From 93c9f9af0aa3356a2a50bf920ad32be5b07f3d59 Mon Sep 17 00:00:00 2001 From: Pierre-Emmanuel Patry Date: Thu, 17 Apr 2025 17:53:15 +0200 Subject: [PATCH] gccrs: Add execute test for black_box intrinsic gcc/testsuite/ChangeLog: * rust/execute/black_box.rs: New test. Signed-off-by: Pierre-Emmanuel Patry --- gcc/testsuite/rust/execute/black_box.rs | 30 +++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 gcc/testsuite/rust/execute/black_box.rs diff --git a/gcc/testsuite/rust/execute/black_box.rs b/gcc/testsuite/rust/execute/black_box.rs new file mode 100644 index 00000000000..7a9920eba94 --- /dev/null +++ b/gcc/testsuite/rust/execute/black_box.rs @@ -0,0 +1,30 @@ +/* { dg-output "Value is: 42\r*\n" } */ +#![feature(rustc_attrs)] + +extern "C" { + fn printf(s: *const i8, ...); +} + +#[lang = "sized"] +pub trait Sized {} + +#[rustc_builtin_macro] +macro_rules! llvm_asm { + () => {}; +} + +pub fn black_box(mut dummy: T) -> T { + unsafe { + llvm_asm!("" : : "r"(&mut dummy) : "memory" : "volatile"); + } + + dummy +} + +fn main() { + let dummy: i32 = 42; + let result = black_box(dummy); + unsafe { + printf("Value is: %i\n\0" as *const str as *const i8, result); + } +} -- 2.47.2