Re: [PATCH v3 11/19] qom: field_prop_set_default_value() helper

[Eduardo Habkost]

On Tue, Nov 24, 2020 at 10:58:27AM +0100, Markus Armbruster wrote:
> Eduardo Habkost <ehabkost@redhat.com> writes:
> 
> > Move code that sets the property default value to a separate
> > function, to reduce duplication and make refactoring easier.
> >
> > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> > ---
> > This is a new patch added in v3 of this series.
> > Hopefully, this will make the series easier to review.
> >
> > The field_prop_set_default_value() was added in v2 at
> > "qom: Use qlit to represent property defaults".
> > ---
> >  qom/field-property.c | 24 ++++++++++++++++--------
> >  1 file changed, 16 insertions(+), 8 deletions(-)
> >
> > diff --git a/qom/field-property.c b/qom/field-property.c
> > index cb729626ce..6a0df7c6ea 100644
> > --- a/qom/field-property.c
> > +++ b/qom/field-property.c
> > @@ -62,6 +62,17 @@ static void static_prop_release_dynamic_prop(Object 
> > *obj, const char *name,
> >      g_free(prop);
> >  }
> >  
> > +static void field_prop_set_default_value(ObjectProperty *op,
> > +                                         Property *prop)
> > +{
> > +    if (!prop->set_default) {
> > +        return;
> > +    }
> > +
> > +    assert(prop->info->set_default_value);
> > +    prop->info->set_default_value(op, prop);
> > +}
> > +
> >  ObjectProperty *
> >  object_property_add_field(Object *obj, const char *name,
> >                            Property *prop,
> > @@ -83,11 +94,9 @@ object_property_add_field(Object *obj, const char *name,
> >      object_property_set_description(obj, name,
> >                                      newprop->info->description);
> >  
> > -    if (newprop->set_default) {
> > -        newprop->info->set_default_value(op, newprop);
> > -        if (op->init) {
> > -            op->init(obj, op);
> > -        }
> > +    field_prop_set_default_value(op, newprop);
> > +    if (op->init) {
> > +        op->init(obj, op);
> >      }
> 
> op->init() is now called even when !newprop->set_default.  Why is that
> okay?

op->init() will be NULL if object_property_set_default() was not
called.

It's subtle, and worth mentioning in the commit message.  I think
we should encapsulate op->init() behind a
object_property_reset_to_default_value() function.

> 
> >  
> >      op->allow_set = allow_set;
> > @@ -113,9 +122,8 @@ object_class_property_add_field_static(ObjectClass *oc, 
> > const char *name,
> >                                         prop->info->release,
> >                                         prop);
> >      }
> > -    if (prop->set_default) {
> > -        prop->info->set_default_value(op, prop);
> > -    }
> > +
> > +    field_prop_set_default_value(op, prop);
> >      if (prop->info->description) {
> >          object_class_property_set_description(oc, name,
> >                                                prop->info->description);

-- 
Eduardo