qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF

Now that we can safely call QOBJECT() on QObject * as well as its
subtypes, we can have macros qobject_ref() / qobject_unref() that work
everywhere instead of having to use QINCREF() / QDECREF() for QObject
and qobject_incref() / qobject_decref() for its subtypes.

The replacement is mechanical, except I broke a long line, and added a
cast in monitor_qmp_cleanup_req_queue_locked(). Unlike
qobject_decref(), qobject_unref() doesn't accept void *.

Note that the new macros evaluate their argument exactly once, thus no
need to shout them.

Backports commit cb3e7f08aeaab0ab13e629ce8496dca150a449ba from qemu

qemu/include/qapi/qmp/qnull.h

@@ -23,7 +23,7 @@ extern QNull qnull_;
 
 static inline QNull *qnull(void)
 {
-    QINCREF(&qnull_);
+    qobject_ref(&qnull_);
     return &qnull_;
 }
 

qemu/include/qapi/qmp/qobject.h

@@ -15,17 +15,17 @@
  * ------------------------------------
  *
  *  - Returning references: A function that returns an object may
- *  return it as either a weak or a strong reference.  If the reference
- *  is strong, you are responsible for calling QDECREF() on the reference
- *  when you are done.
+ *  return it as either a weak or a strong reference.  If the
+ *  reference is strong, you are responsible for calling
+ *  qobject_unref() on the reference when you are done.
  *
  *  If the reference is weak, the owner of the reference may free it at
  *  any time in the future.  Before storing the reference anywhere, you
- *  should call QINCREF() to make the reference strong.
+ *  should call qobject_ref() to make the reference strong.
  *
  *  - Transferring ownership: when you transfer ownership of a reference
  *  by calling a function, you are no longer responsible for calling
- *  QDECREF() when the reference is no longer needed.  In other words,
+ *  qobject_unref() when the reference is no longer needed.  In other words,
  *  when the function returns you must behave as if the reference to the
  *  passed object was weak.
  */
@@ -50,14 +50,6 @@ struct QObject {
     _obj ? container_of(&(_obj)->base, QObject, base) : NULL;   \
 })
 
-/* High-level interface for qobject_incref() */
-#define QINCREF(obj)      \
-    qobject_incref(QOBJECT(obj))
-
-/* High-level interface for qobject_decref() */
-#define QDECREF(obj)              \
-    qobject_decref(obj ? QOBJECT(obj) : NULL)
-
 /* Required for qobject_to() */
 #define QTYPE_CAST_TO_QNull     QTYPE_QNULL
 #define QTYPE_CAST_TO_QNum      QTYPE_QNUM
@@ -80,10 +72,7 @@ static inline void qobject_init(QObject *obj, QType type)
     obj->base.type = type;
 }
 
-/**
- * qobject_incref(): Increment QObject's reference count
- */
-static inline void qobject_incref(QObject *obj)
+static inline void qobject_ref_impl(QObject *obj)
 {
     if (obj) {
         obj->base.refcnt++;
@@ -104,11 +93,7 @@ bool qobject_is_equal(const QObject *x, const QObject *y);
  */
 void qobject_destroy(QObject *obj);
 
-/**
- * qobject_decref(): Decrement QObject's reference count, deallocate
- * when it reaches zero
- */
-static inline void qobject_decref(QObject *obj)
+static inline void qobject_unref_impl(QObject *obj)
 {
     assert(!obj || obj->base.refcnt);
     if (obj && --obj->base.refcnt == 0) {
@@ -116,6 +101,17 @@ static inline void qobject_decref(QObject *obj)
     }
 }
 
+/**
+ * qobject_ref(): Increment QObject's reference count
+ */
+#define qobject_ref(obj) qobject_ref_impl(QOBJECT(obj))
+
+/**
+ * qobject_unref(): Decrement QObject's reference count, deallocate
+ * when it reaches zero
+ */
+#define qobject_unref(obj) qobject_unref_impl(QOBJECT(obj))
+
 /**
  * qobject_type(): Return the QObject's type
  */

qemu/qapi/qapi-dealloc-visitor.c

@@ -100,7 +100,7 @@ static void qapi_dealloc_type_anything(Visitor *v, const char *name,
                                        QObject **obj, Error **errp)
 {
     if (obj) {
-        qobject_decref(*obj);
+        qobject_unref(*obj);
     }
 }
 
@@ -108,7 +108,7 @@ static void qapi_dealloc_type_null(Visitor *v, const char *name,
                                    QNull **obj, Error **errp)
 {
     if (obj) {
-        QDECREF(*obj);
+        qobject_unref(*obj);
     }
 }
 

qemu/qapi/qobject-input-visitor.c

@@ -463,7 +463,7 @@ static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
         return;
     }
 
-    qobject_incref(qobj);
+    qobject_ref(qobj);
     *obj = qobj;
 }
 
@@ -511,7 +511,7 @@ static void qobject_input_free(Visitor *v)
         qobject_input_stack_object_free(tos);
     }
 
