#![feature(core_intrinsics)] extern crate core; use core::intrinsics::mir::*; //~ custom_mir #[custom_mir(dialect = "built")] //~ ERROR the `#[custom_mir]` attribute is just used for the Rust test suite pub fn foo(_x: i32) -> i32 { mir! { { Return() //~ custom_mir } } } fn main() { assert_eq!(2, foo(2)); }