Re: [Qemu-devel] [PATCH] audio: Add missing fall through comments

[Philippe Mathieu-Daudé]

On 7/19/19 9:43 AM, Aleksandar Markovic wrote:
> 
> On Jul 19, 2019 9:30 AM, "Philippe Mathieu-Daudé" <address@hidden
> <mailto:address@hidden>> wrote:
>>
>> On 7/18/19 9:34 PM, Stefan Weil wrote:
>> > Signed-off-by: Stefan Weil <address@hidden <mailto:address@hidden>>
>>
>> Reviewed-by: Philippe Mathieu-Daudé <address@hidden
> <mailto:address@hidden>>
>> Tested-by: Philippe Mathieu-Daudé <address@hidden
> <mailto:address@hidden>>
>>
> 
> Philippe, how do you test these comments?

The testing is quite easy since it doesn't build with
'-Wimplicit-fallthrough=2':

  CC      audio/audio.o
/home/phil/source/qemu/audio/audio.c: In function ‘audio_pcm_init_info’:
/home/phil/source/qemu/audio/audio.c:308:14: error: this statement may
fall through [-Werror=implicit-fallthrough=]
  308 |         sign = 1;
      |         ~~~~~^~~
/home/phil/source/qemu/audio/audio.c:309:5: note: here
  309 |     case AUDIO_FORMAT_U16:
      |     ^~~~
/home/phil/source/qemu/audio/audio.c:315:14: error: this statement may
fall through [-Werror=implicit-fallthrough=]
  315 |         sign = 1;
      |         ~~~~~^~~
/home/phil/source/qemu/audio/audio.c:316:5: note: here
  316 |     case AUDIO_FORMAT_U32:
      |     ^~~~
cc1: all warnings being treated as errors

With Stefan patch applied:

  CC      audio/audio.o
  CC      audio/audio_legacy.o
  CC      audio/noaudio.o
  CC      audio/wavaudio.o
  CC      audio/mixeng.o
  CC      audio/spiceaudio.o
  CC      audio/wavcapture.o
[...]

> 
> Yours, Aleksandar
> 
>> > ---
>> >  audio/audio.c | 2 ++
>> >  1 file changed, 2 insertions(+)
>> >
>> > diff --git a/audio/audio.c b/audio/audio.c
>> > index 5fd9a58a80..a7a13e900a 100644
>> > --- a/audio/audio.c
>> > +++ b/audio/audio.c
>> > @@ -304,6 +304,7 @@ void audio_pcm_init_info (struct audio_pcm_info
> *info, struct audsettings *as)
>> > 
>> >      case AUDIO_FORMAT_S16:
>> >          sign = 1;
>> > +        /* fall through */
>> >      case AUDIO_FORMAT_U16:
>> >          bits = 16;
>> >          shift = 1;
>> > @@ -311,6 +312,7 @@ void audio_pcm_init_info (struct audio_pcm_info
> *info, struct audsettings *as)
>> > 
>> >      case AUDIO_FORMAT_S32:
>> >          sign = 1;
>> > +        /* fall through */
>> >      case AUDIO_FORMAT_U32:
>> >          bits = 32;
>> >          shift = 2;
>> >
>>
>