84 lines
4.0 KiB
Rust
84 lines
4.0 KiB
Rust
|
// Copyright 2022 The Fuchsia Authors
|
||
|
|
//
|
||
|
|
// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
|
||
|
|
// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
|
||
|
|
// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
|
||
|
|
// This file may not be copied, modified, or distributed except according to
|
||
|
|
// those terms.
|
||
|
|
|
||
|
|
include!("../include.rs");
|
||
|
|
|
||
|
|
use util::NotZerocopy;
|
||
|
|
use zerocopy::{FromBytes, FromZeros, Immutable, IntoBytes, KnownLayout, TryFromBytes, Unaligned};
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
// We expect the proper diagnostic to be emitted on Rust 1.78.0 and later.
|
||
|
|
takes_from_bytes::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: FromBytes` is not satisfied
|
||
|
|
takes_from_zeros::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: FromZeros` is not satisfied
|
||
|
|
takes_immutable::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: Immutable` is not satisfied
|
||
|
|
takes_into_bytes::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: IntoBytes` is not satisfied
|
||
|
|
takes_known_layout::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: KnownLayout` is not satisfied
|
||
|
|
takes_try_from_bytes::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: TryFromBytes` is not satisfied
|
||
|
|
takes_unaligned::<NotZerocopy>();
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: zerocopy::Unaligned` is not satisfied
|
||
|
|
|
||
|
|
// This is adapted from #1296, which includes the following text:
|
||
|
|
//
|
||
|
|
// The compiler errors when a type is missing Immutable are somewhat
|
||
|
|
// misleading, although I'm not sure there's much zerocopy can do about
|
||
|
|
// this. An example where the compiler recommends adding a reference
|
||
|
|
// rather than implementing Immutable (some were even more confusing than
|
||
|
|
// this):
|
||
|
|
//
|
||
|
|
// error[E0277]: the trait bound `virtio::wl::CtrlVfdNewDmabuf: zerocopy::Immutable` is not satisfied
|
||
|
|
// --> devices/src/virtio/wl.rs:317:20
|
||
|
|
// |
|
||
|
|
// 317 | .write_obj(ctrl_vfd_new_dmabuf)
|
||
|
|
// | --------- ^^^^^^^^^^^^^^^^^^^ the trait `zerocopy::Immutable` is not implemented for `virtio::wl::CtrlVfdNewDmabuf`
|
||
|
|
// | |
|
||
|
|
// | required by a bound introduced by this call
|
||
|
|
// |
|
||
|
|
// note: required by a bound in `virtio::descriptor_utils::Writer::write_obj`
|
||
|
|
// --> devices/src/virtio/descriptor_utils.rs:536:25
|
||
|
|
// |
|
||
|
|
// 536 | pub fn write_obj<T: Immutable + IntoBytes>(&mut self, val: T) -> io::Result<()> {
|
||
|
|
// | ^^^^^^^^^ required by this bound in `Writer::write_obj`
|
||
|
|
// help: consider borrowing here
|
||
|
|
// |
|
||
|
|
// 317 | .write_obj(&ctrl_vfd_new_dmabuf)
|
||
|
|
// | +
|
||
|
|
// 317 | .write_obj(&mut ctrl_vfd_new_dmabuf)
|
||
|
|
// | ++++
|
||
|
|
//
|
||
|
|
// Taking the compiler's suggestion results in a different error with a
|
||
|
|
// recommendation to remove the reference (back to the original code).
|
||
|
|
//
|
||
|
|
// As of this writing, the described problem is still happening thanks to
|
||
|
|
// https://github.com/rust-lang/rust/issues/130563. We include this test so
|
||
|
|
// that we can capture the current behavior, but we will update it once that
|
||
|
|
// Rust issue is fixed.
|
||
|
|
Foo.write_obj(NotZerocopy(()));
|
||
|
|
//~[msrv, stable, nightly]^ ERROR: the trait bound `NotZerocopy: Immutable` is not satisfied
|
||
|
|
//~[msrv, stable, nightly]^^ ERROR: the trait bound `NotZerocopy: IntoBytes` is not satisfied
|
||
|
|
|
||
|
|
struct Foo;
|
||
|
|
|
||
|
|
impl Foo {
|
||
|
|
fn write_obj<T: Immutable + IntoBytes>(&mut self, _val: T) {}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
fn takes_from_bytes<T: FromBytes>() {}
|
||
|
|
fn takes_from_zeros<T: FromZeros>() {}
|
||
|
|
fn takes_immutable<T: Immutable>() {}
|
||
|
|
fn takes_into_bytes<T: IntoBytes>() {}
|
||
|
|
fn takes_known_layout<T: KnownLayout>() {}
|
||
|
|
fn takes_try_from_bytes<T: TryFromBytes>() {}
|
||
|
|
fn takes_unaligned<T: Unaligned>() {}
|