Strange behaviour | Together C & C++ | Page 1

willow burrowBOT Oct 26, 2024, 1:32 PM

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merry aspen Oct 26, 2024, 3:35 PM

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dereferencing a null pointer is UB thinkies

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void test_c(struct c * v){
                     //^ v = NULL here
    printf("c2: %p -> %p -> %p\n", &v, v, *v);
}

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Okay I'm on my phone rn so i wont test

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But run this woth ubsan

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On something like godbolt.org

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Oh wait I'm just dumb yamikek

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Oh wait you probably shouldn't yamikek

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But look up casting rules I guess

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I don't really know C, the type system is very weird

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It allows a lot of things that break stuff

chrome dagger Oct 26, 2024, 3:57 PM

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also note that you are trying to print things that are not pointers with %p

chrome dagger Oct 26, 2024, 5:12 PM

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casting a struct **a to a struct *a?

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maybe the cast isn't UB, but de-referencing it afterwards definitely is

willow burrowBOT Oct 26, 2024, 5:18 PM

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Thank you and let us know if you have any more questions!

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#Strange behaviour