Re: [PATCH v4 10/16] qom/object.c: add object_class_property_add_bool_ptr()

[Mark Cave-Ayland]

On 24/08/2026 13:53, Daniel P. Berrangé wrote:

On Fri, Aug 21, 2026 at 12:14:22PM +0100, Mark Cave-Ayland wrote:
This adds a class property that references a bool within the object instance
and is intended to be used as a replacement for object_class_property_add_bool()
where possible.
Signed-off-by: Mark Cave-Ayland <mark.caveayl...@nutanix.com>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
  include/qom/object.h | 18 ++++++++++++++++++
  qom/object.c         | 43 +++++++++++++++++++++++++++++++++++++++++++
  2 files changed, 61 insertions(+)

diff --git a/include/qom/object.h b/include/qom/object.h
index 8dead29284..de37016ba8 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -2017,6 +2017,24 @@ typedef enum {
      OBJ_PROP_FLAG_READWRITE = (OBJ_PROP_FLAG_READ | OBJ_PROP_FLAG_WRITE),
  } ObjectPropertyFlags;
  
+/**
+ * object_class_property_add_bool_ptr:
+ * @klass: the object class to add a property to
+ * @name: the name of the property
+ * @offset: the offset from the object instance where the bool value is
+ *   stored
+ * @flags: bitwise-or'd ObjectPropertyFlags
+ *
+ * Add an boolean property in memory.  This function will add a
+ * property of type 'bool'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_class_property_add_bool_ptr(ObjectClass *klass,
+                                         const char *name,
+                                         ptrdiff_t offset,
+                                         ObjectPropertyFlags flags);
+
  /**
   * object_property_add_uint8_ptr:
   * @obj: the object to add a property to
diff --git a/qom/object.c b/qom/object.c
index f91764aaa7..635eeeac77 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -2750,6 +2750,49 @@ DEFINE_OBJECT_CLASS_PROPERTY_SCALAR_METHODS(uint64)
  #undef DEFINE_OBJECT_CLASS_PROPERTY_SCALAR_METHODS
  
  
+static void property_class_get_bool_ptr(Object *obj, Visitor *v,
+                                        const char *name,
+                                        void *opaque, Error **errp)
+{
+    bool value = *(bool *)object_class_prop_ptr(obj, (ptrdiff_t)opaque);
+
+    visit_type_bool(v, name, &value, errp);
+}
+
+static void property_class_set_bool_ptr(Object *obj, Visitor *v,
+                                        const char *name,
+                                        void *opaque, Error **errp)
+{
+    bool *field = (bool *)object_class_prop_ptr(obj, (ptrdiff_t)opaque);
+    bool value;
+
+    if (!visit_type_bool(v, name, &value, errp)) {
+        return;
+    }
+
+    *field = value;
+}

Am I missing the reason why we can't use

   DEFINE_OBJECT_CLASS_PROPERTY_SCALAR_METHODS(bool)

?  If so, could that be mentioned in the commit message.

It's because bool is actually a macro according to C99 which causes the 
expansion to fail.

I'll update the commit message accordingly for v5.

+
+ObjectProperty *
+object_class_property_add_bool_ptr(ObjectClass *klass, const char *name,
+                                   ptrdiff_t offset,
+                                   ObjectPropertyFlags flags)
+{
+    ObjectPropertyAccessor *getter = NULL;
+    ObjectPropertyAccessor *setter = NULL;
+
+    if ((flags & OBJ_PROP_FLAG_READ) == OBJ_PROP_FLAG_READ) {
+        getter = property_class_get_bool_ptr;
+    }
+
+    if ((flags & OBJ_PROP_FLAG_WRITE) == OBJ_PROP_FLAG_WRITE) {
+        setter = property_class_set_bool_ptr;
+    }
+
+    return object_class_property_add(klass, name, "bool",
+                                     getter, setter, NULL, (void *)offset);
+}
+
  ObjectProperty *
  object_property_add_uint8_ptr(Object *obj, const char *name,
                                const uint8_t *v,
--
2.43.0

ATB,

Mark.