Re: [PATCH 30/41] qom: Make type checker functions accept const pointers

[Daniel P . Berrangé]

On Thu, Aug 13, 2020 at 06:26:14PM -0400, Eduardo Habkost wrote:
> The existing type check macros all unconditionally drop const
> qualifiers from their arguments.  Keep this behavior in the
> macros generated by DECLARE_*CHECKER* by now.
> 
> In the future, we might use _Generic to preserve const-ness of
> the cast function arguments.

I'm not sure what you mean by "use _Generic" ?

> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  include/qom/object.h | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

> 
> diff --git a/include/qom/object.h b/include/qom/object.h
> index 4cd84998c2..1d6a520d35 100644
> --- a/include/qom/object.h
> +++ b/include/qom/object.h
> @@ -567,7 +567,7 @@ struct Object
>   */
>  #define DECLARE_INSTANCE_CHECKER(InstanceType, OBJ_NAME, TYPENAME) \
>      static inline G_GNUC_UNUSED InstanceType * \
> -    OBJ_NAME(void *obj) \
> +    OBJ_NAME(const void *obj) \
>      { return OBJECT_CHECK(InstanceType, obj, TYPENAME); }
>  
>  /**
> @@ -581,14 +581,16 @@ struct Object
>   *
>   * This macro will provide the three standard type cast functions for a
>   * QOM type.
> + *
> + *FIXME: Use _Generic to make this const-safe
>   */
>  #define DECLARE_CLASS_CHECKERS(ClassType, OBJ_NAME, TYPENAME) \
>      static inline G_GNUC_UNUSED ClassType * \
> -    OBJ_NAME##_GET_CLASS(void *obj) \
> +    OBJ_NAME##_GET_CLASS(const void *obj) \
>      { return OBJECT_GET_CLASS(ClassType, obj, TYPENAME); } \
>      \
>      static inline G_GNUC_UNUSED ClassType * \
> -    OBJ_NAME##_CLASS(void *klass) \
> +    OBJ_NAME##_CLASS(const void *klass) \
>      { return OBJECT_CLASS_CHECK(ClassType, klass, TYPENAME); }
>  
>  /**
> -- 
> 2.26.2
> 

Regards,
Daniel
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