/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:14:9: 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:16:13: 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:19:13: note: in expansion of macro 'leap'
   td += mon[leap(d2.y)][i];
             ^~~~