For empty structs, such as the 'Abort' helper type used as part
of the 'transaction' command, we were emitting a no-op
visit_type_FOO_fields(). Optimize things to instead omit calls
for empty structs. Generated code changes resemble:
|-static void visit_type_Abort_fields(Visitor *v, Abort **obj, Error **errp)
|-{
|- Error *err = NULL;
|-
|- error_propagate(errp, err);
|-}
|-
| void visit_type_Abort(Visitor *v, Abort **obj, const char *name, Error **errp)
| {
| Error *err = NULL;
|@@ -112,7 +105,6 @@ void visit_type_Abort(Visitor *v, Abort
| if (!*obj) {
| goto out_obj;
| }
|- visit_type_Abort_fields(v, obj, &err);
| out_obj:
| error_propagate(errp, err);
Another reason for doing this optimization is that it gets us
closer to merging the code for visiting structs and unions:
since flat unions have no local members, they do not need to
have a visit_type_UNION_fields() emitted, even when they start
sharing the code used to visit structs.
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
v6: new patch
---
scripts/qapi-visit.py | 53 ++++++++++++++++++++++++++++-----------------------
1 file changed, 29 insertions(+), 24 deletions(-)
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 391bdfb..ed4fb20 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -35,22 +35,22 @@ void visit_type_%(c_name)s(Visitor *v, %(c_type)sobj, const
char *name, Error **
def gen_visit_fields_decl(typ):
- ret = ''
- if typ.name not in struct_fields_seen:
- ret += mcgen('''
+ if typ.is_empty() or 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):
- if typ in implicit_structs_seen:
+ if typ.is_empty() or typ in implicit_structs_seen:
return ''
+
implicit_structs_seen.add(typ)
-
ret = gen_visit_fields_decl(typ)
ret += mcgen('''
@@ -74,7 +74,10 @@ static void visit_type_implicit_%(c_type)s(Visitor *v,
%(c_type)s **obj, Error *
def gen_visit_struct_fields(name, base, members):
ret = ''
- if base:
+ if (not base or base.is_empty()) and not members:
+ return ret
+
+ if base and not base.is_empty():
ret += gen_visit_fields_decl(base)
struct_fields_seen.add(name)
@@ -87,7 +90,7 @@ static void visit_type_%(c_name)s_fields(Visitor *v,
%(c_name)s **obj, Error **e
''',
c_name=c_name(name))
- if base:
+ if base and not base.is_empty():
ret += mcgen('''
visit_type_%(c_type)s_fields(v, (%(c_type)s **)obj, &err);
''',
@@ -96,13 +99,9 @@ static void visit_type_%(c_name)s_fields(Visitor *v,
%(c_name)s **obj, Error **e
ret += gen_visit_fields(members, prefix='(*obj)->')
- # 'goto out' produced for base, and by gen_visit_fields() for each member
- if base or members:
- ret += mcgen('''
+ ret += mcgen('''
out:
-''')
- ret += mcgen('''
error_propagate(errp, err);
}
''')
@@ -129,16 +128,22 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj,
const char *name, Error
if (!*obj) {
goto out_obj;
}
- visit_type_%(c_name)s_fields(v, obj, &err);
-out_obj:
- error_propagate(errp, err);
- err = NULL;
- visit_end_struct(v, &err);
-out:
- error_propagate(errp, err);
-}
''',
name=name, c_name=c_name(name))
+ if (base and not base.is_empty()) or members:
+ ret += mcgen('''
+ visit_type_%(c_name)s_fields(v, obj, &err);
+''',
+ c_name=c_name(name))
+ ret += mcgen('''
+out_obj:
+ error_propagate(errp, err);
+ err = NULL;
+ visit_end_struct(v, &err);
+out:
+ error_propagate(errp, err);
+}
+''')
return ret
@@ -300,7 +305,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj,
const char *name, Error
''',
c_type=simple_union_type.c_name(),
c_name=c_name(var.name))
- else:
+ elif not var.type.is_empty():
ret += mcgen('''
visit_type_implicit_%(c_type)s(v, &(*obj)->u.%(c_name)s, &err);
''',
--
2.4.3
