rust/compiler/rustc_data_structures
bors 168a020900 Auto merge of #92686 - saethlin:unsafe-debug-asserts, r=Amanieu
Add debug assertions to some unsafe functions

As suggested by https://github.com/rust-lang/rust/issues/51713

~~Some similar code calls `abort()` instead of `panic!()` but aborting doesn't work in a `const fn`, and the intrinsic for doing dispatch based on whether execution is in a const is unstable.~~

This picked up some invalid uses of `get_unchecked` in the compiler, and fixes them.

I can confirm that they do in fact pick up invalid uses of `get_unchecked` in the wild, though the user experience is less-than-awesome:
```
     Running unittests (target/x86_64-unknown-linux-gnu/debug/deps/rle_decode_fast-04b7918da2001b50)

running 6 tests
error: test failed, to rerun pass '--lib'

Caused by:
  process didn't exit successfully: `/home/ben/rle-decode-helper/target/x86_64-unknown-linux-gnu/debug/deps/rle_decode_fast-04b7918da2001b50` (signal: 4, SIGILL: illegal instruction)
```

~~As best I can tell these changes produce a 6% regression in the runtime of `./x.py test` when `[rust] debug = true` is set.~~
Latest commit (6894d559bd) brings the additional overhead from this PR down to 0.5%, while also adding a few more assertions. I think this actually covers all the places in `core` that it is reasonable to check for safety requirements at runtime.

Thoughts?
2022-04-03 16:04:47 +00:00
..
src Auto merge of #92686 - saethlin:unsafe-debug-asserts, r=Amanieu 2022-04-03 16:04:47 +00:00
Cargo.toml Propagate parallel_compiler feature through rustc crates. Turned off feature gives change of builded crates: 238 -> 224. 2022-03-28 08:41:12 +03:00