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, 35 deletions

diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 1c1d3aa029..a451a51bce 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -195,12 +195,10 @@ out:
     return ret
 
 def gen_marshal_input_decl(name, args, ret_type, middle_mode):
-    if middle_mode:
-        return 'int qmp_marshal_input_%s(Monitor *mon, const QDict *qdict, QObject **ret)' % c_name(name)
-    else:
-        return 'static void qmp_marshal_input_%s(QDict *args, QObject **ret, Error **errp)' % c_name(name)
-
-
+    ret = 'void qmp_marshal_input_%s(QDict *args, QObject **ret, Error **errp)' % c_name(name)
+    if not middle_mode:
+        ret = "static " + ret
+    return ret
 
 def gen_marshal_input(name, args, ret_type, middle_mode):
     hdr = gen_marshal_input_decl(name, args, ret_type, middle_mode)
@@ -212,11 +210,6 @@ def gen_marshal_input(name, args, ret_type, middle_mode):
 ''',
                 header=hdr)
 
-    if middle_mode:
-        ret += mcgen('''
-    QDict *args = (QDict *)qdict;
-''')
-
     if ret_type:
         if is_c_ptr(ret_type):
             retval = "    %s retval = NULL;" % c_type(ret_type)
@@ -253,35 +246,13 @@ def gen_marshal_input(name, args, ret_type, middle_mode):
 
 out:
 ''')
-    if not middle_mode:
-        ret += mcgen('''
-    error_propagate(errp, local_err);
-''')
     ret += mcgen('''
+    error_propagate(errp, local_err);
 %(visitor_input_block_cleanup)s
+}
 ''',
                  visitor_input_block_cleanup=gen_visitor_input_block(args,
                                                                      dealloc=True))
-
-    if middle_mode:
-        ret += mcgen('''
-
-    if (local_err) {
-        qerror_report_err(local_err);
-        error_free(local_err);
-        return -1;
-    }
-    return 0;
-''')
-    else:
-        ret += mcgen('''
-    return;
-''')
-
-    ret += mcgen('''
-}
-''')
-
     return ret
 
 def gen_registry(commands):