Am 30.11.2011 22:03, schrieb Anthony Liguori:
> Expose all legacy properties through the new QOM property mechanism. The qdev
> property types are exposed through the 'legacy<>' namespace. They are always
> visited as strings since they do their own string parsing.
>
> Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
> ---
> hw/qdev.c | 82
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> hw/qdev.h | 7 +++++
> 2 files changed, 89 insertions(+), 0 deletions(-)
Not directly related to this patch, but looking for the first time at
visitor code, visitors are clearly underdocumented.
> +static void qdev_get_legacy_property(DeviceState *dev, Visitor *v, void
> *opaque,
> + const char *name, Error **errp)
> +{
> + Property *prop = opaque;
> +
> + if (prop->info->print) {
> + char buffer[1024];
> + char *ptr = buffer;
> +
> + prop->info->print(dev, prop, buffer, sizeof(buffer));
> + visit_type_str(v, &ptr, name, errp);
So a string output visitor (this is what it's called, right?) takes a
buffer on the stack that the visitor must not free...
> + } else {
> + error_set(errp, QERR_PERMISSION_DENIED);
> + }
> +}
> +
> +static void qdev_set_legacy_property(DeviceState *dev, Visitor *v, void
> *opaque,
> + const char *name, Error **errp)
> +{
> + Property *prop = opaque;
> +
> + if (dev->state != DEV_STATE_CREATED) {
> + error_set(errp, QERR_PERMISSION_DENIED);
> + return;
> + }
> +
> + if (prop->info->parse) {
> + Error *local_err = NULL;
> + char *ptr = NULL;
> +
> + visit_type_str(v, &ptr, name, &local_err);
> + if (!local_err) {
> + int ret;
> + ret = prop->info->parse(dev, prop, ptr);
> + if (ret != 0) {
> + error_set(errp, QERR_INVALID_PARAMETER_VALUE,
> + name, prop->info->name);
> + }
> + g_free(ptr);
...but a string input visitor creates a copy that must be freed.
Kind of surprising behaviour, and qapi-visit-core.h doesn't document it.
Kevin
