add span to struct pattern rest (..)
Struct pattern rest (`..`) did not retain span information compared to normal fields. This patch adds span information for it.
The motivation of this patch comes from when I implemented this PR for Clippy: https://github.com/rust-lang/rust-clippy/pull/15000#discussion_r2134145163
It is possible to get the span of the Et cetera in a bit roundabout way, but I thought this would be nicer.
This was done in #145740 and #145947. It is causing problems for people
using r-a on anything that uses the rustc-dev rustup package, e.g. Miri,
clippy.
This repository has lots of submodules and subtrees and various
different projects are carved out of pieces of it. It seems like
`[workspace.dependencies]` will just be more trouble than it's worth.
Experiment: Reborrow trait
Tracking issue: rust-lang/rust#145612
Starting off really small here: just introduce the unstable feature and the feature gate, and one of the two traits that the Reborrow experiment deals with.
### Cliff-notes explanation
The `Reborrow` trait is conceptually a close cousin of `Copy` with the exception that it disables the source (`self`) for the lifetime of the target / result of the reborrow action. It can be viewed as a method of `fn reborrow(self: Self<'a>) -> Self<'a>` with the compiler adding tracking of the resulting `Self<'a>` (or any value derived from it that retains the `'a` lifetime) to keep the `self` disabled for reads and writes.
No method is planned to be surfaced to the user, however, as reborrowing cannot be seen in code (except for method calls [`a.foo()` reborrows `a`] and explicit reborrows [`&*a`]) and thus triggering user-code in it could be viewed as "spooky action at a distance". Furthermore, the added compiler tracking cannot be seen on the method itself, violating the Golden Rule. Note that the userland "reborrow" method is not True Reborrowing, but rather a form of a "Fancy Deref":
```rust
fn reborrow(&'short self: Self<'long>) -> Self<'short>;
```
The lifetime shortening is the issue here: a reborrowed `Self` or any value derived from it is bound to the method that called `reborrow`, since `&'short` is effectively a local variable. True Reborrowing does not shorten the lifetime of the result.
To avoid having to introduce new kinds of references, new kinds of lifetime annotations, or a blessed trait method, no method will be introduced at all. Instead, the `Reborrow` trait is intended to be a derived trait that effectively reborrows each field individually; `Copy` fields end up just copying, while fields that themselves `Reborrow` get disabled in the source, usually leading to the source itself being disabled (some differences may appear with structs that contain multiple reborrowable fields). The goal of the experiment is to determine how the actual implementation here will shape out, and what the "bottom case" for the recursive / deriving `Reborrow` is.
`Reborrow` has a friend trait, `CoerceShared`, which is equivalent to a `&'a mut T -> &'a T` conversion. This is needed as a different trait and different operation due to the different semantics it enforces on the source: a `CoerceShared` operation only disables the source for writes / exclusive access for the lifetime of the result. That trait is not yet introduced in this PR, though there is no particular reason why it could not be introduced.
Some crates depend on `rustc_hir` but only want `HirId` and similar id
types. `rustc_hir` is a heavy dependency, since it pulls in
`rustc_target`. Split these types out into their own crate
`rustc_hir_id`.
This allows `rustc_errors` to drop its direct dependency on `rustc_hir`.
(`rustc_errors` still depends on `rustc_hir` indirectly through
`rustc_lint_defs`; a subsequent commit will fix that.)
`rustc_errors` depends on numerous crates, solely to implement its
`IntoDiagArg` trait on types from those crates. Many crates depend on
`rustc_errors`, and it's on the critical path.
We can't swap things around to make all of those crates depend on
`rustc_errors` instead, because `rustc_errors` would end up in
dependency cycles.
Instead, move `IntoDiagArg` into `rustc_error_messages`, which has far
fewer dependencies, and then have most of these crates depend on
`rustc_error_messages`.
This allows `rustc_errors` to drop dependencies on several crates,
including the large `rustc_target`.
(This doesn't fully reduce dependency chains yet, as `rustc_errors`
still depends on `rustc_hir` which depends on `rustc_target`. That will
get fixed in a subsequent commit.)
Revert "Partially outline code inside the panic! macro".
This reverts https://github.com/rust-lang/rust/pull/115670
Without any tests/benchmarks that show some improvement, it's hard to know whether the change had any positive effect. (And if it did, whether that effect is still achieved today.)
- Added a few more variants which are needed for various attributes
- Previously a trait method with default block had the same target representation as a method in a `impl trait for` block, this has been changed (See `MethodKind`)
- Added `plural_name` for more precision on the form of the name
Handle macros with multiple kinds, and improve errors
(I recommend reviewing this commit-by-commit.)
Switch to a bitflags `MacroKinds` to support macros with more than one kind
Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`.
Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds.
This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`.
Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes.
This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules.
Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors.
This also handles cases of forward-referenced attributes and cyclic attributes.
----
In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds.
rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that.
----
r? ````````@petrochenkov````````
Review everything that uses `MacroKind`, and switch anything that could
refer to more than one kind to use `MacroKinds`.
Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros,
using the concrete `MacroRulesMacroExpander` type, and have it track
which kinds it can handle. Eliminate the separate optional `attr_ext`,
now that a `SyntaxExtension` can handle multiple macro kinds.
This also avoids the need to downcast when calling methods on
`MacroRulesMacroExpander`, such as `get_unused_rule`.
Integrate macro kind checking into name resolution's
`sub_namespace_match`, so that we only find a macro if it's the right
type, and eliminate the special-case hack for attributes.
Without any tests/benchmarks that show some improvement, it's hard to
know whether the change had any positive effect at all. (And if it did,
whether that effect is still achieved today.)
Port `#[allow_internal_unsafe]` to the new attribute system (attempt 2)
This is a slightly modified version of ae1487aa9922de7642c448cc0908584026699e1c, which caused a performance regression (reverted in https://github.com/rust-lang/rust/pull/145086#issue-3303428759). The diff between this PR and the previous one can be seen in 027a1def.
r? ```````@jdonszelmann``````` 💖
Implement `stability_implications` without a visitor.
Since https://github.com/rust-lang/rust/pull/143845, the `Annotator` visitor was a no-op when the crate is not staged_api. This PR avoids using a visitor altogether, making `stability_implications` truly a no-op in most cases.
