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-fwrapv should fix it (no warranties of any kind, batteries not included).

IIRC this particular case was only seen on a specific version of one compiler for MacOS that was provided with extra patches, so it's at first glance less of a problem than it originally looks. That said, I don't think it was doing anything illegal according to the standard (no an expert on this), and as compiled software and a library, the reach of that case may be larger than we might otherwise assume.

There are undoubtedly ways to tell the compiler to be careful, but that isn't always in control of the person writing the code, and even if some level of control exists, compilers change.

To the best of my knowledge, the only compilers to exploit overflows, are GCC/Clang (and those commercial compilers I know about, explicitly said that they are NOT going to exploit signed-overflow UB, IIRC I heard it from MSVC and xlC). And for GCC/Clang, -frapw achieves the same thing. Still, I agree that things change, but this kind of behaviour won't be easy to change (at all); OTOH, I am going to campaign to remove this UB from the standard altogether (there is no real reason for this UB, at least for the platforms 99.9% of developers are working on).

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