warning: outside array bound #22218
Description
System information (version)
- OpenCV => recent master ( 139c443 ), 3.4 ( 0a88f84 )
- Operating System / Platform => Debian 11 Aarch64 / Ubuntu 22.04 Arm v7
- Compiler => GCC 10.2 (Aarch64) / GCC 11.2 (Armv7)
Detailed description
[ 60%] Building CXX object modules/core/CMakeFiles/opencv_test_core.dir/test/test_mat.cpp.o
/opencv-fork/modules/core/test/test_mat.cpp: In member function 'void cv::Mat::forEach_impl(const Functor&)::PixelOperationWrapper::operator()(const cv::Range&) const [with _Tp = cv::Point3_<int>; Functor = opencv_test::{anonymous}::InitializerFunctor<cv::Point3_<int> >]':
/opencv-fork/modules/core/test/test_mat.cpp:595:24: warning: array subscript 2 is outside array bounds of 'cv::Mat::forEach_impl<cv::Point3_<int>, opencv_test::{anonymous}::InitializerFunctor<cv::Point3_<int> > >(const opencv_test::{anonymous}::InitializerFunctor<cv::Point3_<int> >&)::PixelOperationWrapper::rowCall2(int, int) const::Index [1]' [-Warray-bounds]
595 | pixel.z = idx[2];
| ~~~~~^
In file included from /opencv-fork/modules/core/include/opencv2/core.hpp:3294,
from /opencv-fork/modules/ts/include/opencv2/ts.hpp:10,
from /opencv-fork/modules/core/test/test_precomp.hpp:7,
from /opencv-fork/modules/core/test/test_mat.cpp:4:
/opencv-fork/modules/core/include/opencv2/core/utility.hpp:681:15: note: while referencing 'idx'
681 | } idx = {{row, 0}};
| ^~~
/opencv-fork/modules/core/test/test_mat.cpp: In member function 'void cv::Mat::forEach_impl(const Functor&)::PixelOperationWrapper::operator()(const cv::Range&) const [with _Tp = cv::Vec<int, 5>; Functor = opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> >]':
/opencv-fork/modules/core/test/test_mat.cpp:605:25: warning: array subscript 2 is outside array bounds of 'cv::Mat::forEach_impl<cv::Vec<int, 5>, opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> > >(const opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> >&)::PixelOperationWrapper::rowCall2(int, int) const::Index [1]' [-Warray-bounds]
605 | pixel[2] = idx[2];
| ~~~~~^
In file included from /opencv-fork/modules/core/include/opencv2/core.hpp:3294,
from /opencv-fork/modules/ts/include/opencv2/ts.hpp:10,
from /opencv-fork/modules/core/test/test_precomp.hpp:7,
from /opencv-fork/modules/core/test/test_mat.cpp:4:
/opencv-fork/modules/core/include/opencv2/core/utility.hpp:681:15: note: while referencing 'idx'
681 | } idx = {{row, 0}};
| ^~~
/opencv-fork/modules/core/test/test_mat.cpp:606:25: warning: array subscript 3 is outside array bounds of 'cv::Mat::forEach_impl<cv::Vec<int, 5>, opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> > >(const opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> >&)::PixelOperationWrapper::rowCall2(int, int) const::Index [1]' [-Warray-bounds]
606 | pixel[3] = idx[3];
| ~~~~~^
In file included from /opencv-fork/modules/core/include/opencv2/core.hpp:3294,
from /opencv-fork/modules/ts/include/opencv2/ts.hpp:10,
from /opencv-fork/modules/core/test/test_precomp.hpp:7,
from /opencv-fork/modules/core/test/test_mat.cpp:4:
/opencv-fork/modules/core/include/opencv2/core/utility.hpp:681:15: note: while referencing 'idx'
681 | } idx = {{row, 0}};
| ^~~
/opencv-fork/modules/core/test/test_mat.cpp:607:25: warning: array subscript 4 is outside array bounds of 'cv::Mat::forEach_impl<cv::Vec<int, 5>, opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> > >(const opencv_test::{anonymous}::InitializerFunctor5D<cv::Vec<int, 5> >&)::PixelOperationWrapper::rowCall2(int, int) const::Index [1]' [-Warray-bounds]
607 | pixel[4] = idx[4];
| ~~~~~^
In file included from /opencv-fork/modules/core/include/opencv2/core.hpp:3294,
from /opencv-fork/modules/ts/include/opencv2/ts.hpp:10,
from /opencv-fork/modules/core/test/test_precomp.hpp:7,
from /opencv-fork/modules/core/test/test_mat.cpp:4:
/opencv-fork/modules/core/include/opencv2/core/utility.hpp:681:15: note: while referencing 'idx'
681 | } idx = {{row, 0}};
| ^~~
The warning is triggered by this 2 structures, especially the idx[2], idx[3] and idx[4]
opencv/modules/core/test/test_mat.cpp
Lines 589 to 609 in 057c3da
and the actual cause is here
opencv/modules/core/include/opencv2/core/utility.hpp
Lines 674 to 681 in 057c3da
If an index i = 2 or greater arrived to this function (operator []), then it'll access outside of array body
So, I feel that the warning message from the compiler is valid.
On the other hand, this file existed from years ago, and no issue was reported.
That indicates that the warning message is a false alarm.
So, basically, I'm confused which way to go.
A: ignore this and keep it as is
B: increase the size of body
C: add pragma around test_mat.cpp (suppress the warning)
Solution B doesn't seem valid at all, though.
The size is constant, but the parameter can be arbitrary number.
Steps to reproduce
Build under the above situation
Issue submission checklist
- I report the issue, it's not a question
- I checked the problem with documentation, FAQ, open issues,
forum.opencv.org, Stack Overflow, etc and have not found any solution - I updated to the latest OpenCV version and the issue is still there
- There is reproducer code and related data files: videos, images, onnx, etc