qapi: Convert simple union TransactionAction 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 TransactionAction
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: Kevin Wolf <kwolf@redhat.com>
Cc: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20210917143134.412106-11-armbru@redhat.com>

diff --git a/qapi/transaction.json b/qapi/transaction.json
index 894258d9e2428cacd8f80bcd13bbd359acbf76ed..d175b5f863070cd4813032d7e7b0e305c7208c29 100644 (file)
--- a/qapi/transaction.json
+++ b/qapi/transaction.json
@@ -38,41 +38,128 @@
 { 'enum': 'ActionCompletionMode',
   'data': [ 'individual', 'grouped' ] }
 
+##
+# @TransactionActionKind:
+#
+# @abort: Since 1.6
+# @block-dirty-bitmap-add: Since 2.5
+# @block-dirty-bitmap-remove: Since 4.2
+# @block-dirty-bitmap-clear: Since 2.5
+# @block-dirty-bitmap-enable: Since 4.0
+# @block-dirty-bitmap-disable: Since 4.0
+# @block-dirty-bitmap-merge: Since 4.0
+# @blockdev-backup: Since 2.3
+# @blockdev-snapshot: Since 2.5
+# @blockdev-snapshot-internal-sync: Since 1.7
+# @blockdev-snapshot-sync: since 1.1
+# @drive-backup: Since 1.6
+#
+# Since: 1.1
+##
+{ 'enum': 'TransactionActionKind',
+  'data': [ 'abort', 'block-dirty-bitmap-add', 'block-dirty-bitmap-remove',
+            'block-dirty-bitmap-clear', 'block-dirty-bitmap-enable',
+            'block-dirty-bitmap-disable', 'block-dirty-bitmap-merge',
+            'blockdev-backup', 'blockdev-snapshot',
+            'blockdev-snapshot-internal-sync', 'blockdev-snapshot-sync',
+            'drive-backup' ] }
+
+##
+# @AbortWrapper:
+#
+# Since: 1.6
+##
+{ 'struct': 'AbortWrapper',
+  'data': { 'data': 'Abort' } }
+
+##
+# @BlockDirtyBitmapAddWrapper:
+#
+# Since: 2.5
+##
+{ 'struct': 'BlockDirtyBitmapAddWrapper',
+  'data': { 'data': 'BlockDirtyBitmapAdd' } }
+
+##
+# @BlockDirtyBitmapWrapper:
+#
+# Since: 2.5
+##
+{ 'struct': 'BlockDirtyBitmapWrapper',
+  'data': { 'data': 'BlockDirtyBitmap' } }
+
+##
+# @BlockDirtyBitmapMergeWrapper:
+#
+# Since: 4.0
+##
+{ 'struct': 'BlockDirtyBitmapMergeWrapper',
+  'data': { 'data': 'BlockDirtyBitmapMerge' } }
+
+##
+# @BlockdevBackupWrapper:
+#
+# Since: 2.3
+##
+{ 'struct': 'BlockdevBackupWrapper',
+  'data': { 'data': 'BlockdevBackup' } }
+
+##
+# @BlockdevSnapshotWrapper:
+#
+# Since: 2.5
+##
+{ 'struct': 'BlockdevSnapshotWrapper',
+  'data': { 'data': 'BlockdevSnapshot' } }
+
+##
+# @BlockdevSnapshotInternalWrapper:
+#
+# Since: 1.7
+##
+{ 'struct': 'BlockdevSnapshotInternalWrapper',
+  'data': { 'data': 'BlockdevSnapshotInternal' } }
+
+##
+# @BlockdevSnapshotSyncWrapper:
+#
+# Since: 1.1
+##
+{ 'struct': 'BlockdevSnapshotSyncWrapper',
+  'data': { 'data': 'BlockdevSnapshotSync' } }
+
+##
+# @DriveBackupWrapper:
+#
+# Since: 1.6
+##
+{ 'struct': 'DriveBackupWrapper',
+  'data': { 'data': 'DriveBackup' } }
+
 ##
 # @TransactionAction:
 #
 # A discriminated record of operations that can be performed with
-# @transaction. Action @type can be:
-#
-# - @abort: since 1.6
-# - @block-dirty-bitmap-add: since 2.5
-# - @block-dirty-bitmap-remove: since 4.2
-# - @block-dirty-bitmap-clear: since 2.5
-# - @block-dirty-bitmap-enable: since 4.0
-# - @block-dirty-bitmap-disable: since 4.0
-# - @block-dirty-bitmap-merge: since 4.0
-# - @blockdev-backup: since 2.3
-# - @blockdev-snapshot: since 2.5
-# - @blockdev-snapshot-internal-sync: since 1.7
-# - @blockdev-snapshot-sync: since 1.1
-# - @drive-backup: since 1.6
+# @transaction.
 #
 # Since: 1.1
 ##
 { 'union': 'TransactionAction',
+  'base': { 'type': 'TransactionActionKind' },
+  'discriminator': 'type',
   'data': {
-       'abort': 'Abort',
-       'block-dirty-bitmap-add': 'BlockDirtyBitmapAdd',
-       'block-dirty-bitmap-remove': 'BlockDirtyBitmap',
-       'block-dirty-bitmap-clear': 'BlockDirtyBitmap',
-       'block-dirty-bitmap-enable': 'BlockDirtyBitmap',
-       'block-dirty-bitmap-disable': 'BlockDirtyBitmap',
-       'block-dirty-bitmap-merge': 'BlockDirtyBitmapMerge',
-       'blockdev-backup': 'BlockdevBackup',
-       'blockdev-snapshot': 'BlockdevSnapshot',
-       'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
-       'blockdev-snapshot-sync': 'BlockdevSnapshotSync',
-       'drive-backup': 'DriveBackup'
+       'abort': 'AbortWrapper',
+       'block-dirty-bitmap-add': 'BlockDirtyBitmapAddWrapper',
+       'block-dirty-bitmap-remove': 'BlockDirtyBitmapWrapper',
+       'block-dirty-bitmap-clear': 'BlockDirtyBitmapWrapper',
+       'block-dirty-bitmap-enable': 'BlockDirtyBitmapWrapper',
+       'block-dirty-bitmap-disable': 'BlockDirtyBitmapWrapper',
+       'block-dirty-bitmap-merge': 'BlockDirtyBitmapMergeWrapper',
+       'blockdev-backup': 'BlockdevBackupWrapper',
+       'blockdev-snapshot': 'BlockdevSnapshotWrapper',
+       'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternalWrapper',
+       'blockdev-snapshot-sync': 'BlockdevSnapshotSyncWrapper',
+       'drive-backup': 'DriveBackupWrapper'
    } }
 
 ##