The Visibility bug from issue 242's back

[Philippe593]

Hi,

While compiling, cmake throws a cog with these messages :

[ 70%] Building CXX object adaptations/CMakeFiles/knobkraft-generic-adaptation.dir/CreateNewAdaptationDialog.cpp.o In file included from /home/philippe/git/KnobKraft-orm/adaptations/CreateNewAdaptationDialog.cpp:9: /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:50:65: warning: ‘visibility’ attribute ignored [-Wattributes] 50 | #define DEFAULT_VISIBILITY __attribute__((visibility("default"))) | ^ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:189:52: note: in expansion of macro ‘DEFAULT_VISIBILITY’ 189 | pybind11::module adaptation_module DEFAULT_VISIBILITY; | ^~~~~~~~~~~~~~~~~~ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:56:15: warning: ‘knobkraft::GenericAdaptation’ declared with greater visibility than the type of its field ‘knobkraft::GenericAdaptation::adaptation_module’ [-Wattributes] 56 | class GenericAdaptation : public midikraft::Synth, public midikraft::SimpleDiscoverableDevice, | ^~~~~~~~~~~~~~~~~ [ 70%] Building CXX object adaptations/CMakeFiles/knobkraft-generic-adaptation.dir/GenericAdaptation.cpp.o In file included from /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.cpp:7: /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:50:65: warning: ‘visibility’ attribute ignored [-Wattributes] 50 | #define DEFAULT_VISIBILITY __attribute__((visibility("default"))) | ^ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:189:52: note: in expansion of macro ‘DEFAULT_VISIBILITY’ 189 | pybind11::module adaptation_module DEFAULT_VISIBILITY; | ^~~~~~~~~~~~~~~~~~ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:56:15: warning: ‘knobkraft::GenericAdaptation’ declared with greater visibility than the type of its field ‘knobkraft::GenericAdaptation::adaptation_module’ [-Wattributes] 56 | class GenericAdaptation : public midikraft::Synth, public midikraft::SimpleDiscoverableDevice, | ^~~~~~~~~~~~~~~~~ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:50:65: warning: ‘visibility’ attribute ignored [-Wattributes] 50 | #define DEFAULT_VISIBILITY __attribute__((visibility("default"))) | ^ /home/philippe/git/KnobKraft-orm/adaptations/PythonUtils.h:32:34: note: in expansion of macro ‘DEFAULT_VISIBILITY’ 32 | pybind11::object _stdout DEFAULT_VISIBILITY; | ^~~~~~~~~~~~~~~~~~ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:50:65: warning: ‘visibility’ attribute ignored [-Wattributes] 50 | #define DEFAULT_VISIBILITY __attribute__((visibility("default"))) | ^ /home/philippe/git/KnobKraft-orm/adaptations/PythonUtils.h:33:34: note: in expansion of macro ‘DEFAULT_VISIBILITY’ 33 | pybind11::object _stderr DEFAULT_VISIBILITY; | ^~~~~~~~~~~~~~~~~~ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:50:65: warning: ‘visibility’ attribute ignored [-Wattributes] 50 | #define DEFAULT_VISIBILITY __attribute__((visibility("default"))) | ^ /home/philippe/git/KnobKraft-orm/adaptations/PythonUtils.h:34:41: note: in expansion of macro ‘DEFAULT_VISIBILITY’ 34 | pybind11::object _stdout_buffer DEFAULT_VISIBILITY; | ^~~~~~~~~~~~~~~~~~ /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.h:50:65: warning: ‘visibility’ attribute ignored [-Wattributes] 50 | #define DEFAULT_VISIBILITY __attribute__((visibility("default"))) | ^ /home/philippe/git/KnobKraft-orm/adaptations/PythonUtils.h:35:41: note: in expansion of macro ‘DEFAULT_VISIBILITY’ 35 | pybind11::object _stderr_buffer DEFAULT_VISIBILITY; | ^~~~~~~~~~~~~~~~~~ In file included from /home/philippe/git/KnobKraft-orm/adaptations/GenericAdaptation.cpp:13: /home/philippe/git/KnobKraft-orm/adaptations/PythonUtils.h:20:7: warning: ‘PyStdErrOutStreamRedirect’ declared with greater visibility than the type of its field ‘PyStdErrOutStreamRedirect::_stdout’ [-Wattributes] 20 | class PyStdErrOutStreamRedirect { | ^~~~~~~~~~~~~~~~~~~~~~~~~
I searched the issues and saw it had been solved with issue 242.
Seems it's back, unfortunately.
Any ideas on how to kill it for good ?
TIA
Philippe

[christofmuc]

Hm, I looked at that but the fix from back then was only to make the warning as error go away on Linux.

Can you give a bit more info on what platform you are on, and which compiler version you are using? We have builds that work on Ubuntu 22 and Ubuntu 24, but other platforms might differ. I recall this was about the gcc version, what are you seeing?

[Philippe593]

My gcc version is 14.2, on Ubuntu 24.10.

[christofmuc]

These warnings come from pybind11, this is a currently open question in pybind11 about this topic:

pybind/pybind11#4862

The suggested solution is to set a global compiler parameter -fvisibility=hidden. Unsatisfactory, but I can give it a try.

[christofmuc]

Fixed with release 2.5.0