xref: /qemu/qapi/qobject-input-visitor.c (revision 922d42bb) 
1 /*
2  * Input Visitor
3  *
4  * Copyright (C) 2012-2017 Red Hat, Inc.
5  * Copyright IBM, Corp. 2011
6  *
7  * Authors:
8  *  Anthony Liguori   <aliguori@us.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
11  * See the COPYING.LIB file in the top-level directory.
12  *
13  */
14 
15 #include "qemu/osdep.h"
16 #include <math.h>
17 #include "qapi/error.h"
18 #include "qapi/qobject-input-visitor.h"
19 #include "qapi/visitor-impl.h"
20 #include "qemu/queue.h"
21 #include "qapi/qmp/qjson.h"
22 #include "qapi/qmp/qbool.h"
23 #include "qapi/qmp/qdict.h"
24 #include "qapi/qmp/qerror.h"
25 #include "qapi/qmp/qlist.h"
26 #include "qapi/qmp/qnull.h"
27 #include "qapi/qmp/qnum.h"
28 #include "qapi/qmp/qstring.h"
29 #include "qemu/cutils.h"
30 #include "qemu/option.h"
31 
32 typedef struct StackObject {
33     const char *name;            /* Name of @obj in its parent, if any */
34     QObject *obj;                /* QDict or QList being visited */
35     void *qapi; /* sanity check that caller uses same pointer */
36 
37     GHashTable *h;              /* If @obj is QDict: unvisited keys */
38     const QListEntry *entry;    /* If @obj is QList: unvisited tail */
39     unsigned index;             /* If @obj is QList: list index of @entry */
40 
41     QSLIST_ENTRY(StackObject) node; /* parent */
42 } StackObject;
43 
44 struct QObjectInputVisitor {
45     Visitor visitor;
46 
47     /* Root of visit at visitor creation. */
48     QObject *root;
49     bool keyval;                /* Assume @root made with keyval_parse() */
50 
51     /* Stack of objects being visited (all entries will be either
52      * QDict or QList). */
53     QSLIST_HEAD(, StackObject) stack;
54 
55     GString *errname;           /* Accumulator for full_name() */
56 };
57 
58 static QObjectInputVisitor *to_qiv(Visitor *v)
59 {
60     return container_of(v, QObjectInputVisitor, visitor);
61 }
62 
63 /*
64  * Find the full name of something @qiv is currently visiting.
65  * @qiv is visiting something named @name in the stack of containers
66  * @qiv->stack.
67  * If @n is zero, return its full name.
68  * If @n is positive, return the full name of the @n-th container
69  * counting from the top.  The stack of containers must have at least
70  * @n elements.
71  * The returned string is valid until the next full_name_nth(@v) or
72  * destruction of @v.
73  */
74 static const char *full_name_nth(QObjectInputVisitor *qiv, const char *name,
75                                  int n)
76 {
77     StackObject *so;
78     char buf[32];
79 
80     if (qiv->errname) {
81         g_string_truncate(qiv->errname, 0);
82     } else {
83         qiv->errname = g_string_new("");
84     }
85 
86     QSLIST_FOREACH(so , &qiv->stack, node) {
87         if (n) {
88             n--;
89         } else if (qobject_type(so->obj) == QTYPE_QDICT) {
90             g_string_prepend(qiv->errname, name ?: "<anonymous>");
91             g_string_prepend_c(qiv->errname, '.');
92         } else {
93             snprintf(buf, sizeof(buf),
94                      qiv->keyval ? ".%u" : "[%u]",
95                      so->index);
96             g_string_prepend(qiv->errname, buf);
97         }
98         name = so->name;
99     }
100     assert(!n);
101 
102     if (name) {
103         g_string_prepend(qiv->errname, name);
104     } else if (qiv->errname->str[0] == '.') {
105         g_string_erase(qiv->errname, 0, 1);
106     } else if (!qiv->errname->str[0]) {
107         return "<anonymous>";
108     }
109 
110     return qiv->errname->str;
111 }
112 
113 static const char *full_name(QObjectInputVisitor *qiv, const char *name)
114 {
115     return full_name_nth(qiv, name, 0);
116 }
117 
118 static QObject *qobject_input_try_get_object(QObjectInputVisitor *qiv,
119                                              const char *name,
120                                              bool consume)
121 {
122     StackObject *tos;
