…new`

It's the same as `Delimiter`, minus the `Invisible` variant. I'm
generally in favour of using types to make impossible states
unrepresentable, but this one feels very low-value, and the conversions
between the two types are annoying and confusing.

Look at the change in `src/tools/rustfmt/src/expr.rs` for an example:
the old code converted from `MacDelimiter` to `Delimiter` and back
again, for no good reason. This suggests the author was confused about
the types.

…bank

Suggests turbofish in patterns

Fixes rust-lang#114112

r? ```@estebank```

Indexing is similar to method calls in having an arbitrary
left-hand-side and then something on the right, which is the main part
of the expression. Method calls already have a span for that right part,
but indexing does not. This means that long method chains that use
indexing have really bad spans, especially when the indexing panics and
that span in coverted into a panic location.

This does the same thing as method calls for the AST and HIR, storing an
extra span which is then put into the `fn_span` field in THIR.

Lots of tiny incremental simplifications of `EmitterWriter` internals

ignore the first commit, it's rust-lang#114088 squashed and rebased, but it's needed to use to use `derive_setters`, as they need a newer `syn` version.

Then this PR starts out with removing many arguments that are almost always defaulted to `None` or `false` and replace them with builder methods that can set these fields in the few cases that want to set them.

After that it's one commit after the other that removes or merges things until everything becomes some very simple trait objects

Improve spans for indexing expressions

fixes rust-lang#114388

Indexing is similar to method calls in having an arbitrary left-hand-side and then something on the right, which is the main part of the expression. Method calls already have a span for that right part, but indexing does not. This means that long method chains that use indexing have really bad spans, especially when the indexing panics and that span in coverted into a panic location.

This does the same thing as method calls for the AST and HIR, storing an extra span which is then put into the `fn_span` field in THIR.

r? compiler-errors

…iaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#113945 (Fix wrong span for trait selection failure error reporting)
 - rust-lang#114351 ([rustc_span][perf] Remove unnecessary string joins and allocs.)
 - rust-lang#114418 (bump parking_lot to 0.12)
 - rust-lang#114434 (Improve spans for indexing expressions)
 - rust-lang#114450 (Fix ICE failed to get layout for ReferencesError)
 - rust-lang#114461 (Fix unwrap on None)
 - rust-lang#114462 (interpret: add mplace_to_ref helper method)
 - rust-lang#114472 (Reword `confusable_idents` lint)
 - rust-lang#114477 (Account for `Rc` and `Arc` when suggesting to clone)

r? `@ghost`
`@rustbot` modify labels: rollup

Anonymous structs or unions are only allowed in struct field
definitions.

Co-authored-by: carbotaniuman <[email protected]>

…sync

report `unused_import` for empty reexports even it is pub

Fixes rust-lang#116032

An easy fix. r? `@petrochenkov`

(Discovered this issue while reviewing rust-lang#115993.)

…ce_style

Fixes 5912

When `control_brace_style = "AlwaysNextLine"`, the code seems to always assume that `body_prefix` is `{`. This is however not the case when `match_arm_blocks = false`. This causes `block_sep` to introduce extra white space that causes the error.

The fix was to check if `body_prefix` is empty before matching on `ControlBraceStyle::AlwaysNextLine`.

These changes mostly improve logging out the cargo version and version
of the two rustfmt binaries that are compiled. Some other minor logging
changes were made as well to add some whitespace to improve visual
clarity when looking at the logs in the GitHub Actions console.

rustfmt currently has a runtime dependency on the sysroot. So when we
build a standalone rustfmt binary we need to set `LD_LIBRARY_PATH` so
each rustfmt binary knows where to find it's dependencies.

When running our Diff-Check job to test PRs for breaking changes it's
often the case that both the master rustfmt binary and the feature
branch binary have the same runtime dependencies so we only need to
set `LD_LIBRARY_PATH` once.

However, when running the diff-check job against a subtree sync PR that
assumption doesn't hold. The subtree sync PR bumps the required
toolchain used to build rustfmt and therefore the binary that gets built
for the subtree sync PR has a different runtime dependency than the
master rustfmt binary.

Now we set `LD_LIBRARY_PATH` twice to account for this potential
difference.

Because the API for `with_position` improved in 0.11 and I want to use
it.

- Rename them both `as_str`, which is the typical name for a function
  that returns a `&str`. (`to_string` is appropriate for functions
  returning `String` or maybe `Cow<'a, str>`.)
- Change `UnOp::as_str` from an associated function (weird!) to a
  method.
- Avoid needless `self` dereferences.

…r=compiler-errors

Add `never_patterns` feature gate

This PR adds the feature gate and most basic parsing for the experimental `never_patterns` feature. See the tracking issue (rust-lang#118155) for details on the experiment.

