Re: [Qemu-devel] [PATCH v3 7/9] chardev: add error reporting for qemu_chr_new_from_opts

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 15 Oct 2012 10:06:55 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  qemu-char.c |   24 +++++++++++++++---------
>  qemu-char.h |    3 ++-
>  vl.c        |    7 ++++++-
>  3 files changed, 23 insertions(+), 11 deletions(-)
> 
> diff --git a/qemu-char.c b/qemu-char.c
> index b082bae..e2e1da8 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2755,19 +2755,20 @@ static const struct {
>  };
>  
>  CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
> -                                    void (*init)(struct CharDriverState *s))
> +                                    void (*init)(struct CharDriverState *s),
> +                                    Error **errp)
>  {
>      CharDriverState *chr;
>      int i;
>  
>      if (qemu_opts_id(opts) == NULL) {
> -        fprintf(stderr, "chardev: no id specified\n");
> +        error_setg(errp, "chardev: no id specified\n");
>          return NULL;
>      }
>  
>      if (qemu_opt_get(opts, "backend") == NULL) {
> -        fprintf(stderr, "chardev: \"%s\" missing backend\n",
> -                qemu_opts_id(opts));
> +        error_setg(errp, "chardev: \"%s\" missing backend\n",
> +                   qemu_opts_id(opts));
>          return NULL;
>      }
>      for (i = 0; i < ARRAY_SIZE(backend_table); i++) {
> @@ -2775,15 +2776,15 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
>              break;
>      }
>      if (i == ARRAY_SIZE(backend_table)) {
> -        fprintf(stderr, "chardev: backend \"%s\" not found\n",
> -                qemu_opt_get(opts, "backend"));
> +        error_setg(errp, "chardev: backend \"%s\" not found\n",
> +                   qemu_opt_get(opts, "backend"));
>          return NULL;
>      }
>  
>      chr = backend_table[i].open(opts);
>      if (!chr) {
> -        fprintf(stderr, "chardev: opening backend \"%s\" failed\n",
> -                qemu_opt_get(opts, "backend"));
> +        error_setg(errp, "chardev: opening backend \"%s\" failed\n",
> +                   qemu_opt_get(opts, "backend"));
>          return NULL;
>      }
>  
> @@ -2813,6 +2814,7 @@ CharDriverState *qemu_chr_new(const char *label, const char *filename, void (*in
>      const char *p;
>      CharDriverState *chr;
>      QemuOpts *opts;
> +    Error *err = NULL;
>  
>      if (strstart(filename, "chardev:", &p)) {
>          return qemu_chr_find(p);
> @@ -2822,7 +2824,11 @@ CharDriverState *qemu_chr_new(const char *label, const char *filename, void (*in
>      if (!opts)
>          return NULL;
>  
> -    chr = qemu_chr_new_from_opts(opts, init);
> +    chr = qemu_chr_new_from_opts(opts, init, &err);
> +    if (error_is_set(&err)) {
> +        fprintf(stderr, "%s\n", error_get_pretty(err));
> +        error_free(err);
> +    }
>      if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
>          monitor_init(chr, MONITOR_USE_READLINE);
>      }
> diff --git a/qemu-char.h b/qemu-char.h
> index 486644b..adae13e 100644
> --- a/qemu-char.h
> +++ b/qemu-char.h
> @@ -88,7 +88,8 @@ struct CharDriverState {
>   * Returns: a new character backend
>   */
>  CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
> -                                    void (*init)(struct CharDriverState *s));
> +                                    void (*init)(struct CharDriverState *s),
> +                                    Error **errp);
>  
>  /**
>   * @qemu_chr_new:
> diff --git a/vl.c b/vl.c
> index 5b357a3..35eb627 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1940,8 +1940,13 @@ static int device_init_func(QemuOpts *opts, void *opaque)
>  static int chardev_init_func(QemuOpts *opts, void *opaque)
>  {
>      CharDriverState *chr;
> +    Error *err = NULL;
>  
> -    chr = qemu_chr_new_from_opts(opts, NULL);
> +    chr = qemu_chr_new_from_opts(opts, NULL, &err);
> +    if (error_is_set(&err)) {
> +        fprintf(stderr, "%s\n", error_get_pretty(err));
> +        error_free(err);
> +    }
>      if (!chr)
>          return -1;

If you respin, please drop that check as it's not needed. Also, we usually
name the "internal" Error variable local_err.

>      return 0;