/in/foo.cc: In function 'void dfn(int, int)':
/in/foo.cc:12:19: warning: 'ny' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int i,j,h,x,y,nx,ny;
                   ^~
/in/foo.cc:12:16: warning: 'nx' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int i,j,h,x,y,nx,ny;
                ^~
/in/foo.cc:12:14: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int i,j,h,x,y,nx,ny;
              ^
/in/foo.cc:12:12: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int i,j,h,x,y,nx,ny;
            ^