123     QObject *qobj;
124     QObject *ret;
125 
126     if (QSLIST_EMPTY(&qiv->stack)) {
127         /* Starting at root, name is ignored. */
128         assert(qiv->root);
129         return qiv->root;
130     }
131 
132     /* We are in a container; find the next element. */
133     tos = QSLIST_FIRST(&qiv->stack);
134     qobj = tos->obj;
135     assert(qobj);
136 
137     if (qobject_type(qobj) == QTYPE_QDICT) {
138         assert(name);
139         ret = qdict_get(qobject_to(QDict, qobj), name);
140         if (tos->h && consume && ret) {
141             bool removed = g_hash_table_remove(tos->h, name);
142             assert(removed);
143         }
144     } else {
145         assert(qobject_type(qobj) == QTYPE_QLIST);
146         assert(!name);
147         if (tos->entry) {
148             ret = qlist_entry_obj(tos->entry);
149             if (consume) {
150                 tos->entry = qlist_next(tos->entry);
151             }
152         } else {
153             ret = NULL;
154         }
155         if (consume) {
156             tos->index++;
157         }
158     }
159 
160     return ret;
161 }
162 
163 static QObject *qobject_input_get_object(QObjectInputVisitor *qiv,
164                                          const char *name,
165                                          bool consume, Error **errp)
166 {
167     QObject *obj = qobject_input_try_get_object(qiv, name, consume);
168 
169     if (!obj) {
170         error_setg(errp, QERR_MISSING_PARAMETER, full_name(qiv, name));
171     }
172     return obj;
173 }
174 
175 static const char *qobject_input_get_keyval(QObjectInputVisitor *qiv,
176                                             const char *name,
177                                             Error **errp)
178 {
179     QObject *qobj;
180     QString *qstr;
181 
182     qobj = qobject_input_get_object(qiv, name, true, errp);
183     if (!qobj) {
184         return NULL;
185     }
186 
187     qstr = qobject_to(QString, qobj);
188     if (!qstr) {
189         switch (qobject_type(qobj)) {
190         case QTYPE_QDICT:
191         case QTYPE_QLIST:
192             error_setg(errp, "Parameters '%s.*' are unexpected",
193                        full_name(qiv, name));
194             return NULL;
195         default:
196             /* Non-string scalar (should this be an assertion?) */
197             error_setg(errp, "Internal error: parameter %s invalid",
198                        full_name(qiv, name));
199             return NULL;
200         }
201     }
202 
203     return qstring_get_str(qstr);
204 }
205 
206 static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
207                                             const char *name,
208                                             QObject *obj, void *qapi)
209 {
210     GHashTable *h;
211     StackObject *tos = g_new0(StackObject, 1);
212     QDict *qdict = qobject_to(QDict, obj);
213     QList *qlist = qobject_to(QList, obj);
214     const QDictEntry *entry;
215 
216     assert(obj);
217     tos->name = name;
218     tos->obj = obj;
219     tos->qapi = qapi;
220 
221     if (qdict) {
222         h = g_hash_table_new(g_str_hash, g_str_equal);
223         for (entry = qdict_first(qdict);
224              entry;
225              entry = qdict_next(qdict, entry)) {
226             g_hash_table_insert(h, (void *)qdict_entry_key(entry), NULL);
227         }
228         tos->h = h;
229     } else {
230         assert(qlist);
231         tos->entry = qlist_first(qlist);
232         tos->index = -1;
233     }
234 
235     QSLIST_INSERT_HEAD(&qiv->stack, tos, node);
236     return tos->entry;
237 }
238 
239 
240 static bool qobject_input_check_struct(Visitor *v, Error **errp)
241 {
242     QObjectInputVisitor *qiv = to_qiv(v);
243     StackObject *tos = QSLIST_FIRST(&qiv->stack);
244     GHashTableIter iter;
245     const char *key;
246 
247     assert(tos && !tos->entry);
248 
249     g_hash_table_iter_init(&iter, tos->h);
