There's no point in emitting a goto if the very next thing
emitted will be the label. A bit of cleverness in gen_visit_fields()
will let us choose when to omit a final error check (basically,
swap the order of emitted text within the loop, with the error
check omitted on the first pass, then checking whether to emit a
final check after the loop); and in turn omit unused labels.
The change to generated code is a bit easier because we split out
the reindentation of the remaining gotos in the previous patch.
For example, in visit_type_ChardevReturn_fields():
| if (visit_optional(v, "pty", &obj->has_pty)) {
| visit_type_str(v, "pty", &obj->pty, &err);
| }
|- if (err) {
|- goto out;
|- }
|-
|-out:
| error_propagate(errp, err);
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
v10: new patch
---
scripts/qapi-event.py | 7 +++++--
scripts/qapi-visit.py | 10 ++++++----
scripts/qapi.py | 8 ++++++--
3 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py
index 544ae12..b50ac29 100644
--- a/scripts/qapi-event.py
+++ b/scripts/qapi-event.py
@@ -68,9 +68,12 @@ def gen_event_send(name, arg_type):
name=name)
ret += gen_err_check()
ret += gen_visit_fields(arg_type.members, need_cast=True,
- label='out_obj')
- ret += mcgen('''
+ label='out_obj', skiplast=True)
+ if len(arg_type.members) > 1:
+ ret += mcgen('''
out_obj:
+''')
+ ret += mcgen('''
visit_end_struct(v, err ? NULL : &err);
if (err) {
goto out;
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 0cc9b08..0be396b 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -92,12 +92,14 @@ static void visit_type_%(c_name)s_fields(Visitor *v,
%(c_name)s **obj, Error **e
visit_type_%(c_type)s_fields(v, (%(c_type)s **)obj, &err);
''',
c_type=base.c_name())
- ret += gen_err_check()
+ if members:
+ ret += gen_err_check()
- ret += gen_visit_fields(members, prefix='(*obj)->')
+ ret += gen_visit_fields(members, prefix='(*obj)->', skiplast=True)
- # 'goto out' produced for base, and by gen_visit_fields() for each member
- if base or members:
+ # 'goto out' produced for base, and by gen_visit_fields() for each
+ # member except the last
+ if bool(base) + len(members) > 1:
ret += mcgen('''
out:
diff --git a/scripts/qapi.py b/scripts/qapi.py
index fab5001..4d75d75 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -1645,14 +1645,17 @@ def gen_err_check(label='out', skiperr=False):
def gen_visit_fields(members, prefix='', need_cast=False, skiperr=False,
- label='out'):
+ label='out', skiplast=False):
ret = ''
if skiperr:
errparg = 'NULL'
else:
errparg = '&err'
+ local_skiperr = True
for memb in members:
+ ret += gen_err_check(skiperr=local_skiperr, label=label)
+ local_skiperr = skiperr
if memb.optional:
ret += mcgen('''
if (visit_optional(v, "%(name)s", &%(prefix)shas_%(c_name)s)) {
@@ -1679,8 +1682,9 @@ def gen_visit_fields(members, prefix='', need_cast=False,
skiperr=False,
ret += mcgen('''
}
''')
+
+ if members and not skiplast:
ret += gen_err_check(skiperr=skiperr, label=label)
-
return ret
--
2.5.0
