[Qemu-devel] [PATCH v2] qom: Reject attempts to add a property that already exists

[Peter Maydell <peter.maydell@linaro.org>]

Reject attempts to add a property to an object if one of
that name already exists. This is always a bug in the caller;
this is merely diagnosing it gracefully rather than behaving
oddly later.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
Changes v1->v2:
 * use abort() rather than assert(0), as suggested by Paolo
 * make the diagnostic message a little more helpful by
   including the type name, and adding '' around names
 * the patches fixing bugs which this patch makes fatal errors
   have both now been committed to master, so there's no
   barrier to committing it now

 qom/object.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/qom/object.c b/qom/object.c
index e3e9242..3da4c0e 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -620,7 +620,18 @@ void object_property_add(Object *obj, const char *name, const char *type,
                          ObjectPropertyRelease *release,
                          void *opaque, Error **errp)
 {
-    ObjectProperty *prop = g_malloc0(sizeof(*prop));
+    ObjectProperty *prop;
+
+    QTAILQ_FOREACH(prop, &obj->properties, node) {
+        if (strcmp(prop->name, name) == 0) {
+            /* This is always a bug in the caller */
+            fprintf(stderr, "attempt to add duplicate property '%s'"
+                    " to object (type '%s')\n", name, object_get_typename(obj));
+            abort();
+        }
+    }
+
+    prop = g_malloc0(sizeof(*prop));
 
     prop->name = g_strdup(name);
     prop->type = g_strdup(type);
-- 
1.7.9.5