250     if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
251         error_setg(errp, "Parameter '%s' is unexpected",
252                    full_name(qiv, key));
253         return false;
254     }
255     return true;
256 }
257 
258 static void qobject_input_stack_object_free(StackObject *tos)
259 {
260     if (tos->h) {
261         g_hash_table_unref(tos->h);
262     }
263 
264     g_free(tos);
265 }
266 
267 static void qobject_input_pop(Visitor *v, void **obj)
268 {
269     QObjectInputVisitor *qiv = to_qiv(v);
270     StackObject *tos = QSLIST_FIRST(&qiv->stack);
271 
272     assert(tos && tos->qapi == obj);
273     QSLIST_REMOVE_HEAD(&qiv->stack, node);
274     qobject_input_stack_object_free(tos);
275 }
276 
277 static bool qobject_input_start_struct(Visitor *v, const char *name, void **obj,
278                                        size_t size, Error **errp)
279 {
280     QObjectInputVisitor *qiv = to_qiv(v);
281     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
282 
283     if (obj) {
284         *obj = NULL;
285     }
286     if (!qobj) {
287         return false;
288     }
289     if (qobject_type(qobj) != QTYPE_QDICT) {
290         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
291                    full_name(qiv, name), "object");
292         return false;
293     }
294 
295     qobject_input_push(qiv, name, qobj, obj);
296 
297     if (obj) {
298         *obj = g_malloc0(size);
299     }
300     return true;
301 }
302 
303 static void qobject_input_end_struct(Visitor *v, void **obj)
304 {
305     QObjectInputVisitor *qiv = to_qiv(v);
306     StackObject *tos = QSLIST_FIRST(&qiv->stack);
307 
308     assert(qobject_type(tos->obj) == QTYPE_QDICT && tos->h);
309     qobject_input_pop(v, obj);
310 }
311 
312 
313 static bool qobject_input_start_list(Visitor *v, const char *name,
314                                      GenericList **list, size_t size,
315                                      Error **errp)
316 {
317     QObjectInputVisitor *qiv = to_qiv(v);
318     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
319     const QListEntry *entry;
320 
321     if (list) {
322         *list = NULL;
323     }
324     if (!qobj) {
325         return false;
326     }
327     if (qobject_type(qobj) != QTYPE_QLIST) {
328         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
329                    full_name(qiv, name), "array");
330         return false;
331     }
332 
333     entry = qobject_input_push(qiv, name, qobj, list);
334     if (entry && list) {
335         *list = g_malloc0(size);
336     }
337     return true;
338 }
339 
340 static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
341                                             size_t size)
342 {
343     QObjectInputVisitor *qiv = to_qiv(v);
344     StackObject *tos = QSLIST_FIRST(&qiv->stack);
345 
346     assert(tos && qobject_to(QList, tos->obj));
347 
348     if (!tos->entry) {
349         return NULL;
350     }
351     tail->next = g_malloc0(size);
352     return tail->next;
353 }
354 
355 static bool qobject_input_check_list(Visitor *v, Error **errp)
356 {
357     QObjectInputVisitor *qiv = to_qiv(v);
358     StackObject *tos = QSLIST_FIRST(&qiv->stack);
359 
360     assert(tos && qobject_to(QList, tos->obj));
361 
362     if (tos->entry) {
363         error_setg(errp, "Only %u list elements expected in %s",
364                    tos->index + 1, full_name_nth(qiv, NULL, 1));
365         return false;
366     }
367     return true;
368 }
369 
370 static void qobject_input_end_list(Visitor *v, void **obj)
371 {
372     QObjectInputVisitor *qiv = to_qiv(v);
373     StackObject *tos = QSLIST_FIRST(&qiv->stack);
374 
375     assert(qobject_type(tos->obj) == QTYPE_QLIST && !tos->h);
376     qobject_input_pop(v, obj);
377 }
378 
379 static bool qobject_input_start_alternate(Visitor *v, const char *name,
380                                           GenericAlternate **obj, size_t size,
381                                           Error **errp)
382 {
383     QObjectInputVisitor *qiv = to_qiv(v);
384     QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
385 
386     if (!qobj) {
387         *obj = NULL;
388         return false;
389     }
390     *obj = g_malloc0(size);
391     (*obj)->type = qobject_type(qobj);
392     return true;
393 }
394 
395 static bool qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
396                                      Error **errp)
397 {
398     QObjectInputVisitor *qiv = to_qiv(v);
399     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
400     QNum *qnum;
401 
402     if (!qobj) {
403         return false;
404     }
405     qnum = qobject_to(QNum, qobj);
406     if (!qnum || !qnum_get_try_int(qnum, obj)) {
407         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
408                    full_name(qiv, name), "integer");
409         return false;
410     }
411     return true;
412 }
413 
414 static bool qobject_input_type_int64_keyval(Visitor *v, const char *name,
415                                             int64_t *obj, Error **errp)
416 {
417     QObjectInputVisitor *qiv = to_qiv(v);
418     const char *str = qobject_input_get_keyval(qiv, name, errp);
419 
420     if (!str) {
421         return false;
422     }
423 
424     if (qemu_strtoi64(str, NULL, 0, obj) < 0) {
425         /* TODO report -ERANGE more nicely */
426         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
427                    full_name(qiv, name), "integer");
428         return false;
429     }
430     return true;
431 }
432 
433 static bool qobject_input_type_uint64(Visitor *v, const char *name,
434                                       uint64_t *obj, Error **errp)
435 {
436     QObjectInputVisitor *qiv = to_qiv(v);
437     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
438     QNum *qnum;
439     int64_t val;
440 
441     if (!qobj) {
442         return false;
443     }
444     qnum = qobject_to(QNum, qobj);
445     if (!qnum) {
446         goto err;
447     }
448 
449     if (qnum_get_try_uint(qnum, obj)) {
450         return true;
451     }
452 
453     /* Need to accept negative values for backward compatibility */
454     if (qnum_get_try_int(qnum, &val)) {
455         *obj = val;
456         return true;
457     }
458 
459 err:
460     error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
461                full_name(qiv, name), "uint64");
462     return false;
463 }
464 
465 static bool qobject_input_type_uint64_keyval(Visitor *v, const char *name,
466                                              uint64_t *obj, Error **errp)
467 {
468     QObjectInputVisitor *qiv = to_qiv(v);
469     const char *str = qobject_input_get_keyval(qiv, name, errp);
470 
471     if (!str) {
472         return false;
473     }
474 
475     if (qemu_strtou64(str, NULL, 0, obj) < 0) {
476         /* TODO report -ERANGE more nicely */
477         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
478                    full_name(qiv, name), "integer");
479         return false;
480     }
481     return true;
482 }
483 
484 static bool qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
485                                     Error **errp)
486 {
487     QObjectInputVisitor *qiv = to_qiv(v);
488     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
489     QBool *qbool;
490 
491     if (!qobj) {
492         return false;
493     }
494     qbool = qobject_to(QBool, qobj);
495     if (!qbool) {
496         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
497                    full_name(qiv, name), "boolean");
498         return false;
499     }
500 
501     *obj = qbool_get_bool(qbool);
502     return true;
503 }
504 
505 static bool qobject_input_type_bool_keyval(Visitor *v, const char *name,
506                                            bool *obj, Error **errp)
507 {
508     QObjectInputVisitor *qiv = to_qiv(v);
509     const char *str = qobject_input_get_keyval(qiv, name, errp);
510 
511     if (!str) {
512         return false;
513     }
514 
515     if (!qapi_bool_parse(name, str, obj, NULL)) {
516         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
517                    full_name(qiv, name), "'on' or 'off'");
518         return false;
519     }
520     return true;
521 }
522 
523 static bool qobject_input_type_str(Visitor *v, const char *name, char **obj,
524                                    Error **errp)
525 {
526     QObjectInputVisitor *qiv = to_qiv(v);
527     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
528     QString *qstr;
529 
530     *obj = NULL;
531     if (!qobj) {
532         return false;
533     }
534     qstr = qobject_to(QString, qobj);
535     if (!qstr) {
536         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
537                    full_name(qiv, name), "string");
538         return false;
539     }
540 
541     *obj = g_strdup(qstring_get_str(qstr));
542     return true;
543 }
544 
545 static bool qobject_input_type_str_keyval(Visitor *v, const char *name,
546                                           char **obj, Error **errp)
547 {
548     QObjectInputVisitor *qiv = to_qiv(v);
549     const char *str = qobject_input_get_keyval(qiv, name, errp);
550 
551     *obj = g_strdup(str);
552     return !!str;
553 }
554 
555 static bool qobject_input_type_number(Visitor *v, const char *name, double *obj,
556                                       Error **errp)
557 {
558     QObjectInputVisitor *qiv = to_qiv(v);
559     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
560     QNum *qnum;
561 
562     if (!qobj) {
563         return false;
564     }
565     qnum = qobject_to(QNum, qobj);
566     if (!qnum) {
567         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
568                    full_name(qiv, name), "number");
569         return false;
570     }
571 
572     *obj = qnum_get_double(qnum);
573     return true;
574 }
575 
576 static bool qobject_input_type_number_keyval(Visitor *v, const char *name,
577                                              double *obj, Error **errp)
578 {
579     QObjectInputVisitor *qiv = to_qiv(v);
580     const char *str = qobject_input_get_keyval(qiv, name, errp);
581     double val;
582 
583     if (!str) {
584         return false;
585     }
586 
587     if (qemu_strtod_finite(str, NULL, &val)) {
588         /* TODO report -ERANGE more nicely */
589         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
590                    full_name(qiv, name), "number");
591         return false;
592     }
593 
594     *obj = val;
595     return true;
596 }
597 
598 static bool qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
599                                    Error **errp)
600 {
601     QObjectInputVisitor *qiv = to_qiv(v);
602     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
603 
604     *obj = NULL;
605     if (!qobj) {
606         return false;
607     }
608 
609     *obj = qobject_ref(qobj);
610     return true;
611 }
612 
613 static bool qobject_input_type_null(Visitor *v, const char *name,
614                                     QNull **obj, Error **errp)
615 {
616     QObjectInputVisitor *qiv = to_qiv(v);
617     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
618 
619     *obj = NULL;
620     if (!qobj) {
621         return false;
622     }
623 
624     if (qobject_type(qobj) != QTYPE_QNULL) {
625         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
626                    full_name(qiv, name), "null");
627         return false;
628     }
629     *obj = qnull();
630     return true;
631 }
632 
633 static bool qobject_input_type_size_keyval(Visitor *v, const char *name,
634                                            uint64_t *obj, Error **errp)
635 {
636     QObjectInputVisitor *qiv = to_qiv(v);
637     const char *str = qobject_input_get_keyval(qiv, name, errp);
638 
639     if (!str) {
640         return false;
641     }
642 
643     if (qemu_strtosz(str, NULL, obj) < 0) {
