Now that const_refs_static can be assumed, convert the members of
the DeviceImpl trait from functions to constants. This lets the
compiler know that they have a 'static lifetime, and removes the
need for the weird "Box::leak()".
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250908105005.2119297-10-pbonzini@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
rust/hw/char/pl011/src/device.rs | 4 +--
rust/hw/timer/hpet/src/device.rs | 9 ++-----
rust/qemu-api-macros/src/lib.rs | 8 +++---
rust/qemu-api-macros/src/tests.rs | 44 ++++++++++++++-----------------
rust/qemu-api/src/qdev.rs | 19 +++++--------
rust/qemu-api/tests/tests.rs | 4 +--
6 files changed, 33 insertions(+), 55 deletions(-)
diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
index 87a17716fed..8411db8d00c 100644
--- a/rust/hw/char/pl011/src/device.rs
+++ b/rust/hw/char/pl011/src/device.rs
@@ -172,9 +172,7 @@ impl ObjectImpl for PL011State {
}
impl DeviceImpl for PL011State {
- fn vmsd() -> Option<VMStateDescription<Self>> {
- Some(VMSTATE_PL011)
- }
+ const VMSTATE: Option<VMStateDescription<Self>> = Some(VMSTATE_PL011);
const REALIZE: Option<fn(&Self) -> qemu_api::Result<()>> = Some(Self::realize);
}
diff --git a/rust/hw/timer/hpet/src/device.rs b/rust/hw/timer/hpet/src/device.rs
index eb5bd042b1c..dd5326a40d4 100644
--- a/rust/hw/timer/hpet/src/device.rs
+++ b/rust/hw/timer/hpet/src/device.rs
@@ -1008,16 +1008,11 @@ impl ObjectImpl for HPETState {
// SAFETY: HPET_PROPERTIES is a valid Property array constructed with the
// qemu_api::declare_properties macro.
unsafe impl qemu_api::qdev::DevicePropertiesImpl for HPETState {
- fn properties() -> &'static [Property] {
- &HPET_PROPERTIES
- }
+ const PROPERTIES: &'static [Property] = &HPET_PROPERTIES;
}
impl DeviceImpl for HPETState {
- fn vmsd() -> Option<VMStateDescription<Self>> {
- Some(VMSTATE_HPET)
- }
-
+ const VMSTATE: Option<VMStateDescription<Self>> = Some(VMSTATE_HPET);
const REALIZE: Option<fn(&Self) -> qemu_api::Result<()>> = Some(Self::realize);
}
diff --git a/rust/qemu-api-macros/src/lib.rs b/rust/qemu-api-macros/src/lib.rs
index 97b2c214b62..a65a7ce2fe9 100644
--- a/rust/qemu-api-macros/src/lib.rs
+++ b/rust/qemu-api-macros/src/lib.rs
@@ -289,11 +289,9 @@ macro_rules! str_to_c_str {
Ok(quote_spanned! {input.span() =>
unsafe impl ::qemu_api::qdev::DevicePropertiesImpl for #name {
- fn properties() -> &'static [::qemu_api::bindings::Property] {
- static PROPERTIES: &[::qemu_api::bindings::Property] = &[#(#properties_expanded),*];
-
- PROPERTIES
- }
+ const PROPERTIES: &'static [::qemu_api::bindings::Property] = &[
+ #(#properties_expanded),*
+ ];
}
})
}
diff --git a/rust/qemu-api-macros/src/tests.rs b/rust/qemu-api-macros/src/tests.rs
index aafffcdce91..0e5a5728908 100644
--- a/rust/qemu-api-macros/src/tests.rs
+++ b/rust/qemu-api-macros/src/tests.rs
@@ -101,18 +101,16 @@ pub struct DummyState {
},
quote! {
unsafe impl ::qemu_api::qdev::DevicePropertiesImpl for DummyState {
- fn properties() -> &'static [::qemu_api::bindings::Property] {
- static PROPERTIES: &[::qemu_api::bindings::Property] =
- &[::qemu_api::bindings::Property {
- name: ::std::ffi::CStr::as_ptr(c"migrate_clock"),
- info: <bool as ::qemu_api::qdev::QDevProp>::VALUE,
- offset: ::core::mem::offset_of!(DummyState, migrate_clock) as isize,
- set_default: true,
- defval: ::qemu_api::bindings::Property__bindgen_ty_1 { u: true as u64 },
- ..::qemu_api::zeroable::Zeroable::ZERO
- }];
- PROPERTIES
- }
+ const PROPERTIES: &'static [::qemu_api::bindings::Property] = &[
+ ::qemu_api::bindings::Property {
