xref: /openbmc/qemu/scripts/qapi/events.py (revision d1b21b393e7ae1a387a7c81f633d924a66d29408)
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
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    QAPISchemaObjectType,
24)
25from .source import QAPISourceInfo
26from .types import gen_enum, gen_enum_lookup
27
28
29def build_event_send_proto(name: str,
30                           arg_type: QAPISchemaObjectType,
31                           boxed: bool) -> str:
32    return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
33        'c_name': c_name(name.lower()),
34        'param': build_params(arg_type, boxed)}
35
36
37def gen_event_send_decl(name: str,
38                        arg_type: QAPISchemaObjectType,
39                        boxed: bool) -> str:
40    return mcgen('''
41
42%(proto)s;
43''',
44                 proto=build_event_send_proto(name, arg_type, boxed))
45
46
47# Declare and initialize an object 'qapi' using parameters from build_params()
48def gen_param_var(typ: QAPISchemaObjectType) -> str:
49    assert not typ.variants
50    ret = mcgen('''
51    %(c_name)s param = {
52''',
53                c_name=typ.c_name())
54    sep = '        '
55    for memb in typ.members:
56        ret += sep
57        sep = ', '
58        if memb.optional:
59            ret += 'has_' + c_name(memb.name) + sep
60        if memb.type.name == 'str':
61            # Cast away const added in build_params()
62            ret += '(char *)'
63        ret += c_name(memb.name)
64    ret += mcgen('''
65
66    };
67''')
68    if not typ.is_implicit():
69        ret += mcgen('''
70    %(c_name)s *arg = &param;
71''',
72                     c_name=typ.c_name())
73    return ret
74
75
76def gen_event_send(name: str,
77                   arg_type: QAPISchemaObjectType,
78                   boxed: bool,
79                   event_enum_name: str,
80                   event_emit: str) -> str:
81    # FIXME: Our declaration of local variables (and of 'errp' in the
82    # parameter list) can collide with exploded members of the event's
83    # data type passed in as parameters.  If this collision ever hits in
84    # practice, we can rename our local variables with a leading _ prefix,
85    # or split the code into a wrapper function that creates a boxed
86    # 'param' object then calls another to do the real work.
87    have_args = boxed or (arg_type and not arg_type.is_empty())
88
89    ret = mcgen('''
90
91%(proto)s
92{
93    QDict *qmp;
94''',
95                proto=build_event_send_proto(name, arg_type, boxed))
96
97    if have_args:
98        ret += mcgen('''
99    QObject *obj;
100    Visitor *v;
101''')
102        if not boxed:
103            ret += gen_param_var(arg_type)
104
105    ret += mcgen('''
106
107    qmp = qmp_event_build_dict("%(name)s");
108
109''',
110                 name=name)
111
112    if have_args:
113        ret += mcgen('''
114    v = qobject_output_visitor_new(&obj);
115''')
116        if not arg_type.is_implicit():
117            ret += mcgen('''
118    visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
119''',
120                         name=name, c_name=arg_type.c_name())
121        else:
122            ret += mcgen('''
123
124    visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
125    visit_type_%(c_name)s_members(v, &param, &error_abort);
126    visit_check_struct(v, &error_abort);
127    visit_end_struct(v, NULL);
128''',
129                         name=name, c_name=arg_type.c_name())
130        ret += mcgen('''
131
132    visit_complete(v, &obj);
133    qdict_put_obj(qmp, "data", obj);
134''')
135
136    ret += mcgen('''
137    %(event_emit)s(%(c_enum)s, qmp);
138
139''',
140                 event_emit=event_emit,
141                 c_enum=c_enum_const(event_enum_name, name))
142
143    if have_args:
144        ret += mcgen('''
145    visit_free(v);
146''')
147    ret += mcgen('''
148    qobject_unref(qmp);
149}
150''')
151    return ret
152
153
154class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
155
156    def __init__(self, prefix: str):
157        super().__init__(
158            prefix, 'qapi-events',
159            ' * Schema-defined QAPI/QMP events', None, __doc__)
160        self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
161        self._event_enum_members: List[QAPISchemaEnumMember] = []
162        self._event_emit_name = c_name(prefix + 'qapi_event_emit')
163
164    def _begin_user_module(self, name: str) -> None:
165        events = self._module_basename('qapi-events', name)
166        types = self._module_basename('qapi-types', name)
167        visit = self._module_basename('qapi-visit', name)
168        self._genc.add(mcgen('''
169#include "qemu/osdep.h"
170#include "%(prefix)sqapi-emit-events.h"
171#include "%(events)s.h"
172#include "%(visit)s.h"
173#include "qapi/error.h"
174#include "qapi/qmp/qdict.h"
175#include "qapi/qobject-output-visitor.h"
176#include "qapi/qmp-event.h"
177
178''',
179                             events=events, visit=visit,
180                             prefix=self._prefix))
181        self._genh.add(mcgen('''
182#include "qapi/util.h"
183#include "%(types)s.h"
184''',
185                             types=types))
186
187    def visit_end(self) -> None:
188        self._add_system_module('emit', ' * QAPI Events emission')
189        self._genc.preamble_add(mcgen('''
190#include "qemu/osdep.h"
191#include "%(prefix)sqapi-emit-events.h"
192''',
193                                      prefix=self._prefix))
194        self._genh.preamble_add(mcgen('''
195#include "qapi/util.h"
196'''))
197        self._genh.add(gen_enum(self._event_enum_name,
198                                self._event_enum_members))
199        self._genc.add(gen_enum_lookup(self._event_enum_name,
200                                       self._event_enum_members))
201        self._genh.add(mcgen('''
202
203void %(event_emit)s(%(event_enum)s event, QDict *qdict);
204''',
205                             event_emit=self._event_emit_name,
206                             event_enum=self._event_enum_name))
207
208    def visit_event(self,
209                    name: str,
210                    info: QAPISourceInfo,
211                    ifcond: List[str],
212                    features: List[QAPISchemaFeature],
213                    arg_type: QAPISchemaObjectType,
214                    boxed: bool) -> None:
215        with ifcontext(ifcond, self._genh, self._genc):
216            self._genh.add(gen_event_send_decl(name, arg_type, boxed))
217            self._genc.add(gen_event_send(name, arg_type, boxed,
218                                          self._event_enum_name,
219                                          self._event_emit_name))
220        # Note: we generate the enum member regardless of @ifcond, to
221        # keep the enumeration usable in target-independent code.
222        self._event_enum_members.append(QAPISchemaEnumMember(name, None))
223
224
225def gen_events(schema: QAPISchema,
226               output_dir: str,
227               prefix: str) -> None:
228    vis = QAPISchemaGenEventVisitor(prefix)
229    schema.visit(vis)
230    vis.write(output_dir)
231