qom: Make functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-28-armbru@redhat.com>

include/qom/object.h

@@ -703,7 +703,7 @@ Object *object_new_with_propv(const char *typename,
                               Error **errp,
                               va_list vargs);
 
-void object_apply_global_props(Object *obj, const GPtrArray *props,
+bool object_apply_global_props(Object *obj, const GPtrArray *props,
                                Error **errp);
 void object_set_machine_compat_props(GPtrArray *compat_props);
 void object_set_accelerator_compat_props(GPtrArray *compat_props);
@@ -798,8 +798,10 @@ void object_initialize(void *obj, size_t size, const char *typename);
  * strings. The propname of %NULL indicates the end of the property list.
  * If the object implements the user creatable interface, the object will
  * be marked complete once all the properties have been processed.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_initialize_child_with_props(Object *parentobj,
+bool object_initialize_child_with_props(Object *parentobj,
                              const char *propname,
                              void *childobj, size_t size, const char *type,
                              Error **errp, ...) QEMU_SENTINEL;
@@ -815,8 +817,10 @@ void object_initialize_child_with_props(Object *parentobj,
  * @vargs: list of property names and values
  *
  * See object_initialize_child() for documentation.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_initialize_child_with_propsv(Object *parentobj,
+bool object_initialize_child_with_propsv(Object *parentobj,
                               const char *propname,
                               void *childobj, size_t size, const char *type,
                               Error **errp, va_list vargs);
@@ -1209,8 +1213,10 @@ void object_unparent(Object *obj);
  * @errp: returns an error if this function fails
  *
  * Reads a property from a object.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_get(Object *obj, const char *name, Visitor *v,
+bool object_property_get(Object *obj, const char *name, Visitor *v,
                          Error **errp);
 
 /**
@@ -1220,8 +1226,10 @@ void object_property_get(Object *obj, const char *name, Visitor *v,
  * @errp: returns an error if this function fails
  *
  * Writes a string value to a property.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set_str(Object *obj, const char *name,
+bool object_property_set_str(Object *obj, const char *name,
                              const char *value, Error **errp);
 
 /**
@@ -1249,8 +1257,9 @@ char *object_property_get_str(Object *obj, const char *name,
  * <code>OBJ_PROP_LINK_STRONG</code> bit, the old target object is
  * unreferenced, and a reference is added to the new target object.
  *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set_link(Object *obj, const char *name,
+bool object_property_set_link(Object *obj, const char *name,
                               Object *value, Error **errp);
 
 /**
@@ -1273,8 +1282,10 @@ Object *object_property_get_link(Object *obj, const char *name,
  * @errp: returns an error if this function fails
  *
  * Writes a bool value to a property.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set_bool(Object *obj, const char *name,
+bool object_property_set_bool(Object *obj, const char *name,
                               bool value, Error **errp);
 
 /**
@@ -1296,8 +1307,10 @@ bool object_property_get_bool(Object *obj, const char *name,
  * @errp: returns an error if this function fails
  *
  * Writes an integer value to a property.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set_int(Object *obj, const char *name,
+bool object_property_set_int(Object *obj, const char *name,
                              int64_t value, Error **errp);
 
 /**
@@ -1319,8 +1332,10 @@ int64_t object_property_get_int(Object *obj, const char *name,
  * @errp: returns an error if this function fails
  *
  * Writes an unsigned integer value to a property.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set_uint(Object *obj, const char *name,
+bool object_property_set_uint(Object *obj, const char *name,
                               uint64_t value, Error **errp);
 
 /**
@@ -1359,8 +1374,10 @@ int object_property_get_enum(Object *obj, const char *name,
  * @errp: returns an error if this function fails
  *
  * Writes a property to a object.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set(Object *obj, const char *name, Visitor *v,
+bool object_property_set(Object *obj, const char *name, Visitor *v,
                          Error **errp);
 
 /**
@@ -1371,8 +1388,10 @@ void object_property_set(Object *obj, const char *name, Visitor *v,
  * @errp: returns an error if this function fails
  *
  * Parses a string and writes the result into a property of an object.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_parse(Object *obj, const char *name,
+bool object_property_parse(Object *obj, const char *name,
                            const char *string, Error **errp);
 
