xref: /qemu/scripts/qapi/events.py (revision 016a335bd8ca624f43adbb08fa1698c29ec52a1a) 
1#
2# QAPI event generator
3#
4# Copyright (c) 2014 Wenchao Xia
5#
6# Authors:
7#  Wenchao Xia <wenchaoqemu@gmail.com>
8#
9# This work is licensed under the terms of the GNU GPL, version 2.
10# See the COPYING file in the top-level directory.
11
12from ordereddict import OrderedDict
13from qapi import *
14
15def _generate_event_api_name(event_name, params):
16    api_name = "void qapi_event_send_%s(" % c_name(event_name).lower();
17    l = len(api_name)
18
19    if params:
20        for argname, argentry, optional in parse_args(params):
21            if optional:
22                api_name += "bool has_%s,\n" % c_name(argname)
23                api_name += "".ljust(l)
24
25            api_name += "%s %s,\n" % (c_type(argentry, is_param=True),
26                                      c_name(argname))
27            api_name += "".ljust(l)
28
29    api_name += "Error **errp)"
30    return api_name;
31
32
33# Following are the core functions that generate C APIs to emit event.
34
35def generate_event_declaration(api_name):
36    return mcgen('''
37
38%(api_name)s;
39''',
40                 api_name = api_name)
41
42def generate_event_implement(api_name, event_name, params):
43    # step 1: declare any variables
44    ret = mcgen("""
45
46%(api_name)s
47{
48    QDict *qmp;
49    Error *local_err = NULL;
50    QMPEventFuncEmit emit;
51""",
52                api_name = api_name)
53
54    if params:
55        ret += mcgen("""
56    QmpOutputVisitor *qov;
57    Visitor *v;
58    QObject *obj;
59
60""")
61
62    # step 2: check emit function, create a dict
63    ret += mcgen("""
64    emit = qmp_event_get_func_emit();
65    if (!emit) {
66        return;
67    }
68
69    qmp = qmp_event_build_dict("%(event_name)s");
70
71""",
72                 event_name = event_name)
73
74    # step 3: visit the params if params != None
75    if params:
76        ret += mcgen("""
77    qov = qmp_output_visitor_new();
78    g_assert(qov);
79
80    v = qmp_output_get_visitor(qov);
81    g_assert(v);
82
83    /* Fake visit, as if all members are under a structure */
84    visit_start_struct(v, NULL, "", "%(event_name)s", 0, &local_err);
85    if (local_err) {
86        goto clean;
87    }
88
89""",
90                event_name = event_name)
91
92        for argname, argentry, optional in parse_args(params):
93            if optional:
94                ret += mcgen("""
95    if (has_%(var)s) {
96""",
97                             var = c_name(argname))
98                push_indent()
99
100            if argentry == "str":
101                var_type = "(char **)"
102            else:
103                var_type = ""
104
105            ret += mcgen("""
106    visit_type_%(type)s(v, %(var_type)s&%(var)s, "%(name)s", &local_err);
107    if (local_err) {
108        goto clean;
109    }
110""",
111                         var_type = var_type,
112                         var = c_name(argname),
113                         type = type_name(argentry),
114                         name = argname)
115
116            if optional:
117                pop_indent()
118                ret += mcgen("""
119    }
120""")
121
122        ret += mcgen("""
123
124    visit_end_struct(v, &local_err);
125    if (local_err) {
126        goto clean;
127    }
128
129    obj = qmp_output_get_qobject(qov);
130    g_assert(obj != NULL);
131
132    qdict_put_obj(qmp, "data", obj);
133""")
134
135    # step 4: call qmp event api
136    ret += mcgen("""
137    emit(%(event_enum_value)s, qmp, &local_err);
138
139""",
140                 event_enum_value = event_enum_value)
141
142    # step 5: clean up
143    if params:
144        ret += mcgen("""
145 clean:
146    qmp_output_visitor_cleanup(qov);
147""")
148    ret += mcgen("""
149    error_propagate(errp, local_err);
150    QDECREF(qmp);
151}
152""")
153
154    return ret
155
156
157# Following are the functions that generate an enum type for all defined
158# events, similar to qapi-types.py. Here we already have enum name and
159# values which were generated before and recorded in event_enum_*. It also
160# works around the issue that "import qapi-types" can't work.
