答复： [PATCH v4 5/5] object: Add 'help' option for all available backends and properties

Commit Message

James J. Nutaro Dec. 2, 2016, 6:37 p.m. UTC

Hi Lin,

My comments are inline with the patch.

ping...

>>> Lin Ma <address@hidden> 2016/10/20 星期四 下午 7:28 >>>

'-object help' prints available user creatable backends.
'-object $typename,help' prints relevant properties.

Signed-off-by: Lin Ma <address@hidden>

---
include/qom/object_interfaces.h |  2 ++
qemu-options.hx                          |  7 +++++-
qom/object_interfaces.c          | 55 +++++++++++++++++++++++++++++++++++++++++
vl.c                                                |  5 ++++
4 files changed, 68 insertions(+), 1 deletion(-)

-- 
2.9.2

Patch

diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h
index 8b17f4d..197cd5f 100644
--- a/include/qom/object_interfaces.h
+++ b/include/qom/object_interfaces.h
@@ -165,4 +165,6 @@  int user_creatable_add_opts_foreach(void *opaque,
  */
void user_creatable_del(const char *id, Error **errp);

+int user_creatable_help_func(void *opaque, QemuOpts *opts, Error **errp);
+
#endif
diff --git a/qemu-options.hx b/qemu-options.hx
index b1fbdb0..b9573ce 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3761,7 +3761,9 @@  DEF("object", HAS_ARG, QEMU_OPTION_object,
         "                          create a new object of type TYPENAME 
setting properties\n"
         "                          in the order they are specified.  Note that 
the 'id'\n"
         "                          property must be set.  These objects are 
placed in the\n"
-    "                     '/objects' path.\n",
+    "                     '/objects' path.\n"
+    "                     Use '-object help' to print available backend types 
and\n"
+    "                     '-object typename,help' to print relevant 
properties.\n",
         QEMU_ARCH_ALL)
STEXI
@item -object @var{typename}[,@address@hidden,...]
@@ -3771,6 +3773,9 @@  in the order they are specified.  Note that the 'id'
property must be set.  These objects are placed in the
'/objects' path.

+Use @code{-object help} to print available backend types and
address@hidden @var{typename},help} to print relevant properties.
+
@table @option

@item -object 
memory-backend-file,address@hidden,address@hidden,address@hidden,address@hidden|off}
diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index bf59846..da8be39 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -5,6 +5,7 @@ 
#include "qapi-visit.h"
#include "qapi/qmp-output-visitor.h"
#include "qapi/opts-visitor.h"
+#include "qemu/help_option.h"

void user_creatable_complete(Object *obj, Error **errp)
{
@@ -212,6 +213,60 @@  void user_creatable_del(const char *id, Error **errp)
         object_unparent(obj);
}

+int user_creatable_help_func(void *opaque, QemuOpts *opts, Error **errp)
+{
+    const char *type = NULL;
+    Object *obj = NULL;
+    ObjectClass *klass;
+    ObjectProperty *prop;
+    ObjectPropertyIterator iter;
+
+    type = qemu_opt_get(opts, "qom-type");
+    if (type && is_help_option(type)) {
+           GSList *list;
+           printf("Available object backend types:\n");
+           for (list = object_class_get_list(TYPE_USER_CREATABLE, false);  \
+                           list;                                               
                                                  \
+                           list = list->next) {
+                   const char *name;
+                   name = object_class_get_name(OBJECT_CLASS(list->data));
+                   if (strcmp(name, TYPE_USER_CREATABLE)) {
+                           printf("%s\n", name);
+                   }
+           }
+           g_slist_free(list);
+           goto out;
+    }
+

Is obj == NULL at this call to goto out? If so, you could simply return 1.

+    if (!type || !qemu_opt_has_help_opt(opts)) {
+           return 0;
+    }
+
+    klass = object_class_by_name(type);
+    if (!klass) {
+           printf("invalid object type: %s\n", type);
+           goto out;
+    }

If obj == NULL here too?

+    if (object_class_is_abstract(klass)) {
+           printf("object type '%s' is abstract\n", type);
+           goto out;
+    }

And here?

+    obj = object_new(type);

If this is the only place that obj is set to a non-NULL value, then the goto calls above can be replaced with returns.

+    object_property_iter_init(&iter, obj);
+
+    while ((prop = object_property_iter_next(&iter))) {
+           if (prop->description) {
+                   printf("%s (%s, %s)\n", prop->name, prop->type, 
prop->description);
+           } else {
+                   printf("%s (%s)\n", prop->name, prop->type);
+           }
+    }
+
+out:
+    object_unref(obj);
+    return 1;
+}
+

static void register_types(void)
{
         static const TypeInfo uc_interface_info = {
diff --git a/vl.c b/vl.c
index ebd47af..145
6eca 100644
--- a/vl.c
+++ b/vl.c
@@ -4100,6 +4100,11 @@  int main(int argc, char **argv, char **envp)
                 exit(0);
         }

+    if (qemu_opts_foreach(qemu_find_opts("object"), user_creatable_help_func,
+                                                 NULL, NULL)) {
+           exit(1);
+    }
+
         if (!trace_init_backends()) {
                 exit(1);
         }