Re: [PATCH] [net-next] socket: fix unused-function warning

[David Miller]

From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Tue,  7 Jan 2020 22:35:59 +0100

> When procfs is disabled, the fdinfo code causes a harmless
> warning:
> 
> net/socket.c:1000:13: error: 'sock_show_fdinfo' defined but not used [-Werror=unused-function]
>  static void sock_show_fdinfo(struct seq_file *m, struct file *f)
> 
> Change the preprocessor conditional to a compiler conditional
> to avoid the warning and let the compiler throw away the
> function itself.
> 
> Fixes: b4653342b151 ("net: Allow to show socket-specific information in /proc/[pid]/fdinfo/[fd]")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

This isn't the prettiest thing I've ever seen.

I really think it's nicer to just explicitly put ifdef's around the
forward declaration and the implementation of sock_show_fdinfo().

Alternatively, move the implementation up to the location of the
forward declaration and then you just need one new ifdef guard.