qemu/scripts/qapi/events.py
John Snow 2184bca7b1 qapi: Replace List[str] with Sequence[str] for ifcond
It does happen to be a list (as of now), but we can describe it in more
general terms with no loss in accuracy to allow tuples and other
constructs.

In the future, we can write "ifcond: Sequence[str] = ()" as a default
parameter, which we could not do safely with a Mutable type like a List.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210216021809.134886-2-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2021-02-18 17:10:29 +01:00

237 lines
7.0 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, Optional, Sequence
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: Optional[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: Optional[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: Optional[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:
assert arg_type is not None
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:
assert arg_type is not None
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_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: Optional[QAPISourceInfo],
ifcond: Sequence[str],
features: List[QAPISchemaFeature],
arg_type: Optional[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)