[Qemu-block] [PATCH v3 18/18] qapi: Add parameter to visit_end_*

[Eric Blake]

Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*.  The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL.  The dealloc visitor is then greatly simplified.

The clone visitor also gets a minor simplification of not having
to track quite as much depth.

Signed-off-by: Eric Blake <address@hidden>

---
v3: new patch
---
 include/qapi/visitor.h           | 32 ++++++++++++++++-----------
 include/qapi/visitor-impl.h      |  6 ++---
 scripts/qapi-commands.py         |  4 ++--
 scripts/qapi-event.py            |  2 +-
 scripts/qapi-visit.py            |  8 +++----
 qapi/qapi-visit-core.c           | 12 +++++-----
 block/crypto.c                   |  4 ++--
 hw/ppc/spapr_drc.c               |  4 ++--
 hw/virtio/virtio-balloon.c       |  4 ++--
 migration/savevm.c               | 10 ++++-----
 migration/vmstate.c              | 10 ++++-----
 qapi/json-output-visitor.c       |  4 ++--
 qapi/opts-visitor.c              |  4 ++--
 qapi/qapi-clone-visitor.c        | 11 +++++-----
 qapi/qapi-dealloc-visitor.c      | 47 +++-------------------------------------
 qapi/qmp-input-visitor.c         |  2 +-
 qapi/qmp-output-visitor.c        |  4 ++--
 qapi/string-input-visitor.c      |  2 +-
 qapi/string-output-visitor.c     |  2 +-
 qom/object.c                     |  2 +-
 qom/object_interfaces.c          |  4 ++--
 tests/test-json-output-visitor.c |  4 ++--
 tests/test-qmp-input-visitor.c   |  2 +-
 tests/test-qmp-output-visitor.c  |  2 +-
 docs/qapi-code-gen.txt           |  4 ++--
 25 files changed, 77 insertions(+), 113 deletions(-)

diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index 4c122cc..34fdd44 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -196,12 +196,12 @@
  *      goto outlist;
  *  }
  * outlist:
- *  visit_end_list(v);
+ *  visit_end_list(v, NULL);
  *  if (!err) {
  *      visit_check_struct(v, &err);
  *  }
  * outobj:
- *  visit_end_struct(v);
+ *  visit_end_struct(v, NULL);
  *  error_propagate(errp, err);
  *  ...clean up v...
  * </example>
@@ -244,8 +244,8 @@ typedef struct GenericAlternate {
  * After visit_start_struct() succeeds, the caller may visit its
  * members one after the other, passing the member's name and address
  * within the struct.  Finally, visit_end_struct() needs to be called
- * to clean up, even if intermediate visits fail.  See the examples
- * above.
+ * with the same @obj to clean up, even if intermediate visits fail.
+ * See the examples above.
  *
  * FIXME Should this be named visit_start_object, since it is also
  * used for QAPI unions, and maps to JSON objects?
@@ -269,12 +269,14 @@ void visit_check_struct(Visitor *v, Error **errp);
 /*
  * Complete an object visit started earlier.
  *
+ * @obj must match what was passed to the paired visit_start_struct().
+ *
  * Must be called after any successful use of visit_start_struct(),
  * even if intermediate processing was skipped due to errors, to allow
  * the backend to release any resources.  Destroying the visitor early
  * behaves as if this was implicitly called.
  */
-void visit_end_struct(Visitor *v);
+void visit_end_struct(Visitor *v, void **obj);


