Re: [Qemu-devel] [PATCH 2/7] qapi: QMP input visitor, handle floats parsed as ints

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 27 Apr 2012 15:21:18 -0500
Michael Roth <mdroth@linux.vnet.ibm.com> wrote:

> JSON numbers can be interpreted as either integers or floating point
> values depending on their representation. As a result, QMP input visitor
> might visit a QInt when it was expecting a QFloat, so add handling to
> account for this.
> 
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> ---
>  qapi/qmp-input-visitor.c |    9 +++++++--
>  1 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
> index 4cdc47d..bc91134 100644
> --- a/qapi/qmp-input-visitor.c
> +++ b/qapi/qmp-input-visitor.c
> @@ -246,13 +246,18 @@ static void qmp_input_type_number(Visitor *v, double *obj, const char *name,
>      QmpInputVisitor *qiv = to_qiv(v);
>      QObject *qobj = qmp_input_get_object(qiv, name);
>  
> -    if (!qobj || qobject_type(qobj) != QTYPE_QFLOAT) {
> +    if (!qobj || (qobject_type(qobj) != QTYPE_QFLOAT &&
> +        qobject_type(qobj) != QTYPE_QINT)) {
>          error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
>                    "double");

s/double/number

It's also important to note that migrate_set_downtime is (positively) affected
by this change. Today, it only accepts a double, eg.:

{ "execute": "migrate_set_downtime", "arguments": { "value": 1 } }
{
    "error": {
        "class": "InvalidParameterType", 
        "desc": "Invalid parameter type for 'value', expected: double", 
        "data": {
            "name": "value", 
            "expected": "double"
        }
    }
}

That's a bug (as it's documented to accept a number) and this patch fixes it.
There's an interface change, but I think it won't cause problems in practice.

Please, fix the error message above and would be nice to get this (and patch
02/07) as a separate series for 1.1.


>          return;
>      }
>  
> -    *obj = qfloat_get_double(qobject_to_qfloat(qobj));
> +    if (qobject_type(qobj) == QTYPE_QINT) {
> +        *obj = qint_get_int(qobject_to_qint(qobj));
> +    } else {
> +        *obj = qfloat_get_double(qobject_to_qfloat(qobj));
> +    }
>  }
>  
>  static void qmp_input_start_optional(Visitor *v, bool *present,