Re: [PATCH 2/2] nedmalloc: work around overzealous GCC 6 warning

From: Jeff King <peff@peff.net>
Date: Aug 5, 2016, 07:42 UTC
Message-ID: <20160805074219.3vvgzaqnn6kvsh3s@sigill.intra.peff.net>
In-Reply-To: <xmqq7fbvzqan.fsf@gitster.mtv.corp.google.com>

On Thu, Aug 04, 2016 at 11:24:32PM -0700, Junio C Hamano wrote:

> I do not know if we want to worry about st_add(1, strlen(s1))
> overflow around here, though.
> [...]
> +	size_t len = strlen(s1) + 1;

I wondered that, too, but I don't think it's possible.

To overflow the size_t with "+1", strlen() must return the maximum value that it can hold. But such a string would need one more byte than that, for its trailing NUL. So assuming you cannot have a string that exceeds size_t in the first place, I think it is impossible to overflow here.

-Peff