Commit Graph

583 Commits

Author SHA1 Message Date
Bryanskiy
2a73553513 Support ?Trait bounds in supertraits and dyn Trait under a feature gate 2024-07-25 20:53:33 +03:00
Matthias Krüger
cfc5f25b3d
Rollup merge of #127054 - compiler-errors:bound-ordering, r=fmease
Reorder trait bound modifiers *after* `for<...>` binder in trait bounds

This PR suggests changing the grammar of trait bounds from:

```
[CONSTNESS] [ASYNCNESS] [?] [BINDER] [TRAIT_PATH]

const async ? for<'a> Sized
```

to

```
([BINDER] [CONSTNESS] [ASYNCNESS] | [?]) [TRAIT_PATH]
```

i.e., either

```
? Sized
```

or

```
for<'a> const async Sized
```

(but not both)

### Why?

I think it's strange that the binder applies "more tightly" than the `?` trait polarity. This becomes even weirder when considering that we (or at least, I) want to have `async` trait bounds expressed like:

```
where T: for<'a> async Fn(&'a ()) -> i32,
```

and not:

```
where T: async for<'a> Fn(&'a ()) -> i32,
```

### Fallout

No crates on crater use this syntax, presumably because it's literally useless. This will require modifying the reference grammar, though.

### Alternatives

If this is not desirable, then we can alternatively keep parsing `for<'a>` after the `?` but deprecate it with either an FCW (or an immediate hard error), and begin parsing `for<'a>` *before* the `?`.
2024-07-25 04:43:18 +02:00
Santiago Pastorino
8366c7fe9c
Stabilize unsafe extern blocks (RFC 3484) 2024-07-23 00:29:39 -03:00
Michael Goulet
3862095bd2 Just totally fully deny late-bound consts 2024-07-20 19:45:24 -04:00
Michael Goulet
2f5a84ea16 Don't allow unsafe statics outside of extern blocks 2024-07-18 18:02:29 -04:00
Trevor Gross
9833e21c5d
Rollup merge of #126762 - compiler-errors:kw-lt, r=michaelwoerister
Deny keyword lifetimes pre-expansion

https://github.com/rust-lang/rust/pull/126452#issuecomment-2179464266

> Secondly, we confirmed that we're OK with moving the validation of keywords in lifetimes to pre-expansion from post-expansion. We similarly consider this a bug fix. While the breakage of the convenience feature of the with_locals crate that relies on this is unfortunate, and we wish we had not overlooked this earlier for that reason, we're fortunate that the breakage is contained to only one crate, and we're going to accept this breakage as the extra complexity we'd need to carry in the compiler to work around this isn't deemed worth it.

T-lang considers it to be a bugfix to deny `'keyword` lifetimes in the parser, rather than during AST validation that only happens post-expansion. This has one breakage: https://github.com/rust-lang/rust/pull/126452#issuecomment-2171654756

This probably should get lang FCP'd just for consistency.
2024-07-16 16:15:15 -05:00
Michael Goulet
d0a1851ec2 Deny keyword lifetimes pre-expansion 2024-07-16 12:06:25 -04:00
Oli Scherer
d9f9592924 Remove a boilerplaty abstraction 2024-07-16 15:46:45 +00:00
Oli Scherer
b879e29864 Remove a needless borrow 2024-07-16 15:46:45 +00:00
Oli Scherer
9a4c1058fa Just store a span instead of the whole item 2024-07-16 15:44:17 +00:00
Michael Goulet
de88bc5c89 And additionally enforce ? and async/const aren't mixed 2024-07-11 00:00:03 -04:00
Michael Goulet
153a381104 Report usage of lib features in ast validation 2024-07-10 16:53:41 -04:00
Matthias Krüger
33e9f25e91
Rollup merge of #127092 - compiler-errors:rtn-dots-redux, r=estebank
Change return-type-notation to use `(..)`

Aligns the syntax with the current wording of [RFC 3654](https://github.com/rust-lang/rfcs/pull/3654). Also implements rustfmt support (along with making a match exhaustive).

Tracking:
* https://github.com/rust-lang/rust/issues/109417
2024-07-03 23:30:07 +02:00
Matthias Krüger
77152955b8
Rollup merge of #127106 - spastorino:improve-unsafe-extern-blocks-diagnostics, r=compiler-errors
Improve unsafe extern blocks diagnostics

Closes #126327

For this code:

```rust
extern {
    pub fn foo();
    pub safe fn bar();
}
```

We get ...

```
error: items in unadorned `extern` blocks cannot have safety qualifiers
 --> test.rs:3:5
  |
3 |     pub safe fn bar();
  |     ^^^^^^^^^^^^^^^^^^
  |
help: add unsafe to this `extern` block
  |
1 | unsafe extern {
  | ++++++

error[E0658]: `unsafe extern {}` blocks and `safe` keyword are experimental
 --> test.rs:3:9
  |
3 |     pub safe fn bar();
  |         ^^^^
  |
  = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
  = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.
```

