qapi-visit: Split off visit_type_FOO_fields forward decl
We generate a static visit_type_FOO_fields() for every type
FOO. However, sometimes we need a forward declaration. Split
the code to generate the forward declaration out of
gen_visit_implicit_struct() into a new gen_visit_fields_decl(),
and also prepare for a forward declaration to be emitted
during gen_visit_struct(), so that a future patch can switch
from using visit_type_FOO_implicit() to the simpler
visit_type_FOO_fields() as part of unboxing the base class
of a struct.
No change to generated code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 2dc3aed..d4408f2 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -15,7 +15,12 @@
from qapi import *
import re
+# visit_type_FOO_implicit() is emitted as needed; track if it has already
+# been output.
implicit_structs_seen = set()
+
+# visit_type_FOO_fields() is always emitted; track if a forward declaration
+# or implementation has already been output.
struct_fields_seen = set()
@@ -29,19 +34,24 @@
c_name=c_name(name), c_type=c_type)
-def gen_visit_implicit_struct(typ):
- if typ in implicit_structs_seen:
- return ''
- implicit_structs_seen.add(typ)
-
+def gen_visit_fields_decl(typ):
ret = ''
if typ.name not in struct_fields_seen:
- # Need a forward declaration
ret += 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
+
+
+def gen_visit_implicit_struct(typ):
+ if typ in implicit_structs_seen:
+ return ''
+ implicit_structs_seen.add(typ)
+
+ ret = gen_visit_fields_decl(typ)
ret += mcgen('''