Messages in this thread | | | Date | Sat, 9 Aug 2003 17:23:32 +0100 | From | Jamie Lokier <> | Subject | Re: [PATCH] 2.4.22pre10: {,un}likely_p() macros for pointers |
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Alan Cox wrote: > > I believe the C language allows for systems where the NULL pointer is > > not zero.
The representation is not zero, however in the C language (since ANSI, not sure about K&R), 0 is a valid name for the NULL pointer whatever its representation.
> > I can't think of any reason why the NULL macro exists otherwise. > > <OldFart> > NULL is really important in K&R C because you don't have prototypes and > sizeof(foo *) may not be the same as sizeof(int). This leads to very > nasty problems that people nowdays forget about. > </OldFart>
Not just K&R. These are different because of varargs:
printf ("%p", NULL); printf ("%p", 0);
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