xref: /qemu/scripts/qapi/events.py (revision 61bfb2e1a4666817b9d94f0a96109f8ef51b812b)
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.types import gen_enum, gen_enum_lookup
17
18
19def build_event_send_proto(name, arg_type, boxed):
20    return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
21        'c_name': c_name(name.lower()),
22        'param': build_params(arg_type, boxed)}
23
24
25def gen_event_send_decl(name, arg_type, boxed):
26    return mcgen('''
27
28%(proto)s;
29''',
30                 proto=build_event_send_proto(name, arg_type, boxed))
31
32
33# Declare and initialize an object 'qapi' using parameters from build_params()
34def gen_param_var(typ):
35    assert not typ.variants
36    ret = mcgen('''
37    %(c_name)s param = {
38''',
39                c_name=typ.c_name())
40    sep = '        '
41    for memb in typ.members:
42        ret += sep
43        sep = ', '
44        if memb.optional:
45            ret += 'has_' + c_name(memb.name) + sep
46        if memb.type.name == 'str':
47            # Cast away const added in build_params()
48            ret += '(char *)'
49        ret += c_name(memb.name)
50    ret += mcgen('''
51
52    };
53''')
54    if not typ.is_implicit():
55        ret += mcgen('''
56    %(c_name)s *arg = &param;
57''',
58                     c_name=typ.c_name())
59    return ret
60
61
62def gen_event_send(name, arg_type, boxed, event_enum_name, event_emit):
63    # FIXME: Our declaration of local variables (and of 'errp' in the
64    # parameter list) can collide with exploded members of the event's
65    # data type passed in as parameters.  If this collision ever hits in
66    # practice, we can rename our local variables with a leading _ prefix,
67    # or split the code into a wrapper function that creates a boxed
68    # 'param' object then calls another to do the real work.
69    have_args = boxed or (arg_type and not arg_type.is_empty())
70
71    ret = mcgen('''
72
73%(proto)s
74{
75    QDict *qmp;
76''',
77                proto=build_event_send_proto(name, arg_type, boxed))
78
79    if have_args:
80        ret += mcgen('''
81    QObject *obj;
82    Visitor *v;
83''')
84        if not boxed:
85            ret += gen_param_var(arg_type)
86
87    ret += mcgen('''
88
89    qmp = qmp_event_build_dict("%(name)s");
90
91''',
92                 name=name)
93
94    if have_args:
95        ret += mcgen('''
96    v = qobject_output_visitor_new(&obj);
97''')
98        if not arg_type.is_implicit():
99            ret += mcgen('''
100    visit_type_%(c_name)s(v, "%(name)s", &arg, &error_abort);
101''',
102                         name=name, c_name=arg_type.c_name())
103        else:
104            ret += mcgen('''
105
106    visit_start_struct(v, "%(name)s", NULL, 0, &error_abort);
107    visit_type_%(c_name)s_members(v, &param, &error_abort);
108    visit_check_struct(v, &error_abort);
109    visit_end_struct(v, NULL);
110''',
111                         name=name, c_name=arg_type.c_name())
112        ret += mcgen('''
113
114    visit_complete(v, &obj);
115    qdict_put_obj(qmp, "data", obj);
116''')
117
118    ret += mcgen('''
119    %(event_emit)s(%(c_enum)s, qmp);
120
121''',
122                 event_emit=event_emit,
123                 c_enum=c_enum_const(event_enum_name, name))
124
125    if have_args:
126        ret += mcgen('''
127    visit_free(v);
128''')
129    ret += mcgen('''
130    qobject_unref(qmp);
131}
132''')
133    return ret
134
135
136class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
137
138    def __init__(self, prefix):
139        QAPISchemaModularCVisitor.__init__(
140            self, prefix, 'qapi-events',
141            ' * Schema-defined QAPI/QMP events', __doc__)
142        self._event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
143        self._event_enum_members = []
144        self._event_emit_name = c_name(prefix + 'qapi_event_emit')
145
146    def _begin_user_module(self, name):
147        events = self._module_basename('qapi-events', name)
148        types = self._module_basename('qapi-types', name)
149        visit = self._module_basename('qapi-visit', name)
150        self._genc.add(mcgen('''
151#include "qemu/osdep.h"
152#include "%(prefix)sqapi-emit-events.h"
153#include "%(events)s.h"
154#include "%(visit)s.h"
155#include "qapi/error.h"
156#include "qapi/qmp/qdict.h"
157#include "qapi/qobject-output-visitor.h"
158#include "qapi/qmp-event.h"
159
160''',
161                             events=events, visit=visit,
162                             prefix=self._prefix))
163        self._genh.add(mcgen('''
164#include "qapi/util.h"
165#include "%(types)s.h"
166''',
167                             types=types))
168
169    def visit_end(self):
170        self._add_system_module('emit', ' * QAPI Events emission')
171        self._genc.preamble_add(mcgen('''
172#include "qemu/osdep.h"
173#include "%(prefix)sqapi-emit-events.h"
174''',
175                                      prefix=self._prefix))
176        self._genh.preamble_add(mcgen('''
177#include "qapi/util.h"
178'''))
179        self._genh.add(gen_enum(self._event_enum_name,
180                                self._event_enum_members))
181        self._genc.add(gen_enum_lookup(self._event_enum_name,
182                                       self._event_enum_members))
183        self._genh.add(mcgen('''
184
185void %(event_emit)s(%(event_enum)s event, QDict *qdict);
186''',
187                             event_emit=self._event_emit_name,
188                             event_enum=self._event_enum_name))
189
190    def visit_event(self, name, info, ifcond, arg_type, boxed):
191        with ifcontext(ifcond, self._genh, self._genc):
192            self._genh.add(gen_event_send_decl(name, arg_type, boxed))
193            self._genc.add(gen_event_send(name, arg_type, boxed,
194                                          self._event_enum_name,
195                                          self._event_emit_name))
196        # Note: we generate the enum member regardless of @ifcond, to
197        # keep the enumeration usable in target-independent code.
198        self._event_enum_members.append(QAPISchemaEnumMember(name, None))
199
200
201def gen_events(schema, output_dir, prefix):
202    vis = QAPISchemaGenEventVisitor(prefix)
203    schema.visit(vis)
204    vis.write(output_dir)
205