[vtk-developers] Undefined symbols after wrapping my code to Python

[David Gobbi]

I'm just trying to make sure that we're communicating the correct
information back and forth here...

Are you saying that after adding vtkWrappingPythonCore to
target_link_libraries(), you were able to successfully compile your
project, but when trying to import the module you saw unresolved symbol
errors for PyVTKClass_New and other "PyVTK_*" methods?

The vtkWrappingPythonCore library existed in VTK 5, as well, but it was
called vtkPythonCore back then.

 - David


On Mon, Oct 9, 2017 at 9:28 PM, Ronald Römer <rroemer at gmail.com> wrote:

> There are still undefined symbols:
>
> 00000000002074e0 d DW.ref.__gxx_personality_v0
> U PyBool_FromLong
> U PyDict_SetItemString
> U PyErr_Occurred
> U PyInt_FromLong
> U PyModule_GetDict
> U PyString_FromString
> 00000000000040f9 T PyVTKAddFile_vtkPolyDataBooleanFilter
> U PyVTKClass_New
> U PyVTKClass_Type
> U PyVTKClass_vtkPolyDataAlgorithmNew
> 0000000000004087 T PyVTKClass_vtkPolyDataBooleanFilterNew
> U PyVTKObject_GetObject
> U PyVTKObject_SetFlag
> U PyVTKObject_Type
> U Py_FatalError
> U Py_InitModule4_64
>
> I think it is a problem with the modularized VTK, that is present since
> version 6.
>
> libvtkWrappingPython27Core-6.3.so exists in the lib directory.
>
>
>
>
> On 10.10.2017 05:18, David Gobbi wrote:
>
> Did it fail because it didn't find the library?  Or did it fail because it
> still had unresolved symbols?
>
> On Mon, Oct 9, 2017 at 9:14 PM, Ronald Römer <rroemer at gmail.com> wrote:
>
>> I already tried this without any success. I have no idea what is wrong
>> with it. You can try to modify my code to find out the correct necessary
>> changes.
>>
>> Best regards
>> Ronald
>>
>>
>>
>> On 10.10.2017 04:59, David Gobbi wrote:
>>
>> Hi Ronald,
>>
>> Use the following:
>>
>> target_link_libraries(${PROJECT_NAME}PythonD ${PROJECT_NAME}
>> vtkWrappingPythonCore)
>>
>> You might also have to add vtkWrappingPythonCore to the components
>> for find_package(VTK).
>>
>>  - David
>>
>>
>> On Mon, Oct 9, 2017 at 8:34 PM, Ronald Römer <rroemer at gmail.com> wrote:
>>
>>> Hello,
>>>
>>> I'm trying to fix a problem with the python wrapper of my library. In my
>>> CMakeLists.txt there are the following lines:
>>>
>>> find_package(VTK REQUIRED COMPONENTS vtkFiltersSources vtkIOLegacy
>>> vtkFiltersExtraction vtkFiltersGeometry vtkFiltersModeling
>>> vtkRenderingFreeType NO_MODULE)
>>>
>>> include(${VTK_USE_FILE})
>>>
>>> if(VTK_WRAP_PYTHON)
>>>     find_package(PythonLibs 2.7 REQUIRED)
>>>
>>>     if(PYTHONLIBS_FOUND)
>>>
>>>         include_directories(${PYTHON_INCLUDE_DIRS}
>>> ${PROJECT_SOURCE_DIR})
>>>
>>>         include(vtkWrapPython)
>>>
>>>         vtk_wrap_python3(${PROJECT_NAME}Python
>>> ${PROJECT_NAME}Python_srcs vtkPolyDataBooleanFilter.cxx)
>>>
>>>         add_library(${PROJECT_NAME}PythonD
>>> ${${PROJECT_NAME}Python_srcs})
>>>         target_link_libraries(${PROJECT_NAME}PythonD ${PROJECT_NAME})
>>>
>>>         add_library(${PROJECT_NAME}Python MODULE
>>> ${PROJECT_NAME}PythonInit.cxx)
>>>         target_link_libraries(${PROJECT_NAME}Python
>>> ${PROJECT_NAME}PythonD)
>>>
>>>     endif()
>>> endif()
>>>
>>> When I try to import the module into a python script, I get an import
>>> error about undefined symbols like PyVTKObject_Type. After a little
>>> research with nm I found out that the shared object is not linked to
>>> libvtkWrappingPython27Core. Here are the first lines of it:
>>>
>>> U PyBool_FromLong
>>> U PyDict_SetItemString
>>> U PyErr_Occurred
>>> U PyInt_FromLong
>>> U PyModule_GetDict
>>> U PyString_FromString
>>> 0000000000003020 T PyVTKAddFile_vtkPolyDataBooleanFilter
>>> U PyVTKClass_New
>>> U PyVTKClass_Type
>>> U PyVTKClass_vtkPolyDataAlgorithmNew
>>>
>>> How to fix this? There is no documentation about the the python wrapper,
>>> except https://www.vtk.org/Wiki/VTK/Python_Wrapping_FAQ.
>>>
>>> I'm actually using VTK 6.3 and my library can be found on
>>> https://github.com/zippy84/vtkbool.
>>>
>>> Best regards
>>> Ronald
>>>
>>
>>
>>
>
>
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