Fix star handling in block doc comments
Fixes#92872.
Some extra explanation about this PR and why https://github.com/rust-lang/rust/pull/92357 created this regression: when we merge doc comment kinds for example in:
```rust
/// he
/**
* hello
*/
#[doc = "boom"]
```
We don't want to remove the empty lines between them. However, to correctly compute the "horizontal trim", we still need it, so instead, I put back a part of the "vertical trim" directly in the "horizontal trim" computation so it doesn't impact the output buffer but allows us to correctly handle the stars.
r? `@camelid`
Add Attribute::meta_kind
The `AttrItem::meta` function is being called on a lot of places, however almost always the caller is only interested in the `kind` of the result `MetaItem`. Before, the `path` had to be cloned in order to get the kind, now it does not have to be.
There is a larger related "problem". In a lot of places, something wants to know contents of attributes. This is accessed through `Attribute::meta_item_list`, which calls `AttrItem::meta` (now `AttrItem::meta_kind`), among other methods. When this function is called, the meta item list has to be recreated from scratch. Everytime something asks a simple question (like is this item/list of attributes `#[doc(hidden)]`?), the tokens of the attribute(s) are cloned, parsed and the results are allocated on the heap. That seems really unnecessary. What would be the best way to cache this? Turn `meta_item_list` into a query perhaps? Related PR: https://github.com/rust-lang/rust/pull/92227
r? rust-lang/rustdoc
ast: Avoid aborts on fatal errors thrown from mutable AST visitor
Set the node to some dummy value and rethrow the error instead.
When using the old aborting `visit_clobber` in `InvocationCollector::visit_crate` the next tests abort due to fatal errors:
```
ui\modules\path-invalid-form.rs
ui\modules\path-macro.rs
ui\modules\path-no-file-name.rs
ui\parser\issues\issue-5806.rs
ui\parser\mod_file_with_path_attr.rs
```
Follow up to https://github.com/rust-lang/rust/pull/91313.
Remove `SymbolStr`
This was originally proposed in https://github.com/rust-lang/rust/pull/74554#discussion_r466203544. As well as removing the icky `SymbolStr` type, it allows the removal of a lot of `&` and `*` occurrences.
Best reviewed one commit at a time.
r? `@oli-obk`
Stabilise `feature(const_generics_defaults)`
`feature(const_generics_defaults)` is complete implementation wise and has a pretty extensive test suite so I think is ready for stabilisation.
needs stabilisation report and maybe an RFC 😅
r? `@lcnr`
cc `@rust-lang/project-const-generics`
Fix bug with `#[doc]` string single-character last lines
Fixes#90618.
This is because `.iter().all(|c| c == '*')` returns `true` if there is no character checked. And in case the last line has only one character, it simply returns `true`, making the last line behind removed.
TraitKind -> Trait
TyAliasKind -> TyAlias
ImplKind -> Impl
FnKind -> Fn
All `*Kind`s in AST are supposed to be enums.
Tuple structs are converted to braced structs for the types above, and fields are reordered in syntactic order.
Also, mutable AST visitor now correctly visit spans in defaultness, unsafety, impl polarity and constness.
Optimize bidi character detection.
Should fix most of the performance regression of the bidi character detection (#90514), to be confirmed with a perf run.
rustc_ast: Turn `MutVisitor::token_visiting_enabled` into a constant
It's a visitor property rather than something that needs to be determined at runtime
rustc_span: `Ident::invalid` -> `Ident::empty`
The equivalent for `Symbol`s was renamed some time ago (`kw::Invalid` -> `kw::Empty`), and it makes sense to do the same thing for `Ident`s as well.
Revert anon union parsing
Revert PR #84571 and #85515, which implemented anonymous union parsing in a manner that broke the context-sensitivity for the `union` keyword and thus broke stable Rust code.
Fix#88583.
This reverts commit 059b68dd67.
Note that this was manually adjusted to retain some of the refactoring
introduced by commit 059b68dd67, so that it could
likewise retain the correction introduced in commit
5b4bc05fa5
Improve diagnostics for unary plus operators (#88276)
This pull request improves the diagnostics emitted on parsing a unary plus operator. See #88276.
Before:
```
error: expected expression, found `+`
--> src/main.rs:2:13
|
2 | let x = +1;
| ^ expected expression
```
After:
```
error: leading `+` is not supported
--> main.rs:2:13
|
2 | let x = +1;
| ^
| |
| unexpected `+`
| help: try removing the `+`
```
Detect bare blocks with type ascription that were meant to be a `struct` literal
Address part of #34255.
Potential improvement: silence the other knock down errors in `issue-34255-1.rs`.
- [x] Removed `?const` and change uses of `?const`
- [x] Added `~const` to the AST. It is gated behind const_trait_impl.
- [x] Validate `~const` in ast_validation.
- [ ] Add enum `BoundConstness` to the HIR. (With variants `NotConst` and
`ConstIfConst` allowing future extensions)
- [ ] Adjust trait selection and pre-existing code to use `BoundConstness`.
- [ ] Optional steps (*for this PR, obviously*)
- [ ] Fix#88155
- [ ] Do something with constness bounds in chalk
Use if-let guards in the codebase and various other pattern cleanups
Dogfooding if-let guards as experimentation for the feature.
Tracking issue #51114. Conflicts with #87937.
rfc3052 followup: Remove authors field from Cargo manifests
Since RFC 3052 soft deprecated the authors field, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information for contributors, we may as well
remove it from crates in this repo.
Since RFC 3052 soft deprecated the authors field anyway, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information, we should remove it from
crates in this repo.
The special case breaks several useful invariants (`ExpnId`s are
globally unique, and never change). This special case
was added back in 2016 in https://github.com/rust-lang/rust/pull/34355
Stabilize "RangeFrom" patterns in 1.55
Implements a partial stabilization of #67264 and #37854.