 /*** Visiting lists ***/
@@ -301,8 +303,9 @@ void visit_end_struct(Visitor *v);
  * visit (where @obj is NULL) uses other means.  For each list
  * element, call the appropriate visit_type_FOO() with name set to
  * NULL and obj set to the address of the value member of the list
- * element.  Finally, visit_end_list() needs to be called to clean up,
- * even if intermediate visits fail.  See the examples above.
+ * element.  Finally, visit_end_list() needs to be called with the
+ * same @list to clean up, even if intermediate visits fail.  See the
+ * examples above.
  */
 void visit_start_list(Visitor *v, const char *name, GenericList **list,
                       size_t size, Error **errp);
@@ -326,12 +329,14 @@ GenericList *visit_next_list(Visitor *v, GenericList 
*tail, size_t size);
 /*
  * Complete a list visit started earlier.
  *
+ * @list must match what was passed to the paired visit_start_list().
+ *
  * Must be called after any successful use of visit_start_list(), even
  * if intermediate processing was skipped due to errors, to allow the
  * backend to release any resources.  Destroying the visitor early
  * behaves as if this was implicitly called.
  */
-void visit_end_list(Visitor *v);
+void visit_end_list(Visitor *v, void **list);


 /*** Visiting alternates ***/
@@ -349,8 +354,9 @@ void visit_end_list(Visitor *v);
  *
  * If @promote_int, treat integers as QTYPE_FLOAT.
  *
- * If successful, this must be paired with visit_end_alternate() to
- * clean up, even if visiting the contents of the alternate fails.
+ * If successful, this must be paired with visit_end_alternate() with
+ * the same @obj to clean up, even if visiting the contents of the
+ * alternate fails.
  */
 void visit_start_alternate(Visitor *v, const char *name,
                            GenericAlternate **obj, size_t size,
@@ -359,15 +365,15 @@ void visit_start_alternate(Visitor *v, const char *name,
 /*
  * Finish visiting an alternate type.
  *
+ * @obj must match what was passed to the paired visit_start_alternate().
+ *
  * Must be called after any successful use of visit_start_alternate(),
  * even if intermediate processing was skipped due to errors, to allow
  * the backend to release any resources.  Destroying the visitor early
  * behaves as if this was implicitly called.
  *
- * TODO: Should all the visit_end_* interfaces take obj parameter, so
- * that dealloc visitor need not track what was passed in visit_start?
  */
-void visit_end_alternate(Visitor *v);
+void visit_end_alternate(Visitor *v, void **obj);


 /*** Other helpers ***/
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index a5a2dd0..fdc1f71 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -48,7 +48,7 @@ struct Visitor
     void (*check_struct)(Visitor *v, Error **errp);

     /* Must be set to visit structs */
-    void (*end_struct)(Visitor *v);
+    void (*end_struct)(Visitor *v, void **obj);

     /* Must be set; implementations may require @list to be non-null,
      * but must document it. */
@@ -59,7 +59,7 @@ struct Visitor
     GenericList *(*next_list)(Visitor *v, GenericList *tail, size_t size);

     /* Must be set */
-    void (*end_list)(Visitor *v);
+    void (*end_list)(Visitor *v, void **list);

     /* Must be set by input and dealloc visitors to visit alternates;
      * optional for output visitors. */
@@ -68,7 +68,7 @@ struct Visitor
                             bool promote_int, Error **errp);

     /* Optional, needed for dealloc visitor */
-    void (*end_alternate)(Visitor *v);
+    void (*end_alternate)(Visitor *v, void **obj);

     /* Must be set */
     void (*type_int64)(Visitor *v, const char *name, int64_t *obj,
diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 8c6acb3..971dc4e 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -129,7 +129,7 @@ def gen_marshal(name, arg_type, ret_type):
     if (!err) {
         visit_check_struct(v, &err);
     }
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
     if (err) {
         goto out;
     }
@@ -160,7 +160,7 @@ out:
     v = qapi_dealloc_get_visitor(qdv);
     visit_start_struct(v, NULL, NULL, 0, NULL);
     visit_type_%(c_name)s_members(v, &arg, NULL);
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
     qapi_dealloc_visitor_cleanup(qdv);
 ''',
                      c_name=arg_type.c_name())
diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py
index 21fb167..084c40a 100644
--- a/scripts/qapi-event.py
+++ b/scripts/qapi-event.py
@@ -101,7 +101,7 @@ def gen_event_send(name, arg_type):
     if (!err) {
         visit_check_struct(v, &err);
     }
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
     if (err) {
         goto out;
     }
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 70ea8ca..7b85d2b 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -129,7 +129,7 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, 
%(c_name)s **obj, Error
         }
     }

