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Comment by klodolph | Hacker News Reader

Dereferencing NULL, in a C program, is ALWAYS undefined behavior. The fact that you are using a Cortex-M processor does not change this fact. It is spelled out very clearly in the C standard.

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I've used at times it to crash the program (core dump), producing a cleaner stack than abort().

You should use __builtin_trap(). Invoking undefined behavior lets the compiler justifiably delete the entire code path leading up to it.

> Dereferencing NULL, in a C program, is ALWAYS undefined behavior.

1. you're not required to use C

2. an extension to the C standard can decide to define that behaviour

Also note that null pointers may not need to be represented by the all-zero bit pattern, ie the conversion

    (void*)(intptr_t)0

can in principle be more involved than a noop.

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