Re: [RFC 07/10] hw/core/qdev-properties: Allow to mark qdev property as deprecated

[Igor Mammedov <imammedo@redhat.com>]

On Wed,  3 Dec 2025 01:04:59 +0800
Zhao Liu <zhao1.liu@intel.com> wrote:

> With deprecation flag, make qdev property interfaces to accept
> ObjectPropertyFlags, and provide the boolean and uint8_t macro variants
> to help on deprecation as examples.
> 
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
> ---
>  hw/core/qdev-properties.c    | 24 +++++++++++++-----------
>  include/hw/qdev-properties.h | 18 ++++++++++++++++++
>  2 files changed, 31 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index 422a486969c8..2cd7de5cec2d 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -1069,11 +1069,12 @@ void qdev_property_add_static(DeviceState *dev, const Property *prop)
>  
>      assert(!prop->info->create);
>  
> -    op = object_property_add(obj, prop->name, prop->info->type,
> -                             field_prop_getter(prop->info),
> -                             field_prop_setter(prop->info),
> -                             prop->info->release,
> -                             (Property *)prop);
> +    op = object_property_try_add_full(obj, prop->name, prop->info->type,
> +                                      field_prop_getter(prop->info),
> +                                      field_prop_setter(prop->info),
> +                                      prop->info->release,
> +                                      prop->flags, (Property *)prop,
> +                                      &error_abort);
>  
>      object_property_set_description(obj, prop->name,
>                                      prop->info->description);
> @@ -1095,12 +1096,13 @@ static void qdev_class_add_property(DeviceClass *klass, const char *name,
>      if (prop->info->create) {
>          op = prop->info->create(oc, name, prop);
>      } else {
> -        op = object_class_property_add(oc,
> -                                       name, prop->info->type,
> -                                       field_prop_getter(prop->info),
> -                                       field_prop_setter(prop->info),
> -                                       prop->info->release,
> -                                       (Property *)prop);
> +        op = object_class_property_add_full(oc,
> +                                            name, prop->info->type,
> +                                            field_prop_getter(prop->info),
> +                                            field_prop_setter(prop->info),
> +                                            prop->info->release,
> +                                            prop->flags,
> +                                            (Property *)prop);
>      }
>      if (prop->set_default) {
>          prop->info->set_default_value(op, prop);
> diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
> index 60b81330097d..383f3f54f0ab 100644
> --- a/include/hw/qdev-properties.h
> +++ b/include/hw/qdev-properties.h
> @@ -11,6 +11,7 @@
>   *     and the field retains whatever value it was given by instance_init).
>   * @defval: default value for the property. This is used only if @set_default
>   *     is true.
> + * @flags: property flags to control uses.
>   */
>  struct Property {
>      const char   *name;
> @@ -27,6 +28,7 @@ struct Property {
>      int          arrayfieldsize;
>      uint8_t      bitnr;
>      bool         set_default;
> +    uint8_t      flags;
>  };
>  
>  struct PropertyInfo {
> @@ -102,6 +104,13 @@ extern const PropertyInfo qdev_prop_link;
>                  .set_default = true,                                       \
>                  .defval.u  = (_type)_defval)
>  
> +#define DEFINE_PROP_UNSIGNED_DEPRECATED(_name, _state, _field, \
> +                                        _defval, _prop, _type) \
> +    DEFINE_PROP(_name, _state, _field, _prop, _type,           \
> +                .set_default = true,                           \
> +                .defval.u    = (_type)_defval,                 \
> +                .flags       = OBJECT_PROPERTY_DEPRECATED)
> +
>  #define DEFINE_PROP_UNSIGNED_NODEFAULT(_name, _state, _field, _prop, _type) \

adding flags to the end of the names, basicaly spawns a lot of vartions of the same macro,

perhaps it's time to just add flags field and consoladate existing 'flag named' variants,
the one won't need to introduce DEFINE_PROP_UNSIGNED_DEPRECATED at all,
just use appropriate flag(s) when decaring property.

>      DEFINE_PROP(_name, _state, _field, _prop, _type)
>  
> @@ -123,6 +132,12 @@ extern const PropertyInfo qdev_prop_link;
>                  .set_default = true,                         \
>                  .defval.u    = (bool)_defval)
>  
> +#define DEFINE_PROP_BOOL_DEPRECATED(_name, _state, _field, _defval)     \
> +    DEFINE_PROP(_name, _state, _field, qdev_prop_bool, bool,            \
> +                .set_default = true,                                    \
> +                .defval.u    = (bool)_defval,                           \
> +                .flags       = OBJECT_PROPERTY_DEPRECATED)
> +
>  /**
>   * The DEFINE_PROP_UINT64_CHECKMASK macro checks a user-supplied value
>   * against corresponding bitmask, rejects the value if it violates.
> @@ -189,6 +204,9 @@ extern const PropertyInfo qdev_prop_link;
>  #define DEFINE_PROP_SIZE32(_n, _s, _f, _d)                       \
>      DEFINE_PROP_UNSIGNED(_n, _s, _f, _d, qdev_prop_size32, uint32_t)
>  
> +#define DEFINE_PROP_UINT8_DEPRECATED(_n, _s, _f, _d)                       \
> +    DEFINE_PROP_UNSIGNED_DEPRECATED(_n, _s, _f, _d, qdev_prop_uint8, uint8_t)
> +
>  /*
>   * Set properties between creation and realization.
>   *