-    visit_end_list(v);
+    visit_end_list(v, (void **)obj);
     if (err && visit_is_input(v)) {
         qapi_free_%(c_name)s(*obj);
         *obj = NULL;
@@ -191,7 +191,7 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, 
%(c_name)s **obj, Error
         if (!err) {
             visit_check_struct(v, &err);
         }
-        visit_end_struct(v);
+        visit_end_struct(v, NULL);
 ''',
                          c_type=var.type.c_name(),
                          c_name=c_name(var.name))
@@ -210,7 +210,7 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, 
%(c_name)s **obj, Error
         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "%(name)s");
     }
-    visit_end_alternate(v);
+    visit_end_alternate(v, (void **)obj);
     if (err && visit_is_input(v)) {
         qapi_free_%(c_name)s(*obj);
         *obj = NULL;
@@ -244,7 +244,7 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, 
%(c_name)s **obj, Error
     }
     visit_check_struct(v, &err);
 out_obj:
-    visit_end_struct(v);
+    visit_end_struct(v, (void **)obj);
     if (err && visit_is_input(v)) {
         qapi_free_%(c_name)s(*obj);
         *obj = NULL;
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 838e5d5..f339dc2 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -43,9 +43,9 @@ void visit_check_struct(Visitor *v, Error **errp)
     }
 }

-void visit_end_struct(Visitor *v)
+void visit_end_struct(Visitor *v, void **obj)
 {
-    v->end_struct(v);
+    v->end_struct(v, obj);
 }

 void visit_start_list(Visitor *v, const char *name, GenericList **list,
@@ -67,9 +67,9 @@ GenericList *visit_next_list(Visitor *v, GenericList *tail, 
size_t size)
     return v->next_list(v, tail, size);
 }

-void visit_end_list(Visitor *v)
+void visit_end_list(Visitor *v, void **obj)
 {
-    v->end_list(v);
+    v->end_list(v, obj);
 }

 void visit_start_alternate(Visitor *v, const char *name,
@@ -89,10 +89,10 @@ void visit_start_alternate(Visitor *v, const char *name,
     error_propagate(errp, err);
 }

-void visit_end_alternate(Visitor *v)
+void visit_end_alternate(Visitor *v, void **obj)
 {
     if (v->end_alternate) {
-        v->end_alternate(v);
+        v->end_alternate(v, obj);
     }
 }

diff --git a/block/crypto.c b/block/crypto.c
index 2424a4c..d2e710a 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -222,7 +222,7 @@ block_crypto_open_opts_init(QCryptoBlockFormat format,
         visit_check_struct(opts_get_visitor(ov), &local_err);
     }

-    visit_end_struct(opts_get_visitor(ov));
+    visit_end_struct(opts_get_visitor(ov), NULL);

  out:
     if (local_err) {
@@ -269,7 +269,7 @@ block_crypto_create_opts_init(QCryptoBlockFormat format,
         visit_check_struct(opts_get_visitor(ov), &local_err);
     }

-    visit_end_struct(opts_get_visitor(ov));
+    visit_end_struct(opts_get_visitor(ov), NULL);

  out:
     if (local_err) {
diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
index 94c875d..c1da698 100644
--- a/hw/ppc/spapr_drc.c
+++ b/hw/ppc/spapr_drc.c
@@ -298,7 +298,7 @@ static void prop_get_fdt(Object *obj, Visitor *v, const 
char *name,
             /* shouldn't ever see an FDT_END_NODE before FDT_BEGIN_NODE */
             g_assert(fdt_depth > 0);
             visit_check_struct(v, &err);
-            visit_end_struct(v);
+            visit_end_struct(v, NULL);
             if (err) {
                 error_propagate(errp, err);
                 return;
@@ -321,7 +321,7 @@ static void prop_get_fdt(Object *obj, Visitor *v, const 
char *name,
                     return;
                 }
             }
-            visit_end_list(v);
+            visit_end_list(v, NULL);
             break;
         }
         default:
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 8c15e09..3c1d03d 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -143,13 +143,13 @@ static void balloon_stats_get_all(Object *obj, Visitor 
*v, const char *name,
     }
     visit_check_struct(v, &err);
 out_nested:
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);

