qmp: Wean off qerror_report()

The traditional QMP command handler interface

    int qmp_FOO(Monitor *mon, const QDict *params, QObject **ret_data);

doesn't provide for returning an Error object.  Instead, the handler
is expected to stash it in the monitor with qerror_report().

When we rebased QMP on top of QAPI, we didn't change this interface.
Instead, commit 776574d introduced "middle mode" as a temporary aid
for converting existing QMP commands to QAPI one by one.  More than
three years later, we're still using it.

Middle mode has two effects:

* Instead of the native input marshallers

      static void qmp_marshal_input_FOO(QDict *, QObject **, Error **)

  it generates input marshallers conforming to the traditional QMP
  command handler interface.

* It suppresses generation of code to register them with
  qmp_register_command()

  This permits giving them internal linkage.

As long as we need qmp-commands.hx, we can't use the registry behind
qmp_register_command(), so the latter has to stay for now.

The former has to go to get rid of qerror_report().  Changing all QMP
commands to fit the QAPI mold in one go was impractical back when we
started, but by now there are just a few stragglers left:
do_qmp_capabilities(), qmp_qom_set(), qmp_qom_get(), qmp_object_add(),
qmp_netdev_add(), do_device_add().

Switch middle mode to generate native input marshallers, and adapt the
stragglers.  Simplifies both the monitor code and the stragglers.

Rename do_qmp_capabilities() to qmp_capabilities(), and
do_device_add() to qmp_device_add, because that's how QMP command
handlers are named today.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 12 insertions, 43 deletions

diff --git a/qmp.c b/qmp.c
index 3ffb34915c..a046b68c99 100644
--- a/qmp.c
+++ b/qmp.c
@@ -227,57 +227,37 @@ ObjectPropertyInfoList *qmp_qom_list(const char *path, Error **errp)
 }
 
 /* FIXME: teach qapi about how to pass through Visitors */
-int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret)
+void qmp_qom_set(QDict *qdict, QObject **ret, Error **errp)
 {
     const char *path = qdict_get_str(qdict, "path");
     const char *property = qdict_get_str(qdict, "property");
     QObject *value = qdict_get(qdict, "value");
-    Error *local_err = NULL;
     Object *obj;
 
     obj = object_resolve_path(path, NULL);
     if (!obj) {
-        error_set(&local_err, ERROR_CLASS_DEVICE_NOT_FOUND,
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
                   "Device '%s' not found", path);
-        goto out;
-    }
-
-    object_property_set_qobject(obj, value, property, &local_err);
-
-out:
-    if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
+        return;
     }
 
-    return 0;
+    object_property_set_qobject(obj, value, property, errp);
 }
 
-int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret)
+void qmp_qom_get(QDict *qdict, QObject **ret, Error **errp)
 {
     const char *path = qdict_get_str(qdict, "path");
     const char *property = qdict_get_str(qdict, "property");
-    Error *local_err = NULL;
     Object *obj;
 
     obj = object_resolve_path(path, NULL);
     if (!obj) {
-        error_set(&local_err, ERROR_CLASS_DEVICE_NOT_FOUND,
+        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
                   "Device '%s' not found", path);
-        goto out;
-    }
-
-    *ret = object_property_get_qobject(obj, property, &local_err);
-
-out:
-    if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
+        return;
     }
 
-    return 0;
+    *ret = object_property_get_qobject(obj, property, errp);
 }
 
 void qmp_set_password(const char *protocol, const char *password,
@@ -673,36 +653,25 @@ out:
     object_unref(obj);
 }
 
-int qmp_object_add(Monitor *mon, const QDict *qdict, QObject **ret)
+void qmp_object_add(QDict *qdict, QObject **ret, Error **errp)
 {
     const char *type = qdict_get_str(qdict, "qom-type");
     const char *id = qdict_get_str(qdict, "id");
     QObject *props = qdict_get(qdict, "props");
     const QDict *pdict = NULL;
-    Error *local_err = NULL;
     QmpInputVisitor *qiv;
 
     if (props) {
         pdict = qobject_to_qdict(props);
         if (!pdict) {
-            error_setg(&local_err, QERR_INVALID_PARAMETER_TYPE,
-                       "props", "dict");
-            goto out;
+            error_setg(errp, QERR_INVALID_PARAMETER_TYPE, "props", "dict");
+            return;
         }
     }
 
     qiv = qmp_input_visitor_new(props);
-    object_add(type, id, pdict, qmp_input_get_visitor(qiv), &local_err);
+    object_add(type, id, pdict, qmp_input_get_visitor(qiv), errp);
     qmp_input_visitor_cleanup(qiv);
-
-out:
-    if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
-    }
-
-    return 0;
 }
 
 void qmp_object_del(const char *id, Error **errp)