unicorn/qemu/scripts/qapi/events.py
Marc-André Lureau 7b4961d75b
qapi/events: add #if conditions to events
Wrap generated code with #if/#endif using an 'ifcontext' on
QAPIGenCSnippet objects.

This makes a conditional event's qapi_event_send_FOO() compile-time
conditional, but its enum QAPIEvent member remains unconditional for
now. A follow up patch "qapi-event: add 'if' condition to implicit
event enum" will improve this.

Backports commit c3cd6aa0201c126eda8dc71b60e7aa259a3e79b9 from qemu
2018-07-05 12:09:05 -04:00

199 lines
5.1 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 qapi.common import *
def build_event_send_proto(name, arg_type, boxed):
return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
'c_name': c_name(name.lower()),
'param': gen_params(arg_type, boxed, 'Error **errp')}
def gen_event_send_decl(name, arg_type, boxed):
return mcgen('''
%(proto)s;
''',
proto=build_event_send_proto(name, arg_type, boxed))
# Declare and initialize an object 'qapi' using parameters from build_params()
def gen_param_var(typ):
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, arg_type, boxed, event_enum_name):
# 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.
ret = mcgen('''
%(proto)s
{
QDict *qmp;
Error *err = NULL;
QMPEventFuncEmit emit;
''',
proto=build_event_send_proto(name, arg_type, boxed))
if arg_type and not arg_type.is_empty():
assert not arg_type.variants
ret += mcgen('''
QObject *obj;
Visitor *v;
''')
if not boxed:
ret += gen_param_var(arg_type)
else:
assert not boxed
ret += mcgen('''
emit = qmp_event_get_func_emit();
if (!emit) {
return;
}
qmp = qmp_event_build_dict("%(name)s");
''',
name=name)
if arg_type and not arg_type.is_empty():
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, &err);
''',
name=name, c_name=arg_type.c_name())
else:
ret += mcgen('''
visit_start_struct(v, "%(name)s", NULL, 0, &err);
if (err) {
goto out;
}
visit_type_%(c_name)s_members(v, &param, &err);
if (!err) {
visit_check_struct(v, &err);
}
visit_end_struct(v, NULL);
''',
name=name, c_name=arg_type.c_name())
ret += mcgen('''
if (err) {
goto out;
}
visit_complete(v, &obj);
qdict_put_obj(qmp, "data", obj);
''')
ret += mcgen('''
emit(%(c_enum)s, qmp, &err);
''',
c_enum=c_enum_const(event_enum_name, name))
if arg_type and not arg_type.is_empty():
ret += mcgen('''
out:
visit_free(v);
''')
ret += mcgen('''
error_propagate(errp, err);
qobject_unref(qmp);
}
''')
return ret
class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
def __init__(self, prefix):
QAPISchemaModularCVisitor.__init__(
self, prefix, 'qapi-events',
' * Schema-defined QAPI/QMP events', __doc__)
self._enum_name = c_name(prefix + 'QAPIEvent', protect=False)
self._event_names = []
def _begin_module(self, name):
types = self._module_basename('qapi-types', name)
visit = self._module_basename('qapi-visit', name)
self._genc.add(mcgen('''
#include "qemu-common.h"
#include "%(prefix)sqapi-events.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"
''',
visit=visit, prefix=self._prefix))
self._genh.add(mcgen('''
/* #include "qapi/util.h" */
#include "%(types)s.h"
''',
types=types))
def visit_end(self):
(genc, genh) = self._module[self._main_module]
genh.add(gen_enum(self._enum_name, self._event_names))
genc.add(gen_enum_lookup(self._enum_name, self._event_names))
def visit_event(self, name, info, ifcond, arg_type, boxed):
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._enum_name))
self._event_names.append(name)
def gen_events(schema, output_dir, prefix):
vis = QAPISchemaGenEventVisitor(prefix)
schema.visit(vis)
vis.write(output_dir)