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Diffstat (limited to 'scripts/qapi/events.py')
| -rw-r--r-- | scripts/qapi/events.py | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py new file mode 100644 index 000000000..27b44c49f --- /dev/null +++ b/scripts/qapi/events.py @@ -0,0 +1,252 @@ +""" +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 + +from .common import c_enum_const, c_name, mcgen +from .gen import QAPISchemaModularCVisitor, build_params, ifcontext +from .schema import ( + QAPISchema, + QAPISchemaEnumMember, + QAPISchemaFeature, + QAPISchemaIfCond, + 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 = ¶m; +''', + c_name=typ.c_name()) + return ret + + +def gen_event_send(name: str, + arg_type: Optional[QAPISchemaObjectType], + features: List[QAPISchemaFeature], + 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) + + for f in features: + if f.is_special(): + ret += mcgen(''' + + if (compat_policy.%(feat)s_output == COMPAT_POLICY_OUTPUT_HIDE) { + return; + } +''', + feat=f.name) + + 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_qmp(&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, ¶m, &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); + if (qdict_size(qobject_to(QDict, obj))) { + qdict_put_obj(qmp, "data", obj); + } else { + qobject_unref(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/compat-policy.h" +#include "qapi/error.h" +#include "qapi/qmp/qdict.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: QAPISchemaIfCond, + 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, features, 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) |