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