[Qemu-devel] [PATCH 1/4] qom: New object_gen_new_property_name()

[Markus Armbruster <armbru@redhat.com>]

The next few commits will use it to replace object_property_add()'s
"automatic arrayification" (commit 3396590).  "Automatic
arrayification" is a convenience feature for creating a bunch of
properties with a common type, accessors and so forth, named in a
peculiar way: "foo[0]", "foo[1]", ...  It's implemented by making
property names ending with "[*]" magical.  The magic is uncalled for,
as names can be just as well generated separately from adding
properties.

The name object_gen_new_property_name() is exceedingly long, but
that's how QOM names are.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 include/qom/object.h |  8 ++++++++
 qom/object.c         | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/qom/object.h b/include/qom/object.h
index 89c3092..b5c9201 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -832,6 +832,14 @@ void object_property_del(Object *obj, const char *name, Error **errp);
 ObjectProperty *object_property_find(Object *obj, const char *name,
                                      Error **errp);
 
+/*
+ * Return a property name that doesn't clash with @obj's existing ones.
+ * The name is of the form %s[%d], where %s is @stem, and %d counts up
+ * from zero.
+ * The caller should free the name.
+ */
+char *object_gen_new_property_name(Object *obj, const char *stem);
+
 void object_unparent(Object *obj);
 
 /**
diff --git a/qom/object.c b/qom/object.c
index 1812c73..4c46662 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -808,6 +808,20 @@ void object_property_del(Object *obj, const char *name, Error **errp)
     g_free(prop);
 }
 
+char *object_gen_new_property_name(Object *obj, const char *stem)
+{
+    int i;
+
+    for (i = 0; ; ++i) {
+        char *name = g_strdup_printf("%s[%d]", stem, i);
+
+        if (!object_property_find(obj, name, NULL)) {
+            return name;
+        }
+        g_free(name);
+    }
+}
+
 void object_property_get(Object *obj, Visitor *v, const char *name,
                          Error **errp)
 {
-- 
1.9.3