Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> writes:
> 02.07.2020 18:49, Markus Armbruster wrote:
>> When using the Error object to check for error, we need to receive it
>> into a local variable, then propagate() it to @errp.
>>
>> Using the return value permits allows receiving it straight to @errp.
>>
>> Signed-off-by: Markus Armbruster <arm...@redhat.com>
>> Reviewed-by: Eric Blake <ebl...@redhat.com>
>> ---
>> qom/object.c | 16 +++++++++-------
>> 1 file changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/qom/object.c b/qom/object.c
>> index 0808da2767..56d858b6a5 100644
>> --- a/qom/object.c
>> +++ b/qom/object.c
>> @@ -549,8 +549,7 @@ void object_initialize_child_with_propsv(Object
>> *parentobj,
>> object_initialize(childobj, size, type);
>> obj = OBJECT(childobj);
>> - object_set_propv(obj, &local_err, vargs);
>> - if (local_err) {
>> + if (object_set_propv(obj, errp, vargs) < 0) {
>> goto out;
>> }
>> @@ -743,7 +742,7 @@ Object *object_new_with_propv(const char
>> *typename,
>> }
>> obj = object_new_with_type(klass->type);
>> - if (object_set_propv(obj, &local_err, vargs) < 0) {
>> + if (object_set_propv(obj, errp, vargs) < 0) {
>> goto error;
>> }
>> @@ -1767,14 +1766,17 @@ static void
>> object_set_link_property(Object *obj, Visitor *v,
>> char *path = NULL;
>> visit_type_str(v, name, &path, &local_err);
>
> why not use return value of visit_type_str ?
Yes, that's better.
>> + if (local_err) {
>> + error_propagate(errp, local_err);
>> + return;
>> + }
>> - if (!local_err && strcmp(path, "") != 0) {
>> - new_target = object_resolve_link(obj, name, path, &local_err);
>> + if (strcmp(path, "") != 0) {
>> + new_target = object_resolve_link(obj, name, path, errp);
>> }
>
> Hmmm. You actually change the logic when visit_type_str succeeded but path
> equal to "":
>
> prepatch, we continue processing with new_target == NULL, after the patch we
> just do nothing and report success (errp == NULL).
>
> I don't know whether pre-patch or after-patch behavior is correct, but if it
> is a logic change, let's note it in the commit message, if path equal to ""
> actually impossible, let's assert it. Or just keep old logic as is, by moving
> return (together with duplicated g_free(path) of course) into "if
> (strcmp(path, "") != 0) {".
After having another stare at the function, I conclude it's awful before
the patch, and only slightly less awful but also wrong after.
>> g_free(path);
>> - if (local_err) {
>> - error_propagate(errp, local_err);
>> + if (!new_target) {
>> return;
>> }
What about this:
@@ -1763,20 +1762,24 @@ static void object_set_link_property(Object *obj,
Visitor *v,
LinkProperty *prop = opaque;
Object **targetp = object_link_get_targetp(obj, prop);
Object *old_target = *targetp;
- Object *new_target = NULL;
+ Object *new_target;
char *path = NULL;
- visit_type_str(v, name, &path, &local_err);
+ if (!visit_type_str(v, name, &path, errp)) {
+ return;
+ }
- if (!local_err && strcmp(path, "") != 0) {
- new_target = object_resolve_link(obj, name, path, &local_err);
+ if (*path) {
+ new_target = object_resolve_link(obj, name, path, errp);
+ if (!new_target) {
+ g_free(path);
+ return;
+ }
+ } else {
+ new_target = NULL;
}
g_free(path);
- if (local_err) {
- error_propagate(errp, local_err);
- return;
- }
prop->check(obj, name, new_target, &local_err);
if (local_err) {
