Re: Return value of malloc(0)

Johannes Weiner <hnazfoo@xxxxxxxxxxxxxx> writes:

On Thu, Jun 29, 2006 at 06:09:37PM +0200, Matthias Andree wrote:

The value returned from malloc(0) must not be dereferenced whatever it
was. It was 0x800, which doesn't count as "failure".

But this would be appropriate for catching the error:

if ((foo = malloc(0)) == foo)
/* make noise */

wouldn't it?

No, sir. Operator precedence: assign first, and then compare, thus the
comparison will always be true (else you'd be comparing to undefined
values, which isn't any better). You might as well write:

foo = malloc(0);
/* make noise */

There is no way to see a 0x800 return from malloc(0) as "error".

--
Matthias Andree
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