diff options
Diffstat (limited to 'rust/qemu-api/src/zeroable.rs')
| -rw-r--r-- | rust/qemu-api/src/zeroable.rs | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/rust/qemu-api/src/zeroable.rs b/rust/qemu-api/src/zeroable.rs index 7b04947cb6..47b6977828 100644 --- a/rust/qemu-api/src/zeroable.rs +++ b/rust/qemu-api/src/zeroable.rs @@ -1,11 +1,13 @@ // SPDX-License-Identifier: GPL-2.0-or-later +//! Defines a trait for structs that can be safely initialized with zero bytes. + /// Encapsulates the requirement that /// `MaybeUninit::<Self>::zeroed().assume_init()` does not cause undefined /// behavior. This trait in principle could be implemented as just: /// /// ``` -/// pub unsafe trait Zeroable { +/// pub unsafe trait Zeroable: Default { /// const ZERO: Self = unsafe { ::core::mem::MaybeUninit::<Self>::zeroed().assume_init() }; /// } /// ``` @@ -56,6 +58,7 @@ pub unsafe trait Zeroable: Default { /// ## Differences with `core::mem::zeroed` /// /// `const_zero` zeroes padding bits, while `core::mem::zeroed` doesn't +#[macro_export] macro_rules! const_zero { // This macro to produce a type-generic zero constant is taken from the // const_zero crate (v0.1.1): @@ -77,10 +80,11 @@ macro_rules! const_zero { } /// A wrapper to implement the `Zeroable` trait through the `const_zero` macro. +#[macro_export] macro_rules! impl_zeroable { ($type:ty) => { - unsafe impl Zeroable for $type { - const ZERO: Self = unsafe { const_zero!($type) }; + unsafe impl $crate::zeroable::Zeroable for $type { + const ZERO: Self = unsafe { $crate::const_zero!($type) }; } }; } @@ -100,3 +104,5 @@ impl_zeroable!(crate::bindings::VMStateField); impl_zeroable!(crate::bindings::VMStateDescription); impl_zeroable!(crate::bindings::MemoryRegionOps__bindgen_ty_1); impl_zeroable!(crate::bindings::MemoryRegionOps__bindgen_ty_2); +impl_zeroable!(crate::bindings::MemoryRegionOps); +impl_zeroable!(crate::bindings::MemTxAttrs); |