And then making the extern block unsafe, we get ...

```
error: extern block cannot be declared unsafe
 --> test.rs:1:1
  |
1 | unsafe extern {
  | ^^^^^^
  |
  = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
  = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable

error: items in unadorned `extern` blocks cannot have safety qualifiers
 --> test.rs:3:5
  |
3 |     pub safe fn bar();
  |     ^^^^^^^^^^^^^^^^^^

error[E0658]: `unsafe extern {}` blocks and `safe` keyword are experimental
 --> test.rs:3:9
  |
3 |     pub safe fn bar();
  |         ^^^^
  |
  = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
  = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0658`.
```

r? ``@compiler-errors``
2024-06-29 22:10:57 +02:00
Santiago Pastorino
15d5dac32e
Avoid suggesting to add unsafe when the extern block is already unsafe 2024-06-29 14:40:32 -03:00
Santiago Pastorino
a62cbda57e
Add feature diagnostic for unsafe_extern_blocks 2024-06-28 23:13:33 -03:00
Matthias Krüger
26df3146ab
Rollup merge of #124091 - jieyouxu:ast-validation-top-level-docs, r=wesleywiser
Update AST validation module docs

Drive-by doc update for AST validation pass:

- Syntax extensions are replaced by proc macros.
- Add rationale for why AST validation pass need to be run
  post-expansion and why the pass is needed in the first place.

This was discussed during this week's [rustc-dev-guide reading club](https://rust-lang.zulipchat.com/#narrow/stream/196385-t-compiler.2Fwg-rustc-dev-guide), and the rationale was explained by cc ``````@bjorn3.``````
2024-06-28 22:04:15 +02:00
Michael Goulet
b1a0c0b123 Change RTN to use .. again 2024-06-28 14:20:43 -04:00
Matthias Krüger
b2720867f1
Rollup merge of #126973 - chenyukang:yukang-fix-126756-unsafe-suggestion-error, r=spastorino
Fix bad replacement for unsafe extern block suggestion

Fixes #126756

r? ``@spastorino``

link #123743
2024-06-26 07:50:21 +02:00
yukang
0addda6578 Fix bad replacement for unsafe extern block suggestion 2024-06-26 08:50:50 +08:00
carbotaniuman
a23917cfd0 Add hard error and migration lint for unsafe attrs 2024-06-23 19:02:14 -05:00
Jubilee Young
43a6b018a2 compiler: Mention C-unwind in C-variadic error 2024-06-22 23:30:31 -07:00
Jubilee Young
26dccadb47 Allow "C-unwind" fn to have C variadics 2024-06-22 15:14:14 -07:00
Santiago Pastorino
22831ed117
Do not allow safe usafe on static and fn items 2024-06-21 09:12:13 -03:00
Matthias Krüger
f577d808b7
Rollup merge of #126767 - compiler-errors:static-foreign-item, r=spastorino
`StaticForeignItem` and `StaticItem` are the same

The struct `StaticItem` and `StaticForeignItem` are the same, so remove `StaticForeignItem`. Having them be separate is unique to `static` items -- unlike `ForeignItemKind::{Fn,TyAlias}`, which use the normal AST item.

r? ``@spastorino`` or ``@oli-obk``
2024-06-21 09:12:37 +02:00
Michael Goulet
3e59f0c3c5 StaticForeignItem and StaticItem are the same 2024-06-20 19:51:09 -04:00
Michael Goulet
108b3f214a Properly gate safe keyword in pre-expansion 2024-06-20 14:14:49 -04:00
Oli Scherer
7ba82d61eb Use a dedicated type instead of a reference for the diagnostic context
This paves the way for tracking more state (e.g. error tainting) in the diagnostic context handle
2024-06-18 15:42:11 +00:00
Michael Goulet
2e03130e11 Detect duplicates 2024-06-17 22:35:25 -04:00
Michael Goulet
f66558d2bf Add tests for illegal use bound syntax 2024-06-17 22:35:25 -04:00
Michael Goulet
b1efe1ab5d Rework precise capturing syntax 2024-06-17 22:35:25 -04:00
Nicholas Nethercote
75b164d836 Use tidy to sort crate attributes for all compiler crates.
We already do this for a number of crates, e.g. `rustc_middle`,
`rustc_span`, `rustc_metadata`, `rustc_span`, `rustc_errors`.

For the ones we don't, in many cases the attributes are a mess.
- There is no consistency about order of attribute kinds (e.g.
  `allow`/`deny`/`feature`).
- Within attribute kind groups (e.g. the `feature` attributes),
  sometimes the order is alphabetical, and sometimes there is no
  particular order.
- Sometimes the attributes of a particular kind aren't even grouped
  all together, e.g. there might be a `feature`, then an `allow`, then
  another `feature`.

This commit extends the existing sorting to all compiler crates,
increasing consistency. If any new attribute line is added there is now
only one place it can go -- no need for arbitrary decisions.

Exceptions:
- `rustc_log`, `rustc_next_trait_solver` and `rustc_type_ir_macros`,
  because they have no crate attributes.
- `rustc_codegen_gcc`, because it's quasi-external to rustc (e.g. it's
  ignored in `rustfmt.toml`).
2024-06-12 15:49:10 +10:00
carbotaniuman
67f5dd1ef1 Parse unsafe attributes 2024-06-06 20:26:27 -05:00
Santiago Pastorino
1afc7d716c
Make MISSING_UNSAFE_ON_EXTERN lint emit future compat info with suggestion to prepend unsafe 2024-06-05 09:36:01 -03:00
Santiago Pastorino
0380321e78
Add unsafe_extern_blocks feature flag 2024-06-05 09:35:57 -03:00
Santiago Pastorino
b4cbdb7246
Fail when using safe/unsafe items inside unadorned extern blocks 2024-06-04 14:19:43 -03:00
Santiago Pastorino
2a377122dd
Handle safety keyword for extern block inner items 2024-06-04 14:19:42 -03:00
Santiago Pastorino
bbddc9b58f
Allow using unsafe on functions inside extern blocks 2024-06-04 14:19:42 -03:00
Santiago Pastorino
3ba8de0b60
Make extern blocks without unsafe warn in edition 2024 2024-06-04 14:19:42 -03:00
Santiago Pastorino
6d670b74e5
Allow unsafe extern on all editions 2024-06-04 14:19:42 -03:00
Matthias Krüger
379233242b
Rollup merge of #125635 - fmease:mv-type-binding-assoc-item-constraint, r=compiler-errors
Rename HIR `TypeBinding` to `AssocItemConstraint` and related cleanup

Rename `hir::TypeBinding` and `ast::AssocConstraint` to `AssocItemConstraint` and update all items and locals using the old terminology.

Motivation: The terminology *type binding* is extremely outdated. "Type bindings" not only include constraints on associated *types* but also on associated *constants* (feature `associated_const_equality`) and on RPITITs of associated *functions* (feature `return_type_notation`). Hence the word *item* in the new name. Furthermore, the word *binding* commonly refers to a mapping from a binder/identifier to a "value" for some definition of "value". Its use in "type binding" made sense when equality constraints (e.g., `AssocTy = Ty`) were the only kind of associated item constraint. Nowadays however, we also have *associated type bounds* (e.g., `AssocTy: Bound`) for which the term *binding* doesn't make sense.

---

Old terminology (HIR, rustdoc):

```
`TypeBinding`: (associated) type binding
├── `Constraint`: associated type bound
└── `Equality`: (associated) equality constraint (?)
    ├── `Ty`: (associated) type binding
    └── `Const`: associated const equality (constraint)
```

Old terminology (AST, abbrev.):

```
`AssocConstraint`
├── `Bound`
└── `Equality`
    ├── `Ty`
    └── `Const`
```

New terminology (AST, HIR, rustdoc):

```
`AssocItemConstraint`: associated item constraint
├── `Bound`: associated type bound
└── `Equality`: associated item equality constraint OR associated item binding (for short)
    ├── `Ty`: associated type equality constraint OR associated type binding (for short)
    └── `Const`: associated const equality constraint OR associated const binding (for short)
```

r? compiler-errors
2024-05-31 08:50:22 +02:00
León Orell Valerian Liehr
34c56c45cf
Rename HIR TypeBinding to AssocItemConstraint and related cleanup 2024-05-30 22:52:33 +02:00
Jubilee
866630d004
Rollup merge of #124048 - veera-sivarajan:bugfix-123773-c23-variadics, r=compiler-errors
Support C23's Variadics Without a Named Parameter

Fixes #123773

This PR removes the static check that disallowed extern functions
with ellipsis (varargs) as the only parameter since this is now
valid in C23.

This will not break any existing code as mentioned in the proposal
document: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf.

Also, adds a doc comment for `check_decl_cvariadic_pos()` and
fixes the name of the function (`varadic` -> `variadic`).
2024-05-26 15:28:26 -07:00
Xiretza
98dd6c7e8f Rename buffer_lint_with_diagnostic to buffer_lint 2024-05-21 20:16:39 +00:00
Xiretza
8004e6a379 Make early lints translatable 2024-05-21 20:16:39 +00:00
Xiretza
c227f35a9c Generate lint diagnostic message from BuiltinLintDiag
Translation of the lint message happens when the actual diagnostic is
created, not when the lint is buffered. Generating the message from
BuiltinLintDiag ensures that all required data to construct the message
is preserved in the LintBuffer, eventually allowing the messages to be
moved to fluent.

Remove the `msg` field from BufferedEarlyLint, it is either generated
from the data in the BuiltinLintDiag or stored inside
BuiltinLintDiag::Normal.
2024-05-21 20:16:39 +00:00
Matthias Krüger
a79737c3f0
Rollup merge of #125314 - jdonszelmann:global-registration-feature-gate, r=pnkfelix
Add an experimental feature gate for global registration

See #125119 for the tracking issue.
2024-05-20 18:13:49 +02:00
Santiago Pastorino
6b46a919e1
Rename Unsafe to Safety 2024-05-17 18:33:37 -03:00
jdonszelmann
42119ff45c
create a feature gate 2024-05-14 16:11:26 +02:00
Ross Smyth
6967d1c0fc Stabilize exclusive_range 2024-05-02 19:42:31 -04:00
León Orell Valerian Liehr
2a1d748254
Replace item names containing an error code with something more meaningful
or inline such functions if useless.
2024-04-30 22:27:19 +02:00
Santiago Pastorino
f06e0f7837
Add StaticForeignItem and use it on ForeignItemKind 2024-04-29 13:15:51 -03:00
Vadim Petrochenkov
5be9fdd636 ast: Generalize item kind visiting
And avoid duplicating logic for visiting `Item`s with different kinds (regular, associated, foreign).
2024-04-25 22:49:58 +03:00
Gary Guo
94c1920497 Stabilise inline_const 2024-04-24 13:12:25 +01:00
Xiretza
5646b65cf5 Pass translation closure to add_to_diag_with() as reference 2024-04-21 07:45:03 +00:00
许杰友 Jieyou Xu (Joe)
0e3521605d ast_passes/validation: update attribute macro example 2024-04-17 19:38:29 +00:00
许杰友 Jieyou Xu (Joe)
356027b709 ast_passes/validation: update module docs
- Syntax extensions are replaced by proc macros.
- Add rationale for why AST validation pass need to be run
  post-expansion and why the pass is needed in the first place.
2024-04-17 19:23:34 +00:00
Jules Bertholet
2a4624ddd1
Rename BindingAnnotation to BindingMode 2024-04-17 09:34:39 -04:00
Veera
f005b451c2 Support C23's Variadics Without a Named Parameter
This PR removes the static check that disallowed extern functions
with ellipsis (varargs) as the only parameter since this is now
valid in C23.

Also, adds a doc comment for `check_decl_cvariadic_pos()` and
fixes the name of the function (`varadic` -> `variadic`).
2024-04-16 18:53:05 -04:00
Michael Goulet
a076eae0d2 Parsing , pre-lowering support for precise captures 2024-04-15 16:45:01 -04:00
Matthias Krüger
15a8b490ea
Rollup merge of #123841 - Kohei316:remove_qualifier_sugg, r=wesleywiser
Improve diagnostic by suggesting to remove visibility qualifier

Resolves #123529
This PR improve diagnostic by suggesting to remove visibility qualifier.
2024-04-12 17:41:35 +02:00
morine0122
ac1bee6493 Improve diagnostic by suggesting to remove visibility qualifier 2024-04-12 12:59:40 +09:00
Michael Goulet
3253c021cb Add a helper for extending a span to include any trailing whitespace 2024-04-09 14:06:09 -04:00
Oli Scherer
c340e67dec Add pattern types to parser 2024-04-08 11:57:17 +00:00
Matthias Krüger
f254ab08f1
Rollup merge of #123397 - krtab:foreign_fn_qualif_diag, r=petrochenkov
Fix diagnostic for qualifier in extern block

Closes: https://github.com/rust-lang/rust/issues/123306
2024-04-04 14:51:17 +02:00
Arthur Carcano
109daa2d4b Fix diagnostic for qualifier in extern block
Closes: https://github.com/rust-lang/rust/issues/123306
2024-04-04 11:58:38 +02:00
Matthias Krüger
8d820c0c47
Rollup merge of #123188 - klensy:clippy-me2, r=Nilstrieb
compiler: fix few unused_peekable and needless_pass_by_ref_mut clippy lints

This fixes few instances of `unused_peekable` and `needless_pass_by_ref_mut`. While i expected to fix more warnings, `needless_pass_by_ref_mut` produced too much for one PR, so i stopped here.

Better reviewed commit by commit, as fixes splitted by chunks.
2024-03-29 15:17:11 +01:00
klensy
aa35530319 compiler: fix few needless_pass_by_ref_mut clippy lints
warning: this argument is a mutable reference, but not used mutably
    --> compiler\rustc_session\src\config.rs:2013:16
     |
2013 |     early_dcx: &mut EarlyDiagCtxt,
     |                ^^^^^^^^^^^^^^^^^^ help: consider changing to: `&EarlyDiagCtxt`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_pass_by_ref_mut

warning: this argument is a mutable reference, but not used mutably
    --> compiler\rustc_ast_passes\src\ast_validation.rs:1555:11
     |
1555 |     this: &mut AstValidator<'_>,
     |           ^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&AstValidator<'_>`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_pass_by_ref_mut

warning: this argument is a mutable reference, but not used mutably
  --> compiler\rustc_infer\src\infer\snapshot\fudge.rs:16:12
   |
16 |     table: &mut UnificationTable<'_, 'tcx, T>,
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&UnificationTable<'_, 'tcx, T>`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_pass_by_ref_mut

warning: this argument is a mutable reference, but not used mutably
   --> compiler\rustc_expand\src\expand.rs:961:13
    |
961 |     parser: &mut Parser<'a>,
    |             ^^^^^^^^^^^^^^^ help: consider changing to: `&Parser<'a>`
    |
    = warning: changing this function will impact semver compatibility
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_pass_by_ref_mut
2024-03-28 11:37:52 +03:00
Jules Bertholet
528d45af18
Feature gate 2024-03-27 11:20:28 -04:00
Matthias Krüger
783778c631
Rollup merge of #121619 - RossSmyth:pfix_match, r=petrochenkov
Experimental feature postfix match

This has a basic experimental implementation for the RFC postfix match (rust-lang/rfcs#3295, #121618). [Liaison is](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Postfix.20Match.20Liaison/near/423301844) ```@scottmcm``` with the lang team's [experimental feature gate process](https://github.com/rust-lang/lang-team/blob/master/src/how_to/experiment.md).

