CODEWITHSUNDEEP
opencvcmakevtknullptr
Ho'jat Kaveh
Ho'jat Kaveh

Reputation: 123

Compiling OpenCV with VTK support for Open Detection

I'm trying to install OpenDetection on Ubuntu 16.04. I have installed all the dependencies according to here except OpenCV. This is the CMake command I used for OpenCV:

cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D WITH_VTK=ON -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D ENABLE_FAST_MATH=1 -D CUDA_FAST_MATH=1 -D WITH_CUBLAS=1 -DOPENCV_EXTRA_MODULES_PATH=/home/tiestu/Documents/GitRepository/OpenCV3/opencv_contrib/modules /home/tiestu/Documents/GitRepository/OpenCV3/opencv

But when I try to make OpenCV, I receive this error which I believe has something to do with VTK!
I have configured VTK using latest prebuilt binary version of cmake with the default settings, as per installation instructions. but this error says:

vtkGenericDataArrayLookupHelper.h:72:23: error: ‘nullptr’ was not declared in this scope

The full error/warning section of the build output is:

In file included from /usr/local/include/vtk-7.1/vtkGenericDataArray.h:72:0,
                 from /usr/local/include/vtk-7.1/vtkAOSDataArrayTemplate.h:35,
                 from /usr/local/include/vtk-7.1/vtkIntArray.h:33,
                 from /usr/local/include/vtk-7.1/vtkCellTypes.h:42,
                 from /usr/local/include/vtk-7.1/vtkPolyData.h:64,
                 from /usr/local/include/vtk-7.1/vtkPolyDataAlgorithm.h:36,
                 from /usr/local/include/vtk-7.1/vtkAppendPolyData.h:35,
                 from /home/tiestu/Documents/GitRepository/OpenCV3/opencv/modules/viz/src/precomp.hpp:56,
                 from /home/tiestu/Documents/GitRepository/OpenCV3/opencv/release/modules/viz/opencv_viz_pch_dephelp.cxx:1:
/usr/local/include/vtk-7.1/vtkGenericDataArrayLookupHelper.h:72:5: warning: identifier ‘nullptr’ is a keyword in C++11 [-Wc++0x-compat]
     : AssociatedArray{nullptr}, SortedArray(nullptr),
     ^
/usr/local/include/vtk-7.1/vtkGenericDataArrayLookupHelper.h: In constructor ‘vtkGenericDataArrayLookupHelper<ArrayTypeT>::vtkGenericDataArrayLookupHelper()’:
/usr/local/include/vtk-7.1/vtkGenericDataArrayLookupHelper.h:72:22: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
     : AssociatedArray{nullptr}, SortedArray(nullptr),
                      ^
/usr/local/include/vtk-7.1/vtkGenericDataArrayLookupHelper.h:72:23: error: ‘nullptr’ was not declared in this scope
     : AssociatedArray{nullptr}, SortedArray(nullptr),
                       ^
/usr/local/include/vtk-7.1/vtkGenericDataArrayLookupHelper.h:73:15: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
     FirstValue{nullptr}, SortedArraySize{0}
               ^
/usr/local/include/vtk-7.1/vtkGenericDataArrayLookupHelper.h:73:41: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
     FirstValue{nullptr}, SortedArraySize{0}
                                         ^
modules/viz/CMakeFiles/opencv_viz_pch_dephelp.dir/build.make:62: recipe for target 'modules/viz/CMakeFiles/opencv_viz_pch_dephelp.dir/opencv_viz_pch_dephelp.cxx.o' failed
make[2]: *** [modules/viz/CMakeFiles/opencv_viz_pch_dephelp.dir/opencv_viz_pch_dephelp.cxx.o] Error 1
CMakeFiles/Makefile2:6005: recipe for target 'modules/viz/CMakeFiles/opencv_viz_pch_dephelp.dir/all' failed
make[1]: *** [modules/viz/CMakeFiles/opencv_viz_pch_dephelp.dir/all] Error 2
Makefile:160: recipe for target 'all' failed
make: *** [all] Error 2

Does it matter what version of compiler (11 or 0x) I've used? If so what version should I use?

Upvotes: 5

Views: 3009

Answers (1)

starball
starball

Reputation: 50035

You need to use a compiler that supports the version of OpenCV that you are using, and the version of the C++ language that it uses, which from your error and warning diagnostic messages, looks be at least C++11.

You can read the documentation for the compiler version you have to see what C++ language versions it supports. There's also a support information table on cppreference.com.

It's interesting that you get such errors and warnings at all. Libraries should be able to tell CMake in its CMake configuration what C++ language version it uses in its source files, and CMake would keep track of that requirement to make sure the correct compiler flags get used wherever needed. See the target_compile_features() command for more info on that.

Upvotes: 0

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