From 15c2f669e3fb2bc97f7b42d1871f595c0ac24af8 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Thu, 28 Apr 2016 15:45:27 -0600 Subject: qapi: Split visit_end_struct() into pieces As mentioned in previous patches, we want to call visit_end_struct() functions unconditionally, so that visitors can release resources tied up since the matching visit_start_struct() without also having to worry about error priority if more than one error occurs. Even though error_propagate() can be safely used to ignore a second error during cleanup caused by a first error, it is simpler if the cleanup cannot set an error. So, split out the error checking portion (basically, input visitors checking for unvisited keys) into a new function visit_check_struct(), which can be safely skipped if any earlier errors are encountered, and leave the cleanup portion (which never fails, but must be called unconditionally if visit_start_struct() succeeded) in visit_end_struct(). Generated code in qapi-visit.c has diffs resembling: |@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v, | goto out_obj; | } | visit_type_ACPIOSTInfo_members(v, obj, &err); |- error_propagate(errp, err); |- err = NULL; |+ if (err) { |+ goto out_obj; |+ } |+ visit_check_struct(v, &err); | out_obj: |- visit_end_struct(v, &err); |+ visit_end_struct(v); | out: and in qapi-event.c: @@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP | goto out; | } | visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, ¶m, &err); |- visit_end_struct(v, err ? NULL : &err); |+ if (!err) { |+ visit_check_struct(v, &err); |+ } |+ visit_end_struct(v); | if (err) { | goto out; Signed-off-by: Eric Blake Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com> [Conflict with a doc fixup resolved] Signed-off-by: Markus Armbruster --- hw/virtio/virtio-balloon.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) (limited to 'hw/virtio') diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 9dbe681790..8c15e09470 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -138,17 +138,18 @@ static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name, for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) { visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err); if (err) { - break; + goto out_nested; } } - error_propagate(errp, err); - err = NULL; - visit_end_struct(v, &err); + visit_check_struct(v, &err); +out_nested: + visit_end_struct(v); + if (!err) { + visit_check_struct(v, &err); + } out_end: - error_propagate(errp, err); - err = NULL; - visit_end_struct(v, &err); + visit_end_struct(v); out: error_propagate(errp, err); } -- cgit v1.2.3