Stabilize casts and coercions to `&[T]` in const fn
Part of #64992
There was never a reason to not stabilize this, we just accidentally prevented them when we implemented the `min_const_fn` feature that gave us `const fn` on stable. This PR stabilizes these casts (which are already stable in `const` outside `const fn`), while keeping all other unsizing casts (so `T` -> `dyn Trait`) unstable within const fn.
These casts have no forward compatibility concerns with any future features for const eval and users were able to use them under the `const_fn` feature gate already since at least the miri merger, possibly longer.
r? @rust-lang/lang
Add core::future::{poll_fn, PollFn}
This is a sibling PR to #70834, adding `future::poll_fn`. This is a small helper function that helps bridge the gap between "poll state machines" and "async/await". It was first introduced in [futures@0.1.7](https://docs.rs/futures/0.1.7/futures/future/fn.poll_fn.html) in December of 2016, and has been tried and tested as part of the ecosystem for the past 3.5 years.
## Implementation
Much of the same reasoning from #70834 applies: by returning a concrete struct rather than an `async fn` we get to mark the future as `Unpin`. It also becomes named which allows storing it in structs without boxing. This implementation has been modified from the implementation in `futures-rs`.
## References
- [`futures::future::poll_fn`](https://docs.rs/futures/0.3.5/futures/future/fn.poll_fn.html)
- [`async_std::future::poll_fn`](https://docs.rs/async-std/1.5.0/async_std/future/fn.poll_fn.html)
Accept tuple.0.0 as tuple indexing (take 2)
If we expect something identifier-like when parsing a field name after `.`, but encounter a float token, we break that float token into parts, similarly to how we break `&&` into `&` `&`, or `<<` into `<` `<`, etc.
An alternative to https://github.com/rust-lang/rust/pull/70420.
Gate GHA on everything but macOS
The macOS spurious failure started happening again. As we discussed during the infra team meeting, this gates on everything but macOS.
r? @Mark-Simulacrum
In our GitHub Actions setup macOS is too unreliable to gate on it, but
the other builders work fine. This commit splits the macOS builders into
a separate job (called auto-fallible), allowing us to gate on the auto
job without failing due to macOS spurious failures.
Rollup of 14 pull requests
Successful merges:
- #73292 (Fixing broken link for the Eq trait)
- #73791 (Allow for parentheses after macro intra-doc-links)
- #74070 ( Use for<'tcx> fn pointers in Providers, instead of having Providers<'tcx>.)
- #74077 (Use relative path for local links to primitives)
- #74079 (Eliminate confusing "globals" terminology.)
- #74107 (Hide `&mut self` methods from Deref in sidebar if there are no `DerefMut` impl for the type.)
- #74136 (Fix broken link in rustdocdoc)
- #74137 (Update cargo)
- #74142 (Liballoc use vec instead of vector)
- #74143 (Try remove unneeded ToString import in liballoc slice)
- #74146 (update miri)
- #74150 (Avoid "blacklist")
- #74184 (Add docs for intra-doc-links)
- #74188 (Tweak `::` -> `:` typo heuristic and reduce verbosity)
Failed merges:
- #74122 (Start-up clean-up)
- #74127 (Avoid "whitelist")
r? @ghost
Tweak `::` -> `:` typo heuristic and reduce verbosity
Do not trigger on correct type ascription expressions with trailing
operators and _do_ trigger on likely path typos where a turbofish is
used.
On likely path typos, remove note explaining type ascription.
Clean up indentation.
r? @petrochenkov
Avoid "blacklist"
Other terms are more inclusive and precise.
Clippy still has a lint named "blacklisted-name", but renaming it would
be a breaking change, so is left for future work.
The target configuration option "abi-blacklist" has been depreciated and
renamed to "unsupported-abis". The old name continues to work.
Update cargo
6 commits in fede83ccf973457de319ba6fa0e36ead454d2e20..4f74d9b2a771c58b7ef4906b2668afd075bc8081
2020-07-02 21:51:34 +0000 to 2020-07-08 17:13:00 +0000
- Disable long_file_names test if not supported on Windows. (rust-lang/cargo#8469)
- Add support for deserializing enums in config files (rust-lang/cargo#8454)
- Write GNU tar files, supporting long names. (rust-lang/cargo#8453)
- Don't overwrite existing `rustdoc` args with --document-private-items (rust-lang/cargo#8449)
- Add some help about rustup's +toolchain syntax. (rust-lang/cargo#8455)
- Update metadata man page. (rust-lang/cargo#8451)
Eliminate confusing "globals" terminology.
