Undefined symbols for architecture x86_64:

Question

Muzafar Pandit 2012-10-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/51455-undefined-symbols-for-architecture-x86_64

#include "mex.h"
void unravel(uint16_T *hx, double *link, double *x, double xsz,int hxsz)
{
    int i=15;
    int j=0, k=0, n=0; 
    while (xsz-k)
    {
        if (*(link + n) >0) {
        if ((*(hx + j) >> i) & 0x0001)
            n=*(link + n);
        else n=*(link + n) - 1;
            if (i) i--; else { j++; i= 15;}
                if (j>hxsz)
                    mexErrMsgTxt("Out of cod ebits ???");
                    }
                else {
                        *(x + k++) =-*(link +n);
                        n=0; }
                    }
                    if (k== xsz -1)
                        *(x+ k++) =-*(link +n);
                        }
                        void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
                        {
                           double *link, *x, xsz;
                            uint16_T *hx;
                            int hxsz;
                            if(nrhs !=3)
                            mexErrMsgTxt("Three inputs required.");
                            else if (nlhs>1)
                                    mexErrMSgTxt("Too many output arguments.");
                                    if(!mxIsDouble(prhs[2]) || mxIsComplex(prhs[2]) ||
                                        mxGetN(prhs[2])*mxGetM(prhs[2]) !=1)
                                        mexErrMsgTxt("Input size must be a scalar");
                                        hx=(uint16_T *) mxGetData(prhs[0]);
                                        link=(double*) mxGetData(prhs[1]);
                                        xsz=mxGetScalar(prhs[2]);
                                        hxsz=mxGetM(prhs[0]);
                                        plhs[0]=mxCreateDoubleMatrix(xsz, 1, mxREAL);
                                        x=(double *) mxGetData(plhs[0]);
                                        unravel(hx, link, x, xsz, hxsz);
                             }

This is my program for unravel function from Gonzalez's book Image processing using matlab. but while executing the program on matlab, it shows the following error

>>mex unrav.c
Undefined symbols for architecture x86_64:
  "_mexErrMSgTxt", referenced from:
      _mexFunction in unrav.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status