[Qemu-devel] [PATCH v8 23.5/35] qmp: Tighten output visitor rules, part 2

[Eric Blake <eblake@redhat.com>]

Nothing was using the return value of qmp_output_pop().  Also,
adding a parameter will let us diagnose any programming bugs
due to mismatched push(struct)/pop(list) or push(list)/pop(struct).

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v9: new patch; probably worth squashing into 23/35
---
 qapi/qmp-output-visitor.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c
index f2c39c5..8a297a6 100644
--- a/qapi/qmp-output-visitor.c
+++ b/qapi/qmp-output-visitor.c
@@ -1,7 +1,7 @@
 /*
  * Core Definitions for QAPI/QMP Command Registry
  *
- * Copyright (C) 2015 Red Hat, Inc.
+ * Copyright (C) 2015-2016 Red Hat, Inc.
  * Copyright IBM, Corp. 2011
  *
  * Authors:
@@ -57,17 +57,15 @@ static void qmp_output_push_obj(QmpOutputVisitor *qov, QObject *value)
     QTAILQ_INSERT_HEAD(&qov->stack, e, node);
 }

-/* Grab and remove the most recent QObject from the stack */
-static QObject *qmp_output_pop(QmpOutputVisitor *qov)
+/* Remove the most recent QObject with given type from the stack */
+static void qmp_output_pop(QmpOutputVisitor *qov, QType type)
 {
     QStackEntry *e = QTAILQ_FIRST(&qov->stack);
-    QObject *value;

     assert(e);
     QTAILQ_REMOVE(&qov->stack, e, node);
-    value = e->value;
+    assert(qobject_type(e->value) == type);
     g_free(e);
-    return value;
 }

 /* Grab the most recent QObject from the stack, if any */
@@ -120,7 +118,7 @@ static void qmp_output_start_struct(Visitor *v, const char *name, void **obj,
 static void qmp_output_end_struct(Visitor *v, Error **errp)
 {
     QmpOutputVisitor *qov = to_qov(v);
-    qmp_output_pop(qov);
+    qmp_output_pop(qov, QTYPE_QDICT);
 }

 static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
@@ -151,7 +149,7 @@ static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp,
 static void qmp_output_end_list(Visitor *v)
 {
     QmpOutputVisitor *qov = to_qov(v);
-    qmp_output_pop(qov);
+    qmp_output_pop(qov, QTYPE_QLIST);
 }

 static void qmp_output_type_int64(Visitor *v, const char *name, int64_t *obj,
-- 
2.4.3