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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/async-await/async-fn-size-uninit-locals.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/async-await/async-fn-size-uninit-locals.rs')
-rw-r--r-- | tests/ui/async-await/async-fn-size-uninit-locals.rs | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/tests/ui/async-await/async-fn-size-uninit-locals.rs b/tests/ui/async-await/async-fn-size-uninit-locals.rs new file mode 100644 index 000000000..546172693 --- /dev/null +++ b/tests/ui/async-await/async-fn-size-uninit-locals.rs @@ -0,0 +1,102 @@ +// 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())); +} |