mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-24 15:54:15 +00:00
103 lines
2.1 KiB
Rust
103 lines
2.1 KiB
Rust
// Test that we don't store uninitialized locals in futures from `async fn`.
|
|
//
|
|
// The exact sizes can change by a few bytes (we'd like to know when they do).
|
|
// What we don't want to see is the wrong multiple of 1024 (the size of `Big`)
|
|
// being reflected in the size.
|
|
|
|
// ignore-emscripten (sizes don't match)
|
|
// needs-unwind Size of Futures change on panic=abort
|
|
// run-pass
|
|
|
|
// edition:2018
|
|
|
|
#![allow(unused_variables, unused_assignments)]
|
|
|
|
use std::future::Future;
|
|
use std::pin::Pin;
|
|
use std::task::{Context, Poll};
|
|
|
|
const BIG_FUT_SIZE: usize = 1024;
|
|
struct Big(#[allow(unused_tuple_struct_fields)] [u8; BIG_FUT_SIZE]);
|
|
|
|
impl Big {
|
|
fn new() -> Self {
|
|
Big([0; BIG_FUT_SIZE])
|
|
}
|
|
}
|
|
|
|
impl Drop for Big {
|
|
fn drop(&mut self) {}
|
|
}
|
|
|
|
#[allow(dead_code)]
|
|
struct Joiner {
|
|
a: Option<Big>,
|
|
b: Option<Big>,
|
|
c: Option<Big>,
|
|
}
|
|
|
|
impl Future for Joiner {
|
|
type Output = ();
|
|
|
|
fn poll(self: Pin<&mut Self>, _ctx: &mut Context<'_>) -> Poll<Self::Output> {
|
|
Poll::Ready(())
|
|
}
|
|
}
|
|
|
|
fn noop() {}
|
|
async fn fut() {}
|
|
|
|
async fn single() {
|
|
let x;
|
|
fut().await;
|
|
x = Big::new();
|
|
}
|
|
|
|
async fn single_with_noop() {
|
|
let x;
|
|
fut().await;
|
|
noop();
|
|
x = Big::new();
|
|
noop();
|
|
}
|
|
|
|
async fn joined() {
|
|
let joiner;
|
|
let a = Big::new();
|
|
let b = Big::new();
|
|
let c = Big::new();
|
|
|
|
fut().await;
|
|
joiner = Joiner { a: Some(a), b: Some(b), c: Some(c) };
|
|
}
|
|
|
|
async fn joined_with_noop() {
|
|
let joiner;
|
|
let a = Big::new();
|
|
let b = Big::new();
|
|
let c = Big::new();
|
|
|
|
fut().await;
|
|
noop();
|
|
joiner = Joiner { a: Some(a), b: Some(b), c: Some(c) };
|
|
noop();
|
|
}
|
|
|
|
async fn join_retval() -> Joiner {
|
|
let a = Big::new();
|
|
let b = Big::new();
|
|
let c = Big::new();
|
|
|
|
fut().await;
|
|
noop();
|
|
Joiner { a: Some(a), b: Some(b), c: Some(c) }
|
|
}
|
|
|
|
fn main() {
|
|
assert_eq!(2, std::mem::size_of_val(&single()));
|
|
assert_eq!(3, std::mem::size_of_val(&single_with_noop()));
|
|
assert_eq!(3074, std::mem::size_of_val(&joined()));
|
|
assert_eq!(3078, std::mem::size_of_val(&joined_with_noop()));
|
|
assert_eq!(3074, std::mem::size_of_val(&join_retval()));
|
|
}
|