Re: [PATCH] Use NULL instead of integer 0 in security/selinux/

[Michael Buesch <mbuesch@freenet.de>]

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Quoting "Richard B. Johnson" <root@chaos.analogic.com>:
> Because NULL is a valid pointer value. 0 is not. If you were
> to make 0 valid, you would use "(void *)0", which is what
> NULL just happens to be in all known architectures so far,
> although that could change in an alternate universe.

No, that is not true.
In C/C++ this is true:
NULL == 0

You can _always_ use 0 instead of NULL. The use of NULL is
_only_ for readability reasons. When you assign 0 to a
pointer, the compiler knows that you want to assign a
NULL-pointer and not the value 0.
Even on architectures where the NULL-pointer is not
represented as 0 in memory (another bitmask), it's still
valid to assign 0 to a pointer, because the compiler
_knows_ that you are handling with a pointer and does
The Right Thing (tm).

- -- 
Regards Michael Buesch  [ http://www.tuxsoft.de.vu ]


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