[PATCH 3/5] discover: Fix unused function warning

[Cyril Bur]

On Tue, 2018-03-06 at 14:32 +1030, Joel Stanley wrote:
> clang errors out about an unused have_busybox function:
> 
>  discover/paths.c:44:13: error: unused function 'have_busybox' [-Werror,-Wunused-function]
>  static bool have_busybox(void)
>             ^
> 
> The function is only used once, so move the preprocessor guard down to
> the use site instead.

This makes it sound like clang is wrong, its single use is inside
#ifndef PETITBOOT_TEST which, I assume you must have had defined.

Might I suggest moving it down ~30 lines into the #ifndef section?

> 
> Signed-off-by: Joel Stanley <joel at jms.id.au>
> ---
> I understand if you don't want to take this one as-is.
> 
>  discover/paths.c | 13 +++----------
>  1 file changed, 3 insertions(+), 10 deletions(-)
> 
> diff --git a/discover/paths.c b/discover/paths.c
> index 24e978b4e2c1..1f279a103b44 100644
> --- a/discover/paths.c
> +++ b/discover/paths.c
> @@ -41,15 +41,6 @@ struct load_task {
>  	void			*async_data;
>  };
>  
> -static inline bool have_busybox(void)
> -{
> -#ifdef WITH_BUSYBOX
> -	return true;
> -#else
> -	return false;
> -#endif
> -}
> -
>  const char *mount_base(void)
>  {
>  	return DEVICE_MOUNT_BASE;
> @@ -571,8 +562,10 @@ struct load_url_result *load_url_async(void *ctx, struct pb_url *url,
>  		task->process->stdout_data = stdout_data;
>  	}
>  
> -	if (!stdout_cb && stdout_data && have_busybox())
> +#ifdef WITH_BUSYBOX
> +	if (!stdout_cb && stdout_data)
>  		task->process->stdout_cb = busybox_progress_cb;
> +#endif

Fair warning, doing this gets meeeesssssyyyyyyy. Feel free to have a
look at the current and previous versions of
arch/powerpc/kernel/process.c in Linux.

The current solution over there is to do
#ifdef WITH_BUSYBOX
static inline bool have_busybox(void) { return true; }
#else
static inline bool have_busybox(void) { return false; }
#endif

Somewhere at the top of the file or in a header.

>  
>  	/* Make sure we save output for any task that has a custom handler */
>  	if (task->process->stdout_cb) {