qapi: Convert simple union KeyValue to flat one

Simple unions predate flat unions.  Having both complicates the QAPI
schema language and the QAPI generator.  We haven't been using simple
unions in new code for a long time, because they are less flexible and
somewhat awkward on the wire.

To prepare for their removal, convert simple union KeyValue to an
equivalent flat one.  Adds some boilerplate to the schema, which is a
bit ugly, but a lot easier to maintain than the simple union feature.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210917143134.412106-4-armbru@redhat.com>

diff --git a/qapi/ui.json b/qapi/ui.json
index b2cf7a6759ae68631981c620cc0be3379d77d764..9e04f9d65d2c6cd0dfefb19913973c2eaf8f381f 100644 (file)
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -824,6 +824,30 @@
             'ac_home', 'ac_back', 'ac_forward', 'ac_refresh', 'ac_bookmarks',
             'lang1', 'lang2' ] }
 
+##
+# @KeyValueKind:
+#
+# Since: 1.3
+##
+{ 'enum': 'KeyValueKind',
+  'data': [ 'number', 'qcode' ] }
+
+##
+# @IntWrapper:
+#
+# Since: 1.3
+##
+{ 'struct': 'IntWrapper',
+  'data': { 'data': 'int' } }
+
+##
+# @QKeyCodeWrapper:
+#
+# Since: 1.3
+##
+{ 'struct': 'QKeyCodeWrapper',
+  'data': { 'data': 'QKeyCode' } }
+
 ##
 # @KeyValue:
 #
@@ -832,9 +856,11 @@
 # Since: 1.3
 ##
 { 'union': 'KeyValue',
+  'base': { 'type': 'KeyValueKind' },
+  'discriminator': 'type',
   'data': {
-    'number': 'int',
-    'qcode': 'QKeyCode' } }
+    'number': 'IntWrapper',
+    'qcode': 'QKeyCodeWrapper' } }
 
 ##
 # @send-key: