Re: [PATCH v2 5/9] qapi: Generalize struct member policy checking

[Eric Blake]

On Thu, Oct 28, 2021 at 12:25:16PM +0200, Markus Armbruster wrote:
> The generated visitor functions call visit_deprecated_accept() and
> visit_deprecated() when visiting a struct member with special feature
> flag 'deprecated'.  This makes the feature flag visible to the actual
> visitors.  I want to make feature flag 'unstable' visible there as
> well, so I can add policy for it.
> 
> To let me make it visible, replace these functions by
> visit_policy_reject() and visit_policy_skip(), which take the member's
> special features as an argument.  Note that the new functions have the
> opposite sense, i.e. the return value flips.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---

> +++ b/qapi/qapi-forward-visitor.c
> @@ -246,25 +246,27 @@ static void forward_field_optional(Visitor *v, const 
> char *name, bool *present)
>      visit_optional(ffv->target, name, present);
>  }
>  
> -static bool forward_field_deprecated_accept(Visitor *v, const char *name,
> -                                            Error **errp)
> +static bool forward_field_policy_reject(Visitor *v, const char *name,
> +                                        unsigned special_features,
> +                                        Error **errp)
>  {
>      ForwardFieldVisitor *ffv = to_ffv(v);
>  
>      if (!forward_field_translate_name(ffv, &name, errp)) {
>          return false;

Should this return value be flipped?

>      }
> -    return visit_deprecated_accept(ffv->target, name, errp);
> +    return visit_policy_reject(ffv->target, name, special_features, errp);
>  }
>  
> -static bool forward_field_deprecated(Visitor *v, const char *name)
> +static bool forward_field_policy_skip(Visitor *v, const char *name,
> +                                      unsigned special_features)
>  {
>      ForwardFieldVisitor *ffv = to_ffv(v);
>  
>      if (!forward_field_translate_name(ffv, &name, NULL)) {
>          return false;

and here too?

>      }
> -    return visit_deprecated(ffv->target, name);
> +    return visit_policy_skip(ffv->target, name, special_features);
>  }
>  

Otherwise, the rest of the logic changes for flipped sense look right.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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