-    qobject_decref(qiv->root);
+    qobject_unref(qiv->root);
     if (qiv->errname) {
         g_string_free(qiv->errname, TRUE);
     }
@@ -537,7 +537,7 @@ static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
     v->visitor.free = qobject_input_free;
 
     v->root = obj;
-    qobject_incref(obj);
+    qobject_ref(obj);
 
     return v;
 }

qemu/qapi/qobject-output-visitor.c

@@ -191,7 +191,7 @@ static void qobject_output_type_any(Visitor *v, const char *name, QObject **obj,
                                     Error **errp)
 {
     QObjectOutputVisitor *qov = to_qov(v);
-    qobject_incref(*obj);
+    qobject_ref(*obj);
     qobject_output_add_obj(qov, name, *obj);
 }
 
@@ -204,7 +204,7 @@ static void qobject_output_type_null(Visitor *v, const char *name,
 
 /* Finish building, and return the root object.
  * The root object is never null. The caller becomes the object's
- * owner, and should use qobject_decref() when done with it.  */
+ * owner, and should use qobject_unref() when done with it.  */
 static void qobject_output_complete(Visitor *v, void *opaque)
 {
     QObjectOutputVisitor *qov = to_qov(v);
@@ -228,7 +228,7 @@ static void qobject_output_free(Visitor *v)
         g_free(e);
     }
 
-    qobject_decref(qov->root);
+    qobject_unref(qov->root);
     g_free(qov);
 }
 

qemu/qobject/qdict.c

@@ -123,7 +123,7 @@ void qdict_put_obj(QDict *qdict, const char *key, QObject *value)
     entry = qdict_find(qdict, key, bucket);
     if (entry) {
         /* replace key's value */
-        qobject_decref(entry->value);
+        qobject_unref(entry->value);
         entry->value = value;
     } else {
         /* allocate a new entry */
@@ -373,7 +373,7 @@ QDict *qdict_clone_shallow(const QDict *src)
 
     for (i = 0; i < QDICT_BUCKET_MAX; i++) {
         QLIST_FOREACH(entry, &src->table[i], next) {
-            qobject_incref(entry->value);
+            qobject_ref(entry->value);
             qdict_put_obj(dest, entry->key, entry->value);
         }
     }
@@ -390,7 +390,7 @@ static void qentry_destroy(QDictEntry *e)
     assert(e->key != NULL);
     assert(e->value != NULL);
 
-    qobject_decref(e->value);
+    qobject_unref(e->value);
     g_free(e->key);
     g_free(e);
 }
@@ -493,7 +493,7 @@ static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix)
             qdict_flatten_qlist(qobject_to(QList, value), target, new_key);
         } else {
             /* All other types are moved to the target unchanged. */
-            qobject_incref(value);
+            qobject_ref(value);
             qdict_put_obj(target, new_key, value);
         }
 
@@ -533,7 +533,7 @@ static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix)
             delete = true;
         } else if (prefix) {
             /* All other objects are moved to the target unchanged. */
-            qobject_incref(value);
+            qobject_ref(value);
             qdict_put_obj(target, new_key, value);
             delete = true;
         }
@@ -576,7 +576,7 @@ bool qdict_rename_keys(QDict *qdict, const QDictRenames *renames, Error **errp)
             }
 
             qobj = qdict_get(qdict, renames->from);
-            qobject_incref(qobj);
+            qobject_ref(qobj);
             qdict_put_obj(qdict, renames->to, qobj);
             qdict_del(qdict, renames->from);
         }
@@ -611,7 +611,7 @@ void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start)
     while (entry != NULL) {
         next = qdict_next(src, entry);
         if (strstart(entry->key, start, &p)) {
-            qobject_incref(entry->value);
+            qobject_ref(entry->value);
             qdict_put_obj(*dst, p, entry->value);
             qdict_del(src, entry->key);
         }
@@ -680,7 +680,7 @@ void qdict_array_split(QDict *src, QList **dst)
             qdict_extract_subqdict(src, &subqdict, prefix);
             assert(qdict_size(subqdict) > 0);
         } else {
-            qobject_incref(subqobj);
+            qobject_ref(subqobj);
             qdict_del(src, indexstr);
         }
 
@@ -890,7 +890,7 @@ QObject *qdict_crumple(const QDict *src, Error **errp)
                 qdict_put_obj(two_level, prefix, QOBJECT(child_dict));
             }
 
-            qobject_incref(ent->value);
+            qobject_ref(ent->value);
             qdict_put_obj(child_dict, suffix, ent->value);
         } else {
             if (child) {
@@ -898,7 +898,7 @@ QObject *qdict_crumple(const QDict *src, Error **errp)
                            prefix);
                 goto error;
             }
-            qobject_incref(ent->value);
+            qobject_ref(ent->value);
             qdict_put_obj(two_level, prefix, ent->value);
         }
 
@@ -921,11 +921,11 @@ QObject *qdict_crumple(const QDict *src, Error **errp)
 
             qdict_put_obj(multi_level, ent->key, child);
         } else {
-            qobject_incref(ent->value);
+            qobject_ref(ent->value);
             qdict_put_obj(multi_level, ent->key, ent->value);
         }
     }
-    QDECREF(two_level);
+    qobject_unref(two_level);
     two_level = NULL;
 