 /**
@@ -1815,6 +1834,7 @@ ObjectProperty *object_property_add_const_link(Object *obj, const char *name,
  *
  * Set an object property's description.
  *
+ * Returns: %true on success, %false on failure.
  */
 void object_property_set_description(Object *obj, const char *name,
                                      const char *description);

include/qom/object_interfaces.h

@@ -57,8 +57,10 @@ typedef struct UserCreatableClass {
  * Wrapper to call complete() method if one of types it's inherited
  * from implements USER_CREATABLE interface, otherwise the call does
  * nothing.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void user_creatable_complete(UserCreatable *uc, Error **errp);
+bool user_creatable_complete(UserCreatable *uc, Error **errp);
 
 /**
  * user_creatable_can_be_deleted:
@@ -100,8 +102,10 @@ Object *user_creatable_add_type(const char *type, const char *id,
  * @qdict.  The object type is taken from the QDict key 'qom-type', its
  * ID from the key 'id'. The remaining entries in @qdict are used to
  * initialize the object properties.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void user_creatable_add_dict(QDict *qdict, bool keyval, Error **errp);
+bool user_creatable_add_dict(QDict *qdict, bool keyval, Error **errp);
 
 /**
  * user_creatable_add_opts:
@@ -167,8 +171,10 @@ bool user_creatable_print_help(const char *type, QemuOpts *opts);
  *
  * Delete an instance of the user creatable object identified
  * by @id.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void user_creatable_del(const char *id, Error **errp);
+bool user_creatable_del(const char *id, Error **errp);
 
 /**
  * user_creatable_cleanup:

include/qom/qom-qobject.h

@@ -33,8 +33,10 @@ struct QObject *object_property_get_qobject(Object *obj, const char *name,
  * @errp: returns an error if this function fails
  *
  * Writes a property to a object.
+ *
+ * Returns: %true on success, %false on failure.
  */
-void object_property_set_qobject(Object *obj,
+bool object_property_set_qobject(Object *obj,
                                  const char *name, struct QObject *value,
                                  struct Error **errp);
 

qom/object.c

@@ -385,12 +385,13 @@ static void object_post_init_with_type(Object *obj, TypeImpl *ti)
     }
 }
 
-void object_apply_global_props(Object *obj, const GPtrArray *props, Error **errp)
+bool object_apply_global_props(Object *obj, const GPtrArray *props,
+                               Error **errp)
 {
     int i;
 
     if (!props) {
-        return;
+        return true;
     }
 
     for (i = 0; i < props->len; i++) {
@@ -415,12 +416,14 @@ void object_apply_global_props(Object *obj, const GPtrArray *props, Error **errp
              */
             if (errp) {
                 error_propagate(errp, err);
-                return;
+                return false;
             } else {
                 warn_report_err(err);
             }
         }
     }
+
+    return true;
 }
 
 /*
@@ -524,25 +527,31 @@ void object_initialize(void *data, size_t size, const char *typename)
     object_initialize_with_type(data, size, type);
 }
 
-void object_initialize_child_with_props(Object *parentobj,
-                             const char *propname,
-                             void *childobj, size_t size, const char *type,
-                             Error **errp, ...)
+bool object_initialize_child_with_props(Object *parentobj,
+                                        const char *propname,
+                                        void *childobj, size_t size,
+                                        const char *type,
+                                        Error **errp, ...)
 {
     va_list vargs;
+    bool ok;
 
     va_start(vargs, errp);
-    object_initialize_child_with_propsv(parentobj, propname,
-                                        childobj, size, type, errp, vargs);
+    ok = object_initialize_child_with_propsv(parentobj, propname,
+                                             childobj, size, type, errp,
+                                             vargs);
     va_end(vargs);
+    return ok;
 }
 
-void object_initialize_child_with_propsv(Object *parentobj,
-                              const char *propname,
-                              void *childobj, size_t size, const char *type,
-                              Error **errp, va_list vargs)
+bool object_initialize_child_with_propsv(Object *parentobj,
+                                         const char *propname,
+                                         void *childobj, size_t size,
+                                         const char *type,
+                                         Error **errp, va_list vargs)
 {
     Error *local_err = NULL;
+    bool ok = false;
     Object *obj;
     UserCreatable *uc;
 
@@ -564,6 +573,8 @@ void object_initialize_child_with_propsv(Object *parentobj,
         }
     }
 
+    ok = true;
+
 out:
     /*
      * We want @obj's reference to be 1 on success, 0 on failure.
@@ -576,6 +587,7 @@ out:
     object_unref(obj);
 
     error_propagate(errp, local_err);
+    return ok;
 }
 
 void object_initialize_child_internal(Object *parent,
@@ -1312,43 +1324,52 @@ void object_property_del(Object *obj, const char *name)
     g_hash_table_remove(obj->properties, name);
 }
 
