xref: /openbmc/qemu/scripts/qapi/events.py (revision 30b6852c) 
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 typing import List, Optional
16
17from .common import c_enum_const, c_name, mcgen
18from .gen import QAPISchemaModularCVisitor, build_params, ifcontext
19from .schema import (
20    QAPISchema,
21    QAPISchemaEnumMember,
22    QAPISchemaFeature,
23    QAPISchemaIfCond,
24    QAPISchemaObjectType,
25)
26from .source import QAPISourceInfo
27from .types import gen_enum, gen_enum_lookup
28
29
30def build_event_send_proto(name: str,
31                           arg_type: Optional[QAPISchemaObjectType],
32                           boxed: bool) -> str:
33    return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
34        'c_name': c_name(name.lower()),
35        'param': build_params(arg_type, boxed)}
36
37
38def gen_event_send_decl(name: str,
39                        arg_type: Optional[QAPISchemaObjectType],
40                        boxed: bool) -> str:
41    return mcgen('''
42
43%(proto)s;
44''',
45                 proto=build_event_send_proto(name, arg_type, boxed))
46
47
48def gen_param_var(typ: QAPISchemaObjectType) -> str:
49    """
50    Generate a struct variable holding the event parameters.
51
52    Initialize it with the function arguments defined in `gen_event_send`.
53    """
54    assert not typ.variants
55    ret = mcgen('''
56    %(c_name)s param = {
57''',
58                c_name=typ.c_name())
59    sep = '        '
60    for memb in typ.members:
61        ret += sep
62        sep = ', '
63        if memb.optional:
64            ret += 'has_' + c_name(memb.name) + sep
65        if memb.type.name == 'str':
66            # Cast away const added in build_params()
67            ret += '(char *)'
68        ret += c_name(memb.name)
69    ret += mcgen('''
70
71    };
72''')
73    if not typ.is_implicit():
74        ret += mcgen('''
75    %(c_name)s *arg = &param;
76''',
77                     c_name=typ.c_name())
78    return ret
79
80
81def gen_event_send(name: str,
82                   arg_type: Optional[QAPISchemaObjectType],
83                   features: List[QAPISchemaFeature],
84                   boxed: bool,
85                   event_enum_name: str,
86                   event_emit: str) -> str:
87    # FIXME: Our declaration of local variables (and of 'errp' in the
88    # parameter list) can collide with exploded members of the event's
89    # data type passed in as parameters.  If this collision ever hits in
90    # practice, we can rename our local variables with a leading _ prefix,
91    # or split the code into a wrapper function that creates a boxed
92    # 'param' object then calls another to do the real work.
93    have_args = boxed or (arg_type and not arg_type.is_empty())
94
95    ret = mcgen('''
96
97%(proto)s
98{
99    QDict *qmp;
100''',
101                proto=build_event_send_proto(name, arg_type, boxed))
102
103    if have_args:
104        assert arg_type is not None
105        ret += mcgen('''
106    QObject *obj;
107    Visitor *v;
108''')
109        if not boxed:
110            ret += gen_param_var(arg_type)
111
112    if 'deprecated' in [f.name for f in features]:
113        ret += mcgen('''
114
115    if (compat_policy.deprecated_output == COMPAT_POLICY_OUTPUT_HIDE) {
116        return;
117    }
118''')
119
120    ret += mcgen('''
121
122    qmp = qmp_event_build_dict("%(name)s");
123
124''',
125                 name=name)
126
127    if have_args:
128        assert arg_type is not None
129        ret += mcgen('''
130    v = qobject_output_visitor_new_qmp(&obj);
131''')
132        if not arg_type.is_implicit():
133            ret += mcgen('''
134    visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
135''',
136                         name=name, c_name=arg_type.c_name())
137        else:
138            ret += mcgen('''
139
140    visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
141    visit_type_%(c_name)s_members(v, &param, &error_abort);
142    visit_check_struct(v, &error_abort);
143    visit_end_struct(v, NULL);
144''',
145                         name=name, c_name=arg_type.c_name())
146        ret += mcgen('''
147
148    visit_complete(v, &obj);
149    if (qdict_size(qobject_to(QDict, obj))) {
150        qdict_put_obj(qmp, "data", obj);
151    } else {
152        qobject_unref(obj);
153    }
154''')
155
156    ret += mcgen('''
157    %(event_emit)s(%(c_enum)s, qmp);
158
159''',
160                 event_emit=event_emit,
161                 c_enum=c_enum_const(event_enum_name, name))
162
163    if have_args:
164        ret += mcgen('''
165    visit_free(v);
166''')
167    ret += mcgen('''
168    qobject_unref(qmp);
169}
170''')
171    return ret
172
173
174class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
175
176    def __init__(self, prefix: str):
177        super().__init__(
178            prefix, 'qapi-events',
179            ' * Schema-defined QAPI/QMP events', None, __doc__)
180        self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
181        self._event_enum_members: List[QAPISchemaEnumMember] = []
182        self._event_emit_name = c_name(prefix + 'qapi_event_emit')
183
184    def _begin_user_module(self, name: str) -> None:
185        events = self._module_basename('qapi-events', name)
186        types = self._module_basename('qapi-types', name)
187        visit = self._module_basename('qapi-visit', name)
188        self._genc.add(mcgen('''
189#include "qemu/osdep.h"
190#include "%(prefix)sqapi-emit-events.h"
191#include "%(events)s.h"
192#include "%(visit)s.h"
193#include "qapi/compat-policy.h"
194#include "qapi/error.h"
195#include "qapi/qmp/qdict.h"
196#include "qapi/qmp-event.h"
197
198''',
199                             events=events, visit=visit,
200                             prefix=self._prefix))
201        self._genh.add(mcgen('''
202#include "qapi/util.h"
203#include "%(types)s.h"
204''',
205                             types=types))
206
207    def visit_end(self) -> None:
208        self._add_module('./emit', ' * QAPI Events emission')
209        self._genc.preamble_add(mcgen('''
210#include "qemu/osdep.h"
211#include "%(prefix)sqapi-emit-events.h"
212''',
213                                      prefix=self._prefix))
214        self._genh.preamble_add(mcgen('''
215#include "qapi/util.h"
216'''))
217        self._genh.add(gen_enum(self._event_enum_name,
218                                self._event_enum_members))
219        self._genc.add(gen_enum_lookup(self._event_enum_name,
220                                       self._event_enum_members))
221        self._genh.add(mcgen('''
222
223void %(event_emit)s(%(event_enum)s event, QDict *qdict);
224''',
225                             event_emit=self._event_emit_name,
226                             event_enum=self._event_enum_name))
227
228    def visit_event(self,
229                    name: str,
230                    info: Optional[QAPISourceInfo],
231                    ifcond: QAPISchemaIfCond,
232                    features: List[QAPISchemaFeature],
233                    arg_type: Optional[QAPISchemaObjectType],
234                    boxed: bool) -> None:
235        with ifcontext(ifcond, self._genh, self._genc):
236            self._genh.add(gen_event_send_decl(name, arg_type, boxed))
237            self._genc.add(gen_event_send(name, arg_type, features, boxed,
238                                          self._event_enum_name,
239                                          self._event_emit_name))
240        # Note: we generate the enum member regardless of @ifcond, to
241        # keep the enumeration usable in target-independent code.
242        self._event_enum_members.append(QAPISchemaEnumMember(name, None))
243
244
245def gen_events(schema: QAPISchema,
246               output_dir: str,
247               prefix: str) -> None:
248    vis = QAPISchemaGenEventVisitor(prefix)
249    schema.visit(vis)
250    vis.write(output_dir)
251