> +/// This macro can be used (by just passing it a type) to forward the
> `VMState`
> +/// trait to the first field of a tuple. This is a workaround for lack of
> +/// support of nested [`offset_of`](core::mem::offset_of) until Rust 1.82.0.
> +///
> +/// # Examples
> +///
> +/// ```
> +/// # use qemu_api::vmstate::impl_vmstate_forward;
> +/// pub struct Fifo([u8; 16]);
> +/// impl_vmstate_forward!(Fifo);
> +/// ```
> +#[macro_export]
> +macro_rules! impl_vmstate_forward {
> + // This is similar to impl_vmstate_transparent below, but it
> + // uses the same trick as vmstate_of! to obtain the type of
> + // the first field of the tuple
> + ($tuple:ty) => {
> + unsafe impl $crate::vmstate::VMState for $tuple {
> + const SCALAR_TYPE: $crate::vmstate::VMStateFieldType =
> +
> $crate::call_func_with_field!($crate::vmstate::vmstate_scalar_type, $tuple,
> 0);
> + const BASE: $crate::bindings::VMStateField =
> + $crate::call_func_with_field!($crate::vmstate::vmstate_base,
> $tuple, 0);
> + }
> + };
> +}
> +
Powerful!
> // Transparent wrappers: just use the internal type
>
> macro_rules! impl_vmstate_transparent {
> @@ -283,6 +318,26 @@ unsafe impl<$base> VMState for $type where $base:
> VMState $($where)* {
> impl_vmstate_transparent!(crate::cell::BqlCell<T> where T: VMState);
> impl_vmstate_transparent!(crate::cell::BqlRefCell<T> where T: VMState);
>
> +#[macro_export]
> +macro_rules! impl_vmstate_bitsized {
> + ($type:ty) => {
> + unsafe impl $crate::vmstate::VMState for $type {
> + const SCALAR_TYPE: $crate::vmstate::VMStateFieldType =
> + <<<$type as
> ::bilge::prelude::Bitsized>::ArbitraryInt
> + as
> ::bilge::prelude::Number>::UnderlyingType
> + as
> $crate::vmstate::VMState>::SCALAR_TYPE;
> + const BASE: $crate::bindings::VMStateField =
> + <<<$type as
> ::bilge::prelude::Bitsized>::ArbitraryInt
> + as
> ::bilge::prelude::Number>::UnderlyingType
> + as $crate::vmstate::VMState>::BASE;
> + const VARRAY_FLAG: $crate::bindings::VMStateFlags =
> + <<<$type as
> ::bilge::prelude::Bitsized>::ArbitraryInt
> + as
> ::bilge::prelude::Number>::UnderlyingType
> + as
> $crate::vmstate::VMState>::VARRAY_FLAG;
> + }
> + };
> +}
> +
> // Scalar types using predefined VMStateInfos
>
> macro_rules! impl_vmstate_scalar {
Reviewed-by: Zhao Liu <zhao1....@intel.com>
