qapi: Replace start_optional()/end_optional() by optional()

Semantics of end_optional() differ subtly from the other end_FOO()
callbacks: when start_FOO() succeeds, the matching end_FOO() gets
called regardless of what happens in between.  end_optional() gets
called only when everything in between succeeds as well.  Entirely
undocumented, like all of the visitor API.

The only user of Visitor Callback end_optional() never did anything,
and was removed in commit 9f9ab46.

I'm about to clean up error handling in the generated visitor code,
and end_optional() is in my way.  No users mean no test cases, and
making non-trivial cleanup transformations without test cases doesn't
strike me as a good idea.

Drop end_optional(), and rename start_optional() to optional().  We
can always go back to a pair of callbacks when we have an actual need.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 4 insertions, 11 deletions

diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 1f7475c0f3..ffd76372d1 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -69,18 +69,11 @@ void visit_end_list(Visitor *v, Error **errp)
     v->end_list(v, errp);
 }
 
-void visit_start_optional(Visitor *v, bool *present, const char *name,
-                          Error **errp)
+void visit_optional(Visitor *v, bool *present, const char *name,
+                    Error **errp)
 {
-    if (!error_is_set(errp) && v->start_optional) {
-        v->start_optional(v, present, name, errp);
-    }
-}
-
-void visit_end_optional(Visitor *v, Error **errp)
-{
-    if (!error_is_set(errp) && v->end_optional) {
-        v->end_optional(v, errp);
+    if (!error_is_set(errp) && v->optional) {
+        v->optional(v, present, name, errp);
     }
 }