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From: Johannes Sixt <j6t@kdbg.org>
To: "René Scharfe" <l.s.r@web.de>
Cc: "Martin Liška" <mliska@suse.cz>, "Jeff King" <peff@peff.net>,
	git@vger.kernel.org
Subject: Re: [PATCH v3 1/2] Fix nonnull errors reported by UBSAN with GCC 7.
Date: Thu, 6 Apr 2017 22:49:17 +0200	[thread overview]
Message-ID: <357d045a-b1c5-1a73-2256-839efb543fe3@kdbg.org> (raw)
In-Reply-To: <e392e05c-2815-8cfa-eed0-bd990f8ce954@web.de>

Am 06.04.2017 um 19:31 schrieb René Scharfe:
> Am 06.04.2017 um 18:33 schrieb Johannes Sixt:
>> Am 06.04.2017 um 17:42 schrieb Martin Liška:
>>> +static inline void *sane_memmove(void *dest, const void *src, size_t n)
>>> +{
>>> +    if (n > 0)
>>> +        return memmove(dest, src, n);
>>> +    else
>>> +        return dest;
>>> +}
>>
>> Huh? memmove with n == 0 is well-defined. This wrapper is pointless.
>
> memmove(3) with NULL pointers is undefined.

Then don't hide this helper behind a macro with a suspiciously similar 
name. Using the name sane_mmemove at the call site is preferable. 
memmove_or_null or something similar perhaps even more so.

-- Hannes


  reply	other threads:[~2017-04-06 20:49 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-06  8:02 [PATCH 1/2] Fix nonnull errors reported by UBSAN with GCC 7 Martin Liška
2017-04-06  8:34 ` Jeff King
2017-04-06  9:52   ` [PATCH v2 " Martin Liška
2017-04-06 12:26     ` René Scharfe
2017-04-06 15:42       ` [PATCH v3 " Martin Liška
2017-04-06 16:33         ` Johannes Sixt
2017-04-06 17:31           ` René Scharfe
2017-04-06 20:49             ` Johannes Sixt [this message]
2017-04-07 14:23               ` Martin Liška
2017-04-07 15:25                 ` René Scharfe
2017-04-07 15:25                 ` [PATCH 1/2] add MOVE_ARRAY René Scharfe
2017-04-07 15:25                 ` [PATCH 2/2] use MOVE_ARRAY René Scharfe
2017-04-17  1:49                 ` [PATCH v3 1/2] Fix nonnull errors reported by UBSAN with GCC 7 Junio C Hamano
2017-04-17  7:59                   ` Johannes Sixt
2017-04-06  8:57 ` [PATCH " Johannes Schindelin

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