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From: Andreas Schwab <schwab@linux-m68k.org>
To: Daniel Colascione <dancol@dancol.org>
Cc: Emacs development discussions <emacs-devel@gnu.org>
Subject: Re: Set operations on bool-vectors
Date: Sat, 21 Sep 2013 09:36:11 +0200	[thread overview]
Message-ID: <87a9j6bp90.fsf@igel.home> (raw)
In-Reply-To: <523CD363.6020400@dancol.org> (Daniel Colascione's message of "Fri, 20 Sep 2013 15:59:47 -0700")

Daniel Colascione <dancol@dancol.org> writes:

> +static
> +ptrdiff_t
> +bool_vector_payload_bytes (EMACS_INT length)
> +{
> +  EMACS_INT exact_needed_bytes;
> +  EMACS_INT needed_bytes;
> +
> +  exact_needed_bytes = (length + CHAR_BIT - 1) / CHAR_BIT;
> +  needed_bytes =  (exact_needed_bytes + sizeof (size_t) - 1)
> +    / sizeof (size_t);
> +
> +  needed_bytes *= sizeof (size_t);

Please check for overflow.  Also, the return type should be EMACS_INT,
not ptrdiff_t.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."



  parent reply	other threads:[~2013-09-21  7:36 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-20 22:59 Set operations on bool-vectors Daniel Colascione
2013-09-21  1:57 ` Stefan Monnier
2013-09-21  2:44   ` Daniel Colascione
2013-09-21 15:51     ` Stefan Monnier
2013-09-21  2:26 ` Dmitry Antipov
2013-09-21  2:49   ` Daniel Colascione
2013-09-21  7:16     ` Eli Zaretskii
2013-09-21  7:43       ` Daniel Colascione
2013-09-21  7:36 ` Andreas Schwab [this message]
2013-09-21  7:38   ` Daniel Colascione
2013-09-21  8:35     ` Andreas Schwab
2013-09-21  8:49       ` Daniel Colascione

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