rust/tests/codegen/function-return.rs
Miguel Ojeda 2d476222e8 Add -Zfunction-return={keep,thunk-extern} option
This is intended to be used for Linux kernel RETHUNK builds.

With this commit (optionally backported to Rust 1.73.0), plus a
patched Linux kernel to pass the flag, I get a RETHUNK build with
Rust enabled that is `objtool`-warning-free and is able to boot in
QEMU and load a sample Rust kernel module.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-11-30 20:21:31 +01:00

29 lines
1.0 KiB
Rust

// Test that the `fn_ret_thunk_extern` function attribute is (not) emitted when
// the `-Zfunction-return={keep,thunk-extern}` flag is (not) set.
// revisions: unset keep thunk-extern keep-thunk-extern thunk-extern-keep
// needs-llvm-components: x86
// compile-flags: --target x86_64-unknown-linux-gnu
// [keep] compile-flags: -Zfunction-return=keep
// [thunk-extern] compile-flags: -Zfunction-return=thunk-extern
// [keep-thunk-extern] compile-flags: -Zfunction-return=keep -Zfunction-return=thunk-extern
// [thunk-extern-keep] compile-flags: -Zfunction-return=thunk-extern -Zfunction-return=keep
#![crate_type = "lib"]
#![feature(no_core, lang_items)]
#![no_core]
#[lang = "sized"]
trait Sized {}
#[no_mangle]
pub fn foo() {
// CHECK: @foo() unnamed_addr #0
// unset-NOT: fn_ret_thunk_extern
// keep-NOT: fn_ret_thunk_extern
// thunk-extern: attributes #0 = { {{.*}}fn_ret_thunk_extern{{.*}} }
// keep-thunk-extern: attributes #0 = { {{.*}}fn_ret_thunk_extern{{.*}} }
// thunk-extern-keep-NOT: fn_ret_thunk_extern
}