[Qemu-devel] [PATCH v2] char: don't exit on hmp 'chardev-add help'

[Qemu-devel] [PATCH v2] char: don't exit on hmp 'chardev-add help'

[Anton Nefedov]

qemu_chr_new_from_opts() is used from both vl.c and hmp,
and it is quite confusing to see qemu suddenly exit after receiving a help
option in hmp.

Do exit(0) from vl.c instead.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
---
 include/chardev/char.h |  4 +++-
 chardev/char.c         |  2 +-
 vl.c                   | 10 ++++++----
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/chardev/char.h b/include/chardev/char.h
index 1604ea9..66dde46 100644
--- a/include/chardev/char.h
+++ b/include/chardev/char.h
@@ -65,7 +65,9 @@ struct Chardev {
  *
  * @opts see qemu-config.c for a list of valid options
  *
- * Returns: a new character backend
+ * Returns: on success: a new character backend
+ *          otherwise:  NULL; @errp specifies the error
+ *                            or left untouched in case of help option
  */
 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
                                 Error **errp);
diff --git a/chardev/char.c b/chardev/char.c
index c34b44a..5d283b9 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -620,7 +620,7 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
 
         error_report("Available chardev backend types: %s", str->str);
         g_string_free(str, true);
-        exit(0);
+        return NULL;
     }
 
     if (id == NULL) {
diff --git a/vl.c b/vl.c
index fb6b2ef..47bfe51 100644
--- a/vl.c
+++ b/vl.c
@@ -2344,10 +2344,12 @@ static int chardev_init_func(void *opaque, QemuOpts *opts, Error **errp)
 {
     Error *local_err = NULL;
 
-    qemu_chr_new_from_opts(opts, &local_err);
-    if (local_err) {
-        error_report_err(local_err);
-        return -1;
+    if (!qemu_chr_new_from_opts(opts, &local_err)) {
+        if (local_err) {
+            error_report_err(local_err);
+            return -1;
+        }
+        exit(0);
     }
     return 0;
 }
-- 
2.7.4

Re: [Qemu-devel] [PATCH v2] char: don't exit on hmp 'chardev-add help'

[Paolo Bonzini]

On 25/07/2017 12:04, Anton Nefedov wrote:
> qemu_chr_new_from_opts() is used from both vl.c and hmp,
> and it is quite confusing to see qemu suddenly exit after receiving a help
> option in hmp.
> 
> Do exit(0) from vl.c instead.

Queued, thanks.

Paolo

> Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
> ---
>  include/chardev/char.h |  4 +++-
>  chardev/char.c         |  2 +-
>  vl.c                   | 10 ++++++----
>  3 files changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/include/chardev/char.h b/include/chardev/char.h
> index 1604ea9..66dde46 100644
> --- a/include/chardev/char.h
> +++ b/include/chardev/char.h
> @@ -65,7 +65,9 @@ struct Chardev {
>   *
>   * @opts see qemu-config.c for a list of valid options
>   *
> - * Returns: a new character backend
> + * Returns: on success: a new character backend
> + *          otherwise:  NULL; @errp specifies the error
> + *                            or left untouched in case of help option
>   */
>  Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
>                                  Error **errp);
> diff --git a/chardev/char.c b/chardev/char.c
> index c34b44a..5d283b9 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -620,7 +620,7 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
>  
>          error_report("Available chardev backend types: %s", str->str);
>          g_string_free(str, true);
> -        exit(0);
> +        return NULL;
>      }
>  
>      if (id == NULL) {
> diff --git a/vl.c b/vl.c
> index fb6b2ef..47bfe51 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2344,10 +2344,12 @@ static int chardev_init_func(void *opaque, QemuOpts *opts, Error **errp)
>  {
>      Error *local_err = NULL;
>  
> -    qemu_chr_new_from_opts(opts, &local_err);
> -    if (local_err) {
> -        error_report_err(local_err);
> -        return -1;
> +    if (!qemu_chr_new_from_opts(opts, &local_err)) {
> +        if (local_err) {
> +            error_report_err(local_err);
> +            return -1;
> +        }
> +        exit(0);
>      }
>      return 0;
>  }
>