origin 0.26.2

Program startup and thread support written in Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78

//! Limited wrapper around and polyfill for the `#[naked]` attribute.
//!
//! # Example
//!
//! ```no_compile
//! naked_fn!(
//!     "
//!     A documentation comment.
//!
//!     In the macro expansion, this string will be expanded as a documentation
//!     comment for the generated code.
//!     ";
//!
//!     // Declare a `pub(crate` function named `function_name` with no
//!     // arguments that does not return.
//!     pub(crate) fn function_name() -> !;
//!
//!     // Assembly code for the body.
//!     "assembly code here",
//!     "more assembly code here",
//!     "we can even use {symbols} like {this}",
//!
//!     // Provide symbols for use in the assembly code.
//!     symbols = sym path::to::symbols,
//!     this = sym path::to::this
//! );
//! ```

#![allow(unused_macros)]

/// `#[naked]` is nightly-only. We use it when we can, and fall back to
/// `global_asm` otherwise. This macro supports a limited subset of the
/// features of `#[naked]`.
#[cfg(feature = "nightly")]
macro_rules! naked_fn {
    (
        $doc:literal;
        $vis:vis fn $name:ident $args:tt -> $ret:ty;
        $($code:literal),*;
        $($label:ident = $kind:ident $path:path),*
    ) => {
        #[doc = $doc]
        #[unsafe(naked)]
        #[unsafe(no_mangle)]
        $vis unsafe extern "C" fn $name $args -> $ret {
            core::arch::naked_asm!(
                $($code),*,
                $($label = $kind $path),*
            )
        }
    };
}

/// `#[naked]` is nightly-only. We use it when we can, and fall back to
/// `global_asm` otherwise. This macro supports a limited subset of the
/// features of `#[naked]`.
#[cfg(not(feature = "nightly"))]
macro_rules! naked_fn {
    (
        $doc:literal;
        $vis:vis fn $name:ident $args:tt -> $ret:ty;
        $($code:literal),*;
        $($label:ident = $kind:ident $path:path),*
    ) => {
        unsafe extern "C" {
            #[doc = $doc]
            $vis fn $name $args -> $ret;
        }
        core::arch::global_asm!(
            concat!(".global ", stringify!($name)),
            concat!(".type ", stringify!($name), ", @function"),
            concat!(stringify!($name), ":"),
            $($code),*,
            concat!(".size ", stringify!($name), ", .-", stringify!($name)),
            $($label = $kind $path),*
        );
    };
}