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From: Joe Perches <joe@perches.com>
To: George Spelvin <linux@sciencehorizons.net>,
	andriy.shevchenko@linux.intel.com
Cc: akpm@linux-foundation.org, bbjorn@mork.no,
	linux-kernel@vger.kernel.org, tytso@mit.edu
Subject: Re: [PATCH] lib/uuid.c: eliminate uuid_[bl]e_index arrays
Date: Tue, 31 May 2016 14:36:44 -0700	[thread overview]
Message-ID: <1464730604.14627.66.camel@perches.com> (raw)
In-Reply-To: <20160531203122.7243.qmail@ns.sciencehorizons.net>

On Tue, 2016-05-31 at 16:31 -0400, George Spelvin wrote:
> Here's a patch implementing the suggestion I made earlier.  This reduces
> code size, data size, and run time for input and output of UUIDs.
[]
> diff --git a/lib/uuid.c b/lib/uuid.c
[]
> @@ -97,32 +97,28 @@ bool uuid_is_valid(const char *uuid)
>  }
>  EXPORT_SYMBOL(uuid_is_valid);
>  
> -static int __uuid_to_bin(const char *uuid, __u8 b[16], const u8 ei[16])
> +static int __uuid_to_bin(const char uuid[36], __u8 b[16], const u8 si[16])

Functions with sized array arguments are generally undesired.

Linus once wrote: (http://comments.gmane.org/gmane.linux.kernel/2031400)

    array arguments in C don't
    actually exist. Sadly, compilers accept it for various bad historical
    reasons, and silently turn it into just a pointer argument. There are
    arguments for them, but they are from weak minds.

Perhaps this would be better using simple pointers and without the __

static int __uuid_to_bin(const char *uuid, u8 *b, const u8 *si)

  reply	other threads:[~2016-05-31 21:36 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1464594339.27624.45.camel@linux.intel.com>
2016-05-30 17:32 ` [PATCH] lib/vsprintf.c: Further simplify uuid_string() George Spelvin
2016-05-31 20:31   ` [PATCH] lib/uuid.c: eliminate uuid_[bl]e_index arrays George Spelvin
2016-05-31 21:36     ` Joe Perches [this message]
2016-05-31 22:05       ` George Spelvin
2016-06-01 12:32       ` Andy Shevchenko
2016-06-01 15:07         ` George Spelvin
2016-06-02 16:48           ` Joe Perches
2016-06-01 19:58     ` Andrew Morton
2016-06-01 20:13       ` Andy Shevchenko
2016-06-03 11:17     ` Andy Shevchenko

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