qapi: Introduce a first class 'null' type

I expect the 'null' type to be useful mostly for members of alternate
types.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

2 files changed, 3 insertions, 2 deletions

diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
index 3543b552f4..eab29edd12 100644
--- a/include/qapi/qmp/qobject.h
+++ b/include/qapi/qmp/qobject.h
@@ -93,9 +93,9 @@ static inline QType qobject_type(const QObject *obj)
     return obj->type;
 }
 
-typedef struct QNull {
+struct QNull {
     QObject base;
-} QNull;
+};
 
 extern QNull qnull_;
 
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 7b0d4e7e05..39bc8351a3 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -89,6 +89,7 @@ typedef struct QEMUSGList QEMUSGList;
 typedef struct QEMUTimer QEMUTimer;
 typedef struct QEMUTimerListGroup QEMUTimerListGroup;
 typedef struct QObject QObject;
+typedef struct QNull QNull;
 typedef struct RAMBlock RAMBlock;
 typedef struct Range Range;
 typedef struct SerialState SerialState;