503 Commits

Author SHA1 Message Date
Alice Ryhl
dacae07b6d Rename Location::file_with_nul to file_as_c_str 2025-08-27 12:42:49 +00:00
Esteban Küber
049c32797b On E0277, point at type that doesn't implement bound
When encountering an unmet trait bound, point at local type that doesn't implement the trait:

```
error[E0277]: the trait bound `Bar<T>: Foo` is not satisfied
  --> $DIR/issue-64855.rs:9:19
   |
LL | pub struct Bar<T>(<Self as Foo>::Type) where Self: ;
   |                   ^^^^^^^^^^^^^^^^^^^ unsatisfied trait bound
   |
help: the trait `Foo` is not implemented for `Bar<T>`
  --> $DIR/issue-64855.rs:9:1
   |
LL | pub struct Bar<T>(<Self as Foo>::Type) where Self: ;
   | ^^^^^^^^^^^^^^^^^
```
2025-08-22 17:55:15 +00:00
Jana Dönszelmann
2158e2d4d7
refactor target checking, move out of context.rs and rename MaybeWarn to Policy 2025-08-21 13:15:30 +02:00
lcnr
8365ad17da handle opaque types before region inference 2025-08-20 11:04:38 +02:00
Karol Zwolak
d14b83e378 bless tests with new lint messages 2025-08-19 21:27:10 +02:00
Jacob Pratt
7a05f26a3b
Rollup merge of #144054 - jsimmons:stabilize-as-array-of-cells, r=tgross35
Stabilize as_array_of_cells

This PR stabilizes

```rust
impl<T, const N: usize> Cell<[T; N]> {
    pub const fn as_array_of_cells(&self) -> &[Cell<T>; N];
}
```

Stabilization report: https://github.com/rust-lang/rust/issues/88248#issuecomment-3082986863
Closes: https://github.com/rust-lang/rust/issues/88248
2025-08-15 18:13:27 -04:00
bors
3507a749b3 Auto merge of #145407 - Kobzol:rollup-g6yhx82, r=Kobzol
Rollup of 11 pull requests

Successful merges:

 - rust-lang/rust#137872 (Include whitespace in "remove |" suggestion and make it hidden)
 - rust-lang/rust#144631 (Fix test intrinsic-raw_eq-const-bad for big-endian)
 - rust-lang/rust#145233 (cfg_select: Support unbraced expressions)
 - rust-lang/rust#145261 (Improve tracing in bootstrap)
 - rust-lang/rust#145324 (Rename and document `ONLY_HOSTS` in bootstrap)
 - rust-lang/rust#145353 (bootstrap: Fix jemalloc 64K page support for aarch64 tools)
 - rust-lang/rust#145379 (bootstrap: Support passing `--timings` to cargo)
 - rust-lang/rust#145397 (Rust documentation, use `rustc-dev-guide` :3)
 - rust-lang/rust#145398 (Use `default_field_values` in `Resolver`)
 - rust-lang/rust#145401 (cleanup: Remove useless `[T].iter().last()`)
 - rust-lang/rust#145403 (Adjust error message grammar to be less awkward)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-08-14 23:30:10 +00:00
Jakub Beránek
18afb69767
Rollup merge of #137872 - estebank:extra-vert, r=compiler-errors
Include whitespace in "remove |" suggestion and make it hidden

Tweak error rendering of patterns with an extra `|` on either end.

Built on #137409. Only last commit is relevant.

? ``@compiler-errors``
2025-08-14 21:48:41 +02:00
Jonathan Brouwer
4bb7bf64e0
Update uitests
Signed-off-by: Jonathan Brouwer <jonathantbrouwer@gmail.com>
2025-08-14 18:18:42 +02:00
Stuart Cook
9d989bf1cf
Rollup merge of #145115 - lcnr:less-borrowck-tainting, r=compiler-errors
defer opaque type errors, generally greatly reduce tainting

fixes the test for rust-lang/rust#135528, does not actually fix that issue properly.

