mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-05 05:04:24 +00:00
131 lines
3.3 KiB
Rust
131 lines
3.3 KiB
Rust
// run-pass
|
|
#![allow(unused_braces)]
|
|
#![allow(non_snake_case)]
|
|
#![allow(unused_variables)]
|
|
// Test that destructors for rvalue temporaries run either at end of
|
|
// statement or end of block, as appropriate given the temporary
|
|
// lifetime rules.
|
|
|
|
#![feature(box_patterns)]
|
|
|
|
use std::ops::Drop;
|
|
|
|
static mut FLAGS: u64 = 0;
|
|
|
|
struct Box<T> { f: T }
|
|
struct AddFlags { bits: u64 }
|
|
|
|
fn AddFlags(bits: u64) -> AddFlags {
|
|
AddFlags { bits: bits }
|
|
}
|
|
|
|
fn arg(exp: u64, _x: &AddFlags) {
|
|
check_flags(exp);
|
|
}
|
|
|
|
fn pass<T>(v: T) -> T {
|
|
v
|
|
}
|
|
|
|
fn check_flags(exp: u64) {
|
|
unsafe {
|
|
let x = FLAGS;
|
|
FLAGS = 0;
|
|
println!("flags {}, expected {}", x, exp);
|
|
assert_eq!(x, exp);
|
|
}
|
|
}
|
|
|
|
impl AddFlags {
|
|
fn check_flags<'a>(&'a self, exp: u64) -> &'a AddFlags {
|
|
check_flags(exp);
|
|
self
|
|
}
|
|
|
|
fn bits(&self) -> u64 {
|
|
self.bits
|
|
}
|
|
}
|
|
|
|
impl Drop for AddFlags {
|
|
fn drop(&mut self) {
|
|
unsafe {
|
|
FLAGS = FLAGS + self.bits;
|
|
}
|
|
}
|
|
}
|
|
|
|
macro_rules! end_of_block {
|
|
($pat:pat, $expr:expr) => (
|
|
{
|
|
println!("end_of_block({})", stringify!({let $pat = $expr;}));
|
|
|
|
{
|
|
// Destructor here does not run until exit from the block.
|
|
let $pat = $expr;
|
|
check_flags(0);
|
|
}
|
|
check_flags(1);
|
|
}
|
|
)
|
|
}
|
|
|
|
macro_rules! end_of_stmt {
|
|
($pat:pat, $expr:expr) => (
|
|
{
|
|
println!("end_of_stmt({})", stringify!($expr));
|
|
|
|
{
|
|
// Destructor here run after `let` statement
|
|
// terminates.
|
|
let $pat = $expr;
|
|
check_flags(1);
|
|
}
|
|
|
|
check_flags(0);
|
|
}
|
|
)
|
|
}
|
|
|
|
pub fn main() {
|
|
|
|
// In all these cases, we trip over the rules designed to cover
|
|
// the case where we are taking addr of rvalue and storing that
|
|
// addr into a stack slot, either via `let ref` or via a `&` in
|
|
// the initializer.
|
|
|
|
end_of_block!(_x, AddFlags(1));
|
|
end_of_block!(_x, &AddFlags(1));
|
|
end_of_block!(_x, & &AddFlags(1));
|
|
end_of_block!(_x, Box { f: AddFlags(1) });
|
|
end_of_block!(_x, Box { f: &AddFlags(1) });
|
|
end_of_block!(_x, Box { f: &AddFlags(1) });
|
|
end_of_block!(_x, pass(AddFlags(1)));
|
|
end_of_block!(ref _x, AddFlags(1));
|
|
end_of_block!(AddFlags { bits: ref _x }, AddFlags(1));
|
|
end_of_block!(&AddFlags { bits }, &AddFlags(1));
|
|
end_of_block!((_, ref _y), (AddFlags(1), 22));
|
|
end_of_block!(box ref _x, std::boxed::Box::new(AddFlags(1)));
|
|
end_of_block!(box _x, std::boxed::Box::new(AddFlags(1)));
|
|
end_of_block!(_, { { check_flags(0); &AddFlags(1) } });
|
|
end_of_block!(_, &((Box { f: AddFlags(1) }).f));
|
|
end_of_block!(_, &(([AddFlags(1)])[0]));
|
|
|
|
// LHS does not create a ref binding, so temporary lives as long
|
|
// as statement, and we do not move the AddFlags out:
|
|
end_of_stmt!(_, AddFlags(1));
|
|
end_of_stmt!((_, _), (AddFlags(1), 22));
|
|
|
|
// `&` operator appears inside an arg to a function,
|
|
// so it is not prolonged:
|
|
end_of_stmt!(ref _x, arg(0, &AddFlags(1)));
|
|
|
|
// autoref occurs inside receiver, so temp lifetime is not
|
|
// prolonged:
|
|
end_of_stmt!(ref _x, AddFlags(1).check_flags(0).bits());
|
|
|
|
// No reference is created on LHS, thus RHS is moved into
|
|
// a temporary that lives just as long as the statement.
|
|
end_of_stmt!(AddFlags { bits }, AddFlags(1));
|
|
}
|