Eric Blake <ebl...@redhat.com> writes: > Don't embed the root of the visit into the stack of current > containers being visited. That way, we no longer get confused > on whether the first visit of a dictionary is to the dictionary > itself or to one of the members of the dictionary, based on > whether the caller passed name=NULL; and makes the QMP Input > visitor like other visitors where the value of 'name' is now > ignored on the root visit. (We may someday want to revisit > the rules on what 'name' should be on a top-level visit, > rather than just ignoring it; but that would be the topic of > another patch). > > An audit of all qmp_input_visitor_new() call sites shows that > there were only two places where callers had previously been > visiting to a QDict with a non-NULL name to bypass a call to > visit_start_struct(), and those were fixed in prior patches. > > Signed-off-by: Eric Blake <ebl...@redhat.com> > > --- > v15: hoist earlier in series, improve variable naming > v14: no change > v13: no change > v12: new patch > --- > qapi/qmp-input-visitor.c | 45 ++++++++++++++++++++++++--------------------- > 1 file changed, 24 insertions(+), 21 deletions(-) > > diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c > index cae6387..6409a83 100644 > --- a/qapi/qmp-input-visitor.c > +++ b/qapi/qmp-input-visitor.c > @@ -35,9 +35,11 @@ struct QmpInputVisitor > { > Visitor visitor; > > - /* Stack of objects being visited. stack[0] is root of visit, > - * stack[1..] records the nesting of start_struct()/end_struct() > - * and start_list()/end_list() pairs. */ > + /* Root of visit at visitor creation. */ > + QObject *root; > + > + /* Stack of objects being visited (all entries will be either > + * QDict or QList). */ > StackObject stack[QIV_STACK_SIZE]; > int nb_stack; > > @@ -54,33 +56,34 @@ static QObject *qmp_input_get_object(QmpInputVisitor *qiv, > const char *name, > bool consume) > { > - StackObject *tos = &qiv->stack[qiv->nb_stack - 1]; > - QObject *qobj = tos->obj; > - QObject *ret; > + StackObject *tos; > + QObject *qobj; > + QObject *ret = NULL;
Dead initializer? > > + if (!qiv->nb_stack) { > + /* Starting at root, name is ignored. */ > + return qiv->root; > + } > + > + /* We are in a container; find the next element. */ > + tos = &qiv->stack[qiv->nb_stack - 1]; > + qobj = tos->obj; > assert(qobj); > > - /* If we have a name, and we're in a dictionary, then return that > - * value. */ > - if (name && qobject_type(qobj) == QTYPE_QDICT) { > + if (qobject_type(qobj) == QTYPE_QDICT) { > + assert(name); > ret = qdict_get(qobject_to_qdict(qobj), name); > if (tos->h && consume && ret) { > bool removed = g_hash_table_remove(tos->h, name); > assert(removed); > } > - return ret; > - } > - > - /* If we are in the middle of a list, then return the next element > - * of the list. */ > - if (tos->entry) { > + } else { > assert(qobject_type(qobj) == QTYPE_QLIST); > - return qlist_entry_obj(tos->entry); > + assert(!name); > + ret = qlist_entry_obj(tos->entry); > } > > - /* Otherwise, we are at the root of the visit or the start of a > - * list, and return the object as-is. */ > - return qobj; > + return ret; > } > > static void qdict_add_key(const char *key, QObject *obj, void *opaque) > @@ -355,7 +358,7 @@ Visitor *qmp_input_get_visitor(QmpInputVisitor *v) > > void qmp_input_visitor_cleanup(QmpInputVisitor *v) > { > - qobject_decref(v->stack[0].obj); > + qobject_decref(v->root); > g_free(v); > } > > @@ -381,7 +384,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj, bool > strict) > v->visitor.optional = qmp_input_optional; > v->strict = strict; > > - qmp_input_push(v, obj, NULL); > + v->root = obj; > qobject_incref(obj); > > return v;