-void object_property_get(Object *obj, const char *name, Visitor *v,
+bool object_property_get(Object *obj, const char *name, Visitor *v,
                          Error **errp)
 {
+    Error *err = NULL;
     ObjectProperty *prop = object_property_find(obj, name, errp);
+
     if (prop == NULL) {
-        return;
+        return false;
     }
 
     if (!prop->get) {
         error_setg(errp, QERR_PERMISSION_DENIED);
-    } else {
-        prop->get(obj, v, name, prop->opaque, errp);
+        return false;
     }
+    prop->get(obj, v, name, prop->opaque, &err);
+    error_propagate(errp, err);
+    return !err;
 }
 
-void object_property_set(Object *obj, const char *name, Visitor *v,
+bool object_property_set(Object *obj, const char *name, Visitor *v,
                          Error **errp)
 {
+    Error *err = NULL;
     ObjectProperty *prop = object_property_find(obj, name, errp);
+
     if (prop == NULL) {
-        return;
+        return false;
     }
 
     if (!prop->set) {
         error_setg(errp, QERR_PERMISSION_DENIED);
-    } else {
-        prop->set(obj, v, name, prop->opaque, errp);
+        return false;
     }
+    prop->set(obj, v, name, prop->opaque, &err);
+    error_propagate(errp, err);
+    return !err;
 }
 
-void object_property_set_str(Object *obj, const char *name,
+bool object_property_set_str(Object *obj, const char *name,
                              const char *value, Error **errp)
 {
     QString *qstr = qstring_from_str(value);
-    object_property_set_qobject(obj, name, QOBJECT(qstr), errp);
+    bool ok = object_property_set_qobject(obj, name, QOBJECT(qstr), errp);
 
     qobject_unref(qstr);
+    return ok;
 }
 
 char *object_property_get_str(Object *obj, const char *name,
@@ -1370,16 +1391,15 @@ char *object_property_get_str(Object *obj, const char *name,
     return retval;
 }
 
-void object_property_set_link(Object *obj, const char *name,
+bool object_property_set_link(Object *obj, const char *name,
                               Object *value, Error **errp)
 {
+    g_autofree char *path = NULL;
+
     if (value) {
-        char *path = object_get_canonical_path(value);
-        object_property_set_str(obj, name, path, errp);
-        g_free(path);
-    } else {
-        object_property_set_str(obj, name, "", errp);
+        path = object_get_canonical_path(value);
     }
+    return object_property_set_str(obj, name, path ?: "", errp);
 }
 
 Object *object_property_get_link(Object *obj, const char *name,
@@ -1400,13 +1420,14 @@ Object *object_property_get_link(Object *obj, const char *name,
     return target;
 }
 
-void object_property_set_bool(Object *obj, const char *name,
+bool object_property_set_bool(Object *obj, const char *name,
                               bool value, Error **errp)
 {
     QBool *qbool = qbool_from_bool(value);
-    object_property_set_qobject(obj, name, QOBJECT(qbool), errp);
+    bool ok = object_property_set_qobject(obj, name, QOBJECT(qbool), errp);
 
     qobject_unref(qbool);
+    return ok;
 }
 
 bool object_property_get_bool(Object *obj, const char *name,
@@ -1431,13 +1452,14 @@ bool object_property_get_bool(Object *obj, const char *name,
     return retval;
 }
 
-void object_property_set_int(Object *obj, const char *name,
+bool object_property_set_int(Object *obj, const char *name,
                              int64_t value, Error **errp)
 {
     QNum *qnum = qnum_from_int(value);
-    object_property_set_qobject(obj, name, QOBJECT(qnum), errp);
+    bool ok = object_property_set_qobject(obj, name, QOBJECT(qnum), errp);
 
     qobject_unref(qnum);
+    return ok;
 }
 
 int64_t object_property_get_int(Object *obj, const char *name,
@@ -1500,13 +1522,14 @@ void object_property_set_default_uint(ObjectProperty *prop, uint64_t value)
     object_property_set_default(prop, QOBJECT(qnum_from_uint(value)));
 }
 
-void object_property_set_uint(Object *obj, const char *name,
+bool object_property_set_uint(Object *obj, const char *name,
                               uint64_t value, Error **errp)
 {
     QNum *qnum = qnum_from_uint(value);
+    bool ok = object_property_set_qobject(obj, name, QOBJECT(qnum), errp);
 
