qom: Factor out user_creatable_process_cmdline()

The implementation for --object can be shared between
qemu-storage-daemon and other binaries, so move it into a function in
qom/object_interfaces.c that is accessible from everywhere.

This also requires moving the implementation of qmp_object_add() into a
new user_creatable_add_qapi(), because qom/qom-qmp-cmds.c is not linked
for tools.

user_creatable_print_help_from_qdict() can become static now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

include/qom/object_interfaces.h

@@ -2,6 +2,7 @@
 #define OBJECT_INTERFACES_H
 
 #include "qom/object.h"
+#include "qapi/qapi-types-qom.h"
 #include "qapi/visitor.h"
 
 #define TYPE_USER_CREATABLE "user-creatable"
@@ -86,6 +87,18 @@ Object *user_creatable_add_type(const char *type, const char *id,
                                 const QDict *qdict,
                                 Visitor *v, Error **errp);
 
+/**
+ * user_creatable_add_qapi:
+ * @options: the object definition
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Create an instance of the user creatable object according to the
+ * options passed in @opts as described in the QAPI schema documentation.
+ *
+ * Returns: the newly created object or NULL on error
+ */
+void user_creatable_add_qapi(ObjectOptions *options, Error **errp);
+
 /**
  * user_creatable_add_opts:
  * @opts: the object definition
@@ -131,6 +144,21 @@ typedef bool (*user_creatable_add_opts_predicate)(const char *type);
 int user_creatable_add_opts_foreach(void *opaque,
                                     QemuOpts *opts, Error **errp);
 
+/**
+ * user_creatable_process_cmdline:
+ * @optarg: the object definition string as passed on the command line
+ *
+ * Create an instance of the user creatable object by parsing optarg
+ * with a keyval parser and implicit key 'qom-type', converting the
+ * result to ObjectOptions and calling into qmp_object_add().
+ *
+ * If a help option is given, print help instead and exit.
+ *
+ * This function is only meant to be called during command line parsing.
+ * It exits the process on failure or after printing help.
+ */
+void user_creatable_process_cmdline(const char *optarg);
+
 /**
  * user_creatable_print_help:
  * @type: the QOM type to be added
@@ -145,19 +173,6 @@ int user_creatable_add_opts_foreach(void *opaque,
  */
 bool user_creatable_print_help(const char *type, QemuOpts *opts);
 
-/**
- * user_creatable_print_help_from_qdict:
- * @args: options to create
- *
- * Prints help considering the other options given in @args (if "qom-type" is
- * given and valid, print properties for the type, otherwise print valid types)
- *
- * In contrast to user_creatable_print_help(), this function can't return that
- * no help was requested. It should only be called if we know that help is
- * requested and it will always print some help.
- */
-void user_creatable_print_help_from_qdict(QDict *args);
-
 /**
  * user_creatable_del:
  * @id: the unique ID for the object

qom/object_interfaces.c

@@ -2,10 +2,13 @@
 
 #include "qemu/cutils.h"
 #include "qapi/error.h"
+#include "qapi/qapi-commands-qom.h"
+#include "qapi/qapi-visit-qom.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qjson.h"
 #include "qapi/qobject-input-visitor.h"
+#include "qapi/qobject-output-visitor.h"
 #include "qom/object_interfaces.h"
 #include "qemu/help_option.h"
 #include "qemu/id.h"
@@ -113,6 +116,30 @@ out:
     return obj;
 }
 
+void user_creatable_add_qapi(ObjectOptions *options, Error **errp)
+{
+    Visitor *v;
+    QObject *qobj;
+    QDict *props;
+    Object *obj;
+
+    v = qobject_output_visitor_new(&qobj);
+    visit_type_ObjectOptions(v, NULL, &options, &error_abort);
+    visit_complete(v, &qobj);
+    visit_free(v);
+
+    props = qobject_to(QDict, qobj);
+    qdict_del(props, "qom-type");
+    qdict_del(props, "id");
+
+    v = qobject_input_visitor_new(QOBJECT(props));
+    obj = user_creatable_add_type(ObjectType_str(options->qom_type),
+                                  options->id, props, v, errp);
+    object_unref(obj);
+    qobject_unref(qobj);
+    visit_free(v);
+}
+
 Object *user_creatable_add_opts(QemuOpts *opts, Error **errp)
 {
     Visitor *v;
@@ -256,7 +283,7 @@ bool user_creatable_print_help(const char *type, QemuOpts *opts)
     return false;
 }
 
