xref: /qemu/scripts/qapi/events.py (revision abff1abf) 
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 qapi.common import *
16from qapi.gen import QAPISchemaModularCVisitor, ifcontext
17from qapi.schema import QAPISchemaEnumMember
18from qapi.types import gen_enum, gen_enum_lookup
19
20
21def build_event_send_proto(name, arg_type, boxed):
22    return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
23        'c_name': c_name(name.lower()),
24        'param': build_params(arg_type, boxed)}
25
26
27def gen_event_send_decl(name, arg_type, boxed):
28    return mcgen('''
29
30%(proto)s;
31''',
32                 proto=build_event_send_proto(name, arg_type, boxed))
33
34
35# Declare and initialize an object 'qapi' using parameters from build_params()
36def gen_param_var(typ):
37    assert not typ.variants
38    ret = mcgen('''
39    %(c_name)s param = {
40''',
41                c_name=typ.c_name())
42    sep = '        '
43    for memb in typ.members:
44        ret += sep
45        sep = ', '
46        if memb.optional:
47            ret += 'has_' + c_name(memb.name) + sep
48        if memb.type.name == 'str':
49            # Cast away const added in build_params()
50            ret += '(char *)'
51        ret += c_name(memb.name)
52    ret += mcgen('''
53
54    };
55''')
56    if not typ.is_implicit():
57        ret += mcgen('''
58    %(c_name)s *arg = &param;
59''',
60                     c_name=typ.c_name())
61    return ret
62
63
64def gen_event_send(name, arg_type, boxed, event_enum_name, event_emit):
65    # FIXME: Our declaration of local variables (and of 'errp' in the
66    # parameter list) can collide with exploded members of the event's
67    # data type passed in as parameters.  If this collision ever hits in
68    # practice, we can rename our local variables with a leading _ prefix,
69    # or split the code into a wrapper function that creates a boxed
70    # 'param' object then calls another to do the real work.
71    have_args = boxed or (arg_type and not arg_type.is_empty())
72
73    ret = mcgen('''
74
75%(proto)s
76{
77    QDict *qmp;
78''',
79                proto=build_event_send_proto(name, arg_type, boxed))
80
81    if have_args:
82        ret += mcgen('''
83    QObject *obj;
84    Visitor *v;
85''')
86        if not boxed:
87            ret += gen_param_var(arg_type)
88
89    ret += mcgen('''
90
91    qmp = qmp_event_build_dict("%(name)s");
92
93''',
94                 name=name)
95
96    if have_args:
97        ret += mcgen('''
98    v = qobject_output_visitor_new(&obj);
99''')
100        if not arg_type.is_implicit():
101            ret += mcgen('''
102    visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
103''',
104                         name=name, c_name=arg_type.c_name())
105        else:
106            ret += mcgen('''
107
108    visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
109    visit_type_%(c_name)s_members(v, &param, &error_abort);
110    visit_check_struct(v, &error_abort);
111    visit_end_struct(v, NULL);
112''',
113                         name=name, c_name=arg_type.c_name())
114        ret += mcgen('''
115
116    visit_complete(v, &obj);
117    qdict_put_obj(qmp, "data", obj);
118''')
119
120    ret += mcgen('''
121    %(event_emit)s(%(c_enum)s, qmp);
122
123''',
124                 event_emit=event_emit,
125                 c_enum=c_enum_const(event_enum_name, name))
126
127    if have_args:
128        ret += mcgen('''
129    visit_free(v);
130''')
131    ret += mcgen('''
132    qobject_unref(qmp);
133}
134''')
135    return ret
136
137
138class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
139
140    def __init__(self, prefix):
141        super().__init__(
142            prefix, 'qapi-events',
143            ' * Schema-defined QAPI/QMP events', None, __doc__)
144        self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
145        self._event_enum_members = []
146        self._event_emit_name = c_name(prefix + 'qapi_event_emit')
147
148    def _begin_user_module(self, name):
149        events = self._module_basename('qapi-events', name)
150        types = self._module_basename('qapi-types', name)
151        visit = self._module_basename('qapi-visit', name)
152        self._genc.add(mcgen('''
153#include "qemu/osdep.h"
154#include "%(prefix)sqapi-emit-events.h"
155#include "%(events)s.h"
156#include "%(visit)s.h"
157#include "qapi/error.h"
158#include "qapi/qmp/qdict.h"
159#include "qapi/qobject-output-visitor.h"
160#include "qapi/qmp-event.h"
161
162''',
163                             events=events, visit=visit,
164                             prefix=self._prefix))
165        self._genh.add(mcgen('''
166#include "qapi/util.h"
167#include "%(types)s.h"
168''',
169                             types=types))
170
171    def visit_end(self):
172        self._add_system_module('emit', ' * QAPI Events emission')
173        self._genc.preamble_add(mcgen('''
174#include "qemu/osdep.h"
175#include "%(prefix)sqapi-emit-events.h"
176''',
177                                      prefix=self._prefix))
178        self._genh.preamble_add(mcgen('''
179#include "qapi/util.h"
180'''))
181        self._genh.add(gen_enum(self._event_enum_name,
182                                self._event_enum_members))
183        self._genc.add(gen_enum_lookup(self._event_enum_name,
184                                       self._event_enum_members))
185        self._genh.add(mcgen('''
186
187void %(event_emit)s(%(event_enum)s event, QDict *qdict);
188''',
189                             event_emit=self._event_emit_name,
190                             event_enum=self._event_enum_name))
191
192    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
193        with ifcontext(ifcond, self._genh, self._genc):
194            self._genh.add(gen_event_send_decl(name, arg_type, boxed))
195            self._genc.add(gen_event_send(name, arg_type, boxed,
196                                          self._event_enum_name,
197                                          self._event_emit_name))
198        # Note: we generate the enum member regardless of @ifcond, to
199        # keep the enumeration usable in target-independent code.
200        self._event_enum_members.append(QAPISchemaEnumMember(name, None))
201
202
203def gen_events(schema, output_dir, prefix):
204    vis = QAPISchemaGenEventVisitor(prefix)
205    schema.visit(vis)
206    vis.write(output_dir)
207