There are some structures that are called "globals", but are they global
to a compilation session, and not truly global. I have always found this
highly confusing, so this commit renames them as "session globals" and
adds a comment explaining things.
Also, the commit fixes an unnecessary nesting of `set()` calls
`src/librustc_errors/json/tests.rs`
r? @Aaron1011
Use relative path for local links to primitives
Else, links to `char::foo` would point into `/path/to/src/libcore/std/primitive.char.html#method.foo`.
Split out from #73804.
Use for<'tcx> fn pointers in Providers, instead of having Providers<'tcx>.
In order to work around normalization-under-HRTB (for `provide!` in `rustc_metadata`), we ended up with this:
```rust
struct Providers<'tcx> {
type_of: fn(TyCtxt<'tcx>, DefId) -> Ty<'tcx>,
// ...
}
```
But what I initially wanted to do, IIRC, was this:
```rust
struct Providers {
type_of: for<'tcx> fn(TyCtxt<'tcx>, DefId) -> Ty<'tcx>,
// ...
}
```
This PR moves to the latter, for the simple reason that only the latter allows keeping a `Providers` value, or a subset of its `fn` pointer fields, around in a `static` or `thread_local!`, which can be really useful for custom drivers that override queries.
(@jyn514 and I came across a concrete usecase of that in `rustdoc`)
The `provide!` macro in `rustc_metadata` is fixed by making the query key/value types available as type aliases under `ty::query::query_{keys,values}`, not just associated types (this is the first commit).
r? @nikomatsakis
Do not trigger on correct type ascription expressions with trailing
operators and _do_ trigger on likely path typos where a turbofish is
used.
On likely path typos, remove note explaining type ascription.
There are some structures that are called "globals", but are they global
to a compilation session, and not truly global. I have always found this
highly confusing, so this commit renames them as "session globals" and
adds a comment explaining things.
Also, the commit fixes an unnecessary nesting of `set()` calls
`src/librustc_errors/json/tests.rs`
Fix x.py test for librustc crates.
#73352 introduced a bug where `x.py test src/librustc_ast` would fail to actually run the tests. The issue is that `krate` and `all_krates` were changed to return relative paths. This caused the code to do a test of "relative_path ends with absolute path" which is always false. The solution is to swap that around.
The change to `Crate` isn't necessary, it just simplifies the code and makes it uniform with `CrateLibrustc`.
There don't seem to be any other compiletests that are 1) building a standalone "no_core" create and then 2) trying to link against it. There seems to be a platform-specific limitation in doing so:
```
2020-07-08T16:07:42.9419409Z = note: Creating library D:\a\rust\rust\build\i686-pc-windows-msvc\test\rustdoc\intra-link-prim-methods-external-core\auxiliary\my_core.dll.lib and object D:\a\rust\rust\build\i686-pc-windows-msvc\test\rustdoc\intra-link-prim-methods-external-core\auxiliary\my_core.dll.exp
2020-07-08T16:07:42.9419810Z LINK : error LNK2001: unresolved external symbol __DllMainCRTStartup@12
2020-07-08T16:07:42.9420032Z D:\a\rust\rust\build\i686-pc-windows-msvc\test\rustdoc\intra-link-prim-methods-external-core\auxiliary\my_core.dll : fatal error LNK1120: 1 unresolved externals
```
Possibly this could be resolved by adding a `__DllMainCRTStartup` or `__DllMainCRTStartup@12` symbol in an architecture- and platform-specific way.
Other terms are more inclusive and precise.
Clippy still has a lint named "blacklisted-name", but renaming it would
be a breaking change, so is left for future work.
The target configuration option "abi-blacklist" has been depreciated and
renamed to "unsupported-abis". The old name continues to work.
Fix occasional bootstrap panic in docs.
I am occasionally running into this panic when running `x.py`:
> thread 'main' panicked at 'source "/Users/eric/Proj/rust/rust/build/x86_64-apple-darwin/md-doc/unstable-book" failed to get metadata: No such file or directory (os error 2)', src/build_helper/lib.rs:173:19
I have not been able to figure out the exact sequence of commands that leads to this error (I tried for quite a while to reproduce it). I think it may involve updating my tree, but I am uncertain. An artificial way to trigger it is to build the documentation, and then delete the `md-doc` directory manually.
The cause is that bootstrap does a "dry run" before every command, and in this case `up_to_date` panics because the destination exists (`build/x86_64-apple-darwin/doc/unstable-book/index.html `) but the source does not (`build/x86_64-apple-darwin/md-doc/unstable-book`).
I am uncertain if it is important that the last line `builder.run(…)` needs to be called during the dry run. This patch seems to fix the issue, though.
