[alsa-devel] [PATCH] [alsa-lib] Removed compilation warning from test/namehint.c

[Takashi Sakamoto]

On Apr 10 2017 02:45, soodvarun78 at gmail.com wrote:
> From: varun <soodvarun78 at gmail.com>
>
> Changed hint variable from char ** to void ** to match function snd_device_name_hint
>
> Signed-off-by: varun <soodvarun78 at gmail.com>
> ---
>  test/namehint.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

This patch can suppress below compiler warnings:

```
alsa-lib/test$ make namehint
   CC       namehint.o
namehint.c: In function ‘main’:
namehint.c:12:40: warning: passing argument 3 of ‘snd_device_name_hint’ 
from incompatible pointer type [-Wincompatible-pointer-types]
   err = snd_device_name_hint(-1, iface, &hints);
                                         ^
In file included from ../include/asoundlib.h:58:0,
                  from namehint.c:1:
../include/alsa/control.h:228:5: note: expected ‘void ***’ but argument 
is of type ‘char ***’
  int snd_device_name_hint(int card, const char *iface, void ***hints);
      ^~~~~~~~~~~~~~~~~~~~
namehint.c:20:28: warning: passing argument 1 of 
‘snd_device_name_free_hint’ from incompatible pointer type 
[-Wincompatible-pointer-types]
   snd_device_name_free_hint(hints);
                             ^~~~~
In file included from ../include/asoundlib.h:58:0,
                  from namehint.c:1:
../include/alsa/control.h:229:5: note: expected ‘void **’ but argument 
is of type ‘char **’
  int snd_device_name_free_hint(void **hints);
      ^~~~~~~~~~~~~~~~~~~~~~~~~
   CCLD     namehint
```

The combination of 'void ***' and 'char **' variables are also used by 
'aplay' in alsa-utils.git, therefore it's not so odd.

Reviewed-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>

> diff --git a/test/namehint.c b/test/namehint.c
> index e978d5c..18bad1d 100644
> --- a/test/namehint.c
> +++ b/test/namehint.c
> @@ -4,7 +4,8 @@
>  int main(int argc, char *argv[])
>  {
>  	const char *iface = "pcm";
> -	char **hints, **n;
> +	void **hints;
> +	char **n;
>  	int err;
>
>  	if (argc > 1)
> @@ -12,7 +13,7 @@ int main(int argc, char *argv[])
>  	err = snd_device_name_hint(-1, iface, &hints);
>  	if (err < 0)
>  		errx(1, "snd_device_name_hint error: %s", snd_strerror(err));
> -	n = hints;
> +	n = (char **)hints;
>  	while (*n != NULL) {
>  		printf("%s\n", *n);
>  		n++;


Thanks

Takashi Sakamoto