[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Tinycc-devel] Bug Report (offset+cast)
From: |
Dave Dodge |
Subject: |
Re: [Tinycc-devel] Bug Report (offset+cast) |
Date: |
Fri, 11 May 2007 15:01:36 -0400 |
User-agent: |
Mutt/1.5.12-2006-07-14 |
On Fri, May 11, 2007 at 03:32:47PM -0400, David A. Wheeler wrote:
> Dave Dodge:
> > Well, the term "correctly" is a bit suspect. You can't convert an
> > arbitrary char* to a short* and dereference it without risking
> > undefined behavior, because among other things there's no guarantee
> > that the pointed-to location will be aligned properly as a short.
[...]
> It'd be wiser to rewrite that code (e.g., as a memcpy to a short
> which you KNOW it's aligned), since no matter what it's non-portable.
Yeah that's probably how I'd do it.
Aside: from a purely C standpoint the memcpy() solution isn't actually
guaranteed to work either, thanks to C99's concept of padding bits. I
don't know of any real hardware where it would actually break, though,
and if such a system does exist it's almost certainly some weird
DSP/ASIC where if you're writing code for it you already know about
these issues.
-Dave Dodge
- [Tinycc-devel] Bug Report (offset+cast), Gil Dabah, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), kf, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), David A. Wheeler, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), Gil Dabah, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), Dave Dodge, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), kf, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), Gil Dabah, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), David A. Wheeler, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast),
Dave Dodge <=
- Re: [Tinycc-devel] Bug Report (offset+cast), Rob Landley, 2007/05/11
- Re: [Tinycc-devel] Bug Report (offset+cast), Dave Dodge, 2007/05/12
- Re: [Tinycc-devel] Bug Report (offset+cast), Rob Landley, 2007/05/12
- Re: [Tinycc-devel] Bug Report (offset+cast), Rob Landley, 2007/05/11
Re: [Tinycc-devel] Bug Report (offset+cast), Rob Landley, 2007/05/11