qapi: Implement deprecated-input=reject for QMP commands

This policy rejects deprecated input, and thus permits "testing the
future".  Implement it for QMP commands: make deprecated ones fail.
Example: when QEMU is run with -compat deprecated-input=reject, then

    {"execute": "query-cpus"}

fails like this

    {"error": {"class": "CommandNotFound", "desc": "Deprecated command query-cpus disabled by policy"}}

When the deprecated command is removed, the error will change to

    {"error": {"class": "CommandNotFound", "desc": "The command query-cpus has not been found"}}

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210318155519.1224118-10-armbru@redhat.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index b7e577a5d1..c4628517ee 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -210,12 +210,16 @@ out:
 
 
 def gen_register_command(name: str,
+                         features: List[QAPISchemaFeature],
                          success_response: bool,
                          allow_oob: bool,
                          allow_preconfig: bool,
                          coroutine: bool) -> str:
     options = []
 
+    if 'deprecated' in [f.name for f in features]:
+        options += ['QCO_DEPRECATED']
+
     if not success_response:
         options += ['QCO_NO_SUCCESS_RESP']
     if allow_oob:
@@ -326,9 +330,9 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
             self._genc.add(gen_marshal(name, arg_type, boxed, ret_type))
         with self._temp_module('./init'):
             with ifcontext(ifcond, self._genh, self._genc):
-                self._genc.add(gen_register_command(name, success_response,
-                                                    allow_oob, allow_preconfig,
-                                                    coroutine))
+                self._genc.add(gen_register_command(
+                    name, features, success_response, allow_oob,
+                    allow_preconfig, coroutine))
 
 
 def gen_commands(schema: QAPISchema,