[RFC PATCH] qom: Extract object_try_new() from qdev_new()

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

The module resolving in qdev_new() is specific to QOM, not to
QDev. Extract the code as a new QOM object_try_new() helper so
it can be reused by non-QDev code.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
RFC because I'm wonder if we can't find a better name...

Also, should we refactor object_initialize() similarly,
having object_try_initialize(..., Error *)?
---
 hw/core/qdev.c       | 23 ++---------------------
 include/qom/object.h | 12 ++++++++++++
 qom/object.c         | 23 +++++++++++++++++++++++
 3 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index d759c4602c..3a076dcc7f 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -147,31 +147,12 @@ bool qdev_set_parent_bus(DeviceState *dev, BusState *bus, Error **errp)
 
 DeviceState *qdev_new(const char *name)
 {
-    ObjectClass *oc = object_class_by_name(name);
-#ifdef CONFIG_MODULES
-    if (!oc) {
-        int rv = module_load_qom(name, &error_fatal);
-        if (rv > 0) {
-            oc = object_class_by_name(name);
-        } else {
-            error_report("could not find a module for type '%s'", name);
-            exit(1);
-        }
-    }
-#endif
-    if (!oc) {
-        error_report("unknown type '%s'", name);
-        abort();
-    }
-    return DEVICE(object_new(name));
+    return DEVICE(object_try_new(name, &error_fatal));
 }
 
 DeviceState *qdev_try_new(const char *name)
 {
-    if (!module_object_class_by_name(name)) {
-        return NULL;
-    }
-    return DEVICE(object_new(name));
+    return DEVICE(object_try_new(name, NULL));
 }
 
 static QTAILQ_HEAD(, DeviceListener) device_listeners
diff --git a/include/qom/object.h b/include/qom/object.h
index ef7258a5e1..9cc5bf30ec 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -565,6 +565,18 @@ Object *object_new_with_class(ObjectClass *klass);
  */
 Object *object_new(const char *typename);
 
+/**
+ * object_try_new: Try to create an object on the heap
+ * @name: The name of the type of the object to instantiate.
+ * @errp: pointer to Error object.
+ *
+ * This is like object_new(), except it returns %NULL when type @name
+ * does not exist, rather than asserting.
+ *
+ * Returns: The newly allocated and instantiated object, or %NULL.
+ */
+Object *object_try_new(const char *name, Error **errp);
+
 /**
  * object_new_with_props:
  * @typename:  The name of the type of the object to instantiate.
diff --git a/qom/object.c b/qom/object.c
index e25f1e96db..6d3faaeb6e 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -755,6 +755,29 @@ Object *object_new(const char *typename)
 }
 
 
+Object *object_try_new(const char *name, Error **errp)
+{
+    TypeImpl *ti = type_get_by_name(name);
+
+    if (!ti) {
+#ifdef CONFIG_MODULES
+        int rv = module_load_qom(name, errp);
+        if (rv <= 0) {
+            error_report("could not find a module for type '%s'", name);
+            exit(1);
+        }
+        ti = type_get_by_name(name);
+#endif
+    }
+    if (!ti) {
+        error_setg(errp, "unknown type '%s'", name);
+        return NULL;
+    }
+
+    return object_new_with_type(ti);
+}
+
+
 Object *object_new_with_props(const char *typename,
                               Object *parent,
                               const char *id,
-- 
2.38.1