| // Copyright 2017 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| // ignore-wasm32-bare compiled with panic=abort by default |
| |
| use std::cell::RefCell; |
| use std::panic; |
| |
| pub struct DropLogger<'a> { |
| id: usize, |
| log: &'a panic::AssertUnwindSafe<RefCell<Vec<usize>>> |
| } |
| |
| impl<'a> Drop for DropLogger<'a> { |
| fn drop(&mut self) { |
| self.log.0.borrow_mut().push(self.id); |
| } |
| } |
| |
| struct InjectedFailure; |
| |
| #[allow(unreachable_code)] |
| fn main() { |
| let log = panic::AssertUnwindSafe(RefCell::new(vec![])); |
| let d = |id| DropLogger { id: id, log: &log }; |
| let get = || -> Vec<_> { |
| let mut m = log.0.borrow_mut(); |
| let n = m.drain(..); |
| n.collect() |
| }; |
| |
| { |
| let _x = (d(0), &d(1), d(2), &d(3)); |
| // all borrows are extended - nothing has been dropped yet |
| assert_eq!(get(), vec![]); |
| } |
| // in a let-statement, extended lvalues are dropped |
| // *after* the let result (tho they have the same scope |
| // as far as scope-based borrowck goes). |
| assert_eq!(get(), vec![0, 2, 3, 1]); |
| |
| let _ = std::panic::catch_unwind(|| { |
| (d(4), &d(5), d(6), &d(7), panic!(InjectedFailure)); |
| }); |
| |
| // here, the temporaries (5/7) live until the end of the |
| // containing statement, which is destroyed after the operands |
| // (4/6) on a panic. |
| assert_eq!(get(), vec![6, 4, 7, 5]); |
| } |