qemu/scripts/qapi/events.py
John Snow 1a503761e4 qapi/events.py: Move comments into docstrings
Clarify them while we're here.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20201009161558.107041-21-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2020-10-10 11:37:48 +02:00

235 lines
6.9 KiB
Python

"""
QAPI event generator
Copyright (c) 2014 Wenchao Xia
Copyright (c) 2015-2018 Red Hat Inc.
Authors:
Wenchao Xia <wenchaoqemu@gmail.com>
Markus Armbruster <armbru@redhat.com>
This work is licensed under the terms of the GNU GPL, version 2.
See the COPYING file in the top-level directory.
"""
from typing import List
from .common import c_enum_const, c_name, mcgen
from .gen import QAPISchemaModularCVisitor, build_params, ifcontext
from .schema import (
QAPISchema,
QAPISchemaEnumMember,
QAPISchemaFeature,
QAPISchemaObjectType,
)
from .source import QAPISourceInfo
from .types import gen_enum, gen_enum_lookup
def build_event_send_proto(name: str,
arg_type: QAPISchemaObjectType,
boxed: bool) -> str:
return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
'c_name': c_name(name.lower()),
'param': build_params(arg_type, boxed)}
def gen_event_send_decl(name: str,
arg_type: QAPISchemaObjectType,
boxed: bool) -> str:
return mcgen('''
%(proto)s;
''',
proto=build_event_send_proto(name, arg_type, boxed))
def gen_param_var(typ: QAPISchemaObjectType) -> str:
"""
Generate a struct variable holding the event parameters.
Initialize it with the function arguments defined in `gen_event_send`.
"""
assert not typ.variants
ret = mcgen('''
%(c_name)s param = {
''',
c_name=typ.c_name())
sep = ' '
for memb in typ.members:
ret += sep
sep = ', '
if memb.optional:
ret += 'has_' + c_name(memb.name) + sep
if memb.type.name == 'str':
# Cast away const added in build_params()
ret += '(char *)'
ret += c_name(memb.name)
ret += mcgen('''
};
''')
if not typ.is_implicit():
ret += mcgen('''
%(c_name)s *arg = &param;
''',
c_name=typ.c_name())
return ret
def gen_event_send(name: str,
arg_type: QAPISchemaObjectType,
boxed: bool,
event_enum_name: str,
event_emit: str) -> str:
# FIXME: Our declaration of local variables (and of 'errp' in the
# parameter list) can collide with exploded members of the event's
# data type passed in as parameters. If this collision ever hits in
# practice, we can rename our local variables with a leading _ prefix,
# or split the code into a wrapper function that creates a boxed
# 'param' object then calls another to do the real work.
have_args = boxed or (arg_type and not arg_type.is_empty())
ret = mcgen('''
%(proto)s
{
QDict *qmp;
''',
proto=build_event_send_proto(name, arg_type, boxed))
if have_args:
ret += mcgen('''
QObject *obj;
Visitor *v;
''')
if not boxed:
ret += gen_param_var(arg_type)
ret += mcgen('''
qmp = qmp_event_build_dict("%(name)s");
''',
name=name)
if have_args:
ret += mcgen('''
v = qobject_output_visitor_new(&obj);
''')
if not arg_type.is_implicit():
ret += mcgen('''
visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
''',
name=name, c_name=arg_type.c_name())
else:
ret += mcgen('''
visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
visit_type_%(c_name)s_members(v, &param, &error_abort);
visit_check_struct(v, &error_abort);
visit_end_struct(v, NULL);
''',
name=name, c_name=arg_type.c_name())
ret += mcgen('''
visit_complete(v, &obj);
qdict_put_obj(qmp, "data", obj);
''')
ret += mcgen('''
%(event_emit)s(%(c_enum)s, qmp);
''',
event_emit=event_emit,
c_enum=c_enum_const(event_enum_name, name))
if have_args:
ret += mcgen('''
visit_free(v);
''')
ret += mcgen('''
qobject_unref(qmp);
}
''')
return ret
class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
def __init__(self, prefix: str):
super().__init__(
prefix, 'qapi-events',
' * Schema-defined QAPI/QMP events', None, __doc__)
self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
self._event_enum_members: List[QAPISchemaEnumMember] = []
self._event_emit_name = c_name(prefix + 'qapi_event_emit')
def _begin_user_module(self, name: str) -> None:
events = self._module_basename('qapi-events', name)
types = self._module_basename('qapi-types', name)
visit = self._module_basename('qapi-visit', name)
self._genc.add(mcgen('''
#include "qemu/osdep.h"
#include "%(prefix)sqapi-emit-events.h"
#include "%(events)s.h"
#include "%(visit)s.h"
#include "qapi/error.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qobject-output-visitor.h"
#include "qapi/qmp-event.h"
''',
events=events, visit=visit,
prefix=self._prefix))
self._genh.add(mcgen('''
#include "qapi/util.h"
#include "%(types)s.h"
''',
types=types))
def visit_end(self) -> None:
self._add_system_module('emit', ' * QAPI Events emission')
self._genc.preamble_add(mcgen('''
#include "qemu/osdep.h"
#include "%(prefix)sqapi-emit-events.h"
''',
prefix=self._prefix))
self._genh.preamble_add(mcgen('''
#include "qapi/util.h"
'''))
self._genh.add(gen_enum(self._event_enum_name,
self._event_enum_members))
self._genc.add(gen_enum_lookup(self._event_enum_name,
self._event_enum_members))
self._genh.add(mcgen('''
void %(event_emit)s(%(event_enum)s event, QDict *qdict);
''',
event_emit=self._event_emit_name,
event_enum=self._event_enum_name))
def visit_event(self,
name: str,
info: QAPISourceInfo,
ifcond: List[str],
features: List[QAPISchemaFeature],
arg_type: QAPISchemaObjectType,
boxed: bool) -> None:
with ifcontext(ifcond, self._genh, self._genc):
self._genh.add(gen_event_send_decl(name, arg_type, boxed))
self._genc.add(gen_event_send(name, arg_type, boxed,
self._event_enum_name,
self._event_emit_name))
# Note: we generate the enum member regardless of @ifcond, to
# keep the enumeration usable in target-independent code.
self._event_enum_members.append(QAPISchemaEnumMember(name, None))
def gen_events(schema: QAPISchema,
output_dir: str,
prefix: str) -> None:
vis = QAPISchemaGenEventVisitor(prefix)
schema.visit(vis)
vis.write(output_dir)