xref: /openbmc/qemu/scripts/qapi/events.py (revision 5af8263d40c698c47befd4c0bed3d6c452b56d82)
1"""
2QAPI event generator
3
4Copyright (c) 2014 Wenchao Xia
5Copyright (c) 2015-2018 Red Hat Inc.
6
7Authors:
8 Wenchao Xia <wenchaoqemu@gmail.com>
9 Markus Armbruster <armbru@redhat.com>
10
11This work is licensed under the terms of the GNU GPL, version 2.
12See the COPYING file in the top-level directory.
13"""
14
15from .common import (
16    build_params,
17    c_enum_const,
18    c_name,
19    mcgen,
20)
21from .gen import QAPISchemaModularCVisitor, ifcontext
22from .schema import QAPISchemaEnumMember
23from .types import gen_enum, gen_enum_lookup
24
25
26def build_event_send_proto(name, arg_type, boxed):
27    return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
28        'c_name': c_name(name.lower()),
29        'param': build_params(arg_type, boxed)}
30
31
32def gen_event_send_decl(name, arg_type, boxed):
33    return mcgen('''
34
35%(proto)s;
36''',
37                 proto=build_event_send_proto(name, arg_type, boxed))
38
39
40# Declare and initialize an object 'qapi' using parameters from build_params()
41def gen_param_var(typ):
42    assert not typ.variants
43    ret = mcgen('''
44    %(c_name)s param = {
45''',
46                c_name=typ.c_name())
47    sep = '        '
48    for memb in typ.members:
49        ret += sep
50        sep = ', '
51        if memb.optional:
52            ret += 'has_' + c_name(memb.name) + sep
53        if memb.type.name == 'str':
54            # Cast away const added in build_params()
55            ret += '(char *)'
56        ret += c_name(memb.name)
57    ret += mcgen('''
58
59    };
60''')
61    if not typ.is_implicit():
62        ret += mcgen('''
63    %(c_name)s *arg = &param;
64''',
65                     c_name=typ.c_name())
66    return ret
67
68
69def gen_event_send(name, arg_type, boxed, event_enum_name, event_emit):
70    # FIXME: Our declaration of local variables (and of 'errp' in the
71    # parameter list) can collide with exploded members of the event's
72    # data type passed in as parameters.  If this collision ever hits in
73    # practice, we can rename our local variables with a leading _ prefix,
74    # or split the code into a wrapper function that creates a boxed
75    # 'param' object then calls another to do the real work.
76    have_args = boxed or (arg_type and not arg_type.is_empty())
77
78    ret = mcgen('''
79
80%(proto)s
81{
82    QDict *qmp;
83''',
84                proto=build_event_send_proto(name, arg_type, boxed))
85
86    if have_args:
87        ret += mcgen('''
88    QObject *obj;
89    Visitor *v;
90''')
91        if not boxed:
92            ret += gen_param_var(arg_type)
93
94    ret += mcgen('''
95
96    qmp = qmp_event_build_dict("%(name)s");
97
98''',
99                 name=name)
100
101    if have_args:
102        ret += mcgen('''
103    v = qobject_output_visitor_new(&obj);
104''')
105        if not arg_type.is_implicit():
106            ret += mcgen('''
107    visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
108''',
109                         name=name, c_name=arg_type.c_name())
110        else:
111            ret += mcgen('''
112
113    visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
114    visit_type_%(c_name)s_members(v, &param, &error_abort);
115    visit_check_struct(v, &error_abort);
116    visit_end_struct(v, NULL);
117''',
118                         name=name, c_name=arg_type.c_name())
119        ret += mcgen('''
120
121    visit_complete(v, &obj);
122    qdict_put_obj(qmp, "data", obj);
123''')
124
125    ret += mcgen('''
126    %(event_emit)s(%(c_enum)s, qmp);
127
128''',
129                 event_emit=event_emit,
130                 c_enum=c_enum_const(event_enum_name, name))
131
132    if have_args:
133        ret += mcgen('''
134    visit_free(v);
135''')
136    ret += mcgen('''
137    qobject_unref(qmp);
138}
139''')
140    return ret
141
142
143class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
144
145    def __init__(self, prefix):
146        super().__init__(
147            prefix, 'qapi-events',
148            ' * Schema-defined QAPI/QMP events', None, __doc__)
149        self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
150        self._event_enum_members = []
151        self._event_emit_name = c_name(prefix + 'qapi_event_emit')
152
153    def _begin_user_module(self, name):
154        events = self._module_basename('qapi-events', name)
155        types = self._module_basename('qapi-types', name)
156        visit = self._module_basename('qapi-visit', name)
157        self._genc.add(mcgen('''
158#include "qemu/osdep.h"
159#include "%(prefix)sqapi-emit-events.h"
160#include "%(events)s.h"
161#include "%(visit)s.h"
162#include "qapi/error.h"
163#include "qapi/qmp/qdict.h"
164#include "qapi/qobject-output-visitor.h"
165#include "qapi/qmp-event.h"
166
167''',
168                             events=events, visit=visit,
169                             prefix=self._prefix))
170        self._genh.add(mcgen('''
171#include "qapi/util.h"
172#include "%(types)s.h"
173''',
174                             types=types))
175
176    def visit_end(self):
177        self._add_system_module('emit', ' * QAPI Events emission')
178        self._genc.preamble_add(mcgen('''
179#include "qemu/osdep.h"
180#include "%(prefix)sqapi-emit-events.h"
181''',
182                                      prefix=self._prefix))
183        self._genh.preamble_add(mcgen('''
184#include "qapi/util.h"
185'''))
186        self._genh.add(gen_enum(self._event_enum_name,
187                                self._event_enum_members))
188        self._genc.add(gen_enum_lookup(self._event_enum_name,
189                                       self._event_enum_members))
190        self._genh.add(mcgen('''
191
192void %(event_emit)s(%(event_enum)s event, QDict *qdict);
193''',
194                             event_emit=self._event_emit_name,
195                             event_enum=self._event_enum_name))
196
197    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
198        with ifcontext(ifcond, self._genh, self._genc):
199            self._genh.add(gen_event_send_decl(name, arg_type, boxed))
200            self._genc.add(gen_event_send(name, arg_type, boxed,
201                                          self._event_enum_name,
202                                          self._event_emit_name))
203        # Note: we generate the enum member regardless of @ifcond, to
204        # keep the enumeration usable in target-independent code.
205        self._event_enum_members.append(QAPISchemaEnumMember(name, None))
206
207
208def gen_events(schema, output_dir, prefix):
209    vis = QAPISchemaGenEventVisitor(prefix)
210    schema.visit(vis)
211    vis.write(output_dir)
212