error: attribute must be applied to a `static` variable
  --> $DIR/used.rs:4:1
   |
LL | #[used]
   | ^^^^^^^

error: attribute must be applied to a `static` variable
  --> $DIR/used.rs:7:1
   |
LL | #[used]
   | ^^^^^^^

error: attribute must be applied to a `static` variable
  --> $DIR/used.rs:10:1
   |
LL | #[used]
   | ^^^^^^^

error: attribute must be applied to a `static` variable
  --> $DIR/used.rs:13:1
   |
LL | #[used]
   | ^^^^^^^

error: aborting due to 4 previous errors