[FFmpeg-devel] [PATCH 4/4] lavu/log: do not assume AVClass.item_name is always set

[James Almer]

On 11/7/2023 9:58 AM, Anton Khirnov wrote:
> ---
>   libavutil/log.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/libavutil/log.c b/libavutil/log.c
> index 2d358b7ab9..46662f3db0 100644
> --- a/libavutil/log.c
> +++ b/libavutil/log.c
> @@ -291,6 +291,11 @@ static const char *get_level_str(int level)
>       }
>   }
>   
> +static const char *item_name(void *obj, const AVClass *cls)
> +{
> +    return (cls->item_name ? cls->item_name : av_default_item_name)(obj);
> +}
> +
>   static void format_line(void *avcl, int level, const char *fmt, va_list vl,
>                           AVBPrint part[4], int *print_prefix, int type[2])
>   {
> @@ -307,12 +312,12 @@ static void format_line(void *avcl, int level, const char *fmt, va_list vl,
>                                      avc->parent_log_context_offset);
>               if (parent && *parent) {
>                   av_bprintf(part+0, "[%s @ %p] ",
> -                         (*parent)->item_name(parent), parent);
> +                           item_name(parent, *parent), parent);
>                   if(type) type[0] = get_category(parent);
>               }
>           }
>           av_bprintf(part+1, "[%s @ %p] ",
> -                 avc->item_name(avcl), avcl);
> +                   item_name(avcl, avc), avcl);
>           if(type) type[1] = get_category(avcl);
>       }

If this lets us define an AVClass without having to add the item_name = 
av_default_item_name line, then +1.

Btw, there's also .version that's always set to LIBAVUTIL_VERSION_INT, 
but that can't be changed as they are compile time constants. What can 
probably be dropped however are the checks in log.c for runtime major 
version 50 and 51.