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>
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index c6579be..9f22eee 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -61,7 +61,7 @@
for argname, argentry, optional, structured in parse_args(members):
if optional:
ret += mcgen('''
-visit_start_optional(m, &(*obj)->%(c_prefix)shas_%(c_name)s, "%(name)s", &err);
+visit_optional(m, &(*obj)->%(c_prefix)shas_%(c_name)s, "%(name)s", &err);
if ((*obj)->%(prefix)shas_%(c_name)s) {
''',
c_prefix=c_var(field_prefix), prefix=field_prefix,
@@ -82,7 +82,6 @@
pop_indent()
ret += mcgen('''
}
-visit_end_optional(m, &err);
''')
pop_indent()