Re: [Qemu-devel] [RFC PATCH 1/3] qdev: Add a description field for qdev properties for documentation

[Markus Armbruster]

Amit Shah <address@hidden> writes:

> Add a 'description' along with each qdev property to document the input
> each qdev property takes.
>
> Signed-off-by: Amit Shah <address@hidden>

I always wanted this, and never got around to code it up.  Thanks!

[...]
> diff --git a/block_int.h b/block_int.h
> index 1a7240c..767cd29 100644
> --- a/block_int.h
> +++ b/block_int.h
> @@ -231,12 +231,12 @@ static inline unsigned int 
> get_physical_block_exp(BlockConf *conf)
>  }
>  
>  #define DEFINE_BLOCK_PROPERTIES(_state, _conf)                          \
> -    DEFINE_PROP_DRIVE("drive", _state, _conf.dinfo),                    \
> +    DEFINE_PROP_DRIVE("drive", _state, _conf.dinfo, ""),                \
>      DEFINE_PROP_UINT16("logical_block_size", _state,                    \
> -                       _conf.logical_block_size, 512),                  \
> +                       _conf.logical_block_size, 512, ""),              \
>      DEFINE_PROP_UINT16("physical_block_size", _state,                   \
> -                       _conf.physical_block_size, 512),                 \
> -    DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 512),  \
> -    DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 512)
> +                       _conf.physical_block_size, 512, ""),             \
> +    DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 512, ""), \
> +    DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 512, "")

NULL feels more natural than "" for missing description.

[...]
> diff --git a/hw/qdev.c b/hw/qdev.c
> index af17486..2cd205b 100644
> --- a/hw/qdev.c
> +++ b/hw/qdev.c
> @@ -187,7 +187,8 @@ int qdev_device_help(QemuOpts *opts)
>          if (!prop->info->parse) {
>              continue;           /* no way to set it, don't show */
>          }
> -        error_printf("%s.%s=%s\n", info->name, prop->name, prop->info->name);
> +        error_printf("%s.%s=%s, %s\n", info->name, prop->name,
> +                     prop->info->name, prop->desc ?: "");

The ?: operator a gcc extension.  Do we care?

>      }
>      return 1;
>  }
[...]