python (found version "2.7.10") 
-- Looking for include file pthread.h
-- Looking for include file pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Configuring incomplete, errors occurred!
See also "/home/teo/repos/rsantos88/teo-body/build/CMakeFiles/CMakeOutput.log".
See also "/home/teo/repos/rsantos88/teo-body/build/CMakeFiles/CMakeError.log".

[rsantos88]

Now, with this commit, the last problem was solved, but when I try to compile, it shows this error:

[ 46%] Building CXX object programs/recordLocomotion/CMakeFiles/recordLocomotion.dir/RecordRateThread.cpp.o
[ 50%] /usr/local/lib/libBodyYarp.a(add_BodyYarp_plugins.cpp.o): En la función `add_BodyYarp_plugins':
add_BodyYarp_plugins.cpp:(.text+0x1f): referencia a `add_owned_CuiAbsolute(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x29): referencia a `add_owned_TechnosoftIpos(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x33): referencia a `add_owned_LacqueyFetch(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x3d): referencia a `add_owned_TextilesHand(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x47): referencia a `add_owned_FakeJoint(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x51): referencia a `add_owned_CanBusHico(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x5b): referencia a `add_owned_CanBusControlboard(char const*)' sin definir
collect2: error: ld returned 1 exit status
programs/recordManipulation/CMakeFiles/recordManipulation.dir/build.make:166: recipe for target 'bin/recordManipulation' failed
make[2]: *** [bin/recordManipulation] Error 1
CMakeFiles/Makefile2:869: recipe for target 'programs/recordManipulation/CMakeFiles/recordManipulation.dir/all' failed
make[1]: *** [programs/recordManipulation/CMakeFiles/recordManipulation.dir/all] Error 2
Building CXX object programs/playbackLocomotion/CMakeFiles/playbackLocomotion.dir/PlaybackThread.cpp.o
[ 53%] Building CXX object programs/playbackLocomotion/CMakeFiles/playbackLocomotion.dir/main.cpp.o
Linking CXX executable ../../bin/recordLocomotion
Linking CXX executable ../../bin/playbackLocomotion
/usr/local/lib/libBodyYarp.a(add_BodyYarp_plugins.cpp.o): En la función `add_BodyYarp_plugins':
add_BodyYarp_plugins.cpp:(.text+0x1f): referencia a `add_owned_CuiAbsolute(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x29): referencia a `add_owned_TechnosoftIpos(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x33): referencia a `add_owned_LacqueyFetch(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x3d): referencia a `add_owned_TextilesHand(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x47): referencia a `add_owned_FakeJoint(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x51): referencia a `add_owned_CanBusHico(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x5b): referencia a `add_owned_CanBusControlboard(char const*)' sin definir
collect2: error: ld returned 1 exit status
programs/recordLocomotion/CMakeFiles/recordLocomotion.dir/build.make:141: recipe for target 'bin/recordLocomotion' failed
make[2]: *** [bin/recordLocomotion] Error 1
CMakeFiles/Makefile2:969: recipe for target 'programs/recordLocomotion/CMakeFiles/recordLocomotion.dir/all' failed
make[1]: *** [programs/recordLocomotion/CMakeFiles/recordLocomotion.dir/all] Error 2
/usr/local/lib/libBodyYarp.a(add_BodyYarp_plugins.cpp.o): En la función `add_BodyYarp_plugins':
add_BodyYarp_plugins.cpp:(.text+0x1f): referencia a `add_owned_CuiAbsolute(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x29): referencia a `add_owned_TechnosoftIpos(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x33): referencia a `add_owned_LacqueyFetch(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x3d): referencia a `add_owned_TextilesHand(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x47): referencia a `add_owned_FakeJoint(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x51): referencia a `add_owned_CanBusHico(char const*)' sin definir
add_BodyYarp_plugins.cpp:(.text+0x5b): referencia a `add_owned_CanBusControlboard(char const*)' sin definir
collect2: error: ld returned 1 exit status
programs/playbackLocomotion/CMakeFiles/playbackLocomotion.dir/build.make:141: recipe for target 'bin/playbackLocomotion' failed
make[2]: *** [bin/playbackLocomotion] Error 1
CMakeFiles/Makefile2:1019: recipe for target 'programs/playbackLocomotion/CMakeFiles/playbackLocomotion.dir/all' failed
make[1]: *** [programs/playbackLocomotion/CMakeFiles/playbackLocomotion.dir/all] Error 2
Makefile:116: recipe for target 'all' failed
make: *** [all] Error 2

[PeterBowman]

You are still linking to /usr/local/lib/libBodyYarp.a somewhere, in my case the compiler doesn't even get that far if libBodyYarp.a is not installed.

[PeterBowman]

@jgvictores

2. In reality, yarp_begin_plugin_library and yarp_end_plugin_library (line 9 and line 11 of the library parent directory) are not actually required for shared libraries.

I'd keep them as long as the BUILD_SHARED_LIBS option/variable is not forced since users may still want to link statically. Similarly, yarp_add_plugin_yarpdev_executable CMake plugin and YARP_DECLARE_PLUGINS / YARP_REGISTER_PLUGINS C macros (used in main.cpp in most programs) should be kept for the same reason.

Just as a side note: if the yarp_begin_plugin_library / yarp_end_plugin_library bundle is omitted and BUILD_SHARED_LIBS is set, all contained plugins are disabled by default (as you can see here: SKIP_CuiAbsolute is set and so on) in that they will still compile, but cannot be dynamically loaded.

[jgvictores]

In fact, the consequences are quite brutal regarding code and cmake (take a look at the current SharedLibraries branch at https://github.com/roboticslab-uc3m/teo-body/network). I'm extremely inclined to force shared libraries, keeping static libraries seems like a giant effort (possibly requiring ugly hacks or at least ugly code) with no visible benefits.

PS: SKIP_CuiAbsolute etc were SKIP_BodyYarp_CuiAbsolute etc before. This has been corrected on the branch (https://github.com/rsantos88/teo-body/commit/7a7b378cb1c32dc69f4a89b690d1a634e7891664).

[PeterBowman]

I believe some of those changes would be necessary even for static libraries in terms of a major cleanup, I just recently found that instructions like this do not make much sense (apart from populating a public interface, which may or may not be intended):

target_link_libraries(TEO_BODY_STATIC_PLUGIN ${YARP_LIBRARIES} ${TEO_BODY_LIBRARIES})

It might not be that hard nor hackish to provide support for static libraries. Having that said, I'm not against forcing shared YARP plugins/TEO libraries/both, but in that case, I'd stress that BUILD_SHARED_LIBS should be set as a CMake variable rather than an user-configurable option. BTW there is a YARP variable available from 2.3.64 that could be investigated: YARP_FORCE_DYNAMIC_PLUGINS.

[PeterBowman]

@jgvictores you might also want to add b342044 to the list at #51 (comment).

[jgvictores]

Done at 92a3cf7.