Terminology: "null pointer" vs NULL

[Vincent Lefevre <vincent-opgr@xxxxxxxxxx>]

In the latest draft (Issue 7 Draft 3), the standard uses various
wordings for a null pointer: "null pointer" (this is correct), but
also "NULL" and derivatives ("NULL pointer" and so on).

Why all these wordings?
Is this deliberate?

Note that the ISO C99 standard only uses the term "null pointer"
("NULL" being a macro). And I think that saying "NULL" instead of
"null pointer" is incorrect because:

  * in C, NULL does not necessarily evaluate to a pointer (though
    Issue 7 requires that, more precisely the type must be void *),

  * all pointers do not have the type void *;

  * (void *) 0 is a constant whereas not all null pointers are
    constants. So, something like "functions need not be thread-safe
    if passed a NULL argument" would not apply when the argument is
    a non-constant null pointer (if the function is implemented as
    a macro, the compiler can make the difference between constant
    values and non-constant values).

You can see a discussion I have with Michael Kerrisk here:

  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=431480

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Vincent Lefèvre <vincent@vinc17.org> - Web: <http://www.vinc17.org/>
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