In the QMP input visitor, visiting a list traverses two objects: the QAPI GenericList of the caller (which gets advanced in visit_next_list() regardless of this patch), and the QList input that we are converting to QAPI. For consistency with QDict visits, we want to consume elements from the input QList during the visit_type_FOO() for the list element; that is, we want ALL the code for consuming an input to live in qmp_input_get_object(), rather than having it split according to whether we are visiting a dict or a list. Making qmp_input_get_object() the common point of consumption will make it easier for a later patch to refactor visit_start_list() to cover the GenericList * head of a QAPI list, and in turn will get rid of the 'first' flag (which lived in qmp_input_next_list() pre-patch, and is hoisted to StackObject by this patch).
This patch is therefore shifting the post-condition use of 'entry' from: start_list next_list type_ELT ... next_list type_ELT end_list entry NULL 1st elt 1st elt last elt last elt gone where type_ELT() returns (entry ? entry : 1st elt) and next_list() steps entry to this usage: start_list next_list type_ELT ... next_list type_ELT end_list entry 1st elt 1nd elt 2nd elt last elt NULL gone where type_ELT() steps entry and returns the old entry, and next_list() leaves entry alone. Signed-off-by: Eric Blake <ebl...@redhat.com> --- v15: rebase, improve commit message, hoist root handling earlier so that this patch is more pinpointed v14: no change v13: no change v12: new patch --- qapi/qmp-input-visitor.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c index 6409a83..eb77adc 100644 --- a/qapi/qmp-input-visitor.c +++ b/qapi/qmp-input-visitor.c @@ -29,6 +29,7 @@ typedef struct StackObject GHashTable *h; /* If obj is dict: unvisited keys */ const QListEntry *entry; /* If obj is list: unvisited tail */ + bool first; /* If obj is list: will next_list() visit head */ } StackObject; struct QmpInputVisitor @@ -80,7 +81,11 @@ static QObject *qmp_input_get_object(QmpInputVisitor *qiv, } else { assert(qobject_type(qobj) == QTYPE_QLIST); assert(!name); + assert(!tos->first); ret = qlist_entry_obj(tos->entry); + if (consume) { + tos->entry = qlist_next(tos->entry); + } } return ret; @@ -104,13 +109,16 @@ static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, Error **errp) } tos->obj = obj; - tos->entry = NULL; - tos->h = NULL; + assert(!tos->h); + assert(!tos->entry); if (qiv->strict && qobject_type(obj) == QTYPE_QDICT) { h = g_hash_table_new(g_str_hash, g_str_equal); qdict_iter(qobject_to_qdict(obj), qdict_add_key, h); tos->h = h; + } else if (qobject_type(obj) == QTYPE_QLIST) { + tos->entry = qlist_first(qobject_to_qlist(obj)); + tos->first = true; } qiv->nb_stack++; @@ -119,10 +127,11 @@ static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, Error **errp) static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp) { + StackObject *tos = &qiv->stack[qiv->nb_stack - 1]; assert(qiv->nb_stack > 0); if (qiv->strict) { - GHashTable * const top_ht = qiv->stack[qiv->nb_stack - 1].h; + GHashTable * const top_ht = tos->h; if (top_ht) { GHashTableIter iter; const char *key; @@ -133,6 +142,7 @@ static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp) } g_hash_table_unref(top_ht); } + tos->h = NULL; } qiv->nb_stack--; @@ -192,23 +202,15 @@ static GenericList *qmp_input_next_list(Visitor *v, GenericList **list, QmpInputVisitor *qiv = to_qiv(v); GenericList *entry; StackObject *so = &qiv->stack[qiv->nb_stack - 1]; - bool first; - if (so->entry == NULL) { - so->entry = qlist_first(qobject_to_qlist(so->obj)); - first = true; - } else { - so->entry = qlist_next(so->entry); - first = false; - } - - if (so->entry == NULL) { + if (!so->entry) { return NULL; } entry = g_malloc0(size); - if (first) { + if (so->first) { *list = entry; + so->first = false; } else { (*list)->next = entry; } -- 2.5.5