1 // Copyright 2019 The Fuchsia Authors 2 // 3 // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0 4 // <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT 5 // license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option. 6 // This file may not be copied, modified, or distributed except according to 7 // those terms. 8 9 // See comment in `include.rs` for why we disable the prelude. 10 #![no_implicit_prelude] 11 #![allow(warnings)] 12 13 include!("include.rs"); 14 15 // A union is `Unaligned` if: 16 // - `repr(align)` is no more than 1 and either 17 // - `repr(C)` or `repr(transparent)` and 18 // - all fields `Unaligned` 19 // - `repr(packed)` 20 21 #[derive(imp::Unaligned)] 22 #[repr(C)] 23 union Foo { 24 a: imp::u8, 25 } 26 27 util_assert_impl_all!(Foo: imp::Unaligned); 28 29 // Transparent unions are unstable; see issue #60405 30 // <https://github.com/rust-lang/rust/issues/60405> for more information. 31 32 // #[derive(Unaligned)] 33 // #[repr(transparent)] 34 // union Bar { 35 // a: u8, 36 // } 37 38 // is_unaligned!(Bar); 39 40 #[derive(imp::Unaligned)] 41 #[repr(packed)] 42 union Baz { 43 // NOTE: The `u16` type is not guaranteed to have alignment 2, although it 44 // does on many platforms. However, to fix this would require a custom type 45 // with a `#[repr(align(2))]` attribute, and `#[repr(packed)]` types are not 46 // allowed to transitively contain `#[repr(align(...))]` types. Thus, we 47 // have no choice but to use `u16` here. Luckily, these tests run in CI on 48 // platforms on which `u16` has alignment 2, so this isn't that big of a 49 // deal. 50 a: u16, 51 } 52 53 util_assert_impl_all!(Baz: imp::Unaligned); 54 55 #[derive(imp::Unaligned)] 56 #[repr(C, align(1))] 57 union FooAlign { 58 a: imp::u8, 59 } 60 61 util_assert_impl_all!(FooAlign: imp::Unaligned); 62 63 #[derive(imp::Unaligned)] 64 #[repr(C)] 65 union TypeParams<'a, T: imp::Copy, I: imp::Iterator> 66 where 67 I::Item: imp::Copy, 68 { 69 a: T, 70 c: I::Item, 71 d: u8, 72 e: imp::PhantomData<&'a [imp::u8]>, 73 f: imp::PhantomData<&'static imp::str>, 74 g: imp::PhantomData<imp::String>, 75 } 76 77 util_assert_impl_all!(TypeParams<'static, (), imp::IntoIter<()>>: imp::Unaligned); 78