On Fri, Jul 03, 2026 at 02:53:04PM +0100, Mark Cave-Ayland wrote:
> This adds a class property that references a uint8_t within the object
> instance
> and is intended to be a replacement for object_property_add_uint8_ptr().
>
> Signed-off-by: Mark Cave-Ayland <[email protected]>
> ---
> include/qom/object.h | 5 +++++
> qom/object.c | 52 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 57 insertions(+)
>
> diff --git a/include/qom/object.h b/include/qom/object.h
> index 89c23d45ab..a55f9d0e97 100644
> --- a/include/qom/object.h
> +++ b/include/qom/object.h
> @@ -1956,6 +1956,11 @@ ObjectProperty *object_property_add_uint8_ptr(Object
> *obj, const char *name,
> const uint8_t *v,
> ObjectPropertyFlags flags);
>
> +ObjectProperty *object_class_property_add_uint8_ptr(ObjectClass *klass,
> + const char *name,
> + ptrdiff_t v,
> + ObjectPropertyFlags
> flags);
> +
> ObjectProperty *object_class_static_property_add_uint8_ptr(ObjectClass
> *klass,
> const char *name,
> const uint8_t *v,
> diff --git a/qom/object.c b/qom/object.c
> index d10bf848c0..263c313cd2 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -2741,6 +2741,38 @@ static void property_set_uint64_ptr(Object *obj,
> Visitor *v, const char *name,
> *field = value;
> }
>
> +static void *object_class_prop_ptr(Object *obj, ptrdiff_t offset)
> +{
> + void *ptr = obj;
> + ptr += offset;
> +
> + return ptr;
> +}
Perhaps just
#define FIELD(obj, offset) ((void *)obj+(ptrdiff_t)offset)
> +
> +static void property_class_get_uint8_ptr(Object *obj, Visitor *v,
> + const char *name,
> + void *opaque, Error **errp)
> +{
> + uint8_t value = *(uint8_t *)object_class_prop_ptr(obj,
> + (ptrdiff_t)opaque);
Do we need this intermediate instead of now
> + visit_type_uint8(v, name, &value, errp);
visit_type_uint8(v, name, FIELD(obj, opaque), errp);
> +}
> +
> +static void property_class_set_uint8_ptr(Object *obj, Visitor *v,
> + const char *name,
> + void *opaque, Error **errp)
> +{
> + uint8_t *field = (uint8_t *)object_class_prop_ptr(obj,
> + (ptrdiff_t)opaque);
> + uint8_t value;
> +
> + if (!visit_type_uint8(v, name, &value, errp)) {
> + return;
> + }
> +
> + *field = value;
Instead of all this is it sufficient to do:
visit_type_uint8(v, name, FIELD(obj, opaque), errp);
Also, since we'll be using this pattern for int8, int16, int32,
and many more, perhaps we could define a macro that can expand
to the getter/setter impl for any scalar type. so we can do
DEFINE_SCALAR_PROP_CALLBACKS(uint8);
DEFINE_SCALAR_PROP_CALLBACKS(uint16);
DEFINE_SCALAR_PROP_CALLBACKS(uint32);
DEFINE_SCALAR_PROP_CALLBACKS(uint64);
DEFINE_SCALAR_PROP_CALLBACKS(bool);
..etc..
> +}
> +
> ObjectProperty *
> object_property_add_uint8_ptr(Object *obj, const char *name,
> const uint8_t *v,
With regards,
Daniel
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