xref: /qemu/scripts/qapi/events.py (revision ad63c549) 
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 *
16
17
18def build_event_send_proto(name, arg_type, boxed):
19    return 'void qapi_event_send_%(c_name)s(%(param)s)' % {
20        'c_name': c_name(name.lower()),
21        'param': build_params(arg_type, boxed, 'Error **errp')}
22
23
24def gen_event_send_decl(name, arg_type, boxed):
25    return mcgen('''
26
27%(proto)s;
28''',
29                 proto=build_event_send_proto(name, arg_type, boxed))
30
31
32# Declare and initialize an object 'qapi' using parameters from build_params()
33def gen_param_var(typ):
34    assert not typ.variants
35    ret = mcgen('''
36    %(c_name)s param = {
37''',
38                c_name=typ.c_name())
39    sep = '        '
40    for memb in typ.members:
41        ret += sep
42        sep = ', '
43        if memb.optional:
44            ret += 'has_' + c_name(memb.name) + sep
45        if memb.type.name == 'str':
46            # Cast away const added in build_params()
47            ret += '(char *)'
48        ret += c_name(memb.name)
49    ret += mcgen('''
50
51    };
52''')
53    if not typ.is_implicit():
54        ret += mcgen('''
55    %(c_name)s *arg = &param;
56''',
57                     c_name=typ.c_name())
58    return ret
59
60
61def gen_event_send(name, arg_type, boxed, event_enum_name):
62    # FIXME: Our declaration of local variables (and of 'errp' in the
63    # parameter list) can collide with exploded members of the event's
64    # data type passed in as parameters.  If this collision ever hits in
65    # practice, we can rename our local variables with a leading _ prefix,
66    # or split the code into a wrapper function that creates a boxed
67    # 'param' object then calls another to do the real work.
68    ret = mcgen('''
69
70%(proto)s
71{
72    QDict *qmp;
73    Error *err = NULL;
74    QMPEventFuncEmit emit;
75''',
76                proto=build_event_send_proto(name, arg_type, boxed))
77
78    if arg_type and not arg_type.is_empty():
79        ret += mcgen('''
80    QObject *obj;
81    Visitor *v;
82''')
83        if not boxed:
84            ret += gen_param_var(arg_type)
85    else:
86        assert not boxed
87
88    ret += mcgen('''
89
90    emit = qmp_event_get_func_emit();
91    if (!emit) {
92        return;
93    }
94
95    qmp = qmp_event_build_dict("%(name)s");
96
97''',
98                 name=name)
99
100    if arg_type and not arg_type.is_empty():
101        ret += mcgen('''
102    v = qobject_output_visitor_new(&obj);
103''')
104        if not arg_type.is_implicit():
105            ret += mcgen('''
106    visit_type_%(c_name)s(v, "%(name)s", &arg, &err);
107''',
108                         name=name, c_name=arg_type.c_name())
109        else:
110            ret += mcgen('''
111
112    visit_start_struct(v, "%(name)s", NULL, 0, &err);
113    if (err) {
114        goto out;
115    }
116    visit_type_%(c_name)s_members(v, &param, &err);
117    if (!err) {
118        visit_check_struct(v, &err);
119    }
120    visit_end_struct(v, NULL);
121''',
122                         name=name, c_name=arg_type.c_name())
123        ret += mcgen('''
124    if (err) {
125        goto out;
126    }
127
128    visit_complete(v, &obj);
129    qdict_put_obj(qmp, "data", obj);
130''')
131
132    ret += mcgen('''
133    emit(%(c_enum)s, qmp, &err);
134
135''',
136                 c_enum=c_enum_const(event_enum_name, name))
137
138    if arg_type and not arg_type.is_empty():
139        ret += mcgen('''
140out:
141    visit_free(v);
142''')
143    ret += mcgen('''
144    error_propagate(errp, err);
145    qobject_unref(qmp);
146}
147''')
148    return ret
149
150
151class QAPISchemaGenEventVisitor(QAPISchemaModularCVisitor):
152
153    def __init__(self, prefix):
154        QAPISchemaModularCVisitor.__init__(
155            self, prefix, 'qapi-events',
156            ' * Schema-defined QAPI/QMP events', __doc__)
157        self._enum_name = c_name(prefix + 'QAPIEvent', protect=False)
158        self._event_names = []
159
160    def _begin_module(self, name):
161        types = self._module_basename('qapi-types', name)
162        visit = self._module_basename('qapi-visit', name)
163        self._genc.add(mcgen('''
164#include "qemu/osdep.h"
165#include "qemu-common.h"
166#include "%(prefix)sqapi-events.h"
167#include "%(visit)s.h"
168#include "qapi/error.h"
169#include "qapi/qmp/qdict.h"
170#include "qapi/qobject-output-visitor.h"
171#include "qapi/qmp-event.h"
172
173''',
174                             visit=visit, prefix=self._prefix))
175        self._genh.add(mcgen('''
176#include "qapi/util.h"
177#include "%(types)s.h"
178
179''',
180                             types=types))
181
182    def visit_end(self):
183        (genc, genh) = self._module[self._main_module]
184        genh.add(gen_enum(self._enum_name, self._event_names))
185        genc.add(gen_enum_lookup(self._enum_name, self._event_names))
186
187    def visit_event(self, name, info, ifcond, arg_type, boxed):
188        with ifcontext(ifcond, self._genh, self._genc):
189            self._genh.add(gen_event_send_decl(name, arg_type, boxed))
190            self._genc.add(gen_event_send(name, arg_type, boxed,
191                                          self._enum_name))
192        self._event_names.append(name)
193
194
195def gen_events(schema, output_dir, prefix):
196    vis = QAPISchemaGenEventVisitor(prefix)
197    schema.visit(vis)
198    vis.write(output_dir)
199