This feature has had an RFC for a while, and there has been discussion on it for a while. It would probably be valuable to see it out in the field rather than continue discussing it. This feature also allows to see how popular postfix expressions like this are for the postfix macros RFC, as those will take more time to implement.

It is entirely implemented in the parser, so it should be relatively easy to remove if needed.

This PR is split in to 5 commits to ease review.

1. The implementation of the feature & gating.
2. Add a MatchKind field, fix uses, fix pretty.
3. Basic rustfmt impl, as rustfmt crashes upon seeing this syntax without a fix.
4. Add new MatchSource to HIR for Clippy & other HIR consumers
2024-03-22 11:36:58 +01:00
Michael Goulet
2d633317f3 Implement macro-based deref!() syntax for deref patterns
Stop using `box PAT` syntax for deref patterns, as it's misleading and
also causes their semantics being tangled up.
2024-03-21 11:42:49 -04:00
Nadrieril
120d3570aa Add barest-bones deref patterns
Co-authored-by: Deadbeef <ent3rm4n@gmail.com>
2024-03-20 22:30:27 +01:00
bors
21d94a3d2c Auto merge of #122055 - compiler-errors:stabilize-atb, r=oli-obk
Stabilize associated type bounds (RFC 2289)

This PR stabilizes associated type bounds, which were laid out in [RFC 2289]. This gives us a shorthand to express nested type bounds that would otherwise need to be expressed with nested `impl Trait` or broken into several `where` clauses.

### What are we stabilizing?

We're stabilizing the associated item bounds syntax, which allows us to put bounds in associated type position within other bounds, i.e. `T: Trait<Assoc: Bounds...>`. See [RFC 2289] for motivation.

In all position, the associated type bound syntax expands into a set of two (or more) bounds, and never anything else (see "How does this differ[...]" section for more info).

Associated type bounds are stabilized in four positions:
* **`where` clauses (and APIT)** - This is equivalent to breaking up the bound into two (or more) `where` clauses. For example, `where T: Trait<Assoc: Bound>` is equivalent to `where T: Trait, <T as Trait>::Assoc: Bound`.
* **Supertraits** - Similar to above, `trait CopyIterator: Iterator<Item: Copy> {}`. This is almost equivalent to breaking up the bound into two (or more) `where` clauses; however, the bound on the associated item is implied whenever the trait is used. See #112573/#112629.
* **Associated type item bounds** - This allows constraining the *nested* rigid projections that are associated with a trait's associated types. e.g. `trait Trait { type Assoc: Trait2<Assoc2: Copy>; }`.
* **opaque item bounds (RPIT, TAIT)** - This allows constraining associated types that are associated with the opaque without having to *name* the opaque. For example, `impl Iterator<Item: Copy>` defines an iterator whose item is `Copy` without having to actually name that item bound.

The latter three are not expressible in surface Rust (though for associated type item bounds, this will change in #120752, which I don't believe should block this PR), so this does represent a slight expansion of what can be expressed in trait bounds.

### How does this differ from the RFC?

Compared to the RFC, the current implementation *always* desugars associated type bounds to sets of `ty::Clause`s internally. Specifically, it does *not* introduce a position-dependent desugaring as laid out in [RFC 2289], and in particular:
* It does *not* desugar to anonymous associated items in associated type item bounds.
* It does *not* desugar to nested RPITs in RPIT bounds, nor nested TAITs in TAIT bounds.

This position-dependent desugaring laid out in the RFC existed simply to side-step limitations of the trait solver, which have mostly been fixed in #120584. The desugaring laid out in the RFC also added unnecessary complication to the design of the feature, and introduces its own limitations to, for example:
* Conditionally lowering to nested `impl Trait` in certain positions such as RPIT and TAIT means that we inherit the limitations of RPIT/TAIT, namely lack of support for higher-ranked opaque inference. See this code example: https://github.com/rust-lang/rust/pull/120752#issuecomment-1979412531.
* Introducing anonymous associated types makes traits no longer object safe, since anonymous associated types are not nameable, and all associated types must be named in `dyn` types.

This last point motivates why this PR is *not* stabilizing support for associated type bounds in `dyn` types, e.g, `dyn Assoc<Item: Bound>`. Why? Because `dyn` types need to have *concrete* types for all associated items, this would necessitate a distinct lowering for associated type bounds, which seems both complicated and unnecessary compared to just requiring the user to write `impl Trait` themselves. See #120719.

### Implementation history:

Limited to the significant behavioral changes and fixes and relevant PRs, ping me if I left something out--
* #57428
* #108063
* #110512
* #112629
* #120719
* #120584

Closes #52662

[RFC 2289]: https://rust-lang.github.io/rfcs/2289-associated-type-bounds.html
2024-03-19 00:04:09 +00:00
León Orell Valerian Liehr
79c1e58801
Rollup merge of #121545 - gvozdvmozgu:fix-attribute-validation-associated-items, r=fmease
fix attribute validation on associated items in traits

#121537, fixed attribute validation on associated items in traits
2024-03-16 23:28:47 +01:00
Trevor Gross
e782d27ec6 Add feature gates for f16 and f128
Includes related tests and documentation pages.

Michael Goulet: Don't issue feature error in resolver for f16/f128
unless finalize

Co-authored-by: Michael Goulet <michael@errs.io>
2024-03-14 13:32:54 -04:00
Nicholas Nethercote
541d7cc65c Rename AddToDiagnostic as Subdiagnostic.
To match `derive(Subdiagnostic)`.

Also rename `add_to_diagnostic{,_with}` as `add_to_diag{,_with}`.
2024-03-11 10:04:49 +11:00
Michael Goulet
c63f3feb0f Stabilize associated type bounds 2024-03-08 20:56:25 +00:00
klensy
52501c2a75 bump itertools to 0.12
still depend on 0.11:
* clippy
* rustfmt, sigh
2024-03-08 12:34:05 +03:00
Guillaume Gomez
2e3bde2bc4
Rollup merge of #122004 - fmease:astvalidator-min-fix, r=compiler-errors
AST validation: Improve handling of inherent impls nested within functions and anon consts

Minimal fix for issue #121607 extracted from PR #120698 for ease of backporting and since I'd like to improve PR #120698 in such a way that it makes AST validator truly robust against such sort of regressions (AST validator is generally *beyond* footgun-y atm). The current version of PR #120698 sort of does that already but there's still room for improvement.

Fixes #89342.
Fixes [after beta-backport] #121607.
Partially addresses #119924 (#120698 aims to fully fix it).

---

### Explainer

The last commit of PR #119505 regressed issue #121607.

Previously we would reject visibilities on associated items with `visibility_not_permitted` if we were in a trait (by checking the parameter `ctxt` of `visit_assoc_item` which was 100% accurate) or if we were in a trait impl (by checking a flag called `in_trait_impl` tracked in `AstValidator` which was/is only accurate if the visitor methods correctly updated it which isn't actually the case giving rise to the old open issue #89342).

In PR #119505, I moved even more state into the `AstValidator` by generalizing the flag `in_trait_impl` to `trait_or_trait_impl` to be able to report more precise diagnostics (modeling *Trait | TraitImpl*). However since we/I didn't update `trait_or_trait_impl` in all places to reflect reality (similar to us not updating `in_trait_impl` before), this lead to https://github.com/rust-lang/rust/issues/121607#issuecomment-1963084636 getting wrongfully rejected. Since PR #119505 we reject visibilities if the “globally tracked” (wrt. to `AstValidator`) `outer_trait_or_trait_impl` is `Some`.

Crucially, when visiting an inherent impl, I never reset `outer_trait_or_trait_impl` back to `None` leading us to believe that `bar` in the stack [`trait Foo` > `fn foo` > `impl Bar` > `pub fn bar`] (from the MCVE) was an inherent associated item (we saw `trait Foo` but not `impl Bar` before it).

The old open issue #89342 is caused by the aforementioned issue of us never updating `in_trait_impl` prior to my PR #119505 / `outer_trait_or_trait` after my PR. Stack: [`impl Default for Foo` > `{` > `impl Foo` > `pub const X`] (we only saw `impl Default for Foo` but not the `impl Foo` before it).

---

This PR is only meant to be a *hot fix*. I plan on completely *rewriting* `AstValidator` from the ground up to not rely on “globally tracked” state like this or at least make it close to impossible to forget updating it when descending into nested items (etc.). Other visitors do a way better job at that (e.g. AST lowering). I actually plan on experimenting with moving more and more logic from `AstValidator` into the AST lowering pass/stage/visitor to follow the [Parse, don't validate](https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/) “pattern”.

---

r? `@compiler-errors`
2024-03-07 18:32:47 +01:00
Guillaume Gomez
b0d7f2bb0e
Rollup merge of #119888 - weiznich:stablize_diagnostic_namespace, r=compiler-errors
Stabilize the `#[diagnostic]` namespace and `#[diagnostic::on_unimplemented]` attribute

This PR stabilizes the `#[diagnostic]` attribute namespace and a minimal option of the `#[diagnostic::on_unimplemented]` attribute.

The `#[diagnostic]` attribute namespace is meant to provide a home for attributes that allow users to influence error messages emitted by the compiler. The compiler is not guaranteed to use any of this hints, however it should accept any (non-)existing attribute in this namespace and potentially emit lint-warnings for unused attributes and options. This is meant to allow discarding certain attributes/options in the future to allow fundamental changes to the compiler without the need to keep then non-meaningful options working.

The `#[diagnostic::on_unimplemented]` attribute is allowed to appear on a trait definition. This allows crate authors to hint the compiler to emit a specific error message if a certain trait is not implemented. For the `#[diagnostic::on_unimplemented]` attribute the following options are implemented:

* `message` which provides the text for the top level error message
* `label` which provides the text for the label shown inline in the broken code in the error message
* `note` which provides additional notes.

The `note` option can appear several times, which results in several note messages being emitted. If any of the other options appears several times the first occurrence of the relevant option specifies the actually used value. Any other occurrence generates an lint warning. For any other non-existing option a lint-warning is generated.

All three options accept a text as argument. This text is allowed to contain format parameters referring to generic argument or `Self` by name via the `{Self}` or `{NameOfGenericArgument}` syntax. For any non-existing argument a lint warning is generated.

This allows to have a trait definition like:

```rust
#[diagnostic::on_unimplemented(
    message = "My Message for `ImportantTrait<{A}>` is not implemented for `{Self}`",
    label = "My Label",
    note = "Note 1",
    note = "Note 2"
)]
trait ImportantTrait<A> {}

```

which then generates for the following code

```rust
fn use_my_trait(_: impl ImportantTrait<i32>) {}

fn main() {
    use_my_trait(String::new());
}
```

this error message:

```
error[E0277]: My Message for `ImportantTrait<i32>` is not implemented for `String`
  --> src/main.rs:14:18
   |
14 |     use_my_trait(String::new());
   |     ------------ ^^^^^^^^^^^^^ My Label
   |     |
   |     required by a bound introduced by this call
   |
   = help: the trait `ImportantTrait<i32>` is not implemented for `String`
   = note: Note 1
   = note: Note 2
```

[Playground with the unstable feature](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=05133acce8e1d163d481e97631f17536)

Fixes #111996
2024-03-07 18:32:46 +01:00
Matthias Krüger
efe9deace8
Rollup merge of #121382 - nnethercote:rework-untranslatable_diagnostic-lint, r=davidtwco
Rework `untranslatable_diagnostic` lint

Currently it only checks calls to functions marked with `#[rustc_lint_diagnostics]`. This PR changes it to check calls to any function with an `impl Into<{D,Subd}iagnosticMessage>` parameter. This greatly improves its coverage and doesn't rely on people remembering to add `#[rustc_lint_diagnostics]`. It also lets us add `#[rustc_lint_diagnostics]` to a number of functions that don't have an `impl Into<{D,Subd}iagnosticMessage>`, such as `Diag::span`.

r? ``@davidtwco``
2024-03-06 22:02:46 +01:00
Ross Smyth
68a58f255a Add postfix-match experimental feature
Co-authored-by: Josh Stone <jistone@redhat.com>
2024-03-05 23:34:45 -05:00
Nicholas Nethercote
b7d58eef4b Rewrite the untranslatable_diagnostic lint.
Currently it only checks calls to functions marked with
`#[rustc_lint_diagnostics]`. This commit changes it to check calls to
any function with an `impl Into<{D,Subd}iagMessage>` parameter. This
greatly improves its coverage and doesn't rely on people remembering to
add `#[rustc_lint_diagnostics]`.

The commit also adds `#[allow(rustc::untranslatable_diagnostic)`]
attributes to places that need it that are caught by the improved lint.
These places that might be easy to convert to translatable diagnostics.

Finally, it also:
- Expands and corrects some comments.
- Does some minor formatting improvements.
- Adds missing `DecorateLint` cases to
  `tests/ui-fulldeps/internal-lints/diagnostics.rs`.
2024-03-06 14:19:01 +11:00
Jason Newcomb
5abfb3775d Move visitor utils to rustc_ast_ir 2024-03-05 12:38:03 -05:00
Nicholas Nethercote
7aa0eea19c Rename BuiltinLintDiagnostics as BuiltinLintDiag.
Not the dropping of the trailing `s` -- this type describes a single
diagnostic and its name should be singular.
2024-03-05 12:15:10 +11:00
Nicholas Nethercote
573267cf3c Rename SubdiagnosticMessageOp as SubdiagMessageOp. 2024-03-05 12:14:49 +11:00
León Orell Valerian Liehr
7d428db605
AST validation: Improve handling of inherent impls nested within functions and anon consts 2024-03-05 00:12:15 +01:00
Nicholas Nethercote
80d2bdb619 Rename all ParseSess variables/fields/lifetimes as psess.
Existing names for values of this type are `sess`, `parse_sess`,
`parse_session`, and `ps`. `sess` is particularly annoying because
that's also used for `Session` values, which are often co-located, and
it can be difficult to know which type a value named `sess` refers to.
(That annoyance is the main motivation for this change.) `psess` is nice
and short, which is good for a name used this much.

The commit also renames some `parse_sess_created` values as
`psess_created`.
2024-03-05 08:11:45 +11:00
León Orell Valerian Liehr
cce81289e6
Detect empty leading where-clauses on type aliases 2024-02-29 17:20:04 +01:00
León Orell Valerian Liehr
2b8060578a
AST: Refactor type alias where clauses 2024-02-29 17:18:40 +01:00
Nicholas Nethercote
899cb40809 Rename DiagnosticBuilder as Diag.
Much better!

Note that this involves renaming (and updating the value of)
`DIAGNOSTIC_BUILDER` in clippy.
2024-02-28 08:55:35 +11:00
Georg Semmler
d013b5a462
Stabilize the #[diagnostic] namespace and #[diagnostic::on_unimplemented] attribute
This PR stabilizes the `#[diagnostic]` attribute namespace and a minimal
option of the `#[diagnostic::on_unimplemented]` attribute.

The `#[diagnostic]` attribute namespace is meant to provide a home for
attributes that allow users to influence error messages emitted by the
compiler. The compiler is not guaranteed to use any of this hints,
however it should accept any (non-)existing attribute in this namespace
and potentially emit lint-warnings for unused attributes and options.
This is meant to allow discarding certain attributes/options in the
future to allow fundamental changes to the compiler without the need to
keep then non-meaningful options working.

