qapi: Drop qapi_event_send_FOO()'s Error ** argument

The generated qapi_event_send_FOO() take an Error ** argument.  They
can't actually fail, because all they do with the argument is passing it
to functions that can't fail: the QObject output visitor, and the
@qmp_emit callback, which is either monitor_qapi_event_queue() or
event_test_emit().

Drop the argument, and pass &error_abort to the QObject output visitor
and @qmp_emit instead.

Suggested-by: Eric Blake <eblake@redhat.com>
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180815133747.25032-4-peterx@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message rewritten, update to qapi-code-gen.txt corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt
index c2e11465f0..220791d737 100644
--- a/docs/devel/qapi-code-gen.txt
+++ b/docs/devel/qapi-code-gen.txt
@@ -1340,7 +1340,7 @@ Example:
     #include "example-qapi-types.h"
 
 
-    void qapi_event_send_my_event(Error **errp);
+    void qapi_event_send_my_event(void);
 
     typedef enum example_QAPIEvent {
         EXAMPLE_QAPI_EVENT_MY_EVENT = 0,
@@ -1356,10 +1356,9 @@ Example:
     $ cat qapi-generated/example-qapi-events.c
 [Uninteresting stuff omitted...]
 
-    void qapi_event_send_my_event(Error **errp)
+    void qapi_event_send_my_event(void)
     {
         QDict *qmp;
-        Error *err = NULL;
         QMPEventFuncEmit emit;
 
         emit = qmp_event_get_func_emit();
@@ -1369,9 +1368,8 @@ Example:
 
         qmp = qmp_event_build_dict("MY_EVENT");
 
-        emit(EXAMPLE_QAPI_EVENT_MY_EVENT, qmp, &err);
+        emit(EXAMPLE_QAPI_EVENT_MY_EVENT, qmp);
 
-        error_propagate(errp, err);
         qobject_unref(qmp);
     }