     if (!err) {
         visit_check_struct(v, &err);
     }
 out_end:
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
 out:
     error_propagate(errp, err);
 }
diff --git a/migration/savevm.c b/migration/savevm.c
index 8cb3af9..ff6b192 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -665,8 +665,8 @@ static void vmstate_save_old_style(QEMUFile *f, 
SaveStateEntry *se,
         tmp = "buffer";
         visit_type_str(vmdesc, "type", (char **)&tmp, &error_abort);
         visit_check_struct(vmdesc, &error_abort);
-        visit_end_struct(vmdesc);
-        visit_end_list(vmdesc);
+        visit_end_struct(vmdesc, NULL);
+        visit_end_list(vmdesc, NULL);
     }
 }

@@ -1112,7 +1112,7 @@ void qemu_savevm_state_complete_precopy(QEMUFile *f, bool 
iterable_only)
         save_section_footer(f, se);

         visit_check_struct(vmdesc, &error_abort);
-        visit_end_struct(vmdesc);
+        visit_end_struct(vmdesc, NULL);
     }

     if (!in_postcopy) {
@@ -1120,9 +1120,9 @@ void qemu_savevm_state_complete_precopy(QEMUFile *f, bool 
iterable_only)
         qemu_put_byte(f, QEMU_VM_EOF);
     }

-    visit_end_list(vmdesc);
+    visit_end_list(vmdesc, NULL);
     visit_check_struct(vmdesc, &error_abort);
-    visit_end_struct(vmdesc);
+    visit_end_struct(vmdesc, NULL);
     vmdesc_str = json_output_get_string(vmdesc_jov);
     vmdesc_len = strlen(vmdesc_str);

diff --git a/migration/vmstate.c b/migration/vmstate.c
index e7f894c..8c789a3 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -284,13 +284,13 @@ static void vmsd_desc_field_end(const VMStateDescription 
*vmsd,
     if (field->flags & VMS_STRUCT) {
         /* We printed a struct in between, close its child object */
         visit_check_struct(vmdesc, &error_abort);
-        visit_end_struct(vmdesc);
+        visit_end_struct(vmdesc, NULL);
     }

     tmp = size;
     visit_type_int(vmdesc, "size", &tmp, &error_abort);
     visit_check_struct(vmdesc, &error_abort);
-    visit_end_struct(vmdesc);
+    visit_end_struct(vmdesc, NULL);
 }


@@ -364,7 +364,7 @@ void vmstate_save_state(QEMUFile *f, const 
VMStateDescription *vmsd,
     }

     if (vmdesc) {
-        visit_end_list(vmdesc);
+        visit_end_list(vmdesc, NULL);
     }

     vmstate_subsection_save(f, vmsd, opaque, vmdesc);
@@ -464,14 +464,14 @@ static void vmstate_subsection_save(QEMUFile *f, const 
VMStateDescription *vmsd,

             if (vmdesc) {
                 visit_check_struct(vmdesc, &error_abort);
-                visit_end_struct(vmdesc);
+                visit_end_struct(vmdesc, NULL);
             }
         }
         sub++;
     }

     if (vmdesc && subsection_found) {
-        visit_end_list(vmdesc);
+        visit_end_list(vmdesc, NULL);
     }
 }

diff --git a/qapi/json-output-visitor.c b/qapi/json-output-visitor.c
index f479034..0d67337 100644
--- a/qapi/json-output-visitor.c
+++ b/qapi/json-output-visitor.c
@@ -58,7 +58,7 @@ static void json_output_start_struct(Visitor *v, const char 
*name, void **obj,
     jov->depth++;
 }

