The regression has been fixed in Slicer/VTK in e0d1851e2 and a merge request in being review in upstream VTK at BUG: Rename vtkInteractionCallback class to avoid symbol clash (!8885) · Merge requests · VTK / VTK · GitLab
Impact of the regression on Slicer application
Enabling the “Lock Normal to Camera” associated with the reformat widget was leading to a crash.
Details
After hunting down the regression (performing a manual bisection of the history), I discovered that the following commits introduced the regression:
kitware/vtk@7451dd2d1: vtkDisplaySizedImplicitPlaneWidget/Representation: Implementation
kitware/vtk@cd42f785d: vtkCoordinateFrameWidget: Implementation
At first, it didn’t make sense because we do not instantiate these new widgets in Slicer.
Looking at the issue more closely, I realized that the commit referenced above introduced the class vtkDisplaySizedImplicitPlaneWidget based of vtkImplicitPlaneWidget2 that we effectively used in Slicer (see here).
It turns out that these classes all defined the class vtkInteractionCallback in their private implementation along with:
|
vtkImplicitPlaneWidget2 |
vtkDisplaySizedImplicitPlaneWidget |
vtkCoordinateFrameWidget |
| static constructor |
link |
link |
link |
friend statement in header |
link |
link |
link |
Since these classes were compiled within the same “program” (in that case the shared library libvtkInteraction-9.1.(dll|dylib|so)), the ODR (One Definition Rule) was violated and it now explains the following backtrace:
Backtrace obtained runing ctest -R vtkMRMLThreeDReformatDisplayableManagerTest1 -V and analyzing the core dump following the Slicer guide C++ debugging on GNU/Linux systems: Analyze a segmentation fault.
Symbol analysis
The following invocation of nm allows to confirm there the patch effectively ensure there are different instances of callback classes instead of a single vtkInteractionCallback:
Before integrating our fix:
$ nm lib/libvtkInteraction-9.1.so | c++filt | ack "typeinfo for vtk.+Callback$"
0000000000501f70 d typeinfo for vtkCWCallback
000000000050b938 d typeinfo for vtkPWCallback
000000000050b950 d typeinfo for vtkPW1Callback
000000000050b968 d typeinfo for vtkPW2Callback
00000000004fae80 d typeinfo for vtkAngleWidgetCallback
00000000004f7a28 d typeinfo for vtkImageViewerCallback
0000000000503d88 d typeinfo for vtkInteractionCallback
00000000004f7c10 d typeinfo for vtkImageViewer2Callback
0000000000500f70 d typeinfo for vtkCaptionAnchorCallback
0000000000505d58 d typeinfo for vtkDistanceWidgetCallback
00000000004fca38 d typeinfo for vtkBiDimensionalWidgetCallback
00000000004f7f28 d typeinfo for vtkResliceImageViewerScrollCallback
After integrating our fix:
$ nm lib/libvtkInteraction-9.1.so | c++filt | ack "typeinfo for vtk.+Callback$"
0000000000501df0 d typeinfo for vtkCWCallback
000000000050b948 d typeinfo for vtkPWCallback
000000000050b960 d typeinfo for vtkPW1Callback
000000000050b978 d typeinfo for vtkPW2Callback
00000000004fad00 d typeinfo for vtkAngleWidgetCallback
00000000004f78a8 d typeinfo for vtkImageViewerCallback
00000000004f7a90 d typeinfo for vtkImageViewer2Callback
0000000000500df0 d typeinfo for vtkCaptionAnchorCallback
0000000000505ca0 d typeinfo for vtkDistanceWidgetCallback
00000000004fc8b8 d typeinfo for vtkBiDimensionalWidgetCallback
00000000004f7da8 d typeinfo for vtkResliceImageViewerScrollCallback
000000000050aa80 d typeinfo for vtkImplicitPlaneWidget2InteractionCallback
0000000000503c08 d typeinfo for vtkCoordinateFrameWidgetInteractionCallback
0000000000504518 d typeinfo for vtkDisplaySizedImplicitPlaneInteractionCallback
Running test interactively disabling event replay
For future reference, it has also been useful to run the test interactively by disabling the replay of event, this was done by appending -I --DisableReplay to the command reported running the test with -V:
SLICER_SOURCE_DIR=/home/jcfr/Projects/Slicer
SLICER_BUILD_DIR=/home/jcfr/Projects/Slicer-rwdi
${SLICER_BUILD_DIR}/Slicer-build/Slicer --launch \
${SLICER_BUILD_DIR}/Slicer-build/bin/MRMLDisplayableManagerCxxTests \
vtkMRMLThreeDReformatDisplayableManagerTest1\
-D ${SLICER_SOURCE_DIR}/Libs/MRML/DisplayableManager/Testing/Cxx/../ \
-T ${SLICER_BUILD_DIR}/Slicer-build/Testing/Temporary \
-V Baseline/vtkMRMLThreeDReformatDisplayableManagerTest1.png \
-I --DisableReplay
Further analysis of the VTK toolkit
Running the following commands allowed to discover other duplication and these ones will be discussed with the team as well:
- #18456 (Remove duplicated class vtkTextureArray)
- #18455 (Remove duplicated class vtkmOutputFilterPolicy)
- #18457 (Improve continuous integration to detect duplicated symbols)
$ cd VTK
$ ack -h --ignore-dir=Testing "^class.+vtk.+ \: " | ack "\:" | sort > /tmp/vtk-classes.txt
$ ack -h --ignore-dir=Testing "^class.+vtk.+ \: " | ack "\:" | sort | uniq > /tmp/vtk-uniq-classes.txt
$ diff /tmp/vtk-classes.txt /tmp/vtk-uniq-classes.txt
diff /tmp/vtk-classes.txt /tmp/vtk-uniq-classes.txt
1481,1482d1480
< class vtkInteractionCallback : public vtkCommand
< class vtkInteractionCallback : public vtkCommand
2047d2044
< class vtkmOutputFilterPolicy : public vtkm::filter::PolicyBase<vtkmOutputFilterPolicy>
2607d2603
< class vtkTextureArray : public std::map<int, vtkSmartPointer<vtkImageData>>
Occurrences of vtkmOutputFilterPolicy:
Occurrences of vtkTextureArray:
