Re: [PATCH v2 2/2] storage-daemon: include current command line option in the errors

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Use the location management facilities that the emulator uses, so that
> the current command line option appears in the error message.
>
> Before:
>
>   $ storage-daemon/qemu-storage-daemon --nbd key..=
>   qemu-storage-daemon: Invalid parameter 'key..'
>
> After:
>
>   $ storage-daemon/qemu-storage-daemon --nbd key..=
>   qemu-storage-daemon: --nbd key..=: Invalid parameter 'key..'
>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

I have a similar patch in an unfinished branch.  You win :)

> ---
>  storage-daemon/qemu-storage-daemon.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c
> index 9aa82e7d96..78ddf619d4 100644
> --- a/storage-daemon/qemu-storage-daemon.c
> +++ b/storage-daemon/qemu-storage-daemon.c
> @@ -152,6 +152,20 @@ static void init_qmp_commands(void)
>                           qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
>  }
>  
> +static int getopt_set_loc(int argc, char **argv, const char *optstring,
> +                          const struct option *longopts)
> +{
> +    int c, save_index;
> +
> +    optarg = NULL;
> +    save_index = optind;
> +    c = getopt_long(argc, argv, optstring, longopts, NULL);
> +    if (optarg) {
> +        loc_set_cmdline(argv, save_index, MAX(1, optind - save_index));
> +    }
> +    return c;
> +}
> +

I think this function is more widely applicable:

    $ git-grep -l getopt_long | xargs grep -l error_report
    qemu-img.c
    qemu-io.c
    qemu-nbd.c
    scsi/qemu-pr-helper.c
    storage-daemon/qemu-storage-daemon.c

>  static void process_options(int argc, char *argv[])
>  {
>      int c;
> @@ -174,7 +188,7 @@ static void process_options(int argc, char *argv[])
>       * they are given on the command lines. This means that things must be
>       * defined first before they can be referenced in another option.
>       */
> -    while ((c = getopt_long(argc, argv, "-hT:V", long_options, NULL)) != -1) {
> +    while ((c = getopt_set_loc(argc, argv, "-hT:V", long_options)) != -1) {
>          switch (c) {
>          case '?':
>              exit(EXIT_FAILURE);
> @@ -275,12 +289,13 @@ static void process_options(int argc, char *argv[])
>                  break;
>              }
>          case 1:
> -            error_report("Unexpected argument: %s", optarg);
> +            error_report("Unexpected argument");
>              exit(EXIT_FAILURE);
>          default:
>              g_assert_not_reached();
>          }
>      }
> +    loc_set_none();
>  }
>  
>  int main(int argc, char *argv[])