panic-on-uninit: adjust checks to 0x01-filling#101061
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bors merged 1 commit intorust-lang:masterfrom Oct 5, 2022
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Now that
mem::uninitiailizedactually fills memory with0x01(#99182), we can make it panic in a few less cases without risking a lot more UB -- which hopefully slightly improves compatibility with some old code, and which might increase the chance that we can check inside arrays in the future.We detect almost all of these with our lint, so authors of such code should still be warned -- but if this happens deep inside a dependency, the panic can be quite interruptive, so it might be better not to do it when there is no risk of LLVM UB. Therefore, adjust the
might_permit_raw_initlogic to care primarily about LLVM UB. To my knowledge, it actually covers all cases of LLVM UB now.Fixes #66151
Cc @5225225