Re: [EXT] [PATCH] tracing: Fix warning on variable 'struct trace_array'

[Arun Easi <aeasi@marvell.com>]

On Mon, 7 Nov 2022, 8:05am, Aashish Sharma wrote:

>
> ----------------------------------------------------------------------
> Move the declaration of 'struct trace_array' out of #ifdef
> CONFIG_TRACING block, to fix the following warning when CONFIG_TRACING
> is not set:
> 
> >> include/linux/trace.h:63:45: warning: 'struct trace_array' declared
> inside parameter list will not be visible outside of this definition or
> declaration
> 
> Fixes: 1a77dd1c2bb5 ("scsi: tracing: Fix compile error in trace_array calls when TRACING is disabled")
> Cc: Arun Easi <aeasi@marvell.com>
> Signed-off-by: Aashish Sharma <shraash@google.com>
> ---
>  include/linux/trace.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/trace.h b/include/linux/trace.h
> index b5e16e438448..80ffda871749 100644
> --- a/include/linux/trace.h
> +++ b/include/linux/trace.h
> @@ -26,13 +26,13 @@ struct trace_export {
>  	int flags;
>  };
>  
> +struct trace_array;
> +
>  #ifdef CONFIG_TRACING
>  
>  int register_ftrace_export(struct trace_export *export);
>  int unregister_ftrace_export(struct trace_export *export);
>  
> -struct trace_array;
> -
>  void trace_printk_init_buffers(void);
>  __printf(3, 4)
>  int trace_array_printk(struct trace_array *tr, unsigned long ip,
> 

Looks good. Thanks!

I was wondering why I did not see this when I compiled the kernel without 
TRACING (for 1a77dd1c2bb5). Apparently, I had linux/trace_events.h 
included, which does exactly this. Anyway, makes sense to move this 
outside the #ifdef block.

Regards,
-Arun