[ajross]

> The issue is that would not be backwards-compatible with all existing code

Well, by definition it would, since the only behavior affected is undefined. But sure, in practice. Any change to the language is a danger, and ISO C is very conservative.

I'm just saying that the mental bandwidth of dealing with the old UB mess is now much higher than what it would take to try to fix it. All those cycles of "run ubsan on this old codebase and have endless arguments about interpretation and false positives[1]" could be trivially replaced with "port old codebase to C-unundefined standard", which would put us in a much better position.

[1] Trust me, I've been in these bikesheds and it's not pretty.