161
162def generate_event_enum_decl(event_enum_name, event_enum_values):
163    lookup_decl = mcgen('''
164
165extern const char *%(event_enum_name)s_lookup[];
166''',
167                        event_enum_name = event_enum_name)
168
169    enum_decl = mcgen('''
170typedef enum %(event_enum_name)s
171{
172''',
173                      event_enum_name = event_enum_name)
174
175    # append automatically generated _MAX value
176    enum_max_value = c_enum_const(event_enum_name, "MAX")
177    enum_values = event_enum_values + [ enum_max_value ]
178
179    i = 0
180    for value in enum_values:
181        enum_decl += mcgen('''
182    %(value)s = %(i)d,
183''',
184                     value = value,
185                     i = i)
186        i += 1
187
188    enum_decl += mcgen('''
189} %(event_enum_name)s;
190''',
191                       event_enum_name = event_enum_name)
192
193    return lookup_decl + enum_decl
194
195def generate_event_enum_lookup(event_enum_name, event_enum_strings):
196    ret = mcgen('''
197
198const char *%(event_enum_name)s_lookup[] = {
199''',
200                event_enum_name = event_enum_name)
201
202    i = 0
203    for string in event_enum_strings:
204        ret += mcgen('''
205    "%(string)s",
206''',
207                     string = string)
208
209    ret += mcgen('''
210    NULL,
211};
212''')
213    return ret
214
215(input_file, output_dir, do_c, do_h, prefix, dummy) = parse_command_line()
216
217c_comment = '''
218/*
219 * schema-defined QAPI event functions
220 *
221 * Copyright (c) 2014 Wenchao Xia
222 *
223 * Authors:
224 *  Wenchao Xia   <wenchaoqemu@gmail.com>
225 *
226 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
227 * See the COPYING.LIB file in the top-level directory.
228 *
229 */
230'''
231h_comment = '''
232/*
233 * schema-defined QAPI event functions
234 *
235 * Copyright (c) 2014 Wenchao Xia
236 *
237 * Authors:
238 *  Wenchao Xia  <wenchaoqemu@gmail.com>
239 *
240 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
241 * See the COPYING.LIB file in the top-level directory.
242 *
243 */
244'''
245
246(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
247                            'qapi-event.c', 'qapi-event.h',
248                            c_comment, h_comment)
249
250fdef.write(mcgen('''
251#include "qemu-common.h"
252#include "%(prefix)sqapi-event.h"
253#include "%(prefix)sqapi-visit.h"
254#include "qapi/qmp-output-visitor.h"
255#include "qapi/qmp-event.h"
256
257''',
258                 prefix=prefix))
259
260fdecl.write(mcgen('''
261#include "qapi/error.h"
262#include "qapi/qmp/qdict.h"
263#include "%(prefix)sqapi-types.h"
264
265''',
266                  prefix=prefix))
267
268exprs = parse_schema(input_file)
269
270event_enum_name = c_name(prefix + "QAPIEvent", protect=False)
271event_enum_values = []
272event_enum_strings = []
273
274for expr in exprs:
275    if expr.has_key('event'):
276        event_name = expr['event']
277        params = expr.get('data')
278        if params and len(params) == 0:
279            params = None
280
281        api_name = _generate_event_api_name(event_name, params)
282        ret = generate_event_declaration(api_name)
283        fdecl.write(ret)
284
285        # We need an enum value per event
286        event_enum_value = c_enum_const(event_enum_name, event_name)
287        ret = generate_event_implement(api_name, event_name, params)
288        fdef.write(ret)
289
290        # Record it, and generate enum later
291        event_enum_values.append(event_enum_value)
292        event_enum_strings.append(event_name)
293
294ret = generate_event_enum_decl(event_enum_name, event_enum_values)
295fdecl.write(ret)
296ret = generate_event_enum_lookup(event_enum_name, event_enum_strings)
297fdef.write(ret)
298
299close_output(fdef, fdecl)
300