gcc/testsuite/rust/compile/rustc_std_internal_symbol1.rs

// { dg-additional-options "-fdump-tree-gimple" }
#![feature(no_core, rustc_attrs)]
#![no_core]

#[rustc_std_internal_symbol]
pub fn _foo() -> i32 {
    0
}

// { dg-final { scan-tree-dump "_foo" "gimple" } }