The `#[diagnostic::on_unimplemented]` attribute is allowed to appear
on a trait definition. This allows crate authors to hint the compiler
to emit a specific error message if a certain trait is not implemented.
For the `#[diagnostic::on_unimplemented]` attribute the following
options are implemented:

* `message` which provides the text for the top level error message
* `label` which provides the text for the label shown inline in the
broken code in the error message
* `note` which provides additional notes.

The `note` option can appear several times, which results in several
note messages being emitted. If any of the other options appears several
times the first occurrence of the relevant option specifies the actually
used value. Any other occurrence generates an lint warning. For any
other non-existing option a lint-warning is generated.

All three options accept a text as argument. This text is allowed to
contain format parameters referring to generic argument or `Self` by
name via the `{Self}` or `{NameOfGenericArgument}` syntax. For any
non-existing argument a lint warning is generated.

Tracking issue: #111996
2024-02-27 08:50:56 +01:00
gvozdvmozgu
8b576d5536 fix attribute validation on associated items in traits 2024-02-24 08:14:38 -05:00
Nicholas Nethercote
09ca866738 Remove an unchecked_error_guaranteed call.
If we abort immediately after complaining about the obsolete `impl Trait
for ..` syntax, then we avoid reaching HIR lowering. This means we can
use `TyKind::Dummy` instead of `TyKind::Err`.
2024-02-21 17:02:30 +11:00
Nicholas Nethercote
f6f8779843 Reduce capabilities of Diagnostic.
Currently many diagnostic modifier methods are available on both
`Diagnostic` and `DiagnosticBuilder`. This commit removes most of them
from `Diagnostic`. To minimize the diff size, it keeps them within
`diagnostic.rs` but changes the surrounding `impl Diagnostic` block to
`impl DiagnosticBuilder`. (I intend to move things around later, to give
a more sensible code layout.)

`Diagnostic` keeps a few methods that it still needs, like `sub`,
`arg`, and `replace_args`.

The `forward!` macro, which defined two additional methods per call
(e.g. `note` and `with_note`), is replaced by the `with_fn!` macro,
which defines one additional method per call (e.g. `with_note`). It's
now also only used when necessary -- not all modifier methods currently
need a `with_*` form. (New ones can be easily added as necessary.)

All this also requires changing `trait AddToDiagnostic` so its methods
take `DiagnosticBuilder` instead of `Diagnostic`, which leads to many
mechanical changes. `SubdiagnosticMessageOp` gains a type parameter `G`.

There are three subdiagnostics -- `DelayedAtWithoutNewline`,
`DelayedAtWithNewline`, and `InvalidFlushedDelayedDiagnosticLevel` --
that are created within the diagnostics machinery and appended to
external diagnostics. These are handled at the `Diagnostic` level, which
means it's now hard to construct them via `derive(Diagnostic)`, so
instead we construct them by hand. This has no effect on what they look
like when printed.

There are lots of new `allow` markers for `untranslatable_diagnostics`
and `diagnostics_outside_of_impl`. This is because
`#[rustc_lint_diagnostics]` annotations were present on the `Diagnostic`
modifier methods, but missing from the `DiagnosticBuilder` modifier
methods. They're now present.
2024-02-20 13:22:17 +11:00
Nicholas Nethercote
5233bc91da Add an ErrorGuaranteed to ast::TyKind::Err.
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.
2024-02-15 09:35:11 +11:00
Matthias Krüger
1b396913a9
Rollup merge of #120751 - estebank:issue-68982, r=nnethercote
Provide more suggestions on invalid equality where bounds

```
error: equality constraints are not yet supported in `where` clauses
  --> $DIR/equality-bound.rs:50:9
   |
LL |         IntoIterator::Item = A
   |         ^^^^^^^^^^^^^^^^^^^^^^ not supported
   |
   = note: see issue #20041 <https://github.com/rust-lang/rust/issues/20041> for more information
help: if `IntoIterator::Item` is an associated type you're trying to set, use the associated type binding syntax
   |
LL ~     fn from_iter<T: IntoIterator<Item = A>>(_: T) -> Self
LL ~
   |

error: equality constraints are not yet supported in `where` clauses
  --> $DIR/equality-bound.rs:63:9
   |
LL |         T::Item = A
   |         ^^^^^^^^^^^ not supported
   |
   = note: see issue #20041 <https://github.com/rust-lang/rust/issues/20041> for more information
help: if `IntoIterator::Item` is an associated type you're trying to set, use the associated type binding syntax
   |
LL ~     fn from_iter<T: IntoIterator<Item = A>>(_: T) -> Self
LL ~
   |
```

Fix #68982.
2024-02-13 06:27:37 +01:00
Frank King
36d7e7fd3f check uniqueness of nested fields 2024-02-12 12:47:29 +08:00
Frank King
879a1e5713 Lower anonymous structs or unions to HIR 2024-02-12 12:47:23 +08:00
Matthias Krüger
46a0448405
Rollup merge of #120693 - nnethercote:invert-diagnostic-lints, r=davidtwco
Invert diagnostic lints.

That is, change `diagnostic_outside_of_impl` and `untranslatable_diagnostic` from `allow` to `deny`, because more than half of the compiler has been converted to use translated diagnostics.

This commit removes more `deny` attributes than it adds `allow` attributes, which proves that this change is warranted.

r? ````@davidtwco````
2024-02-09 14:41:50 +01:00