[rustc.git] / tests / ui / async-await / task-context-arg.rs

// Checks that we don't get conflicting arguments in our debug info with a particular async function
// structure.

// edition:2021
// compile-flags: -Cdebuginfo=2
// build-pass

#![crate_type = "lib"]

use std::future::Future;

// The compiler produces a closure as part of this function. That closure initially takes an
// argument _task_context. Later, when the MIR for that closure is transformed into a coroutine
// state machine, _task_context is demoted to not be an argument, but just part of an unnamed
// argument. If we emit debug info saying that both _task_context and the unnamed argument are both
// argument number 2, then LLVM will fail with "conflicting debug info for argument". See
// https://github.com/rust-lang/rust/pull/109466#issuecomment-1500879195 for details.
async fn recv_unit() {
    std::future::ready(()).await;
}

pub fn poll_recv() {
    // This box is necessary in order to reproduce the problem.
    let _: Box<dyn Future<Output = ()>> = Box::new(recv_unit());
}
Commit	Line	Data
353b0b11 FG	1	// Checks that we don't get conflicting arguments in our debug info with a particular async function
	2	// structure.
	3
	4	// edition:2021
	5	// compile-flags: -Cdebuginfo=2
	6	// build-pass
	7
	8	#![crate_type = "lib"]
	9
	10	use std::future::Future;
	11
	12	// The compiler produces a closure as part of this function. That closure initially takes an
ed00b5ec	13	// argument _task_context. Later, when the MIR for that closure is transformed into a coroutine
353b0b11 FG	14	// state machine, _task_context is demoted to not be an argument, but just part of an unnamed
	15	// argument. If we emit debug info saying that both _task_context and the unnamed argument are both
	16	// argument number 2, then LLVM will fail with "conflicting debug info for argument". See
	17	// https://github.com/rust-lang/rust/pull/109466#issuecomment-1500879195 for details.
	18	async fn recv_unit() {
	19	std::future::ready(()).await;
	20	}
	21
	22	pub fn poll_recv() {
	23	// This box is necessary in order to reproduce the problem.
	24	let _: Box<dyn Future<Output = ()>> = Box::new(recv_unit());
	25	}