1 // This is testing an attempt to corrupt the discriminant of the match
2 // arm in a guard, followed by an attempt to continue matching on that
3 // corrupted discriminant in the remaining match arms.
5 // Basically this is testing that our new NLL feature of emitting a
6 // fake read on each match arm is catching cases like this.
8 // This case is interesting because a borrow of **x is untracked, because **x is
9 // immutable. However, for matches we care that **x refers to the same value
10 // until we have chosen a match arm.
14 let mut x = &mut &Some(&2);
15 let force_fn_once = ForceFnOnce;
17 None => panic!("unreachable"),
19 // ForceFnOnce needed to exploit #27282
20 (|| { *x = &None; drop(force_fn_once); })();
21 //~^ ERROR cannot mutably borrow `x` in match guard [E0510]
24 Some(&a) if { // this binds to garbage if we've corrupted discriminant
28 _ => panic!("unreachable"),