Don't try to render auto-trait bounds with any inference variables
Previously, we checked if the target of a projection type was itself an
inference variable. However, for Rustdoc rendering purposes, there's no
distinction between an inference variable ('_') and a type containing
one (e.g. (MyStruct<u8, _>)) - we don't want to render either of them.
Fixes#60269
Due to the complexity of the original bug, which spans three different
crates (hyper, tower-hyper, and tower), I have been unable to create a
minimized reproduction for the issue.
This commit separates metadata encoding (`tcx.encode_metadata`) from the
creation of the metadata module (which is now handled by
`write_compressed_metadata`, formerly `write_metadata`).
The metadata encoding now occurs slightly earlier in the pipeline, at
the very start of code generation within `start_codegen`.
Metadata *writing* still occurs near the end of compilation; that will
be moved forward in subsequent commits.
It's natural for `retain` to work in order from beginning to end, but
this wasn't actually documented to be the case. If we actually promise
this, then the caller can do useful things like track the index of each
element being tested, as [discussed in the forum][1]. This is now
documented for `Vec`, `VecDeque`, and `String`.
[1]: https://users.rust-lang.org/t/vec-retain-by-index/27697
`HashMap` and `HashSet` also have `retain`, and the `hashbrown`
implementation does happen to use a plain `iter()` order too, but it's
not certain that this should always be the case for these types.
Cleanup the MIR visitor
* Remove useless `BasicBlock` parameters on methods with `Location`s.
* Prefer `visit_terminator_kind` to `visit_terminator`.
* Remove `Region` from PlaceContexts. `visit_rvalue` should be used when the region is important.
* Remove unused visitor methods.
In JSON output, emit a directive after metadata is generated.
To implement pipelining, Cargo needs to know when metadata generation is
finished. This is done via a new JSON "directive".
Unfortunately, metadata file writing currently occurs very late during
compilation, so pipelining won't produce a speed-up. Moving metadata
file writing earlier will be a follow-up.
r? @alexcrichton
To implement pipelining, Cargo needs to know when metadata generation is
finished. This commit adds code to do that. Unfortunately, metadata file
writing currently occurs very late during compilation, so pipelining
won't produce a speed-up. Moving metadata file writing earlier will be a
follow-up.
The change involves splitting the existing `Emitter::emit` method in
two: `Emitter::emit_diagnostic` and `Emitter::emit_directive`.
The JSON directives look like this:
```
{"directive":"metadata file written: liba.rmeta"}
```
The functionality is behind the `-Z emit-directives` option, and also
requires `--error-format=json`.
There are some expressions that can be parsed as a statement without
a trailing semicolon depending on the context, which can lead to
confusing errors due to the same looking code being accepted in some
places and not others. Identify these cases and suggest enclosing in
parenthesis making the parse non-ambiguous without changing the
accepted grammar.
Clarify the short explanation of E0207
After being greatly improved in #33692, https://doc.rust-lang.org/error-index.html#E0207 uses terminology from the related RFC, which is different from the [reference](https://doc.rust-lang.org/reference/items/implementations.html), e.g. "self type" instead of "implementing type" and "trait reference" instead of "implemented trait".
It probably makes no difference to an experienced reader, but for a newbie like me it added to the confusion as you can't look up the definition of the terms being used and can't be sure you've guessed correctly...
I would also move the link to RFC to the top, as it seems to be the only doc that attempts to explain what the third criteria entails), but it seems to go against the accepted style.
Stabilized vectored IO
This renames `std::io::IoVec` to `std::io::IoSlice` and
`std::io::IoVecMut` to `std::io::IoSliceMut`, and stabilizes
`std::io::IoSlice`, `std::io::IoSliceMut`,
`std::io::Read::read_vectored`, and `std::io::Write::write_vectored`.
Closes#58452
r? @alexcrichton