-static void json_output_end_struct(Visitor *v)
+static void json_output_end_struct(Visitor *v, void **obj)
 {
     JsonOutputVisitor *jov = to_jov(v);
     assert(jov->depth);
@@ -87,7 +87,7 @@ static GenericList *json_output_next_list(Visitor *v, 
GenericList *tail,
     return tail->next;
 }

-static void json_output_end_list(Visitor *v)
+static void json_output_end_list(Visitor *v, void **obj)
 {
     JsonOutputVisitor *jov = to_jov(v);
     assert(jov->depth);
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
index 4cf1cf8..dcfbf92 100644
--- a/qapi/opts-visitor.c
+++ b/qapi/opts-visitor.c
@@ -180,7 +180,7 @@ opts_check_struct(Visitor *v, Error **errp)


 static void
-opts_end_struct(Visitor *v)
+opts_end_struct(Visitor *v, void **obj)
 {
     OptsVisitor *ov = to_ov(v);

@@ -273,7 +273,7 @@ opts_next_list(Visitor *v, GenericList *tail, size_t size)


 static void
-opts_end_list(Visitor *v)
+opts_end_list(Visitor *v, void **obj)
 {
     OptsVisitor *ov = to_ov(v);

diff --git a/qapi/qapi-clone-visitor.c b/qapi/qapi-clone-visitor.c
index 42384d3..92771e3 100644
--- a/qapi/qapi-clone-visitor.c
+++ b/qapi/qapi-clone-visitor.c
@@ -29,11 +29,8 @@ static void qapi_clone_start_struct(Visitor *v, const char 
*name, void **obj,
     QapiCloneVisitor *qcv = to_qcv(v);

     if (!obj) {
-        /* Nothing to allocate on the virtual walk during an
-         * alternate, but we still have to push depth.
-         * FIXME: passing obj to visit_end_struct would make this easier */
+        /* Nothing to allocate on the virtual walk */
         assert(qcv->depth);
-        qcv->depth++;
         return;
     }

@@ -41,11 +38,13 @@ static void qapi_clone_start_struct(Visitor *v, const char 
*name, void **obj,
     qcv->depth++;
 }

-static void qapi_clone_end(Visitor *v)
+static void qapi_clone_end(Visitor *v, void **obj)
 {
     QapiCloneVisitor *qcv = to_qcv(v);
     assert(qcv->depth);
-    qcv->depth--;
+    if (obj) {
+        qcv->depth--;
+    }
 }

 static void qapi_clone_start_list(Visitor *v, const char *name,
diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c
index cd68b55..9391dea 100644
--- a/qapi/qapi-dealloc-visitor.c
+++ b/qapi/qapi-dealloc-visitor.c
@@ -19,53 +19,18 @@
 #include "qapi/qmp/types.h"
 #include "qapi/visitor-impl.h"

-typedef struct StackEntry
-{
-    void *value;
-    QTAILQ_ENTRY(StackEntry) node;
-} StackEntry;
-
 struct QapiDeallocVisitor
 {
     Visitor visitor;
-    QTAILQ_HEAD(, StackEntry) stack;
 };

-static QapiDeallocVisitor *to_qov(Visitor *v)
-{
-    return container_of(v, QapiDeallocVisitor, visitor);
-}
-
-static void qapi_dealloc_push(QapiDeallocVisitor *qov, void *value)
-{
-    StackEntry *e = g_malloc0(sizeof(*e));
-
-    e->value = value;
-
-    QTAILQ_INSERT_HEAD(&qov->stack, e, node);
-}
-
-static void *qapi_dealloc_pop(QapiDeallocVisitor *qov)
-{
-    StackEntry *e = QTAILQ_FIRST(&qov->stack);
-    QObject *value;
-    QTAILQ_REMOVE(&qov->stack, e, node);
-    value = e->value;
-    g_free(e);
-    return value;
-}
-
 static void qapi_dealloc_start_struct(Visitor *v, const char *name, void **obj,
                                       size_t unused, Error **errp)
 {
-    QapiDeallocVisitor *qov = to_qov(v);
-    qapi_dealloc_push(qov, obj);
 }

