/in/foo.c: In function 'main':
/in/foo.c:6:16: warning: right-hand operand of comma expression has no effect [-Wunused-value]
    6 |         for(i=1,i<=n,i++);
      |                ^
/in/foo.c:6:25: error: expected ';' before ')' token
    6 |         for(i=1,i<=n,i++);
      |                         ^
      |                         ;
/in/foo.c:6:25: error: expected expression before ')' token
/in/foo.c:6:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    6 |         for(i=1,i<=n,i++);
      |         ^~~
/in/foo.c:7:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    7 |                 sum=sum+i*i;
      |                 ^~~