/in/foo.cc: In function 'int main()':
/in/foo.cc:8:3: warning: 'xx' is used uninitialized in this function [-Wuninitialized]
  x=xx;
  ~^~~
/in/foo.cc:14:2: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(x==y)
  ^~