55 lines
831 B
Rust
55 lines
831 B
Rust
|
// Copyright 2019 The Fuchsia Authors. All rights reserved.
|
||
|
|
// Use of this source code is governed by a BSD-style license that can be
|
||
|
|
// found in the LICENSE file.
|
||
|
|
|
||
|
|
#![allow(warnings)]
|
||
|
|
|
||
|
|
use zerocopy::Unaligned;
|
||
|
|
|
||
|
|
struct IsUnaligned<T: Unaligned>(T);
|
||
|
|
|
||
|
|
// Fail compilation if `$ty: !Unaligned`.
|
||
|
|
macro_rules! is_unaligned {
|
||
|
|
($ty:ty) => {
|
||
|
|
const _: () = {
|
||
|
|
let _: IsUnaligned<$ty>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
// An enum is `Unaligned` if:
|
||
|
|
// - No `repr(align(N > 1))`
|
||
|
|
// - `repr(u8)` or `repr(i8)`
|
||
|
|
|
||
|
|
#[derive(Unaligned)]
|
||
|
|
#[repr(u8)]
|
||
|
|
enum Foo {
|
||
|
|
A,
|
||
|
|
}
|
||
|
|
|
||
|
|
is_unaligned!(Foo);
|
||
|
|
|
||
|
|
#[derive(Unaligned)]
|
||
|
|
#[repr(i8)]
|
||
|
|
enum Bar {
|
||
|
|
A,
|
||
|
|
}
|
||
|
|
|
||
|
|
is_unaligned!(Bar);
|
||
|
|
|
||
|
|
#[derive(Unaligned)]
|
||
|
|
#[repr(u8, align(1))]
|
||
|
|
enum Baz {
|
||
|
|
A,
|
||
|
|
}
|
||
|
|
|
||
|
|
is_unaligned!(Baz);
|
||
|
|
|
||
|
|
#[derive(Unaligned)]
|
||
|
|
#[repr(i8, align(1))]
|
||
|
|
enum Blah {
|
||
|
|
B,
|
||
|
|
}
|
||
|
|
|
||
|
|
is_unaligned!(Blah);
|