Re: [Qemu-devel] [RFC PATCH 1/6] machine: add a deprecated_reason property

[Thomas Huth <thuth@redhat.com>]

On 08.11.2017 03:28, Philippe Mathieu-Daudé wrote:
> If a machine has the deprecated_reason property set:
> - it won't get listed anymore by the "-M help" command,
> - a warning will be displayed if the machine is used.
> 
> Example:
>   $ ppc-softmmu/qemu-system-ppc -M prep
>   qemu-system-ppc: -M prep: warning: The PowerPC PREP platform machine is deprecated (Obsoleted by the "40p" machine)
>   [machine starting ...]
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  include/hw/boards.h | 1 +
>  vl.c                | 7 +++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 191a5b3cd8..4d5c180968 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -182,6 +182,7 @@ struct MachineClass {
>      const char *default_boot_order;
>      const char *default_display;
>      GArray *compat_props;
> +    const char *deprecated_reason;
>      const char *hw_version;
>      ram_addr_t default_ram_size;
>      const char *default_cpu_type;
> diff --git a/vl.c b/vl.c
> index ec299099ff..9ed4648af2 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2742,6 +2742,10 @@ static gint machine_class_cmp(gconstpointer a, gconstpointer b)
>      }
>      if (mc) {
>          g_slist_free(machines);
> +        if (mc->deprecated_reason) {
> +            warn_report("The %s machine is deprecated (%s)",
> +                        mc->desc, mc->deprecated_reason);
> +        }

Just cosmetic, but maybe rather put that into select_machine() instead?

>          return mc;
>      }
>      if (name && !is_help_option(name)) {
> @@ -2752,6 +2756,9 @@ static gint machine_class_cmp(gconstpointer a, gconstpointer b)
>          machines = g_slist_sort(machines, machine_class_cmp);
>          for (el = machines; el; el = el->next) {
>              MachineClass *mc = el->data;
> +            if (mc->deprecated_reason) {
> +                continue;
> +            }

Not sure, but maybe it would be more user-friendly to still list the
machine, but add a "(deprecated)" string at the end?

 Thomas