xemu/hw/virtio
Eric Blake 15c2f669e3 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, &param, &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 <eblake@redhat.com>
Message-Id: <1461879932-9020-20-git-send-email-eblake@redhat.com>
[Conflict with a doc fixup resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-05-12 09:47:55 +02:00
..
Makefile.objs vring: remove 2016-02-25 13:14:19 +02:00
vhost-backend.c virtio: Clean up includes 2016-01-29 15:07:23 +00:00
vhost-user.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
vhost.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
virtio-balloon.c qapi: Split visit_end_struct() into pieces 2016-05-12 09:47:55 +02:00
virtio-bus.c virtio: Clean up includes 2016-01-29 15:07:23 +00:00
virtio-mmio.c virtio: Clean up includes 2016-01-29 15:07:23 +00:00
virtio-pci.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
virtio-pci.h hw/virtio: group virtio flags into an enum 2016-03-11 14:54:28 +02:00
virtio-rng.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
virtio.c virtio: Mark host notifiers as external 2016-04-22 16:43:58 +02:00