1 // The behavior of AST-borrowck and NLL explcitly differ here due to
2 // NLL's increased precision; so we use revisions and do not worry
3 // about the --compare-mode=nll on this test.
6 //[ast]compile-flags: -Z borrowck=ast
7 //[nll]compile-flags: -Z borrowck=migrate -Z two-phase-borrows
9 // ignore-compare-mode-nll
11 // aux-build:dropck_eyepatch_extern_crate.rs
13 // The point of this test is to illustrate that the `#[may_dangle]`
14 // attribute specifically allows, in the context of a type
15 // implementing `Drop`, a generic parameter to be instantiated with a
16 // lifetime that does not strictly outlive the owning type itself,
17 // and that this attribute's effects are preserved when importing
18 // the type from another crate.
20 // See also dropck-eyepatch.rs for more information about the general
21 // structure of the test.
22 #![feature(rustc_attrs)]
23 extern crate dropck_eyepatch_extern_crate as other;
25 use other::{Dt,Dr,Pt,Pr,St,Sr};
27 fn main() { #![rustc_error] // rust-lang/rust#49855
30 let (c, mut dt, mut dr, mut pt, mut pr, st, sr, c_shortest)
31 : (Cell<_>, Dt<_>, Dr<_>, Pt<_, _>, Pr<_>, St<_>, Sr<_>, Cell<_>);
32 c_long = Cell::new(1);
34 c_shortest = Cell::new(1);
36 // No error: sufficiently long-lived state can be referenced in dtors
37 dt = Dt("dt", &c_long);
38 dr = Dr("dr", &c_long);
40 // Error: destructor order imprecisely modelled
42 //[ast]~^ ERROR `c` does not live long enough
44 //[ast]~^ ERROR `c` does not live long enough
46 // Error: `c_shortest` dies too soon for the references in dtors to be valid.
47 dt = Dt("dt", &c_shortest);
48 //[ast]~^ ERROR `c_shortest` does not live long enough
49 //[nll]~^^ ERROR `c_shortest` does not live long enough
50 dr = Dr("dr", &c_shortest);
51 //[ast]~^ ERROR `c_shortest` does not live long enough
52 // No error: Drop impl asserts .1 (A and &'a _) are not accessed
53 pt = Pt("pt", &c_shortest, &c_long);
54 pr = Pr("pr", &c_shortest, &c_long);
56 // Error: Drop impl's assertion does not apply to `B` nor `&'b _`
57 pt = Pt("pt", &c_long, &c_shortest);
58 //[ast]~^ ERROR `c_shortest` does not live long enough
59 pr = Pr("pr", &c_long, &c_shortest);
60 //[ast]~^ ERROR `c_shortest` does not live long enough
62 // No error: St and Sr have no destructor.
63 st = St("st", &c_shortest);
64 sr = Sr("sr", &c_shortest);
66 println!("{:?}", (dt.0, dr.0, pt.0, pr.0, st.0, sr.0));
67 use_imm(sr.1); use_imm(st.1); use_imm(pr.1); use_imm(pt.1); use_imm(dr.1); use_imm(dt.1);
70 fn use_imm<T>(_: &T) { }