Re: [Qemu-devel] [PATCH v2 12/15] qbus_find(): propagate error handling / consumption to callers

[Markus Armbruster]

Laszlo Ersek <ler...@redhat.com> writes:

> Conversion status (call chains covered or substituted by error propagation
> marked with square brackets):
>
> do_device_add -> [qemu_find_opts -> error_report]
> do_device_add -> qdev_device_add -> qerror_report
> do_device_add -> qdev_device_add -> [qbus_find -> qbus_find_recursive
>   -> qerror_report]
> do_device_add -> qdev_device_add -> [qbus_find -> qerror_report]
> do_device_add -> qdev_device_add -> [set_property -> qdev_prop_parse
>   -> qerror_report_err]
>
> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
> ---
>  hw/qdev-monitor.c |   30 ++++++++++++++++--------------
>  1 files changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
> index 728aa24..80fc9f8 100644
> --- a/hw/qdev-monitor.c
> +++ b/hw/qdev-monitor.c
> @@ -371,20 +371,20 @@ static BusState *qbus_find(const char *path, Error 
> **errp)
>          bus = sysbus_get_default();
>          pos = 0;
>      } else {
> -        Error *err = NULL;
> +        Error *named_bus_full = NULL;
>  
>          if (sscanf(path, "%127[^/]%n", elem, &len) != 1) {
>              assert(!path[0]);
>              elem[0] = len = 0;
>          }
> -        bus = qbus_find_recursive(sysbus_get_default(), elem, NULL, &err);
> +        bus = qbus_find_recursive(sysbus_get_default(), elem, NULL,
> +                                  &named_bus_full);
>          if (!bus) {
> -            if (error_is_set(&err)) {
> -                qerror_report_err(err);
> -                error_free(err);
> -            } else {
> -                qerror_report(QERR_BUS_NOT_FOUND, elem);
> -            }
> +            Error *not_found = NULL;
> +
> +            error_set(&not_found, QERR_BUS_NOT_FOUND, elem);
> +            error_propagate(errp, named_bus_full);
> +            error_propagate(errp, not_found);
>              return NULL;
>          }
>          pos = len;

Cute trick!

Would look even cuter if we had a function returning a newly minted
error object.

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