Re: [PATCH v4 26/32] qdev: Separate generic and device-specific property registration

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 11 Dec 2020 17:05:23 -0500
Eduardo Habkost <ehabkost@redhat.com> wrote:

> qdev_class_add_property() and qdev_property_add_static() will
> have code that's specific for device types.
> 
> object_class_property_add_field_static() and
> object_property_add_field() will be generic and part of the QOM
> field property API.  Note that the new functions have a `name`
> parameter because the plan is to eventually get rid of the
> Property.name field.
> 
> The declarations for the new functions are being added to
> qdev-properties-internal.h, but they will be moved to a QOM
> header later.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v2 -> v3:
> * Re-added array-based array registration function, named
>   as object_class_add_field_properties()
> * Renamed object_class_property_add_field() to
>   object_class_property_add_field_static(), to indicate that
>   the function expect the Property argument to have static life
>   time.
> * Keep all new functions as internal API by now,
>   until we decide what's going to be the preferred API for
>   registering class field properties.
> 
> Changes v1 -> v2:
> * Patch redone after changes in previous patches in the series
> * Rename new functions to object*_property_add_field()
> ---
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: "Daniel P. Berrangé" <berrange@redhat.com>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Cc: qemu-devel@nongnu.org
> ---
>  hw/core/qdev-prop-internal.h | 42 ++++++++++++++++++++++++++++++++++++
>  hw/core/qdev-properties.c    | 37 ++++++++++++++++++++++++-------
>  2 files changed, 71 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/core/qdev-prop-internal.h b/hw/core/qdev-prop-internal.h
> index d7b77844fe..6f17ddf271 100644
> --- a/hw/core/qdev-prop-internal.h
> +++ b/hw/core/qdev-prop-internal.h
> @@ -25,4 +25,46 @@ void qdev_propinfo_get_int32(Object *obj, Visitor *v, const char *name,
>  void qdev_propinfo_get_size32(Object *obj, Visitor *v, const char *name,
>                                void *opaque, Error **errp);
>  
> +/**
> + * object_property_add_field: Add a field property to an object instance
> + * @obj: object instance
> + * @name: property name
> + * @prop: property definition
> + *
> + * This function should not be used in new code.  Please add class properties
> + * instead, using object_class_add_field().
> + */
> +ObjectProperty *
> +object_property_add_field(Object *obj, const char *name,
> +                          Property *prop);
> +
> +/**
> + * object_class_property_add_field_static: Add a field property to object class
> + * @oc: object class
> + * @name: property name
> + * @prop: property definition
> + *
> + * Add a field property to an object class.  A field property is
> + * a property that will change a field at a specific offset of the
> + * object instance struct.
> + *
> + * *@prop must have static life time.
> + */
> +ObjectProperty *
> +object_class_property_add_field_static(ObjectClass *oc, const char *name,
> +                                       Property *prop);
> +
> +/**
> + * object_class_add_field_properties: Add field properties from array to a class
> + * @oc: object class
> + * @props: array of property definitions
> + *
> + * Register an array of field properties to a class, using
> + * object_class_property_add_field_static() for each array element.
> + *
> + * The array at @props must end with DEFINE_PROP_END_OF_LIST(), and
> + * must have static life time.
> + */
> +void object_class_add_field_properties(ObjectClass *oc, Property *props);
since it uses object_class_property_add_field_static() may be add _static suffix here as well?

> +
>  #endif
> diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> index fcda0c8f4b..8436b60ec4 100644
> --- a/hw/core/qdev-properties.c
> +++ b/hw/core/qdev-properties.c
> @@ -835,20 +835,21 @@ const PropertyInfo qdev_prop_link = {
>      .create = create_link_property,
>  };
>  
> -void qdev_property_add_static(DeviceState *dev, Property *prop)
> +ObjectProperty *
> +object_property_add_field(Object *obj, const char *name,
> +                          Property *prop)
>  {
> -    Object *obj = OBJECT(dev);
>      ObjectProperty *op;
>  
>      assert(!prop->info->create);
>  
> -    op = object_property_add(obj, prop->name, prop->info->name,
> +    op = object_property_add(obj, name, prop->info->name,
>                               field_prop_getter(prop->info),
>                               field_prop_setter(prop->info),
>                               prop->info->release,
>                               prop);
>  
> -    object_property_set_description(obj, prop->name,
> +    object_property_set_description(obj, name,
>                                      prop->info->description);
>  
>      if (prop->set_default) {
> @@ -857,12 +858,14 @@ void qdev_property_add_static(DeviceState *dev, Property *prop)
>              op->init(obj, op);
>          }
>      }
> +
> +    return op;
>  }
>  
> -static void qdev_class_add_property(DeviceClass *klass, const char *name,
> -                                    Property *prop)
> +ObjectProperty *
> +object_class_property_add_field_static(ObjectClass *oc, const char *name,
> +                                       Property *prop)
>  {
> -    ObjectClass *oc = OBJECT_CLASS(klass);
>      ObjectProperty *op;
>  
>      if (prop->info->create) {
> @@ -882,6 +885,22 @@ static void qdev_class_add_property(DeviceClass *klass, const char *name,
>          object_class_property_set_description(oc, name,
>                                                prop->info->description);
>      }
> +    return op;
> +}
> +
> +void object_class_add_field_properties(ObjectClass *oc, Property *props)
> +{
> +    Property *prop;
> +
> +    for (prop = props; prop && prop->name; prop++) {
> +        object_class_property_add_field_static(oc, prop->name, prop);
> +    }
> +}
> +
> +
> +void qdev_property_add_static(DeviceState *dev, Property *prop)
> +{
> +    object_property_add_field(OBJECT(dev), prop->name, prop);
>  }
>  
>  /**
> @@ -932,13 +951,15 @@ static void qdev_class_add_legacy_property(DeviceClass *dc, Property *prop)
>  
>  void device_class_set_props(DeviceClass *dc, Property *props)
>  {
> +    ObjectClass *oc = OBJECT_CLASS(dc);
>      Property *prop;
>  
>      dc->props_ = props;
>      for (prop = props; prop && prop->name; prop++) {
>          qdev_class_add_legacy_property(dc, prop);
> -        qdev_class_add_property(dc, prop->name, prop);
>      }
> +
> +    object_class_add_field_properties(oc, props);
>  }
>  
>  void qdev_alias_all_properties(DeviceState *target, Object *source)