Add gazebo7 to travis

[triccyx]

Execute Trevis before merge the branch, as at the moment I can't compile with Gazebo7

[traversaro]

It seems that there are still compilation problems in Gazebo 7, see https://travis-ci.com/robotology/gazebo-fmi/jobs/152525711#L6251 .

Scanning dependencies of target FMIActuatorPluginTest
[100%] Building CXX object plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/FMIActuatorPluginTest.cc.o
/home/travis/build/robotology/gazebo-fmi/plugins/actuator/test/FMIActuatorPluginTest.cc: In member function 'void FMIActuatorPluginTest::PluginTestHelper(const string&, const string&, const FMIActuatorPluginTest::PluginTestHelperOptions&)':
/home/travis/build/robotology/gazebo-fmi/plugins/actuator/test/FMIActuatorPluginTest.cc:45:54: error: 'class gazebo::physics::World' has no member named 'Physics'
   gazebo::physics::PhysicsEnginePtr physics = world->Physics();
                                                      ^
/home/travis/build/robotology/gazebo-fmi/plugins/actuator/test/FMIActuatorPluginTest.cc:52:23: error: 'class gazebo::physics::World' has no member named 'ModelByName'
   auto model = world->ModelByName("pendulum_with_base");
                       ^
plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/build.make:62: recipe for target 'plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/FMIActuatorPluginTest.cc.o' failed
make[2]: *** [plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/FMIActuatorPluginTest.cc.o] Error 1
CMakeFiles/Makefile2:851: recipe for target 'plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/all' failed
make[1]: *** [plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2

[traversaro]

Can you just remove this line

Suggested change

add_compile_options(-std=c++11)

and just add a

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

in the main CMakeLists.txt? See https://crascit.com/2015/03/28/enabling-cxx11-in-cmake/ for more discussion. Setting directly the compile options is not ideal because it could create problems if at some point Gazebo uses a newer version of the standard (such as C++17) and so both -std=c++11 and -std=c++17 and the actual standard used by the compile will may be non properly defined.

[traversaro]

Suggested change

add_compile_options(-std=c++11)

as suggested in the libraries/private-utils/CMakeLists.txt comment

[traversaro]

Friendly ping @triccyx .

[triccyx]

Ok done but can't try on gazebo 7

[traversaro]

There is is still the add_compile_options(-std=c++11) in libraries/private-utils/CMakeLists.txt . Can you remove this from here and move the set(CMAKE_CXX_STANDARD in the main CMakeLists.txt, so we do not need to duplicate it?

[traversaro]

You can accept by suggest change just with a click, see https://help.github.com/articles/incorporating-feedback-in-your-pull-request/ .

[traversaro]

See #44 (comment) .

[traversaro]

The last remaining problem is some linker error when linking the tests with Gazebo 7 ( https://travis-ci.com/robotology/gazebo-fmi/jobs/196013982 ) :

Scanning dependencies of target FMIActuatorPluginTest
[100%] Building CXX object plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/FMIActuatorPluginTest.cc.o
[100%] Linking CXX executable ../../../bin/FMIActuatorPluginTest
/usr/bin/ld: /usr/lib/x86_64-linux-gnu/libgazebo_physics.so: undefined reference to symbol '_ZN6gazebo9transport4Node4FiniEv'
/usr/lib/x86_64-linux-gnu/libgazebo_transport.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/build.make:151: recipe for target 'bin/FMIActuatorPluginTest' failed
make[2]: *** [bin/FMIActuatorPluginTest] Error 1
CMakeFiles/Makefile2:851: recipe for target 'plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/all' failed
make[1]: *** [plugins/actuator/test/CMakeFiles/FMIActuatorPluginTest.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2

The issue is probably in Gazebo, and related to how the Gazebo Server fixture is exported. As the problem is not present in later Gazebo versions, I think it is safe to just test normal compilation on Gazebo7, and disable test for that specific build.

[traversaro]

Fixed and rebased.