Reference PR: https://github.com/rust-lang/reference/pull/900
# Stabilization Report
This stabilizes the `X..` pattern, shown as such, offering an exhaustive match for unsigned integers:
```rust
match x as u32 {
0 => println!("zero!"),
1.. => println!("positive number!"),
}
```
Currently if a Rust author wants to write such a match on an integer, they must use `1..={integer}::MAX` . By allowing a "RangeFrom" style pattern, this simplifies the match to not require the MAX path and thus not require specifically repeating the type inside the match, allowing for easier refactoring. This is particularly useful for instances like the above case, where different behavior on "0" vs. "1 or any positive number" is desired, and the actual MAX is unimportant.
Notably, this excepts slice patterns which include half-open ranges from stabilization, as the wisdom of those is still subject to some debate.
## Practical Applications
Instances of this specific usage have appeared in the compiler:
16143d1067/compiler/rustc_middle/src/ty/inhabitedness/mod.rs (L219)673d0db5e3/compiler/rustc_ty_utils/src/ty.rs (L524)
And I have noticed there are also a handful of "in the wild" users who have deployed it to similar effect, especially in the case of rejecting any value of a certain number or greater. It simply makes it much more ergonomic to write an irrefutable match, as done in Katholieke Universiteit Leuven's [SCALE and MAMBA project](05e5db00d5/WebAssembly/scale_std/src/fixed_point.rs (L685-L695)).
## Tests
There were already many tests in [src/test/ui/half-open-range/patterns](90a2e5e3fe/src/test/ui/half-open-range-patterns), as well as [generic pattern tests that test the `exclusive_range_pattern` feature](673d0db5e3/src/test/ui/pattern/usefulness/integer-ranges/reachability.rs), many dating back to the feature's introduction and remaining standing to this day. However, this stabilization comes with some additional tests to explore the... sometimes interesting behavior of interactions with other patterns. e.g. There is, at least, a mild diagnostic improvement in some edge cases, because before now, the pattern `0..=(5+1)` encounters the `half_open_range_patterns` feature gate and can thus emit the request to enable the feature flag, while also emitting the "inclusive range with no end" diagnostic. There is no intent to allow an `X..=` pattern that I am aware of, so removing the flag request is a strict improvement. The arrival of the `J | K` "or" pattern also enables some odd formations.
Some of the behavior tested for here is derived from experiments in this [Playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=58777b3c715c85165ac4a70d93efeefc) example, linked at https://github.com/rust-lang/rust/issues/67264#issuecomment-812770692, which may be useful to reference to observe the current behavior more closely.
In addition tests constituting an explanation of the "slicing range patterns" syntax issue are included in this PR.
## Desiderata
The exclusive range patterns and half-open range patterns are fairly strongly requested by many authors, as they make some patterns much more natural to write, but there is disagreement regarding the "closed" exclusive range pattern or the "RangeTo" pattern, especially where it creates "off by one" gaps in the presence of a "catch-all" wildcard case. Also, there are obviously no range analyses in place that will force diagnostics for e.g. highly overlapping matches. I believe these should be warned on, ideally, and I think it would be reasonable to consider such a blocker to stabilizing this feature, but there is no technical issue with the feature as-is from the purely syntactic perspective as such overlapping or missed matches can already be generated today with such a catch-all case. And part of the "point" of the feature, at least from my view, is to make it easier to omit wildcard matches: a pattern with such an "open" match produces an irrefutable match and does not need the wild card case, making it easier to benefit from exhaustiveness checking.
## History
- Implemented:
- Partially via exclusive ranges: https://github.com/rust-lang/rust/pull/35712
- Fully with half-open ranges: https://github.com/rust-lang/rust/pull/67258
- Unresolved Questions:
- The precedence concerns of https://github.com/rust-lang/rust/pull/48501 were considered as likely requiring adjustment but probably wanting a uniform consistent change across all pattern styles, given https://github.com/rust-lang/rust/issues/67264#issuecomment-720711656, but it is still unknown what changes might be desired
- How we want to handle slice patterns in ranges seems to be an open question still, as witnessed in the discussion of this PR!
I checked but I couldn't actually find an RFC for this, and given "approved provisionally by lang team without an RFC", I believe this might require an RFC before it can land? Unsure of procedure here, on account of this being stabilizing a subset of a feature of syntax.
r? `@scottmcm`
Fix ICE when `main` is declared in an `extern` block
Changes in #84401 to implement `imported_main` changed how the crate entry point is found, and a declared `main` in an `extern` block was detected erroneously. This was causing the ICE described in #86110.
This PR adds a check for this case and emits an error instead. Previously a `main` declaration in an `extern` block was not detected as an entry point at all, so emitting an error shouldn't break anything that worked previously. In 1.52.1 stable this is demonstrated, with a `` `main` function not found`` error.
Fixes#86110
parser: Ensure that all nonterminals have tokens after parsing
`parse_nonterminal` should always result in something with tokens.
This requirement wasn't satisfied in two cases:
- `stmt` nonterminal with expression statements (e.g. `0`, or `{}`, or `path + 1`) because `fn parse_stmt_without_recovery` forgot to propagate `force_collect` in some cases.
- `expr` nonterminal with expressions with built-in attributes (e.g. `#[allow(warnings)] 0`) due to an incorrect optimization in `fn parse_expr_force_collect`, it assumed that all expressions starting with `#` have their tokens collected during parsing, but that's not true if all the attributes on that expression are built-in and inert.
(Discovered when trying to implement eager `cfg` expansion for all attributes https://github.com/rust-lang/rust/pull/83824#issuecomment-817317170.)
r? `@Aaron1011`
