src/test/ui/closures/2229_closure_analysis/migrations/precise.rs

   1 // run-rustfix
   2
   3 #![deny(rust_2021_incompatible_closure_captures)]
   4 //~^ NOTE: the lint level is defined here
   5
   6 #[derive(Debug)]
   7 struct Foo(i32);
   8 impl Drop for Foo {
   9     fn drop(&mut self) {
  10         println!("{:?} dropped", self.0);
  11     }
  12 }
  13
  14 struct ConstainsDropField(Foo, Foo);
  15
  16 // Test that lint is triggered if a path that implements Drop is not captured by move
  17 fn test_precise_analysis_drop_paths_not_captured_by_move() {
  18     let t = ConstainsDropField(Foo(10), Foo(20));
  19
  20     let c = || {
  21         //~^ ERROR: drop order
  22         //~| NOTE: for more information, see
  23         //~| HELP: add a dummy let to cause `t` to be fully captured
  24         let _t = t.0;
  25         //~^ NOTE: in Rust 2018, this closure captures all of `t`, but in Rust 2021, it will only capture `t.0`
  26         let _t = &t.1;
  27     };
  28
  29     c();
  30 }
  31 //~^ NOTE: in Rust 2018, `t` is dropped here, but in Rust 2021, only `t.0` will be dropped here as part of the closure
  32
  33 struct S;
  34 impl Drop for S {
  35     fn drop(&mut self) {}
  36 }
  37
  38 struct T(S, S);
  39 struct U(T, T);
  40
  41 // Test precise analysis for the lint works with paths longer than one.
  42 fn test_precise_analysis_long_path_missing() {
  43     let u = U(T(S, S), T(S, S));
  44
  45     let c = || {
  46         //~^ ERROR: drop order
  47         //~| NOTE: for more information, see
  48         //~| HELP: add a dummy let to cause `u` to be fully captured
  49         let _x = u.0.0;
  50         //~^ NOTE: in Rust 2018, this closure captures all of `u`, but in Rust 2021, it will only capture `u.0.0`
  51         let _x = u.0.1;
  52         //~^ NOTE: in Rust 2018, this closure captures all of `u`, but in Rust 2021, it will only capture `u.0.1`
  53         let _x = u.1.0;
  54         //~^ NOTE: in Rust 2018, this closure captures all of `u`, but in Rust 2021, it will only capture `u.1.0`
  55     };
  56
  57     c();
  58 }
  59 //~^ NOTE: in Rust 2018, `u` is dropped here, but in Rust 2021, only `u.0.0` will be dropped here as part of the closure
  60 //~| NOTE: in Rust 2018, `u` is dropped here, but in Rust 2021, only `u.0.1` will be dropped here as part of the closure
  61 //~| NOTE: in Rust 2018, `u` is dropped here, but in Rust 2021, only `u.1.0` will be dropped here as part of the closure
  62
  63
  64 fn main() {
  65     test_precise_analysis_drop_paths_not_captured_by_move();
  66     test_precise_analysis_long_path_missing();
  67 }