-static void qapi_dealloc_end_struct(Visitor *v)
+static void qapi_dealloc_end_struct(Visitor *v, void **obj)
 {
-    QapiDeallocVisitor *qov = to_qov(v);
-    void **obj = qapi_dealloc_pop(qov);
     if (obj) {
         g_free(*obj);
     }
@@ -75,14 +40,10 @@ static void qapi_dealloc_start_alternate(Visitor *v, const 
char *name,
                                          GenericAlternate **obj, size_t size,
                                          bool promote_int, Error **errp)
 {
-    QapiDeallocVisitor *qov = to_qov(v);
-    qapi_dealloc_push(qov, obj);
 }

-static void qapi_dealloc_end_alternate(Visitor *v)
+static void qapi_dealloc_end_alternate(Visitor *v, void **obj)
 {
-    QapiDeallocVisitor *qov = to_qov(v);
-    void **obj = qapi_dealloc_pop(qov);
     if (obj) {
         g_free(*obj);
     }
@@ -102,7 +63,7 @@ static GenericList *qapi_dealloc_next_list(Visitor *v, 
GenericList *tail,
     return next;
 }

-static void qapi_dealloc_end_list(Visitor *v)
+static void qapi_dealloc_end_list(Visitor *v, void **obj)
 {
 }

@@ -178,7 +139,5 @@ QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
     v->visitor.type_any = qapi_dealloc_type_anything;
     v->visitor.type_null = qapi_dealloc_type_null;

-    QTAILQ_INIT(&v->stack);
-
     return v;
 }
diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index aea90a1..84f32fc 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -145,7 +145,7 @@ static void qmp_input_check_struct(Visitor *v, Error **errp)
     }
 }

-static void qmp_input_pop(Visitor *v)
+static void qmp_input_pop(Visitor *v, void **obj)
 {
     QmpInputVisitor *qiv = to_qiv(v);
     StackObject *tos = &qiv->stack[qiv->nb_stack - 1];
diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c
index ef9f62c..4bdc00d 100644
--- a/qapi/qmp-output-visitor.c
+++ b/qapi/qmp-output-visitor.c
@@ -107,7 +107,7 @@ static void qmp_output_start_struct(Visitor *v, const char 
*name, void **obj,
     qmp_output_push(qov, dict);
 }

-static void qmp_output_end_struct(Visitor *v)
+static void qmp_output_end_struct(Visitor *v, void **obj)
 {
     QmpOutputVisitor *qov = to_qov(v);
     QObject *value = qmp_output_pop(qov);
@@ -131,7 +131,7 @@ static GenericList *qmp_output_next_list(Visitor *v, 
GenericList *tail,
     return tail->next;
 }

-static void qmp_output_end_list(Visitor *v)
+static void qmp_output_end_list(Visitor *v, void **end)
 {
     QmpOutputVisitor *qov = to_qov(v);
     QObject *value = qmp_output_pop(qov);
diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
index 30b5879..1c66d6a 100644
--- a/qapi/string-input-visitor.c
+++ b/qapi/string-input-visitor.c
@@ -181,7 +181,7 @@ static GenericList *next_list(Visitor *v, GenericList 
*tail, size_t size)
     return tail->next;
 }

-static void end_list(Visitor *v)
+static void end_list(Visitor *v, void **obj)
 {
 }

diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
index d013196..1504a89 100644
--- a/qapi/string-output-visitor.c
+++ b/qapi/string-output-visitor.c
@@ -291,7 +291,7 @@ static GenericList *next_list(Visitor *v, GenericList 
*tail, size_t size)
     return ret;
 }

