CalculiX build error using clang

[Mark Brethen]

I’m seeing this build error when using clang (gcc doesn’t complain):

info:build /opt/local/bin/clang-mp-14 -O2 -Wall -Wno-narrowing -I./ 
-I/opt/local/include -I/opt/local/include/GL -I../../libSNL/src 
-I../../glut-3.5/src    -c -o pickFunktions.o pickFunktions.c
:info:build pickFunktions.c:4599:7: error: void function 'moveLineEndPoint' 
should not return a value [-Wreturn-type]
:info:build       return(-1);
:info:build       ^     ~~~~

code snippet below:

 void moveLineEndPoint(int lineNr, int pntNr, double llength)
{
  int p1,p2, flag=0;
  double P1[3], P2[3], u, eva[3], va[3], p0p1_2[3];

    p1=line[lineNr].p1;
    p2=line[lineNr].p2;

    /* determine which side of the line has to be moved */
    if(pntNr==p1) flag=-1;
    else if(pntNr==p2) flag=1;
    else
    {
      printf("ERROR: selected point:%s is no line endpoint\n", 
point[pntNr].name);
      return(-1);
    }
    u=flag*llength;
    u/=scale->w;

    /* calc direction */
    if(line[lineNr].typ=='s')
    {
      if(flag==-1) p2=set[line[lineNr].trk].pnt[1];
      else  p1=set[line[lineNr].trk].pnt[set[line[lineNr].trk].anz_p-2];
    }
    P1[0]=point[p1].px;
    P1[1]=point[p1].py;
    P1[2]=point[p1].pz;
    P2[0]=point[p2].px;
    P2[1]=point[p2].py;
    P2[2]=point[p2].pz;
    v_result( P1, P2, p0p1_2);
    v_norm(p0p1_2,eva);
    v_scal(&u,eva, va);
    point[pntNr].px+=va[0];
    point[pntNr].py+=va[1];
    point[pntNr].pz+=va[2];
    printf("moved by dxyz= %lf %lf %lf\n",
      (va[0]* scale->w),
      (va[1]* scale->w),
      (va[2]* scale->w));
}

I do not code in C, so I’ll pass this up to the developer. How should this be 
patched?

Thanks,
Mark