Re: [RFC 10/18] rust: split "qom" crate

[Paolo Bonzini <pbonzini@redhat.com>]

On 8/27/25 10:57, Marc-André Lureau wrote:
> Hi
> 
> On Wed, Aug 27, 2025 at 10:33 AM Zhao Liu <zhao1.liu@intel.com 
> <mailto:zhao1.liu@intel.com>> wrote:
> 
>      > diff --git a/rust/hw/char/pl011/src/device.rs <http://device.rs>
>     b/rust/hw/char/pl011/src/device.rs <http://device.rs>
>      > index 7cffb894a8..a3bcd1297a 100644
>      > --- a/rust/hw/char/pl011/src/device.rs <http://device.rs>
>      > +++ b/rust/hw/char/pl011/src/device.rs <http://device.rs>
>      > @@ -21,10 +21,13 @@
>      >      memory::{hwaddr, MemoryRegion, MemoryRegionOps,
>     MemoryRegionOpsBuilder},
>      >      prelude::*,
>      >      qdev::{Clock, ClockEvent, DeviceImpl, DeviceState, Property,
>     ResetType, ResettablePhasesImpl},
>      > -    qom::{ObjectImpl, Owned, ParentField, ParentInit},
>      >      sysbus::{SysBusDevice, SysBusDeviceImpl},
>      >      vmstate_clock,
>      >  };
>      > +use qom::{
>      > +    qom_isa, IsA, Object, ObjectClassMethods, ObjectDeref,
>     ObjectImpl, ObjectMethods, ObjectType,
>      > +    Owned, ParentField, ParentInit,
>      > +};
> 
>     These QOM parts are frequently used and very common. at least for qom,
>     I think prelude would help a lot. 
> 
> 
> ack
> 
>     A qom prelude could help reduce the changes in other parts (pl011/
>     hpet/memory...).
> 
>      > diff --git a/rust/qom/meson.build b/rust/qom/meson.build
>      > new file mode 100644
>      > index 0000000000..6e95d75fa0
>      > --- /dev/null
>      > +++ b/rust/qom/meson.build
>      > @@ -0,0 +1,61 @@
>      > +_qom_cfg = run_command(rustc_args,
>      > +  '--config-headers', config_host_h, '--features',
>     files('Cargo.toml'),
>      > +  capture: true, check: true).stdout().strip().splitlines()
>      > +
>      > +# TODO: Remove this comment when the clang/libclang mismatch
>     issue is solved.
>      > +#
>      > +# Rust bindings generation with `bindgen` might fail in some
>     cases where the
>      > +# detected `libclang` does not match the expected `clang`
>     version/target. In
>      > +# this case you must pass the path to `clang` and `libclang` to
>     your build
>      > +# command invocation using the environment variables CLANG_PATH and
>      > +# LIBCLANG_PATH
>      > +_qom_bindings_inc_rs = rust.bindgen(
>      > +  input: 'wrapper.h',
>      > +  dependencies: common_ss.all_dependencies(),
>      > +  output: 'bindings.inc.rs <http://bindings.inc.rs>',
> 
>     There're many binding files with the same name. What about adding a
>     prefix
>     like "qom-bindings" to distinguish it? This can help search and locate
>     specific binding file.
> 
> 
> they are already under different directories :)
> 
> 
>      > +  include_directories: bindings_incdir,
>      > +  bindgen_version: ['>=0.60.0'],
>      > +  args: bindgen_args_common,
>      > +)
> 
>     ...
> 
>      > diff --git a/rust/qom/tests/tests.rs <http://tests.rs> b/rust/
>     qom/tests/tests.rs <http://tests.rs>
>      > new file mode 100644
>      > index 0000000000..49f1cbecf5
>      > --- /dev/null
>      > +++ b/rust/qom/tests/tests.rs <http://tests.rs>
>      > @@ -0,0 +1,47 @@
>      > +use std::{ffi::CStr, sync::LazyLock};
> 
>     LazyLock is useful, but it became stable since v1.80. So if Paolo
>     decide pick this series after v1.83 support, it's fine.
yes, you all can assume 1.83.

Paolo