This is useful as it causes the migration to rust-lang/rust#139587 to be a lot easier.
2025-08-09 13:58:53 +10:00
Josh Triplett
2054a0c56b mbe: In error messages, don't assume attributes are always proc macros
Now that `macro_rules` macros can define attribute rules, make sure
error messages account for that.
2025-08-08 10:35:47 -07:00
lcnr
4eee55691a borrowck: defer opaque type errors 2025-08-08 19:24:53 +02:00
Esteban Küber
2db126d651 Include whitespace in "remove |" suggestion and make it hidden 2025-08-04 18:06:18 +00:00
Vadim Petrochenkov
c56f49dc34 expand: Micro-optimize prelude injection
Use `splice` to avoid shifting the other items twice.
Put `extern crate std;` first so it's already resolved when we resolve `::std::prelude::rust_20XX`.
2025-07-28 17:35:09 +03:00
Jacob Pratt
c92d61d121
Rollup merge of #144409 - GuillaumeGomez:macro-expansion-early-abort, r=oli-obk
Stop compilation early if macro expansion failed

Fixes rust-lang/rust#116180.

So there isn't really a type that is central for macro expansion and some errors are actually emitted (because the resolution happens after the expansion I suppose) after the expansion pass (like "not found macro"). Sometimes, errors are only emitted on the second "try" (to improve error output). So I couldn't reach a similar solution than what was done in https://github.com/rust-lang/rust/pull/133937 and suggested by ````@estebank```` in https://github.com/rust-lang/rust/issues/116180#issuecomment-3109468922. But maybe I missed something?

So in the end, I realized that there is method called every time (except one, described below) a macro error is actually emitted: `ExtCtxt::trace_macros_diag`. Considering I updated what it did, I renamed it into `macro_error_and_trace_macros_diag` to better reflect it.

There is only one call of `trace_macros_diag` which isn't reporting an error but just used for `macro_trace` feature, so I kept it as is.

r? ````@oli-obk````
2025-07-26 22:42:35 -04:00
Trevor Gross
6b1b68f4ee
Rollup merge of #144356 - GuillaumeGomez:gcc-ignore-tests, r=jieyouxu
Add `ignore-backends` annotations in failing GCC backend ui tests

Follow-up of https://github.com/rust-lang/rust/pull/144125.

In the GCC backend, we don't support all ui tests yet and we have a list of tests we currently ignore available [here](https://github.com/rust-lang/rustc_codegen_gcc/blob/master/tests/failing-ui-tests.txt).

This PR adds the `ignore-backends` annotations to the corresponding ui tests.

The second commit is a fix to compiletest, complaining about `ignore-backends`.

r? ```@jieyouxu```
2025-07-26 01:15:08 -05:00
Guillaume Gomez
272513868f Update ui tests with new macro early erroring 2025-07-25 23:46:28 +02:00
Guillaume Gomez
de93fb13fe Add ignore-backends annotations in failing GCC backend ui tests 2025-07-23 13:48:04 +02:00
Josh Simmons
14c6e50d47
Stabilize as_array_of_cells 2025-07-17 09:11:44 +02:00
dianne
41e6f767b6 future-incompat lints: don't link to the nightly edition-guide version 2025-07-16 01:44:02 -07:00
Jonathan Brouwer
027126ce0b
Port #[non_exhaustive] to the new attribute parsing infrastructure 2025-07-04 20:30:42 +02:00
bors
1ce9c977ff Auto merge of #143214 - camsteffen:remove-let-chains-feature, r=est31
Remove let_chains unstable feature

Per https://github.com/rust-lang/rust/issues/53667#issuecomment-3016742982 (but then I also noticed rust-lang/rust#140722)

This replaces the feature gate with a parser error that says let chains require 2024.