+ name: ::std::ffi::CStr::as_ptr(c"migrate_clock"),
+ info: <bool as ::qemu_api::qdev::QDevProp>::VALUE,
+ offset: ::core::mem::offset_of!(DummyState, migrate_clock) as isize,
+ set_default: true,
+ defval: ::qemu_api::bindings::Property__bindgen_ty_1 { u: true as u64 },
+ ..::qemu_api::zeroable::Zeroable::ZERO
+ }
+ ];
}
}
);
@@ -130,18 +128,16 @@ pub struct DummyState {
},
quote! {
unsafe impl ::qemu_api::qdev::DevicePropertiesImpl for DummyState {
- fn properties() -> &'static [::qemu_api::bindings::Property] {
- static PROPERTIES: &[::qemu_api::bindings::Property] =
- &[::qemu_api::bindings::Property {
- name: ::std::ffi::CStr::as_ptr(c"migrate-clk"),
- info: <bool as ::qemu_api::qdev::QDevProp>::VALUE,
- offset: ::core::mem::offset_of!(DummyState, migrate_clock) as isize,
- set_default: true,
- defval: ::qemu_api::bindings::Property__bindgen_ty_1 { u: true as u64 },
- ..::qemu_api::zeroable::Zeroable::ZERO
- }];
- PROPERTIES
- }
+ const PROPERTIES: &'static [::qemu_api::bindings::Property] = &[
+ ::qemu_api::bindings::Property {
+ name: ::std::ffi::CStr::as_ptr(c"migrate-clk"),
+ info: <bool as ::qemu_api::qdev::QDevProp>::VALUE,
+ offset: ::core::mem::offset_of!(DummyState, migrate_clock) as isize,
+ set_default: true,
+ defval: ::qemu_api::bindings::Property__bindgen_ty_1 { u: true as u64 },
+ ..::qemu_api::zeroable::Zeroable::ZERO
+ }
+ ];
}
}
);
diff --git a/rust/qemu-api/src/qdev.rs b/rust/qemu-api/src/qdev.rs
index 4dda8c81131..436142d8aef 100644
--- a/rust/qemu-api/src/qdev.rs
+++ b/rust/qemu-api/src/qdev.rs
@@ -151,11 +151,8 @@ unsafe impl QDevProp for crate::chardev::CharBackend {
/// Caller is responsible for the validity of properties array.
pub unsafe trait DevicePropertiesImpl {
/// An array providing the properties that the user can set on the
- /// device. Not a `const` because referencing statics in constants
- /// is unstable until Rust 1.83.0.
- fn properties() -> &'static [Property] {
- &[]
- }
+ /// device.
+ const PROPERTIES: &'static [Property] = &[];
}
/// Trait providing the contents of [`DeviceClass`].
@@ -173,9 +170,7 @@ pub trait DeviceImpl:
/// A `VMStateDescription` providing the migration format for the device
/// Not a `const` because referencing statics in constants is unstable
/// until Rust 1.83.0.
- fn vmsd() -> Option<VMStateDescription<Self>> {
- None
- }
+ const VMSTATE: Option<VMStateDescription<Self>> = None;
}
/// # Safety
@@ -224,12 +219,10 @@ pub fn class_init<T: DeviceImpl>(&mut self) {
if <T as DeviceImpl>::REALIZE.is_some() {
self.realize = Some(rust_realize_fn::<T>);
}
- if let Some(vmsd) = <T as DeviceImpl>::vmsd() {
- // Give a 'static lifetime to the return value of vmsd().
- // Temporary until vmsd() can be changed into a const.
- self.vmsd = Box::leak(Box::new(vmsd.get()));
+ if let Some(ref vmsd) = <T as DeviceImpl>::VMSTATE {
+ self.vmsd = vmsd.as_ref();
}
- let prop = <T as DevicePropertiesImpl>::properties();
+ let prop = <T as DevicePropertiesImpl>::PROPERTIES;
if !prop.is_empty() {
unsafe {
bindings::device_class_set_props_n(self, prop.as_ptr(), prop.len());
diff --git a/rust/qemu-api/tests/tests.rs b/rust/qemu-api/tests/tests.rs
index 4d4e4653f38..13495687419 100644
--- a/rust/qemu-api/tests/tests.rs
+++ b/rust/qemu-api/tests/tests.rs
@@ -56,9 +56,7 @@ impl ObjectImpl for DummyState {
impl ResettablePhasesImpl for DummyState {}
impl DeviceImpl for DummyState {
- fn vmsd() -> Option<VMStateDescription<Self>> {
- Some(VMSTATE)
- }
+ const VMSTATE: Option<VMStateDescription<Self>> = Some(VMSTATE);
}
#[repr(C)]
--
2.51.0