`@scottmcm` has agreed to be my lang-team liaison for this experiment.

…mpiler-errors

never_patterns: Parse match arms with no body

Never patterns are meant to signal unreachable cases, and thus don't take bodies:
```rust
let ptr: *const Option<!> = ...;
match *ptr {
    None => { foo(); }
    Some(!),
}
```
This PR makes rustc accept the above, and enforces that an arm has a body xor is a never pattern. This affects parsing of match arms even with the feature off, so this is delicate. (Plus this is my first non-trivial change to the parser).

~~The last commit is optional; it introduces a bit of churn to allow the new suggestions to be machine-applicable. There may be a better solution? I'm not sure.~~ EDIT: I removed that commit

r? `@compiler-errors`

Introduce support for `async gen` blocks

I'm delighted to demonstrate that `async gen` block are not very difficult to support. They're simply coroutines that yield `Poll<Option<T>>` and return `()`.

**This PR is WIP and in draft mode for now** -- I'm mostly putting it up to show folks that it's possible. This PR needs a lang-team experiment associated with it or possible an RFC, since I don't think it falls under the jurisdiction of the `gen` RFC that was recently authored by oli (rust-lang/rfcs#3513, rust-lang#117078).

### Technical note on the pre-generator-transform yield type:

The reason that the underlying coroutines yield `Poll<Option<T>>` and not `Poll<T>` (which would make more sense, IMO, for the pre-transformed coroutine), is because the `TransformVisitor` that is used to turn coroutines into built-in state machine functions would have to destructure and reconstruct the latter into the former, which requires at least inserting a new basic block (for a `switchInt` terminator, to match on the `Poll` discriminant).

This does mean that the desugaring (at the `rustc_ast_lowering` level) of `async gen` blocks is a bit more involved. However, since we already need to intercept both `.await` and `yield` operators, I don't consider it much of a technical burden.

r? `@ghost`

**Note** This does not add the `style_edition` config option to rustfmt.
The `StyleEdition` enum will eventually be used to allow users to
configure the `style_edition`, but for now it's added so we can
introduce the the `StyleEditionDefault` trait.

detects redundant imports that can be eliminated.

for rust-lang#117772 :

In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.

This is an extension of the previous commit. It means the output of
something like this:
```
stringify!(let a: Vec<u32> = vec![];)
```
goes from this:
```
let a: Vec<u32> = vec![] ;
```
With this PR, it now produces this string:
```
let a: Vec<u32> = vec![];
```

…KO8Ki

Remove edition umbrella features.

In the 2018 edition, there was an "umbrella" feature `#[feature(rust_2018_preview)]` which was used to enable several other features at once. This umbrella mechanism was not used in the 2021 edition and likely will not be used in 2024 either. During 2018 users reported that setting the feature was awkward, especially since they already needed to opt-in via the edition mechanism.

This PR removes this mechanism because I believe it will not be used (and will clean up and simplify the code). I believe that there are better ways to handle features and editions. In short:

- For highly experimental features, that may or may not be involved in an edition, they can implement regular feature gates like `tcx.features().my_feature`.
- For experimental features that *might* be involved in an edition, they should implement gates with `tcx.features().my_feature && span.at_least_rust_20xx()`. This requires the user to still specify `#![feature(my_feature)]`, to avoid disrupting testing of other edition features which are ready and have been accepted within the edition.
- For experimental features that have graduated to definitely be part of an edition, they should implement gates with `tcx.features().my_feature || span.at_least_rust_20xx()`, or just remove the feature check altogether and just check `span.at_least_rust_20xx()`.
- For relatively simple changes, they can skip the whole feature gating thing and just check `span.at_least_rust_20xx()`, and rely on the instability of the edition itself (which requires `-Zunstable-options`) to gate it.

I am working on documenting all of this in the rustc-dev-guide.

…_12_12

Subtree push 2023-12-12

Currently, `emit_diagnostic` takes `&mut self`.

This commit changes it so `emit_diagnostic` takes `self` and the new
`emit_diagnostic_without_consuming` function takes `&mut self`.

I find the distinction useful. The former case is much more common, and
avoids a bunch of `mut` and `&mut` occurrences. We can also restrict the
latter with `pub(crate)` which is nice.

Closes 3390

`hide_parse_errors` is now deprecated, and was renamed
`show_parse_errors` to avoid confusion around the double negative
default of `hide_parse_errors=false`.

…fiers, r=compiler-errors

Refactor AST trait bound modifiers

Instead of having two types to represent trait bound modifiers in the parser / the AST (`parser::ty::BoundModifiers` & `ast::TraitBoundModifier`), only to map one to the other later, just use `parser::ty::BoundModifiers` (moved & renamed to `ast::TraitBoundModifiers`).