A lot of tests were using the unstable feature. I either added edition:2024 to the test or split out the parts that require 2024.
2025-07-02 17:18:47 +00:00
Cameron Steffen
dc9879cb3d Remove let_chains feature 2025-06-30 07:49:20 -05:00
Oli Scherer
6166cd6b50 Avoid looking at HIR for trait and impl items 2025-06-30 08:45:43 +00:00
Jana Dönszelmann
f9cdf3fd74
fix 142783 2025-06-24 23:00:31 +02:00
Jana Dönszelmann
5c0a625205
move naked checks out of check_attr.rs 2025-06-23 12:22:57 +02:00
mejrs
29ce695cd4 Stop dbg! macro yapping about format modifiers 2025-06-22 10:58:27 +02:00
mejrs
b1d18129d1 Implement DesugaringKind::FormatLiteral 2025-06-22 10:58:25 +02:00
bors
ccf3198de3 Auto merge of #138677 - shepmaster:consistent-elided-lifetime-syntax, r=traviscross,jieyouxu
Add a new `mismatched-lifetime-syntaxes` lint

The lang-team [discussed this](https://hackmd.io/nf4ZUYd7Rp6rq-1svJZSaQ) and I attempted to [summarize](https://github.com/rust-lang/rust/pull/120808#issuecomment-2701863833) their decision. The summary-of-the-summary is:

- Using two different kinds of syntax for elided lifetimes is confusing. In rare cases, it may even [lead to unsound code](https://github.com/rust-lang/rust/issues/48686)! Some examples:

    ```rust
    // Lint will warn about these
    fn(v: ContainsLifetime) -> ContainsLifetime<'_>;
    fn(&'static u8) -> &u8;
    ```

- Matching up references with no lifetime syntax, references with anonymous lifetime syntax, and paths with anonymous lifetime syntax is an exception to the simplest possible rule:

    ```rust
    // Lint will not warn about these
    fn(&u8) -> &'_ u8;
    fn(&'_ u8) -> &u8;
    fn(&u8) -> ContainsLifetime<'_>;
    ```

- Having a lint for consistent syntax of elided lifetimes will make the [future goal](https://github.com/rust-lang/rust/issues/91639) of warning-by-default for paths participating in elision much simpler.

---

This new lint attempts to accomplish the goal of enforcing consistent syntax. In the process, it supersedes and replaces the existing `elided-named-lifetimes` lint, which means it starts out life as warn-by-default.
2025-06-05 19:49:30 +00:00
Taylor Cramer
b541f93372 Add Location::file_with_nul
This is useful for C/C++ APIs which expect the const char* returned
from __FILE__ or std::source_location::file_name.
2025-06-04 09:23:05 -07:00
Jake Goulding
d35ad94849 Replace elided_named_lifetimes with mismatched_lifetime_syntaxes 2025-06-04 10:40:04 -04:00
est31
7b45c59d40 Add match guard chains test for absence of compilation error
based on tests/ui/rfcs/rfc-2497-if-let-chains/temporary-early-drop.rs
2025-05-14 00:45:28 +02:00
mejrs
60c32f61ae Move more tests/ui tests 2025-05-12 16:35:09 +02:00
Kornel
fc20650c6a
Error message for top-level or-patterns suggesting a solution 2025-05-09 22:16:34 +09:00
bors
243c5a35e1 Auto merge of #140453 - Zoxc:next-disambiguator, r=oli-obk
Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type

This removes `Definitions.next_disambiguator` as it doesn't guarantee deterministic def paths when `create_def` is called in parallel. Instead a new `DisambiguatorState` type is passed as a mutable reference to `create_def` to help create unique def paths. `create_def` calls with distinct  `DisambiguatorState` instances must ensure that that the def paths are unique without its help.

Anon associated types did rely on this global state for uniqueness and are changed to use (method they're defined in + their position in the method return type) as the `DefPathData` to ensure uniqueness. This also means that the method they're defined in appears in error messages, which is nicer.

