From: Steven Rostedt <rostedt@goodmis.org>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
linux-kernel@vger.kernel.org,
Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: Re: [PATCH v1 1/3] lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert()
Date: Fri, 31 Jul 2020 10:38:00 -0400 [thread overview]
Message-ID: <20200731103800.36a412eb@oasis.local.home> (raw)
In-Reply-To: <20200731123145.22357-1-andriy.shevchenko@linux.intel.com>
On Fri, 31 Jul 2020 15:31:43 +0300
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> First of all, there is no compile time check for the SMALL
> to be ' ' (0x20, i.e. space). Second, for ZEROPAD the check
> is hidden in the code.
>
> For better maintenance replace BUILD_BUG_ON() with static_assert()
> for ZEROPAD and move it closer to the definition. While at it,
> introduce check for SMALL.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> lib/vsprintf.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 31a674dd2674..8a8ac7ce0289 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -381,6 +381,9 @@ int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
> #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
> #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
>
> +static_assert(ZEROPAD + ' ' == '0');
I would have it match the comment above:
static_assert(ZEROPAD == ('0' - ' '));
But other than that:
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
> +static_assert(SMALL == ' ');
> +
> enum format_type {
> FORMAT_TYPE_NONE, /* Just a string part */
> FORMAT_TYPE_WIDTH,
> @@ -507,7 +510,7 @@ char *number(char *buf, char *end, unsigned long long num,
> /* zero or space padding */
> if (!(spec.flags & LEFT)) {
> char c = ' ' + (spec.flags & ZEROPAD);
> - BUILD_BUG_ON(' ' + ZEROPAD != '0');
> +
> while (--field_width >= 0) {
> if (buf < end)
> *buf = c;
next prev parent reply other threads:[~2020-07-31 14:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-31 12:31 [PATCH v1 1/3] lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert() Andy Shevchenko
2020-07-31 12:31 ` [PATCH v1 2/3] lib/vsprintf: Replace custom spec to print decimals with generic one Andy Shevchenko
2020-07-31 15:15 ` Steven Rostedt
2020-07-31 15:48 ` Andy Shevchenko
2020-07-31 12:31 ` [PATCH v1 3/3] lib/vsprintf: Force type of flags for gfp_t Andy Shevchenko
2020-07-31 15:34 ` Steven Rostedt
2020-07-31 15:49 ` Andy Shevchenko
2020-07-31 16:04 ` Steven Rostedt
2020-07-31 14:38 ` Steven Rostedt [this message]
2020-07-31 15:48 ` [PATCH v1 1/3] lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert() Andy Shevchenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200731103800.36a412eb@oasis.local.home \
--to=rostedt@goodmis.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=pmladek@suse.com \
--cc=sergey.senozhatsky@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).