qapi-visit: Use common idiom in gen_visit_fields_decl()

We have several instances of methods that do an early exit if
output is not needed, then log that output is being generated,
and finally produce the output; see qapi-types.py:gen_object()
and qapi-visit.py:gen_visit_implicit_struct().  The odd man
out was gen_visit_fields_decl(); rearrange it to be more like
the others.  No semantic change or difference to generated code.

Signed-off-by: Eric Blake <[email protected]>
Message-Id: <1455778109[email protected]>
Signed-off-by: Markus Armbruster <[email protected]>

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index dfeef7196bfb239cc83412c8b6fbbb8bd01288e2..d7d7ed5a32a7b74e0b3b90426ed0845cd103dd3b 100644 (file)
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -35,15 +35,14 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_type)sobj, Error **
 
 
 def gen_visit_fields_decl(typ):
-    ret = ''
-    if typ.name not in struct_fields_seen:
-        ret += mcgen('''
+    if typ.name in struct_fields_seen:
+        return ''
+    struct_fields_seen.add(typ.name)
+    return mcgen('''
 
 static void visit_type_%(c_type)s_fields(Visitor *v, %(c_type)s *obj, Error **errp);
 ''',
-                     c_type=typ.c_name())
-        struct_fields_seen.add(typ.name)
-    return ret
+                 c_type=typ.c_name())
 
 
 def gen_visit_implicit_struct(typ):