Re: [Qemu-devel] [PATCH 06/10] qapi: simplify qmp_input_next_list

[Anthony Liguori <anthony@codemonkey.ws>]

On 03/22/2012 06:51 AM, Paolo Bonzini wrote:
> Tweak a bit the code so that there is cleaner separation between
> operation on the list and operation on the output.  The next patch
> requires this change.
>
> Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>

I've been staring a this patch for the past 5 minutes and I can't figure out 
what's going on here.

Maybe the code was too obscure to begin with.  Could you enhance the commit 
message a bit with what's going on here?

Regards,

Anthony Liguori

> ---
>   qapi/qmp-input-visitor.c |   15 +++++++--------
>   1 files changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
> index ef9288f..dfc859a 100644
> --- a/qapi/qmp-input-visitor.c
> +++ b/qapi/qmp-input-visitor.c
> @@ -64,9 +64,7 @@ static const QObject *qmp_input_get_object(QmpInputVisitor *qiv,
>   static void qmp_input_push(QmpInputVisitor *qiv, const QObject *obj, Error **errp)
>   {
>       qiv->stack[qiv->nb_stack].obj = obj;
> -    if (qobject_type(obj) == QTYPE_QLIST) {
> -        qiv->stack[qiv->nb_stack].entry = qlist_first(qobject_to_qlist(obj));
> -    }
> +    qiv->stack[qiv->nb_stack].entry = NULL;
>       qiv->nb_stack++;
>
>       if (qiv->nb_stack>= QIV_STACK_SIZE) {
> @@ -134,16 +132,17 @@ static GenericList *qmp_input_next_list(Visitor *v, GenericList **list,
>       StackObject *so =&qiv->stack[qiv->nb_stack - 1];
>
>       if (so->entry == NULL) {
> +        so->entry = qlist_first(qobject_to_qlist(so->obj));
> +    } else {
> +        so->entry = qlist_next(so->entry);
> +    }
> +
> +    if (so->entry == NULL) {
>           return NULL;
>       }
>
>       entry = g_malloc0(sizeof(*entry));
>       if (*list) {
> -        so->entry = qlist_next(so->entry);
> -        if (so->entry == NULL) {
> -            g_free(entry);
> -            return NULL;
> -        }
>           (*list)->next = entry;
>       }
>