The struct type is more extensible and easier to deal with (see [here](https://github.com/rust-lang/rust/pull/119099/files#r1430749981) and [here](https://github.com/rust-lang/rust/pull/119099/files#r1430752116) for context) since it more closely models what it represents: A compound of two kinds of modifiers, constness and polarity. Modeling this as an enum (the now removed `ast::TraitBoundModifier`) meant one had to add a new variant per *combination* of modifier kind, which simply isn't scalable and which lead to a lot of explicit non-DRY matches.

NB: `hir::TraitBoundModifier` being an enum is fine since HIR doesn't need to worry representing invalid modifier kind combinations as those get rejected during AST validation thereby immensely cutting down the number of possibilities.

Add support for `for await` loops

This adds support for `for await` loops. This includes parsing, desugaring in AST->HIR lowering, and adding some support functions to the library.

Given a loop like:
```rust
for await i in iter {
    ...
}
```
this is desugared to something like:
```rust
let mut iter = iter.into_async_iter();
while let Some(i) = loop {
    match core::pin::Pin::new(&mut iter).poll_next(cx) {
        Poll::Ready(i) => break i,
        Poll::Pending => yield,
    }
} {
    ...
}
```

This PR also adds a basic `IntoAsyncIterator` trait. This is partly for symmetry with the way `Iterator` and `IntoIterator` work. The other reason is that for async iterators it's helpful to have a place apart from the data structure being iterated over to store state. `IntoAsyncIterator` gives us a good place to do this.

I've gated this feature behind `async_for_loop` and opened rust-lang#118898 as the feature tracking issue.

r? `@compiler-errors`

Lots of vectors of messages called `message` or `msg`. This commit
pluralizes them.

Note that `emit_message_default` and `emit_messages_default` both
already existed, and both process a vector, so I renamed the former
`emit_messages_default_inner` because it's called by the latter.

See https://github.com/rust-lang/rust/blob/cee794ee98d49b45a55ba225680d98e0c4672736/compiler/rustc_parse/src/parser/pat.rs#L890-L897 for the only place this is constructed.

…docs, r=compiler-errors

Clairify `ast::PatKind::Struct` presese of `..` by using an enum instead of a bool

The bool is mainly used for when a `..` is present, but it is also set on recovery to avoid errors. The doc comment not describes both of these cases.

See https://github.com/rust-lang/rust/blob/cee794ee98d49b45a55ba225680d98e0c4672736/compiler/rustc_parse/src/parser/pat.rs#L890-L897 for the only place this is constructed.

r? ``@compiler-errors``

…5989)

Fixes 5987

rustfmt already special cases the formatting for the `debug!`, `info!`,
`warn!`, and `error!`, macros from the `log` crate. However, this
speical case handling did not apply to the `trace!` macro.

Now when using `Version=Two` rustfmt will also special case the
formatting for the `trace!` macro.

….77.0_nightly_2023_12_27

…0_nightly_2023_12_28

Subtree push with 1.77.0 nightly 2023-12-28

Otherwise tests fail due to unknown lint and dead code warnings.

For consistency with other `Emitter` impls, such as `JsonEmitter`,
`SilentEmitter`, `SharedEmitter`, etc.

…i-obk

`Emitter` cleanups

Some improvements I found while looking at this code.

r? `@oli-obk`

* clippy: autofix some lint warnings
* fix a couple more clippy warnings

This works for most of its call sites. This is nice, because `emit` very
much makes sense as a consuming operation -- indeed,
`DiagnosticBuilderState` exists to ensure no diagnostic is emitted
twice, but it uses runtime checks.

For the small number of call sites where a consuming emit doesn't work,
the commit adds `DiagnosticBuilder::emit_without_consuming`. (This will
be removed in subsequent commits.)

Likewise, `emit_unless` becomes consuming. And `delay_as_bug` becomes
consuming, while `delay_as_bug_without_consuming` is added (which will
also be removed in subsequent commits.)

All this requires significant changes to `DiagnosticBuilder`'s chaining
methods. Currently `DiagnosticBuilder` method chaining uses a
non-consuming `&mut self -> &mut Self` style, which allows chaining to
be used when the chain ends in `emit()`, like so:
```
    struct_err(msg).span(span).emit();
```
But it doesn't work when producing a `DiagnosticBuilder` value,
requiring this:
```
    let mut err = self.struct_err(msg);
    err.span(span);
    err
```
This style of chaining won't work with consuming `emit` though. For
that, we need to use to a `self -> Self` style. That also would allow
`DiagnosticBuilder` production to be chained, e.g.:
```
    self.struct_err(msg).span(span)
```
However, removing the `&mut self -> &mut Self` style would require that
individual modifications of a `DiagnosticBuilder` go from this:
```
    err.span(span);
```
to this:
```
    err = err.span(span);
```
There are *many* such places. I have a high tolerance for tedious
refactorings, but even I gave up after a long time trying to convert
them all.