     /* Step 3: detect if we need to turn our dict into list */
@@ -948,10 +948,10 @@ QObject *qdict_crumple(const QDict *src, Error **errp)
                 goto error;
             }
 
-            qobject_incref(child);
+            qobject_ref(child);
             qlist_append_obj(qobject_to(QList, dst), child);
         }
-        QDECREF(multi_level);
+        qobject_unref(multi_level);
         multi_level = NULL;
     } else {
         dst = QOBJECT(multi_level);
@@ -961,9 +961,9 @@ QObject *qdict_crumple(const QDict *src, Error **errp)
 
  error:
     g_free(prefix);
-    QDECREF(multi_level);
-    QDECREF(two_level);
-    qobject_decref(dst);
+    qobject_unref(multi_level);
+    qobject_unref(two_level);
+    qobject_unref(dst);
     return NULL;
 }
 
@@ -990,7 +990,7 @@ void qdict_join(QDict *dest, QDict *src, bool overwrite)
         next = qdict_next(src, entry);
 
         if (overwrite || !qdict_haskey(dest, entry->key)) {
-            qobject_incref(entry->value);
+            qobject_ref(entry->value);
             qdict_put_obj(dest, entry->key, entry->value);
             qdict_del(src, entry->key);
         }

qemu/qobject/qlist.c

@@ -39,7 +39,7 @@ static void qlist_copy_elem(QObject *obj, void *opaque)
 {
     QList *dst = opaque;
 
-    qobject_incref(obj);
+    qobject_ref(obj);
     qlist_append_obj(dst, obj);
 }
 
@@ -199,7 +199,7 @@ void qlist_destroy_obj(QObject *obj)
 
     QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
         QTAILQ_REMOVE(&qlist->head, entry, next);
-        qobject_decref(entry->value);
+        qobject_unref(entry->value);
         g_free(entry);
     }
 

qemu/qom/object.c

@@ -1001,7 +1001,7 @@ void object_property_set_str(struct uc_struct *uc, Object *obj, const char *valu
     QString *qstr = qstring_from_str(value);
     object_property_set_qobject(uc, obj, QOBJECT(qstr), name, errp);
 
-    QDECREF(qstr);
+    qobject_unref(qstr);
 }
 
 char *object_property_get_str(struct uc_struct *uc, Object *obj, const char *name,
@@ -1019,7 +1019,7 @@ char *object_property_get_str(struct uc_struct *uc, Object *obj, const char *nam
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
     }
 
-    qobject_decref(ret);
+    qobject_unref(ret);
     return retval;
 }
 
@@ -1059,7 +1059,7 @@ void object_property_set_bool(struct uc_struct *uc, Object *obj, bool value,
     QBool *qbool = qbool_from_bool(value);
     object_property_set_qobject(uc, obj, QOBJECT(qbool), name, errp);
 
-    QDECREF(qbool);
+    qobject_unref(qbool);
 }
 
 bool object_property_get_bool(struct uc_struct *uc, Object *obj, const char *name,
@@ -1080,7 +1080,7 @@ bool object_property_get_bool(struct uc_struct *uc, Object *obj, const char *nam
         retval = qbool_get_bool(qbool);
     }
 
-    qobject_decref(ret);
+    qobject_unref(ret);
     return retval;
 }
 
@@ -1090,7 +1090,7 @@ void object_property_set_int(struct uc_struct *uc, Object *obj, int64_t value,
     QNum *qnum = qnum_from_int(value);
     object_property_set_qobject(uc, obj, QOBJECT(qnum), name, errp);
 
-    QDECREF(qnum);
+    qobject_unref(qnum);
 }
 
 int64_t object_property_get_int(struct uc_struct *uc, Object *obj, const char *name,
@@ -1110,7 +1110,7 @@ int64_t object_property_get_int(struct uc_struct *uc, Object *obj, const char *n
         retval = -1;
     }
 
-    qobject_decref(ret);
+    qobject_unref(ret);
     return retval;
 }
 
@@ -1120,7 +1120,7 @@ void object_property_set_uint(struct uc_struct *uc, Object *obj, uint64_t value,
     QNum *qnum = qnum_from_uint(value);
 
     object_property_set_qobject(uc, obj, QOBJECT(qnum), name, errp);
-    QDECREF(qnum);
+    qobject_unref(qnum);
 }
 
 uint64_t object_property_get_uint(struct uc_struct *uc, Object *obj,
@@ -1139,7 +1139,7 @@ uint64_t object_property_get_uint(struct uc_struct *uc, Object *obj,
         retval = 0;
     }
 
-    qobject_decref(ret);
+    qobject_unref(ret);
     return retval;
 }
 

qemu/scripts/qapi/events.py

@@ -142,7 +142,7 @@ out:
 ''')
     ret += mcgen('''
     error_propagate(errp, err);
-    QDECREF(qmp);
+    qobject_unref(qmp);
 }
 ''')
     return ret