/in/foo.c: In function 'days':
/in/foo.c:2:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
 #define leap(y) ((y)%4==0 && (y)%100!=0 || (y)%400==0)
                  ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.c:12:5: note: in expansion of macro 'leap'
 td+=leap(i)?366:365;
     ^~~~
/in/foo.c:2:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
 #define leap(y) ((y)%4==0 && (y)%100!=0 || (y)%400==0)
                  ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.c:14:9: note: in expansion of macro 'leap'
 td-=mon[leap(d1.y)][i];
         ^~~~
/in/foo.c:2:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
 #define leap(y) ((y)%4==0 && (y)%100!=0 || (y)%400==0)
                  ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.c:17:9: note: in expansion of macro 'leap'
 td+=mon[leap(d2.y)][i];
         ^~~~