分段错误（核心已转储）-无法修复错误

Question

I am having trouble with the following bit of code. I am using Boost to do the matrix multiplication. I am using Gtesting to test my code. When I test the following bit of code I get the following error.

Segmentation fault (core dumped)

I know that is has to do with the pointers I am using, but I cant find the error. I have tried a couple of things but with no luck. My code is the following. I am running Ubuntu 14.04.

BLAS::matrix<double>* PolyFilter::getCoef(const std::queue<double> y const std::queue<double> x, const BLAS::vector<double>& w)
{
    int size = y.size();
    queue<double> yList = y;
    BLAS::matrix<double> pos(size,1);
    BLAS::matrix<double>* vand = makeVandermondeMatrix(x);
    BLAS::matrix<double>* weights = makeDiag(w);
    BLAS::matrix<double> *temp1,*temp2,*temp3,*temp4,*temp5;
    BLAS::matrix<double>* temp6 = new BLAS::matrix<double>(size,size);
    std::cout<<size<<endl;


    for( unsigned int i = 0; i < size; i++)
    {
        pos.insert_element(i,0,yList.front());
        yList.pop();
    }

    *temp1 = BLAS::prod(BLAS::trans(*vand), *weights);

    *temp2 = BLAS::prod(*temp1, *vand);


    if( rfalInverse(*temp2, *temp3) )
    {
        *temp4 = BLAS::prod(*temp3, BLAS::trans(*vand));
        *temp5 = BLAS::prod(*temp4,*weights);
        *temp6 = BLAS::prod(*temp5, BLAS::trans(pos));  
    } 



    return temp6;

}

Thankyou for any help. This error is driving me crazy.

Answer 1

You declared several pointers:

BLAS::matrix<double> *temp1,*temp2,*temp3,*temp4,*temp5;

And then you immediately proceed to dereference the uninitialized pointers:

*temp1 = BLAS::prod(BLAS::trans(*vand), *weights);

*temp2 = BLAS::prod(*temp1, *vand);

There's your problem.

PS You should invest some time in learning how to use a debugger. This should be trivial to figure out with a debugger.