Update stdsimd
This updates stdsimd to a Rust2015 / Rust2018 compatible version. Once this is merged it should be possible to migrate libcore and libstd to Rust2018. Once that happens, we can just require the 2018 edition in stdsimd.
Add vectored read and write support
This functionality has lived for a while in the tokio ecosystem, where
it can improve performance by minimizing copies.
r? @alexcrichton
Stabilize `unrestricted_attribute_tokens`
In accordance with a plan described in https://internals.rust-lang.org/t/unrestricted-attribute-tokens-feature-status/8561/3.
Delimited non-macro non-builtin attributes now support the same syntax as macro attributes:
```
PATH
PATH `(` TOKEN_STREAM `)`
PATH `[` TOKEN_STREAM `]`
PATH `{` TOKEN_STREAM `}`
```
Such attributes mostly serve as inert proc macro helpers or tool attributes.
To some extent these attributes are de-facto stable due to a hole in feature gate checking (feature gating is done too late - after macro expansion.)
So if macro *removes* such helper attributes during expansion (and it must remove them, unless it's a derive macro), then the code will work on stable.
Key-value non-macro non-builtin attributes are now restricted to bare minimum required to support what we support on stable - unsuffixed literals (https://github.com/rust-lang/rust/issues/34981).
```
PATH `=` LITERAL
```
(Key-value macro attributes are not supported at all right now.)
Crater run in https://github.com/rust-lang/rust/pull/57321 found no regressions for this change.
There are multiple possible ways to extend key-value attributes (https://github.com/rust-lang/rust/pull/57321#issuecomment-451574065), but I'd expect an RFC for that and it's not a pressing enough issue to block stabilization of delimited attributes.
Built-in attributes are still restricted to the "classic" meta-item syntax, nothing changes here.
https://github.com/rust-lang/rust/pull/57321 goes further and adds some additional restrictions (more consistent input checking) to built-in attributes.
Closes https://github.com/rust-lang/rust/issues/55208
librustc: deny(elided_lifetimes_in_paths)
As part of the Rust 2018 transition, remove `#![allow(elided_lifetimes_in_paths)]` from `librustc`.
r? @oli-obk
librustc_typeck: deny(elided_lifetimes_in_paths)
As part of the Rust 2018 transition, remove `#![allow(elided_lifetimes_in_paths)]` from `librustc_typeck`.
r? @oli-obk
librustc_codegen_ssa: #![deny(elided_lifetimes_in_paths)]
As part of the Rust 2018 transition, remove `#![allow(elided_lifetimes_in_paths)]` from `librustc_codegen_ssa`.
r? @oli-obk
librustc_codegen_llvm: #![deny(elided_lifetimes_in_paths)]
As part of the Rust 2018 transition, remove `#![allow(elided_lifetimes_in_paths)]` from `librustc_codegen_llvm`.
r? @oli-obk
Deny the `overflowing_literals` lint for all editions
The `overflowing_literals` was made deny by default for the 2018 edition by #54507, however I'm not aware of any reason it can't be made deny by default for the 2015 edition as well.
Use normal mutable borrows in matches
`ref mut` borrows are currently two-phase with NLL enabled. This changes them to be proper mutable borrows. To accommodate this, first the position of fake borrows is changed:
```text
[ 1. Pre-match ]
|
[ (old create fake borrows) ]
[ 2. Discriminant testing -- check discriminants ] <-+
| |
| (once a specific arm is chosen) |
| |
[ (old read fake borrows) ] |
[ 3. Create "guard bindings" for arm ] |
[ (create fake borrows) ] |
| |
[ 4. Execute guard code ] |
[ (read fake borrows) ] --(guard is false)-----------+
|
| (guard results in true)
|
[ 5. Create real bindings and execute arm ]
|
[ Exit match ]
```
The following additional changes are made to accommodate `ref mut` bindings:
* We no longer create fake `Shared` borrows. These borrows are no longer needed for soundness, just to avoid some arguably strange cases.
* `Shallow` borrows no longer conflict with existing borrows, avoiding conflicting access between the guard borrow access and the `ref mut` borrow.
There is some further clean up done in this PR:
* Avoid the "later used here" note for Shallow borrows (since it's not relevant with the message provided)
* Make any use of a two-phase borrow activate it.
* Simplify the cleanup_post_borrowck passes into a single pass.
cc #56254
r? @nikomatsakis
Rollup of 5 pull requests
Successful merges:
- #58370 (Relax some Hash bounds on HashMap<K, V, S> and HashSet<T, S>)
- #58421 (Relax some Ord bounds on BinaryHeap<T>)
- #58686 (replace deprecated rustfmt_skip with rustfmt::skip)
- #58697 (Use ? in some macros)
- #58704 (Remove some unnecessary 'extern crate')
Failed merges:
r? @ghost
