diff --git a/src/test/run-pass/rfc1857-drop-order.rs b/src/test/run-pass/rfc1857-drop-order.rs new file mode 100644 index 00000000000..42f989538c8 --- /dev/null +++ b/src/test/run-pass/rfc1857-drop-order.rs @@ -0,0 +1,231 @@ +// 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![allow(dead_code, unreachable_code)] + +use std::cell::RefCell; +use std::rc::Rc; +use std::panic::{self, AssertUnwindSafe, UnwindSafe}; + +// This struct is used to record the order in which elements are dropped +struct PushOnDrop { + vec: Rc>>, + val: u32 +} + +impl PushOnDrop { + fn new(val: u32, vec: Rc>>) -> PushOnDrop { + PushOnDrop { vec, val } + } +} + +impl Drop for PushOnDrop { + fn drop(&mut self) { + self.vec.borrow_mut().push(self.val) + } +} + +impl UnwindSafe for PushOnDrop { } + +// Structs +struct TestStruct { + x: PushOnDrop, + y: PushOnDrop, + z: PushOnDrop +} + +// Tuple structs +struct TestTupleStruct(PushOnDrop, PushOnDrop, PushOnDrop); + +// Enum variants +enum TestEnum { + Tuple(PushOnDrop, PushOnDrop, PushOnDrop), + Struct { x: PushOnDrop, y: PushOnDrop, z: PushOnDrop } +} + +fn test_drop_tuple() { + // Tuple fields are dropped in the same order they are declared + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let test_tuple = (PushOnDrop::new(1, dropped_fields.clone()), + PushOnDrop::new(2, dropped_fields.clone())); + drop(test_tuple); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); + + // Panic during construction means that fields are treated as local variables + // Therefore they are dropped in reverse order of initialization + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + (PushOnDrop::new(2, cloned.clone()), + PushOnDrop::new(1, cloned.clone()), + panic!("this panic is catched :D")); + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); +} + +fn test_drop_struct() { + // Struct fields are dropped in the same order they are declared + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let test_struct = TestStruct { + x: PushOnDrop::new(1, dropped_fields.clone()), + y: PushOnDrop::new(2, dropped_fields.clone()), + z: PushOnDrop::new(3, dropped_fields.clone()), + }; + drop(test_struct); + assert_eq!(*dropped_fields.borrow(), &[1, 2, 3]); + + // The same holds for tuple structs + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let test_tuple_struct = TestTupleStruct(PushOnDrop::new(1, dropped_fields.clone()), + PushOnDrop::new(2, dropped_fields.clone()), + PushOnDrop::new(3, dropped_fields.clone())); + drop(test_tuple_struct); + assert_eq!(*dropped_fields.borrow(), &[1, 2, 3]); + + // Panic during struct construction means that fields are treated as local variables + // Therefore they are dropped in reverse order of initialization + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + TestStruct { + x: PushOnDrop::new(2, cloned.clone()), + y: PushOnDrop::new(1, cloned.clone()), + z: panic!("this panic is catched :D") + }; + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); + + // Test with different initialization order + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + TestStruct { + y: PushOnDrop::new(2, cloned.clone()), + x: PushOnDrop::new(1, cloned.clone()), + z: panic!("this panic is catched :D") + }; + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); + + // The same holds for tuple structs + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + TestTupleStruct(PushOnDrop::new(2, cloned.clone()), + PushOnDrop::new(1, cloned.clone()), + panic!("this panic is catched :D")); + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); +} + +fn test_drop_enum() { + // Enum variants are dropped in the same order they are declared + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let test_struct_enum = TestEnum::Struct { + x: PushOnDrop::new(1, dropped_fields.clone()), + y: PushOnDrop::new(2, dropped_fields.clone()), + z: PushOnDrop::new(3, dropped_fields.clone()) + }; + drop(test_struct_enum); + assert_eq!(*dropped_fields.borrow(), &[1, 2, 3]); + + // The same holds for tuple enum variants + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let test_tuple_enum = TestEnum::Tuple(PushOnDrop::new(1, dropped_fields.clone()), + PushOnDrop::new(2, dropped_fields.clone()), + PushOnDrop::new(3, dropped_fields.clone())); + drop(test_tuple_enum); + assert_eq!(*dropped_fields.borrow(), &[1, 2, 3]); + + // Panic during enum construction means that fields are treated as local variables + // Therefore they are dropped in reverse order of initialization + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + TestEnum::Struct { + x: PushOnDrop::new(2, cloned.clone()), + y: PushOnDrop::new(1, cloned.clone()), + z: panic!("this panic is catched :D") + }; + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); + + // Test with different initialization order + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + TestEnum::Struct { + y: PushOnDrop::new(2, cloned.clone()), + x: PushOnDrop::new(1, cloned.clone()), + z: panic!("this panic is catched :D") + }; + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); + + // The same holds for tuple enum variants + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + TestEnum::Tuple(PushOnDrop::new(2, cloned.clone()), + PushOnDrop::new(1, cloned.clone()), + panic!("this panic is catched :D")); + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); +} + +fn test_drop_list() { + // Elements in a Vec are dropped in the same order they are pushed + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let xs = vec![PushOnDrop::new(1, dropped_fields.clone()), + PushOnDrop::new(2, dropped_fields.clone()), + PushOnDrop::new(3, dropped_fields.clone())]; + drop(xs); + assert_eq!(*dropped_fields.borrow(), &[1, 2, 3]); + + // The same holds for arrays + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let xs = [PushOnDrop::new(1, dropped_fields.clone()), + PushOnDrop::new(2, dropped_fields.clone()), + PushOnDrop::new(3, dropped_fields.clone())]; + drop(xs); + assert_eq!(*dropped_fields.borrow(), &[1, 2, 3]); + + // Panic during vec construction means that fields are treated as local variables + // Therefore they are dropped in reverse order of initialization + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + vec![ + PushOnDrop::new(2, cloned.clone()), + PushOnDrop::new(1, cloned.clone()), + panic!("this panic is catched :D") + ]; + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); + + // The same holds for arrays + let dropped_fields = Rc::new(RefCell::new(Vec::new())); + let cloned = AssertUnwindSafe(dropped_fields.clone()); + panic::catch_unwind(|| { + [ + PushOnDrop::new(2, cloned.clone()), + PushOnDrop::new(1, cloned.clone()), + panic!("this panic is catched :D") + ]; + }).err().unwrap(); + assert_eq!(*dropped_fields.borrow(), &[1, 2]); +} + +fn main() { + test_drop_tuple(); + test_drop_struct(); + test_drop_enum(); + test_drop_list(); +}