1 files changed, 24 insertions, 73 deletions

diff --git a/rust/qemu-api/src/zeroable.rs b/rust/qemu-api/src/zeroable.rs
index 6125aee..d8239d0 100644
--- a/rust/qemu-api/src/zeroable.rs
+++ b/rust/qemu-api/src/zeroable.rs
@@ -1,86 +1,37 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-use std::ptr;
+//! 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: Default {
-///     const ZERO: Self = unsafe { ::core::mem::MaybeUninit::<Self>::zeroed().assume_init() };
-/// }
-/// ```
-///
-/// The need for a manual implementation is only because `zeroed()` cannot
-/// be used as a `const fn` prior to Rust 1.75.0. Once we can assume a new
-/// enough version of the compiler, we could provide a `#[derive(Zeroable)]`
-/// macro to check at compile-time that all struct fields are Zeroable, and
-/// use the above blanket implementation of the `ZERO` constant.
+/// behavior.
 ///
 /// # Safety
 ///
-/// Because the implementation of `ZERO` is manual, it does not make
-/// any assumption on the safety of `zeroed()`.  However, other users of the
-/// trait could use it that way.  Do not add this trait to a type unless
-/// all-zeroes is a valid value for the type.  In particular, remember that
-/// raw pointers can be zero, but references and `NonNull<T>` cannot
+/// Do not add this trait to a type unless all-zeroes is a valid value for the
+/// type.  In particular, raw pointers can be zero, but references and
+/// `NonNull<T>` cannot.
 pub unsafe trait Zeroable: Default {
-    const ZERO: Self;
+    /// Return a value of Self whose memory representation consists of all
+    /// zeroes, with the possible exclusion of padding bytes.
+    const ZERO: Self = unsafe { ::core::mem::MaybeUninit::<Self>::zeroed().assume_init() };
 }
 
-unsafe impl Zeroable for crate::bindings::Property__bindgen_ty_1 {
-    const ZERO: Self = Self { i: 0 };
+// bindgen does not derive Default here
+#[allow(clippy::derivable_impls)]
+impl Default for crate::bindings::VMStateFlags {
+    fn default() -> Self {
+        Self(0)
+    }
 }
 
-unsafe impl Zeroable for crate::bindings::Property {
-    const ZERO: Self = Self {
-        name: ptr::null(),
-        info: ptr::null(),
-        offset: 0,
-        bitnr: 0,
-        bitmask: 0,
-        set_default: false,
-        defval: Zeroable::ZERO,
-        arrayoffset: 0,
-        arrayinfo: ptr::null(),
-        arrayfieldsize: 0,
-        link_type: ptr::null(),
-    };
-}
-
-unsafe impl Zeroable for crate::bindings::VMStateDescription {
-    const ZERO: Self = Self {
-        name: ptr::null(),
-        unmigratable: false,
-        early_setup: false,
-        version_id: 0,
-        minimum_version_id: 0,
-        priority: crate::bindings::MigrationPriority::MIG_PRI_DEFAULT,
-        pre_load: None,
-        post_load: None,
-        pre_save: None,
-        post_save: None,
-        needed: None,
-        dev_unplug_pending: None,
-        fields: ptr::null(),
-        subsections: ptr::null(),
-    };
-}
-
-unsafe impl Zeroable for crate::bindings::MemoryRegionOps__bindgen_ty_1 {
-    const ZERO: Self = Self {
-        min_access_size: 0,
-        max_access_size: 0,
-        unaligned: false,
-        accepts: None,
-    };
-}
-
-unsafe impl Zeroable for crate::bindings::MemoryRegionOps__bindgen_ty_2 {
-    const ZERO: Self = Self {
-        min_access_size: 0,
-        max_access_size: 0,
-        unaligned: false,
-    };
-}
+unsafe impl Zeroable for crate::bindings::Property__bindgen_ty_1 {}
+unsafe impl Zeroable for crate::bindings::Property {}
+unsafe impl Zeroable for crate::bindings::VMStateFlags {}
+unsafe impl Zeroable for crate::bindings::VMStateField {}
+unsafe impl Zeroable for crate::bindings::VMStateDescription {}
+unsafe impl Zeroable for crate::bindings::MemoryRegionOps__bindgen_ty_1 {}
+unsafe impl Zeroable for crate::bindings::MemoryRegionOps__bindgen_ty_2 {}
+unsafe impl Zeroable for crate::bindings::MemoryRegionOps {}
+unsafe impl Zeroable for crate::bindings::MemTxAttrs {}
+unsafe impl Zeroable for crate::bindings::CharBackend {}