[PULL 12/41] include/hw/qdev-core: Detect most empty Property lists at compile time

[Paolo Bonzini]

From: Richard Henderson <richard.henderson@linaro.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Link: 
20241216035109.3486070-13-richard.henderson@linaro.org">https://lore.kernel.org/r/20241216035109.3486070-13-richard.henderson@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/hw/qdev-core.h    | 8 ++++++++
 hw/core/qdev-properties.c | 2 +-
 migration/migration.c     | 2 +-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 5be9844412f..b2859d1e39e 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -943,6 +943,14 @@ char *qdev_get_own_fw_dev_path_from_handler(BusState *bus, 
DeviceState *dev);
  */
 void device_class_set_props(DeviceClass *dc, const Property *props);
 
+/* Validate at least one Property, plus the terminator. */
+#define device_class_set_props(DC, PROPS) \
+    do {                                                                \
+        QEMU_BUILD_BUG_ON(sizeof(PROPS) != sizeof(const Property *) &&  \
+                          sizeof(PROPS) < 2 * sizeof(Property));        \
+        (device_class_set_props)(DC, PROPS);                            \
+    } while (0)
+
 /**
  * device_class_set_parent_realize() - set up for chaining realize fns
  * @dc: The device class
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 315196bd85a..de618a964a9 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -1061,7 +1061,7 @@ static void qdev_class_add_legacy_property(DeviceClass 
*dc, const Property *prop
         NULL, NULL, (Property *)prop);
 }
 
-void device_class_set_props(DeviceClass *dc, const Property *props)
+void (device_class_set_props)(DeviceClass *dc, const Property *props)
 {
     const Property *prop;
 
diff --git a/migration/migration.c b/migration/migration.c
index 8c5bd0a75c8..6b3b85d31e5 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3822,7 +3822,7 @@ static void migration_class_init(ObjectClass *klass, void 
*data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->user_creatable = false;
-    device_class_set_props(dc, migration_properties);
+    (device_class_set_props)(dc, migration_properties);
 }
 
 static void migration_instance_finalize(Object *obj)
-- 
2.47.1