Re: [PATCH 02/33] fix unused parameter warnings in do_version() and show_usage()

[Michal Kubecek <mkubecek@suse.cz>]

On Thu, Oct 17, 2019 at 11:20:50AM -0700, Maciej Żenczykowski wrote:
> From: Maciej Żenczykowski <maze@google.com>
> 
> This fixes:
>   external/ethtool/ethtool.c:473:43: error: unused parameter 'ctx' [-Werror,-Wunused-parameter]
>   static int do_version(struct cmd_context *ctx)
> 
>   external/ethtool/ethtool.c:5392:43: error: unused parameter 'ctx' [-Werror,-Wunused-parameter]
>   static int show_usage(struct cmd_context *ctx)
> 
> Signed-off-by: Maciej Żenczykowski <maze@google.com>
> Change-Id: I0cc52f33bb0e8d7627f5e84bb4e3dfa821d17cc8
> ---
>  ethtool.c  | 4 ++--
>  internal.h | 2 ++
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/ethtool.c b/ethtool.c
> index 082e37f..5e0deda 100644
> --- a/ethtool.c
> +++ b/ethtool.c
> @@ -470,7 +470,7 @@ static int rxflow_str_to_type(const char *str)
>  	return flow_type;
>  }
>  
> -static int do_version(struct cmd_context *ctx)
> +static int do_version(struct cmd_context *ctx maybe_unused)
>  {

Considering how frequent this pattern (a callback where not all
instances use all parameters) is, maybe we could consider disabling the
warning with -Wno-unused-parameter instead of marking all places where
it is issued.

Michal Kubecek

>  	fprintf(stdout,
>  		PACKAGE " version " VERSION
> @@ -5484,7 +5484,7 @@ static const struct option {
>  	{}
>  };
>  
> -static int show_usage(struct cmd_context *ctx)
> +static int show_usage(struct cmd_context *ctx maybe_unused)
>  {
>  	int i;
>  
> diff --git a/internal.h b/internal.h
> index aecf1ce..ff52c6e 100644
> --- a/internal.h
> +++ b/internal.h
> @@ -23,6 +23,8 @@
>  #include <sys/ioctl.h>
>  #include <net/if.h>
>  
> +#define maybe_unused __attribute__((__unused__))
> +
>  /* ethtool.h expects these to be defined by <linux/types.h> */
>  #ifndef HAVE_BE_TYPES
>  typedef uint16_t __be16;
> -- 
> 2.23.0.866.gb869b98d4c-goog
>