-    object_property_set_qobject(obj, name, QOBJECT(qnum), errp);
     qobject_unref(qnum);
+    return ok;
 }
 
 uint64_t object_property_get_uint(Object *obj, const char *name,
@@ -1567,12 +1590,14 @@ int object_property_get_enum(Object *obj, const char *name,
     return ret;
 }
 
-void object_property_parse(Object *obj, const char *name,
+bool object_property_parse(Object *obj, const char *name,
                            const char *string, Error **errp)
 {
     Visitor *v = string_input_visitor_new(string);
-    object_property_set(obj, name, v, errp);
+    bool ok = object_property_set(obj, name, v, errp);
+
     visit_free(v);
+    return ok;
 }
 
 char *object_property_print(Object *obj, const char *name, bool human,

qom/object_interfaces.c

@@ -14,13 +14,16 @@
 #include "qapi/opts-visitor.h"
 #include "qemu/config-file.h"
 
-void user_creatable_complete(UserCreatable *uc, Error **errp)
+bool user_creatable_complete(UserCreatable *uc, Error **errp)
 {
     UserCreatableClass *ucc = USER_CREATABLE_GET_CLASS(uc);
+    Error *err = NULL;
 
     if (ucc->complete) {
-        ucc->complete(uc, errp);
+        ucc->complete(uc, &err);
+        error_propagate(errp, err);
     }
+    return !err;
 }
 
 bool user_creatable_can_be_deleted(UserCreatable *uc)
@@ -101,7 +104,7 @@ out:
     return obj;
 }
 
-void user_creatable_add_dict(QDict *qdict, bool keyval, Error **errp)
+bool user_creatable_add_dict(QDict *qdict, bool keyval, Error **errp)
 {
     Visitor *v;
     Object *obj;
@@ -111,14 +114,14 @@ void user_creatable_add_dict(QDict *qdict, bool keyval, Error **errp)
     type = g_strdup(qdict_get_try_str(qdict, "qom-type"));
     if (!type) {
         error_setg(errp, QERR_MISSING_PARAMETER, "qom-type");
-        return;
+        return false;
     }
     qdict_del(qdict, "qom-type");
 
     id = g_strdup(qdict_get_try_str(qdict, "id"));
     if (!id) {
         error_setg(errp, QERR_MISSING_PARAMETER, "id");
-        return;
+        return false;
     }
     qdict_del(qdict, "id");
 
@@ -130,6 +133,7 @@ void user_creatable_add_dict(QDict *qdict, bool keyval, Error **errp)
     obj = user_creatable_add_type(type, id, qdict, v, errp);
     visit_free(v);
     object_unref(obj);
+    return !!obj;
 }
 
 Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
@@ -260,7 +264,7 @@ bool user_creatable_print_help(const char *type, QemuOpts *opts)
     return false;
 }
 
-void user_creatable_del(const char *id, Error **errp)
+bool user_creatable_del(const char *id, Error **errp)
 {
     Object *container;
     Object *obj;
@@ -269,12 +273,12 @@ void user_creatable_del(const char *id, Error **errp)
     obj = object_resolve_path_component(container, id);
     if (!obj) {
         error_setg(errp, "object '%s' not found", id);
-        return;
+        return false;
     }
 
     if (!user_creatable_can_be_deleted(USER_CREATABLE(obj))) {
         error_setg(errp, "object '%s' is in use, can not be deleted", id);
-        return;
+        return false;
     }
 
     /*
@@ -285,6 +289,7 @@ void user_creatable_del(const char *id, Error **errp)
                                  id));
 
     object_unparent(obj);
+    return true;
 }
 
 void user_creatable_cleanup(void)

qom/qom-qobject.c

@@ -17,15 +17,17 @@
 #include "qapi/qobject-input-visitor.h"
 #include "qapi/qobject-output-visitor.h"
 
-void object_property_set_qobject(Object *obj,
+bool object_property_set_qobject(Object *obj,
                                  const char *name, QObject *value,
                                  Error **errp)
 {
     Visitor *v;
+    bool ok;
 
     v = qobject_input_visitor_new(value);
-    object_property_set(obj, name, v, errp);
+    ok = object_property_set(obj, name, v, errp);
     visit_free(v);
+    return ok;
 }
 
 QObject *object_property_get_qobject(Object *obj, const char *name,