bors 51e514c0fb Auto merge of #88759 - Amanieu:panic_in_drop, r=nagisa,eddyb ... Add -Z panic-in-drop={unwind,abort} command-line option This PR changes `Drop` to abort if an unwinding panic attempts to escape it, making the process abort instead. This has several benefits: - The current behavior when unwinding out of `Drop` is very unintuitive and easy to miss: unwinding continues, but the remaining drops in scope are simply leaked. - A lot of unsafe code doesn't expect drops to unwind, which can lead to unsoundness: - https://github.com/servo/rust-smallvec/issues/14 - https://github.com/bluss/arrayvec/issues/3 - There is a code size and compilation time cost to this: LLVM needs to generate extra landing pads out of all calls in a drop implementation. This can compound when functions are inlined since unwinding will then continue on to process drops in the callee, which can itself unwind, etc. - Initial measurements show a 3% size reduction and up to 10% compilation time reduction on some crates (`syn`). One thing to note about `-Z panic-in-drop=abort` is that *all* crates must be built with this option for it to be sound since it makes the compiler assume that dropping `Box<dyn Any>` will never unwind. cc https://github.com/rust-lang/lang-team/issues/97		2021-09-12 20:48:09 +00:00
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src	Auto merge of #88759 - Amanieu:panic_in_drop, r=nagisa,eddyb	2021-09-12 20:48:09 +00:00
Cargo.toml	Rename rustc_mir to rustc_const_eval.	2021-09-07 20:46:26 +02:00