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, 6 insertions, 9 deletions

diff --git a/qdev-monitor.c b/qdev-monitor.c
index e3bf84a..124956e 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -756,7 +756,7 @@ void hmp_info_qom_tree(Monitor *mon, const QDict *dict)
     print_qom_composition(mon, obj, 0);
 }
 
-int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
+void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp)
 {
     Error *local_err = NULL;
     QemuOpts *opts;
@@ -764,23 +764,20 @@ int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
 
     opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err);
     if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
+        error_propagate(errp, local_err);
+        return;
     }
     if (!monitor_cur_is_qmp() && qdev_device_help(opts)) {
         qemu_opts_del(opts);
-        return 0;
+        return;
     }
     dev = qdev_device_add(opts, &local_err);
     if (!dev) {
-        qerror_report_err(local_err);
-        error_free(local_err);
+        error_propagate(errp, local_err);
         qemu_opts_del(opts);
-        return -1;
+        return;
     }
     object_unref(OBJECT(dev));
-    return 0;
 }
 
 void qmp_device_del(const char *id, Error **errp)