foo.cc: In function ‘int main()’:
foo.cc:15:13: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   15 |         if(x=y)
      |            ~^~
foo.cc:12:20: warning: ‘y’ may be used uninitialized [-Wmaybe-uninitialized]
   12 |                 y=y*10+r;
      |                   ~^~~
foo.cc:8:18: note: ‘y’ was declared here
    8 |         int xx=x,y;
      |                  ^