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, and we no
longer have to require the root visit to pass name=NULL.
An audit of all qmp_input_visitor_new* call sites shows that
the only places where the visit starts directly on a QDict,
but where the first visit_type_* within the visit had passed
a non-NULL name, were fixed in the previous two places to
properly push into the object with visit_start_struct().
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
v12: new patch
---
include/qapi/visitor.h | 3 +--
include/qapi/qmp-input-visitor.h | 8 ------
qapi/qmp-input-visitor.c | 54 ++++++++++++++++++++++------------------
3 files changed, 31 insertions(+), 34 deletions(-)
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index b3ca93c..fb4582a 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -48,8 +48,7 @@
*
* The @name parameter of visit_type_FOO() describes the relation
* between this QAPI value and its parent container. When visiting
- * the root of a tree, @name is usually ignored (although some
- * visitors require it to be NULL); when visiting a member of an
+ * the root of a tree, @name is ignored; when visiting a member of an
* object, @name is the key associated with the value; and when
* visiting a member of a list, @name is NULL.
*
diff --git a/include/qapi/qmp-input-visitor.h b/include/qapi/qmp-input-visitor.h
index d75ff98..3ed499c 100644
--- a/include/qapi/qmp-input-visitor.h
+++ b/include/qapi/qmp-input-visitor.h
@@ -19,14 +19,6 @@
typedef struct QmpInputVisitor QmpInputVisitor;
-/*
- * FIXME: When visiting a QDict, passing a non-NULL @name for the
- * first visit_type_FOO() when the root is a QDict will find that
- * particular key within the QDict. In the future, the contract may
- * be tightened to require visit_start_struct() with ignored @name as
- * the first visit; in the meantime, the first visit is safest when
- * using NULL for @name.
- */
QmpInputVisitor *qmp_input_visitor_new(QObject *obj);
QmpInputVisitor *qmp_input_visitor_new_strict(QObject *obj);
diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index 6b69e9a..2daf83f 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -38,9 +38,11 @@ struct QmpInputVisitor
{
Visitor visitor;
- /* Stack of objects being visited. stack[0] is root of visit,
- * stack[1] and below correspond to visit_start_struct (nested
- * QDict) and visit_start_list (nested QList). */
+ /* 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;
@@ -57,36 +59,40 @@ 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;
+ StackObject *tos;
+ QObject *qobj;
+ 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);
qobj = qdict_get(qobject_to_qdict(qobj), name);
if (tos->h && consume && qobj) {
bool removed = g_hash_table_remove(tos->h, name);
assert(removed);
}
- return qobj;
- }
-
- /* 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);
- assert(!tos->first);
- qobj = qlist_entry_obj(tos->entry);
- if (consume) {
- tos->entry = qlist_next(tos->entry);
+ /* FIXME: assertion needs adjustment if we fix visit-core
+ * to pass "name.0" style name during lists. */
+ assert(!name);
+
+ if (tos->entry) {
+ assert(!tos->first);
+ qobj = qlist_entry_obj(tos->entry);
+ if (consume) {
+ tos->entry = qlist_next(tos->entry);
+ }
}
- return qobj;
}
-
- /* Otherwise, we are at the root of the visit or the start of a
- * list, and return the object as-is. */
return qobj;
}
@@ -372,7 +378,7 @@ 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);
}
@@ -399,7 +405,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj)
v->visitor.type_null = qmp_input_type_null;
v->visitor.optional = qmp_input_optional;
- qmp_input_push(v, obj, NULL, NULL);
+ v->root = obj;
qobject_incref(obj);
return v;
--
2.5.0
