[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Gnu-arch-users] Re: posible issue on ia64 with va_args.

From: Andrew Suffield
Subject: Re: [Gnu-arch-users] Re: posible issue on ia64 with va_args.
Date: Thu, 18 Mar 2004 15:41:33 +0000
User-agent: Mutt/

On Tue, Mar 16, 2004 at 09:26:29AM -0500, Stefan Monnier wrote:
> > It happens with some debugging systems (which I believe was the
> > original intent), where they use a tagged NULL pointer so that instead
> > of "Dereferenced NULL <segfault>", you get "Dereferenced NULL from
> > foo.c:63 <segfault>", which can be very useful on occasion.
> Wouldn't that tend to cause problems where
>     assert (NULL
>             ==
>             NULL);
> can fail?

No, it's all handled by the compiler. == on pointers is true for two
NULL pointers even if they have different tags. Usually they just
carve out a chunk of the address space for the "tag" value and do
pointer comparisons only on the other part.

  .''`.  ** Debian GNU/Linux ** | Andrew Suffield
 : :' : |
 `. `'                          |
   `-             -><-          |

Attachment: signature.asc
Description: Digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]