qom: simplify object_find_property / object_class_find_property

When debugging QEMU it is often useful to put a breakpoint on the
error_setg_internal method impl.

Unfortunately the object_property_add / object_class_property_add
methods call object_property_find / object_class_property_find methods
to check if a property exists already before adding the new property.

As a result there are a huge number of calls to error_setg_internal
on startup of most QEMU commands, making it very painful to set a
breakpoint on this method.

Most callers of object_find_property and object_class_find_property,
however, pass in a NULL for the Error parameter. This simplifies the
methods to remove the Error parameter entirely, and then adds some
new wrapper methods that are able to raise an Error when needed.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200914135617.1493072-1-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 43 insertions, 5 deletions

diff --git a/include/qom/object.h b/include/qom/object.h
index 19cccd3..9b01888 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -1463,14 +1463,52 @@ void object_property_set_default_uint(ObjectProperty *prop, uint64_t value);
  * object_property_find:
  * @obj: the object
  * @name: the name of the property
+ *
+ * Look up a property for an object.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_property_find(Object *obj, const char *name);
+
+/**
+ * object_property_find_err:
+ * @obj: the object
+ * @name: the name of the property
  * @errp: returns an error if this function fails
  *
- * Look up a property for an object and return its #ObjectProperty if found.
+ * Look up a property for an object.
+ *
+ * Return its #ObjectProperty if found, or NULL.
  */
-ObjectProperty *object_property_find(Object *obj, const char *name,
-                                     Error **errp);
-ObjectProperty *object_class_property_find(ObjectClass *klass, const char *name,
-                                           Error **errp);
+ObjectProperty *object_property_find_err(Object *obj,
+                                         const char *name,
+                                         Error **errp);
+
+/**
+ * object_class_property_find:
+ * @klass: the object class
+ * @name: the name of the property
+ *
+ * Look up a property for an object class.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_class_property_find(ObjectClass *klass,
+                                           const char *name);
+
+/**
+ * object_class_property_find_err:
+ * @klass: the object class
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Look up a property for an object class.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_class_property_find_err(ObjectClass *klass,
+                                               const char *name,
+                                               Error **errp);
 
 typedef struct ObjectPropertyIterator {
     ObjectClass *nextclass;