Date: Tue, 17 Feb 2004 10:11:05 -0800 From: Tim Kientzle <kientzle@acm.org> To: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: freebsd-hackers@freebsd.org Subject: Re: signed char bug in regexp library Message-ID: <40325939.6000104@acm.org> In-Reply-To: <Pine.LNX.4.58.0402162039280.18066@artax.karlin.mff.cuni.cz> References: <Pine.LNX.4.58.0402162039280.18066@artax.karlin.mff.cuni.cz>
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Mikulas Patocka wrote:
> Hi
>
> I ripped regexp library from FreeBSD 4 and use it in another program. I
> get random crashes because the library casts char to int and uses it as
> array index ... the most obvious case is engine.i:189:
> register char *dp;
> dp += charjump[(int)*dp];
> but there are many more and I'm unable to spot them all.
>
> When i compile library with -funsigned-char, it works fine. But it isn't
> compiled with that flag in FreeBSD.
Mikulas,
Could you verify that programs in FreeBSD 4
crash because of this? That would provide
incentive to get it fixed.
One easy fix, by the way, is:
dp += charjump[(int)(unsigned char)*dp];
For what it's worth, the code probably isn't assuming
unsigned characters; it's probably assuming ASCII. ;-)
Tim Kientzle
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