Re: [Tinycc-devel] Testing with ASan and Valgrind

[Edmund Grimley Evans]

>     - cstr.data = 0; (and others)
>     Use NULL.  (This is not C++)

> According to my understanding (and to StackOverflow), a constant of 0 _is_ a
> NULL pointer, but NULL is not always 0 (its bit pattern may differ).

See also http://c-faq.com/null/nullor0.html or google for "c null faq".

I find NULL looks ugly and old-fashioned and I would hate to have to
type it. It doesn't have any practical advantage that I know of.

If this were C++ we'd use nullptr, of course: even longer, but at
least no shift key is involved.

Using 0 rather than NULL is perfectly correct even if the system
doesn't use zero bits to represent a null pointer. However, a system
that didn't use zero bits to represent a null pointer would not work
with much of today's C software. For example, it took me about 30
seconds to find a place in tinycc where it is assumed that you can
initialise a pointer using memset.

Although initialising a pointer with memset is not officially correct
according to the C standard, you would be unlikely to improve the
portability of your software in practice by abstaining from the
practice, and the code with memset may be easier to read and maintain
(and perhaps run faster if you have a not-very-clever compiler).

Edmund