mirror of https://github.com/rust-lang/rust
90 lines
1.8 KiB
Rust
90 lines
1.8 KiB
Rust
#![feature(naked_functions, asm_const, linkage)]
|
|
#![crate_type = "dylib"]
|
|
|
|
use std::arch::asm;
|
|
|
|
pub trait TraitWithConst {
|
|
const COUNT: u32;
|
|
}
|
|
|
|
struct Test;
|
|
|
|
impl TraitWithConst for Test {
|
|
const COUNT: u32 = 1;
|
|
}
|
|
|
|
#[no_mangle]
|
|
fn entry() {
|
|
private_vanilla();
|
|
private_naked();
|
|
|
|
public_vanilla_generic::<Test>();
|
|
public_naked_generic::<Test>();
|
|
}
|
|
|
|
extern "C" fn private_vanilla() -> u32 {
|
|
42
|
|
}
|
|
|
|
#[naked]
|
|
extern "C" fn private_naked() -> u32 {
|
|
unsafe { asm!("mov rax, 42", "ret", options(noreturn)) }
|
|
}
|
|
|
|
#[no_mangle]
|
|
pub extern "C" fn public_vanilla() -> u32 {
|
|
42
|
|
}
|
|
|
|
#[naked]
|
|
#[no_mangle]
|
|
pub extern "C" fn public_naked() -> u32 {
|
|
unsafe { asm!("mov rax, 42", "ret", options(noreturn)) }
|
|
}
|
|
|
|
pub extern "C" fn public_vanilla_generic<T: TraitWithConst>() -> u32 {
|
|
T::COUNT
|
|
}
|
|
|
|
#[naked]
|
|
pub extern "C" fn public_naked_generic<T: TraitWithConst>() -> u32 {
|
|
unsafe { asm!("mov rax, {}", "ret", const T::COUNT, options(noreturn)) }
|
|
}
|
|
|
|
#[linkage = "external"]
|
|
extern "C" fn vanilla_external_linkage() -> u32 {
|
|
42
|
|
}
|
|
|
|
#[naked]
|
|
#[linkage = "external"]
|
|
extern "C" fn naked_external_linkage() -> u32 {
|
|
unsafe { asm!("mov rax, 42", "ret", options(noreturn)) }
|
|
}
|
|
|
|
#[cfg(not(windows))]
|
|
#[linkage = "weak"]
|
|
extern "C" fn vanilla_weak_linkage() -> u32 {
|
|
42
|
|
}
|
|
|
|
#[naked]
|
|
#[cfg(not(windows))]
|
|
#[linkage = "weak"]
|
|
extern "C" fn naked_weak_linkage() -> u32 {
|
|
unsafe { asm!("mov rax, 42", "ret", options(noreturn)) }
|
|
}
|
|
|
|
// functions that are declared in an `extern "C"` block are currently not exported
|
|
// this maybe should change in the future, this is just tracking the current behavior
|
|
// reported in https://github.com/rust-lang/rust/issues/128071
|
|
std::arch::global_asm! {
|
|
".globl function_defined_in_global_asm",
|
|
"function_defined_in_global_asm:",
|
|
"ret",
|
|
}
|
|
|
|
extern "C" {
|
|
pub fn function_defined_in_global_asm();
|
|
}
|