644         /* TODO report -ERANGE more nicely */
645         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
646                    full_name(qiv, name), "size");
647         return false;
648     }
649     return true;
650 }
651 
652 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
653 {
654     QObjectInputVisitor *qiv = to_qiv(v);
655     QObject *qobj = qobject_input_try_get_object(qiv, name, false);
656 
657     if (!qobj) {
658         *present = false;
659         return;
660     }
661 
662     *present = true;
663 }
664 
665 static void qobject_input_free(Visitor *v)
666 {
667     QObjectInputVisitor *qiv = to_qiv(v);
668 
669     while (!QSLIST_EMPTY(&qiv->stack)) {
670         StackObject *tos = QSLIST_FIRST(&qiv->stack);
671 
672         QSLIST_REMOVE_HEAD(&qiv->stack, node);
673         qobject_input_stack_object_free(tos);
674     }
675 
676     qobject_unref(qiv->root);
677     if (qiv->errname) {
678         g_string_free(qiv->errname, TRUE);
679     }
680     g_free(qiv);
681 }
682 
683 static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
684 {
685     QObjectInputVisitor *v = g_malloc0(sizeof(*v));
686 
687     assert(obj);
688 
689     v->visitor.type = VISITOR_INPUT;
690     v->visitor.start_struct = qobject_input_start_struct;
691     v->visitor.check_struct = qobject_input_check_struct;
692     v->visitor.end_struct = qobject_input_end_struct;
693     v->visitor.start_list = qobject_input_start_list;
694     v->visitor.next_list = qobject_input_next_list;
695     v->visitor.check_list = qobject_input_check_list;
696     v->visitor.end_list = qobject_input_end_list;
697     v->visitor.start_alternate = qobject_input_start_alternate;
698     v->visitor.optional = qobject_input_optional;
699     v->visitor.free = qobject_input_free;
700 
701     v->root = qobject_ref(obj);
702 
703     return v;
704 }
705 
706 Visitor *qobject_input_visitor_new(QObject *obj)
707 {
708     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
709 
710     v->visitor.type_int64 = qobject_input_type_int64;
711     v->visitor.type_uint64 = qobject_input_type_uint64;
712     v->visitor.type_bool = qobject_input_type_bool;
713     v->visitor.type_str = qobject_input_type_str;
714     v->visitor.type_number = qobject_input_type_number;
715     v->visitor.type_any = qobject_input_type_any;
716     v->visitor.type_null = qobject_input_type_null;
717 
718     return &v->visitor;
719 }
720 
721 Visitor *qobject_input_visitor_new_keyval(QObject *obj)
722 {
723     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
724 
725     v->visitor.type_int64 = qobject_input_type_int64_keyval;
726     v->visitor.type_uint64 = qobject_input_type_uint64_keyval;
727     v->visitor.type_bool = qobject_input_type_bool_keyval;
728     v->visitor.type_str = qobject_input_type_str_keyval;
729     v->visitor.type_number = qobject_input_type_number_keyval;
730     v->visitor.type_any = qobject_input_type_any;
731     v->visitor.type_null = qobject_input_type_null;
732     v->visitor.type_size = qobject_input_type_size_keyval;
733     v->keyval = true;
734 
735     return &v->visitor;
736 }
737 
738 Visitor *qobject_input_visitor_new_str(const char *str,
739                                        const char *implied_key,
740                                        Error **errp)
741 {
742     bool is_json = str[0] == '{';
743     QObject *obj;
744     QDict *args;
745     Visitor *v;
746 
747     if (is_json) {
748         obj = qobject_from_json(str, errp);
749         if (!obj) {
750             return NULL;
751         }
752         args = qobject_to(QDict, obj);
753         assert(args);
754         v = qobject_input_visitor_new(QOBJECT(args));
755     } else {
756         args = keyval_parse(str, implied_key, NULL, errp);
757         if (!args) {
758             return NULL;
759         }
760         v = qobject_input_visitor_new_keyval(QOBJECT(args));
761     }
762     qobject_unref(args);
763 
764     return v;
765 }
766