`DefPathData::NestedStatic` is added to use for nested data inside statics instead of reusing `DefPathData::AnonConst` to avoid conflicts with those.

cc `@oli-obk`
2025-05-05 11:50:43 +00:00
Vadim Petrochenkov
20faf8532b compiletest: Make diagnostic kind mandatory on line annotations 2025-04-30 10:44:24 +03:00
John Kåre Alsaker
e561ec0e03 Remove global next_disambiguator state and handle it with a DisambiguatorState type 2025-04-29 13:22:38 +02:00
Kivooeo
f072d30741 resolved conflict 2025-04-25 17:02:59 +05:00
bors
8bf5a8d12f Auto merge of #132833 - est31:stabilize_let_chains, r=fee1-dead
Stabilize let chains in the 2024 edition

# Stabilization report

This proposes the stabilization of `let_chains` ([tracking issue], [RFC 2497]) in the [2024 edition] of Rust.

[tracking issue]: https://github.com/rust-lang/rust/issues/53667
[RFC 2497]: https://github.com/rust-lang/rfcs/pull/2497
[2024 edition]: https://doc.rust-lang.org/nightly/edition-guide/rust-2024/index.html

## What is being stabilized

The ability to `&&`-chain `let` statements inside `if` and `while` is being stabilized, allowing intermixture with boolean expressions. The patterns inside the `let` sub-expressions can be irrefutable or refutable.

```Rust
struct FnCall<'a> {
    fn_name: &'a str,
    args: Vec<i32>,
}

fn is_legal_ident(s: &str) -> bool {
    s.chars()
        .all(|c| ('a'..='z').contains(&c) || ('A'..='Z').contains(&c))
}

impl<'a> FnCall<'a> {
    fn parse(s: &'a str) -> Option<Self> {
        if let Some((fn_name, after_name)) = s.split_once("(")
            && !fn_name.is_empty()
            && is_legal_ident(fn_name)
            && let Some((args_str, "")) = after_name.rsplit_once(")")
        {
            let args = args_str
                .split(',')
                .map(|arg| arg.parse())
                .collect::<Result<Vec<_>, _>>();
            args.ok().map(|args| FnCall { fn_name, args })
        } else {
            None
        }
    }
    fn exec(&self) -> Option<i32> {
        let iter = self.args.iter().copied();
        match self.fn_name {
            "sum" => Some(iter.sum()),
            "max" => iter.max(),
            "min" => iter.min(),
            _ => None,
        }
    }
}

fn main() {
    println!("{:?}", FnCall::parse("sum(1,2,3)").unwrap().exec());
    println!("{:?}", FnCall::parse("max(4,5)").unwrap().exec());
}
```

The feature will only be stabilized for the 2024 edition and future editions. Users of past editions will get an error with a hint to update the edition.

closes #53667

## Why 2024 edition?

Rust generally tries to ship new features to all editions. So even the oldest editions receive the newest features. However, sometimes a feature requires a breaking change so much that offering the feature without the breaking change makes no sense. This occurs rarely, but has happened in the 2018 edition already with `async` and `await` syntax. It required an edition boundary in order for `async`/`await` to become keywords, and the entire feature foots on those keywords.

In the instance of let chains, the issue is the drop order of `if let` chains. If we want `if let` chains to be compatible with `if let`, drop order makes it hard for us to [generate correct MIR]. It would be strange to have different behaviour for `if let ... {}` and `if true && let ... {}`. So it's better to [stay consistent with `if let`].

In edition 2024, [drop order changes] have been introduced to make `if let` temporaries be lived more shortly. These changes also affected `if let` chains. These changes make sense even if you don't take the `if let` chains MIR generation problem into account. But if we want to use them as the solution to the MIR generation problem, we need to restrict let chains to edition 2024 and beyond: for let chains, it's not just a change towards more sensible behaviour, but one required for correct function.

[generate correct MIR]: https://github.com/rust-lang/rust/issues/104843
[stay consistent with `if let`]: https://github.com/rust-lang/rust/pull/103293#issuecomment-1293408574
[drop order changes]: https://github.com/rust-lang/rust/issues/124085

## Introduction considerations

As edition 2024 is very new, this stabilization PR only makes it possible to use let chains on 2024 without that feature gate, it doesn't mark that feature gate as stable/removed. I would propose to continue offering the `let_chains` feature (behind a feature gate) for a limited time (maybe 3 months after stabilization?) on older editions to allow nightly users to adopt edition 2024 at their own pace. After that, the feature gate shall be marked as *stabilized*, not removed, and replaced by an error on editions 2021 and below.

