If you're not a compiler writer, you probably have a mental model of undefined behavior that works like this I find that very patronizing. Yes, we mere compil

If you're not a compiler writer, you probably have a mental model of undefined behavior that works like this I find that very patronizing. Yes, we mere compiler users complain about specific examples; that’s because we keep finding specific examples that break in weird ways! But at the same time, we realize that it’s a general approach that causes trouble. As I understand it: assuming that undefined behavior cannot happen and optimizing on that basis. I’m not arguing for specific small tweaks to fix a few known weirdnesses, or even a more general adjustment to the notions of poison and undef (as your mention of “massive email threads” suggests). I’m arguing, first, that the entire approach seems to be misguided and not working well; as evidence, many real-world examples of code doing extremely unexpected things, and the position of the Linux kernel maintainers (surely an important group of users by any standard). Second, that the problem seems to be largely ignored by compiler writers; as evidence, no changes or improvements, despite several proposals from outsiders. You can point to massive internal debate on email threads but it amounts to nothing if nothing comes out of it.