-void user_creatable_print_help_from_qdict(QDict *args)
+static void user_creatable_print_help_from_qdict(QDict *args)
 {
     const char *type = qdict_get_try_str(args, "qom-type");
 
@@ -265,6 +292,28 @@ void user_creatable_print_help_from_qdict(QDict *args)
     }
 }
 
+void user_creatable_process_cmdline(const char *optarg)
+{
+    QDict *args;
+    bool help;
+    Visitor *v;
+    ObjectOptions *options;
+
+    args = keyval_parse(optarg, "qom-type", &help, &error_fatal);
+    if (help) {
+        user_creatable_print_help_from_qdict(args);
+        exit(EXIT_SUCCESS);
+    }
+
+    v = qobject_input_visitor_new_keyval(QOBJECT(args));
+    visit_type_ObjectOptions(v, NULL, &options, &error_fatal);
+    visit_free(v);
+    qobject_unref(args);
+
+    user_creatable_add_qapi(options, &error_fatal);
+    qapi_free_ObjectOptions(options);
+}
+
 bool user_creatable_del(const char *id, Error **errp)
 {
     QemuOptsList *opts_list;

qom/qom-qmp-cmds.c

@@ -228,25 +228,7 @@ ObjectPropertyInfoList *qmp_qom_list_properties(const char *typename,
 
 void qmp_object_add(ObjectOptions *options, Error **errp)
 {
-    Visitor *v;
-    QObject *qobj;
-    QDict *props;
-    Object *obj;
-
-    v = qobject_output_visitor_new(&qobj);
-    visit_type_ObjectOptions(v, NULL, &options, &error_abort);
-    visit_complete(v, &qobj);
-    visit_free(v);
-
-    props = qobject_to(QDict, qobj);
-    qdict_del(props, "qom-type");
-    qdict_del(props, "id");
-
-    v = qobject_input_visitor_new(QOBJECT(props));
-    obj = user_creatable_add_type(ObjectType_str(options->qom_type),
-                                  options->id, props, v, errp);
-    object_unref(obj);
-    visit_free(v);
+    user_creatable_add_qapi(options, errp);
 }
 
 void qmp_object_del(const char *id, Error **errp)

storage-daemon/qemu-storage-daemon.c

@@ -38,7 +38,6 @@
 #include "qapi/qapi-visit-block-core.h"
 #include "qapi/qapi-visit-block-export.h"
 #include "qapi/qapi-visit-control.h"
-#include "qapi/qapi-visit-qom.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qstring.h"
 #include "qapi/qobject-input-visitor.h"
@@ -271,27 +270,8 @@ static void process_options(int argc, char *argv[])
                 break;
             }
         case OPTION_OBJECT:
-            {
-                QDict *args;
-                bool help;
-                Visitor *v;
-                ObjectOptions *options;
-
-                args = keyval_parse(optarg, "qom-type", &help, &error_fatal);
-                if (help) {
-                    user_creatable_print_help_from_qdict(args);
-                    exit(EXIT_SUCCESS);
-                }
-
-                v = qobject_input_visitor_new_keyval(QOBJECT(args));
-                visit_type_ObjectOptions(v, NULL, &options, &error_fatal);
-                visit_free(v);
-                qobject_unref(args);
-
-                qmp_object_add(options, &error_fatal);
-                qapi_free_ObjectOptions(options);
+            user_creatable_process_cmdline(optarg);
             break;
-            }
         case OPTION_PIDFILE:
             pid_file = optarg;
             break;