On Fri, 24 Oct 2025 07:13, Zhao Liu <[email protected]> wrote:
>For bit property, make the type conversion within the #[property] macro
>so that users do not need to handle the conversion.
>
>Suggested-by: Paolo Bonzini <[email protected]>
>Signed-off-by: Zhao Liu <[email protected]>
>---
>Changes Since v2:
> - Check #field_ty::BITS instead of u8::MAX.
> - Update test cases.
>---
LGTM, some questions...
> rust/hw/timer/hpet/src/device.rs | 2 +-
> rust/qemu-macros/src/lib.rs | 23 ++++++++++++++++++-----
> rust/qemu-macros/src/tests.rs | 15 ++++++++++++---
> 3 files changed, 31 insertions(+), 9 deletions(-)
>
>diff --git a/rust/hw/timer/hpet/src/device.rs
>b/rust/hw/timer/hpet/src/device.rs
>index 86638c076666..23f2eefd1cd9 100644
>--- a/rust/hw/timer/hpet/src/device.rs
>+++ b/rust/hw/timer/hpet/src/device.rs
>@@ -539,7 +539,7 @@ pub struct HPETState {
> // Internal state
> /// Capabilities that QEMU HPET supports.
> /// bit 0: MSI (or FSB) support.
>- #[property(rename = "msi", bit = HPET_FLAG_MSI_SUPPORT_SHIFT as u8,
>default = false)]
>+ #[property(rename = "msi", bit = HPET_FLAG_MSI_SUPPORT_SHIFT, default =
>false)]
> flags: u32,
>
> /// Offset of main counter relative to qemu clock.
>diff --git a/rust/qemu-macros/src/lib.rs b/rust/qemu-macros/src/lib.rs
>index 50239f228be2..ee417bb4b4ef 100644
>--- a/rust/qemu-macros/src/lib.rs
>+++ b/rust/qemu-macros/src/lib.rs
>@@ -262,12 +262,25 @@ macro_rules! str_to_c_str {
> },
> )?;
> let field_ty = field.ty.clone();
>- let qdev_prop = if bitnr.is_none() {
>- quote! { <#field_ty as ::hwcore::QDevProp>::BASE_INFO }
>+ let (qdev_prop, bitval) = if let Some(bitval) = bitnr {
>+ (
>+ quote! { <#field_ty as ::hwcore::QDevProp>::BIT_INFO },
>+ quote! {
>+ {
>+ const {
>+ assert!(#bitval >= 0 && #bitval < #field_ty::BITS
>as _,
>+ "bit number exceeds type bits
>range");
Const panic messages cannot use formatting parameters yet, but.
Can we interpolate the type (e.g u32) in the compile-time panic message?
Not important but would make the error message friendlier.
Reviewed-by: Manos Pitsidianakis <[email protected]>
>+ }
>+ #bitval as u8
>+ }
>+ },
>+ )
> } else {
>- quote! { <#field_ty as ::hwcore::QDevProp>::BIT_INFO }
>+ (
>+ quote! { <#field_ty as ::hwcore::QDevProp>::BASE_INFO },
>+ quote! { 0 },
>+ )
> };
>- let bitnr = bitnr.unwrap_or(syn::Expr::Verbatim(quote! { 0 }));
> let set_default = defval.is_some();
> let defval = defval.unwrap_or(syn::Expr::Verbatim(quote! { 0 }));
> properties_expanded.push(quote! {
>@@ -275,7 +288,7 @@ macro_rules! str_to_c_str {
> name: ::std::ffi::CStr::as_ptr(#prop_name),
> info: #qdev_prop,
> offset: ::core::mem::offset_of!(#name, #field_name) as isize,
>- bitnr: #bitnr,
>+ bitnr: #bitval,
> set_default: #set_default,
> defval: ::hwcore::bindings::Property__bindgen_ty_1 { u:
> #defval as u64 },
> ..::common::Zeroable::ZERO
>diff --git a/rust/qemu-macros/src/tests.rs b/rust/qemu-macros/src/tests.rs
>index 65691412ff57..b65cf656fa36 100644
>--- a/rust/qemu-macros/src/tests.rs
>+++ b/rust/qemu-macros/src/tests.rs
>@@ -179,7 +179,10 @@ unsafe impl ::hwcore::DevicePropertiesImpl for DummyState
>{
> name: ::std::ffi::CStr::as_ptr(c"flags"),
> info: <u32 as ::hwcore::QDevProp>::BIT_INFO,
> offset: ::core::mem::offset_of!(DummyState, flags) as
> isize,
>- bitnr: 3,
>+ bitnr : {
>+ const { assert!(3 >= 0 && 3 < u32::BITS as _ ,
>"bit number exceeds type bits range"); }
>+ 3 as u8
>+ },
> set_default: false,
> defval: ::hwcore::bindings::Property__bindgen_ty_1 {
> u: 0 as u64 },
> ..::common::Zeroable::ZERO
>@@ -207,7 +210,10 @@ unsafe impl ::hwcore::DevicePropertiesImpl for DummyState
>{
> name: ::std::ffi::CStr::as_ptr(c"flags"),
> info: <u32 as ::hwcore::QDevProp>::BIT_INFO,
> offset: ::core::mem::offset_of!(DummyState, flags) as
> isize,
>- bitnr: 3,
>+ bitnr : {
>+ const { assert!(3 >= 0 && 3 < u32::BITS as _ ,
>"bit number exceeds type bits range"); }
>+ 3 as u8
>+ },
> set_default: true,
> defval: ::hwcore::bindings::Property__bindgen_ty_1 {
> u: true as u64 },
> ..::common::Zeroable::ZERO
>@@ -235,7 +241,10 @@ unsafe impl ::hwcore::DevicePropertiesImpl for DummyState
>{
> name: ::std::ffi::CStr::as_ptr(c"msi"),
> info: <u64 as ::hwcore::QDevProp>::BIT_INFO,
> offset: ::core::mem::offset_of!(DummyState, flags) as
> isize,
>- bitnr: 3,
>+ bitnr : {
>+ const { assert!(3 >= 0 && 3 < u64::BITS as _ ,
>"bit number exceeds type bits range"); }
>+ 3 as u8
>+ },
> set_default: true,
> defval: ::hwcore::bindings::Property__bindgen_ty_1 {
> u: false as u64 },
> ..::common::Zeroable::ZERO
>--
>2.34.1
>
