Re: [PATCH 3/4] lib/vsprintf.c: Remove SPECIAL handling in pointer()

From: Andy Shevchenko
Date: Mon Sep 28 2015 - 04:55:21 EST


On Fri, 2015-09-25 at 19:41 +0200, Rasmus Villemoes wrote:
> As a quick
>
> git grep -E '%[ +0#-]*#[ +0#-]*(\*|[0-9]+)?(\.(\*|[0-9]+)?)?p'
>
> shows, nobody uses the # flag with %p. Moreover, I think users are
> unlikely to show up since gcc will complain with
>
> warning: `#' flag used with â%pâ gnu_printf format [-Wformat]

I would refer to POSIX here

"# Specifies that the value is to be converted to an alternative form.
...
For other conversion specifiers, the behavior is undefined."

>
> Since default_width is effectively always 2*sizeof(void*), we can
> simplify the prologue of pointer() and save a few instructions.
>
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> ---
> lib/vsprintf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 03fa10b4be96..98b0d7be3fb7 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1457,7 +1457,7 @@ static noinline_for_stack
> char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> struct printf_spec spec)
> {
> - int default_width = 2 * sizeof(void *) + (spec.flags &
> SPECIAL ? 2 : 0);
> + const int default_width = 2 * sizeof(void *);
>
> if (!ptr && *fmt != 'K') {
> /*

--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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