-static void end_list(Visitor *v)
+static void end_list(Visitor *v, void **obj)
 {
     StringOutputVisitor *sov = to_sov(v);

diff --git a/qom/object.c b/qom/object.c
index 3bc8a00..1562f7e 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -2038,7 +2038,7 @@ static void property_get_tm(Object *obj, Visitor *v, 
const char *name,
     }
     visit_check_struct(v, &err);
 out_end:
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
 out:
     error_propagate(errp, err);

diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index 51e62e2..926ec68 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -71,7 +71,7 @@ Object *user_creatable_add(const QDict *qdict,
     obj = user_creatable_add_type(type, id, pdict, v, &local_err);

 out_visit:
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);

 out:
     QDECREF(pdict);
@@ -127,7 +127,7 @@ Object *user_creatable_add_type(const char *type, const 
char *id,
     if (!local_err) {
         visit_check_struct(v, &local_err);
     }
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
     if (local_err) {
         goto out;
     }
diff --git a/tests/test-json-output-visitor.c b/tests/test-json-output-visitor.c
index 5bf6fc5..5e8a5c8 100644
--- a/tests/test-json-output-visitor.c
+++ b/tests/test-json-output-visitor.c
@@ -324,7 +324,7 @@ static void test_visitor_out_any(TestOutputVisitorData 
*data,
     qobj = QOBJECT(qint_from_int(-42));
     visit_start_list(data->ov, NULL, NULL, 0, &error_abort);
     visit_type_any(data->ov, NULL, &qobj, &error_abort);
-    visit_end_list(data->ov);
+    visit_end_list(data->ov, NULL);
     out = json_output_get_string(data->jov);
     if (*pretty) {
         g_assert_cmpstr(out, ==, "[\n    -42\n]");
@@ -341,7 +341,7 @@ static void test_visitor_out_any(TestOutputVisitorData 
*data,
     qobj = QOBJECT(qdict);
     visit_start_list(data->ov, NULL, NULL, 0, &error_abort);
     visit_type_any(data->ov, NULL, &qobj, &error_abort);
-    visit_end_list(data->ov);
+    visit_end_list(data->ov, NULL);
     qobject_decref(qobj);
     out = json_output_get_string(data->jov);
     if (*pretty) {
diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c
index d02306c..56ee943 100644
--- a/tests/test-qmp-input-visitor.c
+++ b/tests/test-qmp-input-visitor.c
@@ -305,7 +305,7 @@ static void test_visitor_in_null(TestInputVisitorData *data,
     visit_type_null(v, "b", &err);
     error_free_or_abort(&err);
     visit_check_struct(v, &error_abort);
-    visit_end_struct(v);
+    visit_end_struct(v, NULL);
 }

 static void test_visitor_in_union_flat(TestInputVisitorData *data,
diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c
index 050d65b..e2aa494 100644
--- a/tests/test-qmp-output-visitor.c
+++ b/tests/test-qmp-output-visitor.c
@@ -494,7 +494,7 @@ static void test_visitor_out_null(TestOutputVisitorData 
*data,
     visit_start_struct(data->ov, NULL, NULL, 0, &error_abort);
     visit_type_null(data->ov, "a", &error_abort);
     visit_check_struct(data->ov, &error_abort);
-    visit_end_struct(data->ov);
+    visit_end_struct(data->ov, NULL);
     arg = qmp_output_get_qobject(data->qov);
     g_assert(qobject_type(arg) == QTYPE_QDICT);
     qdict = qobject_to_qdict(arg);
diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index 92fbb0e..48436aa 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -942,7 +942,7 @@ Example:
         }
         visit_check_struct(v, &err);
     out_obj:
-        visit_end_struct(v);
+        visit_end_struct(v, (void **)obj);
         if (err && visit_is_input(v)) {
             qapi_free_UserDefOne(*obj);
             *obj = NULL;
@@ -970,7 +970,7 @@ Example:
             }
         }

-        visit_end_list(v);
+        visit_end_list(v, (void **)obj);
         if (err && visit_is_input(v)) {
             qapi_free_UserDefOneList(*obj);
             *obj = NULL;
-- 
2.5.5