Re: Missed warning (-Wuse-after-free)

[Alex Colomar via Gcc]

Hi Martin,

On 2/17/23 14:48, Martin Uecker wrote:

This new wording doesn't even allow one to use memcmp(3);
just reading the pointer value, however you do it, is UB.

memcmp would not use the pointer value but work
on the representation bytes and is still allowed.

<https://software.codidact.com/posts/287905>

Cheers!

Alex

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Hmm, interesting. It's rather unspecified behavior. Still unpredictable: (memcmp(&p, &p, sizeof(p) == 0) might evaluate to true or false randomly; the compiler may compile out the call to memcmp(3), since it knows it won't produce any observable behavior.

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