Improve soundness of rustc_arena
Make it runnable in miri by changing the loop iteration count for some tests in miri. Also fix a stacked borrows issue with box.
There was a problem with storing a `Box<T>` in a struct, where
the current rules would invalidate the value. this makes it store
a raw pointer instead, circumventing the aliasing problems.
It's simply a binary thing to allow different behaviour for `Copy` vs
`!Copy` types. The new code makes this much clearer; I was scratching my
head over the old code for some time.
Because it's always `'tcx`. In fact, some of them use a mixture of
passed-in `$tcx` and hard-coded `'tcx`, so no other lifetime would even
work.
This makes the code easier to read.
Most arena-allocate types that impl `Drop` get their own `TypedArena`, but a
few infrequently used ones share a `DropArena`. This sharing adds complexity
but doesn't help performance or memory usage. Perhaps it was more effective in
the past prior to some other improvements to arenas.
This commit removes `DropArena` and the sharing of arenas via the `few`
attribute of the `arena_types` macro. This change removes over 100 lines of
code and nine uses of `unsafe` (one of which affects the parallel compiler) and
makes the remaining code easier to read.
Macros 2.0-ify rustc_arena
For the purpose of battle-testing macros 2.0 I'm looking to dogfood it in rustc, one crate at a time.
(Note that there are only 12 changed lines if you ignore whitespace.)
Since RFC 3052 soft deprecated the authors field anyway, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information, we should remove it from
crates in this repo.
Found with https://github.com/est31/warnalyzer.
Dubious changes:
- Is anyone else using rustc_apfloat? I feel weird completely deleting
x87 support.
- Maybe some of the dead code in rustc_data_structures, in case someone
wants to use it in the future?
- Don't change rustc_serialize
I plan to scrap most of the json module in the near future (see
https://github.com/rust-lang/compiler-team/issues/418) and fixing the
tests needed more work than I expected.
TODO: check if any of the comments on the deleted code should be kept.
This pulls in rust-lang/rustc-rayon#8 to fix#81425. (h/t @ammaraskar)
That revealed weak constraints on `rustc_arena::DropArena`, because its
`DropType` was holding type-erased raw pointers to generic `T`. We can
implement `Send` for `DropType` (under `cfg(parallel_compiler)`) by
requiring all `T: Send` before they're type-erased.
Stabilize by-value `[T; N]` iterator `core::array::IntoIter`
Tracking issue: https://github.com/rust-lang/rust/issues/65798
This is unblocked now that `min_const_generics` has been stabilized in https://github.com/rust-lang/rust/pull/79135.
This PR does *not* include the corresponding `IntoIterator` impl, which is https://github.com/rust-lang/rust/pull/65819. Instead, an iterator can be constructed through the `new` method.
`new` would become unnecessary when `IntoIterator` is implemented and might be deprecated then, although it will stay stable.
Rollup of 15 pull requests
Successful merges:
- #75438 (Use adaptive SVG favicon for rustdoc like other rust sites)
- #76304 (Make delegation methods of `std::net::IpAddr` unstably const)
- #76724 (Allow a unique name to be assigned to dataflow graphviz output)
- #76978 (Documented From impls in std/sync/mpsc/mod.rs)
- #77044 (Liballoc bench vec use mem take not replace)
- #77050 (Typo fix: "satsify" -> "satisfy")
- #77074 (add array::from_ref)
- #77078 (Don't use an if guard to check equality with a constant)
- #77079 (Use `Self` in docs when possible)
- #77081 (Merge two almost identical match arms)
- #77121 (Updated html_root_url for compiler crates)
- #77136 (Suggest `const_mut_refs`, not `const_fn` for mutable references in `const fn`)
- #77160 (Suggest `const_fn_transmute`, not `const_fn`)
- #77164 (Remove workaround for deref issue that no longer exists.)
- #77165 (Followup to #76673)
Failed merges:
r? `@ghost`
Remove redundant nightly features
Removes a bunch of redundant/outdated nightly features. The first commit removes a `core_intrinsics` use for which a stable wrapper has been provided since. The second commit replaces the `const_generics` feature with `min_const_generics` which might get stabilized this year. The third commit is the result of a trial/error run of removing every single feature and then adding it back if compile failed. A bunch of unused features are the result that the third commit removes.
