Re: [Qemu-devel] [PATCH 4/9] QMP: Second half of the new argument checking code

[Markus Armbruster <armbru@redhat.com>]

Luiz Capitulino <lcapitulino@redhat.com> writes:

> On Wed, 02 Jun 2010 09:31:24 +0200
> Markus Armbruster <armbru@redhat.com> wrote:
>
>> Luiz Capitulino <lcapitulino@redhat.com> writes:
>> 
>> > This commit introduces check_client_args_type(), which is
>> > called by qmp_check_client_args() and complements the
>> > previous commit.
>> >
>> > Now the new client's argument checker code is capable of
>> > doing type checking and detecting unknown arguments.
>> >
>> > It works this way: we iterate over the client's arguments
>> > qdict and for each argument we check if it exists and if
>> > its type is correct.
>> >
>> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
>> > ---
>> >  monitor.c |   77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>> >  1 files changed, 76 insertions(+), 1 deletions(-)
>> >
>> > diff --git a/monitor.c b/monitor.c
>> > index 47a0da8..14790e6 100644
>> > --- a/monitor.c
>> > +++ b/monitor.c
>> > @@ -4266,6 +4266,75 @@ typedef struct QMPArgCheckRes {
>> >  } QMPArgCheckRes;
>> >  
>> >  /*
>> > + * Check if client's argument exists and type is correct
>> > + */
>> > +static void check_client_args_type(const char *client_arg_name,
>> > +                                   QObject *client_arg, void *opaque)
>> > +{
>> > +    QObject *obj;
>> > +    QString *arg_type;
>> > +    QMPArgCheckRes *res = opaque;
>> > +
>> > +    if (res->result < 0) {
>> > +        /* report only the first error */
>> > +        return;
>> > +    }
>> > +
>> > +    obj = qdict_get(res->qdict, client_arg_name);
>> > +    if (!obj) {
>> > +        /* client arg doesn't exist */
>> > +        res->result = -1;
>> > +        qerror_report(QERR_INVALID_PARAMETER, client_arg_name);
>> > +        return;
>> > +    }
>> > +
>> > +    arg_type = qobject_to_qstring(obj);
>> > +    assert(arg_type != NULL);
>> > +
>> > +    /* check if argument's type is correct */
>> > +    switch (qstring_get_str(arg_type)[0]) {
>> > +    case 'F':
>> > +    case 'B':
>> > +    case 's':
>> > +        if (qobject_type(client_arg) != QTYPE_QSTRING) {
>> > +            qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name,
>> > +                          "string");
>> > +            res->result = -1;
>> > +        }
>> > +        break;
>> > +    case 'i':
>> > +    case 'l':
>> > +    case 'M':
>> > +        if (qobject_type(client_arg) != QTYPE_QINT) {
>> > +            qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name, "int");
>> > +            res->result = -1;
>> > +        }
>> > +        break;
>> > +    case 'f':
>> > +    case 'T':
>> > +        if (qobject_type(client_arg) != QTYPE_QINT &&
>> > +            qobject_type(client_arg) != QTYPE_QFLOAT) {
>> > +            qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name,
>> > +                          "number");
>> > +            res->result = -1;
>> > +        }
>> > +        break;
>> > +    case 'b':
>> > +    case '-':
>> > +        if (qobject_type(client_arg) != QTYPE_QBOOL) {
>> > +            qerror_report(QERR_INVALID_PARAMETER_TYPE, client_arg_name, "bool");
>> > +            res->result = -1;
>> > +        }
>> > +        break;
>> > +    case 'O':
>> > +        /* Not checked here */
>> > +        break;
>> 
>> What about case '/'?  I guess it doesn't make much sense for QMP, but
>> the old checker handles it.  If we drop it from QMP, we should document
>> the restriction in the source.
>
>  Yes, there're two args_type we don't handle in QMP because we don't have
> any of those handlers converted: '/' and '.'.
>
>  I think it's unlikely to get them converted in this form, so the current
> implementation contains dead-code. I explained this in one commit log, but
> maybe it's the wrong place.

I read that commit message after I sent my comment :)

The commit message is fine; I'd like a comment in the code in addition,
not instead of the commit message.

[...]