[PATCH 05/11] A pointer to a pointer is nonnull.

Peter Rosin peda@lysator.liu.se
Mon Mar 21 16:38:00 GMT 2016

On 2016-03-20 12:15, Corinna Vinschen wrote:
> On Mar 19 13:45, Peter Foley wrote:
>> GCC 6.0+ can assert that this argument is nonnull.
>> Remove the unnecessary check to fix a warning.
>> winsup/cygwin/ChangeLog
>> malloc_wrapper.cc (posix_memalign): Remove always true nonnull check.
> Eh, what?!?  How on earth can gcc assert memptr is always non-NULL?
> An application can call posix_memalign(NULL, 4096, 4096) just fine,
> can't it?  If so, *memptr = res crashes.

I think that passing NULL qualifies as undefined, in which case the
crash is ok, no?

I'm sure it will misbehave if you pass (void **)1 too. So, some might
argue that the business of special-casing NULL here is questionable.

Or is there some reason to protect the posix_memalign users from


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