Instead, this commit has it both ways: the existing `&mut self -> Self`
chaining methods are kept, and new `self -> Self` chaining methods are
added, all of which have a `_mv` suffix (short for "move"). Changes to
the existing `forward!` macro lets this happen with very little
additional boilerplate code. I chose to add the suffix to the new
chaining methods rather than the existing ones, because the number of
changes required is much smaller that way.

This doubled chainging is a bit clumsy, but I think it is worthwhile
because it allows a *lot* of good things to subsequently happen. In this
commit, there are many `mut` qualifiers removed in places where
diagnostics are emitted without being modified. In subsequent commits:
- chaining can be used more, making the code more concise;
- more use of chaining also permits the removal of redundant diagnostic
  APIs like `struct_err_with_code`, which can be replaced easily with
  `struct_err` + `code_mv`;
- `emit_without_diagnostic` can be removed, which simplifies a lot of
  machinery, removing the need for `DiagnosticBuilderState`.

Fixes 5801 when using `version=Two`

Previously, doc comments would wrap one character less than the
`comment_width` when using `wrap_comments=true`, and fn-like attributes
would wrap one character before the `attr_fn_like_width`.

Now, when using `version=Two` enum variant attributes won't wrap early

`is_force_warn` is only possible for diagnostics with `Level::Warning`,
but it is currently stored in `Diagnostic::code`, which every diagnostic
has.

This commit:
- removes the boolean `DiagnosticId::Lint::is_force_warn` field;
- adds a `ForceWarning` variant to `Level`.

Benefits:
- The common `Level::Warning` case now has no arguments, replacing
  lots of `Warning(None)` occurrences.
- `rustc_session::lint::Level` and `rustc_errors::Level` are more
  similar, both having `ForceWarning` and `Warning`.

One consequence is that errors returned by
`maybe_new_parser_from_source_str` now must be consumed, so a bunch of
places that previously ignored those errors now cancel them. (Most of
them explicitly dropped the errors before. I guess that was to indicate
"we are explicitly ignoring these", though I'm not 100% sure.)

`generated_marker_line_search_limit` allows users to configure how many
lines rustfmt should search for an `@generated` marker comment when
`format_generated_files=false`

---------

Co-authored-by: Jordan Eldredge <[email protected]>

…a macro arg in rustfmt

Instead of {filename} at {line}, use {filename}:{line} as this is a
format that many editors allow to be clicked to navigate directly to the
line.

various spelling fixes
---------

Signed-off-by: Josh Soref <[email protected]>

…g#5582)

Fix issue 3805

* Updating dependencies for rustfmt in an attempt to consolidate rustc dependencies
* Updating link for dirs 5.0.1

All the other `emit`/`emit_diagnostic` methods were recently made
consuming (e.g. rust-lang#119606), but this one wasn't. But it makes sense to.

Much of this is straightforward, and lots of `clone` calls are avoided.
There are a couple of tricky bits.
- `Emitter::primary_span_formatted` no longer takes a `Diagnostic` and
  returns a pair. Instead it takes the two fields from `Diagnostic` that
  it used (`span` and `suggestions`) as `&mut`, and modifies them. This
  is necessary to avoid the cloning of `diag.children` in two emitters.
- `from_errors_diagnostic` is rearranged so various uses of `diag` occur
  before the consuming `emit_diagnostic` call.

… r=calebcartwright

Format `async` trait bounds in rustfmt

r? `@ytmimi` or `@calebcartwright`

This PR opts to do formatting in the rust-lang/rust tree because otherwise we'd have to wait until a full sync, and rustfmt is currently totally removing the `async` keyword.

cc rust-lang/rustfmt#6070

Fixes 6069

Calling `item.ident.as_str()` returns an NFC normalized ident, which
might not be what's written in the source code. To avoid panics when
calling `snippet_provider.span_after` use the ident from the source.

This makes it more like `hir::TyKind::Err`, and avoids a
`span_delayed_bug` call in `LoweringContext::lower_ty_direct`.

It also requires adding `ast::TyKind::Dummy`, now that
`ast::TyKind::Err` can't be used for that purpose in the absence of an
error emission.

There are a couple of cases that aren't as neat as I would have liked,
marked with `FIXME` comments.

Subdiagnostics don't need to be lazily translated, they can always be
eagerly translated. Eager translation is slightly more complex as we need
to have a `DiagCtxt` available to perform the translation, which involves
slightly more threading of that context.

This slight increase in complexity should enable later simplifications -
like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages
into the diagnostic structs rather than having them in separate files
(working on that was what led to this change).

Signed-off-by: David Wood <[email protected]>