## Implementation history

* History from before March 14, 2022 can be found in the [original stabilization PR] that was reverted.
* https://github.com/rust-lang/rust/pull/94927
* https://github.com/rust-lang/rust/pull/94951
* https://github.com/rust-lang/rust/pull/94974
* https://github.com/rust-lang/rust/pull/95008
* https://github.com/rust-lang/rust/pull/97295
* https://github.com/rust-lang/rust/pull/98633
* https://github.com/rust-lang/rust/pull/99731
* https://github.com/rust-lang/rust/pull/102394
* https://github.com/rust-lang/rust/pull/100526
* https://github.com/rust-lang/rust/pull/100538
* https://github.com/rust-lang/rust/pull/102998
* https://github.com/rust-lang/rust/pull/103405
* https://github.com/rust-lang/rust/pull/103293
* https://github.com/rust-lang/rust/pull/107251
* https://github.com/rust-lang/rust/pull/110568
* https://github.com/rust-lang/rust/pull/115677
* https://github.com/rust-lang/rust/pull/117743
* https://github.com/rust-lang/rust/pull/117770
* https://github.com/rust-lang/rust/pull/118191
* https://github.com/rust-lang/rust/pull/119554
* https://github.com/rust-lang/rust/pull/129394
* https://github.com/rust-lang/rust/pull/132828
* https://github.com/rust-lang/reference/pull/1179
* https://github.com/rust-lang/reference/pull/1251
* https://github.com/rust-lang/rustfmt/pull/5910

[original stabilization PR]: https://github.com/rust-lang/rust/pull/94927

## Adoption history

### In the compiler

* History before March 14, 2022 can be found in the [original stabilization PR].
* https://github.com/rust-lang/rust/pull/115983
* https://github.com/rust-lang/rust/pull/116549
* https://github.com/rust-lang/rust/pull/116688

### Outside of the compiler

* https://github.com/rust-lang/rust-clippy/pull/11750
* [rspack](https://github.com/web-infra-dev/rspack)
* [risingwave](https://github.com/risingwavelabs/risingwave)
* [dylint](https://github.com/trailofbits/dylint)
* [convex-backend](https://github.com/get-convex/convex-backend)
* [tikv](https://github.com/tikv/tikv)
* [Daft](https://github.com/Eventual-Inc/Daft)
* [greptimedb](https://github.com/GreptimeTeam/greptimedb)

## Tests

<details>

### Intentional restrictions

[`partially-macro-expanded.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/partially-macro-expanded.rs), [`macro-expanded.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/macro-expanded.rs): it is possible to use macros to expand to both the pattern and the expression inside a let chain, but not to the entire `let pat = expr` operand.
[`parens.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/parens.rs): `if (let pat = expr)` is not allowed in chains
[`ensure-that-let-else-does-not-interact-with-let-chains.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.rs): `let...else` doesn't support chaining.

### Overlap with match guards

[`move-guard-if-let-chain.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/move-guard-if-let-chain.rs): test for the `use moved value` error working well in match guards. could maybe be extended with let chains that have more than one `let`
[`shadowing.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/shadowing.rs): shadowing in if let guards works as expected
[`ast-validate-guards.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/ast-validate-guards.rs): let chains in match guards require the match guards feature gate

### Simple cases from the early days

PR #88642 has added some tests with very simple usages of `let else`, mostly as regression tests to early bugs.

[`then-else-blocks.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/then-else-blocks.rs)
[`ast-lowering-does-not-wrap-let-chains.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/ast-lowering-does-not-wrap-let-chains.rs)
[`issue-90722.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/issue-90722.rs)
[`issue-92145.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/issue-92145.rs)

### Drop order/MIR scoping tests

[`issue-100276.rs`](4adafcf40a/tests/ui/drop/issue-100276.rs): let expressions on RHS aren't terminating scopes
[`drop_order.rs`](4adafcf40a/tests/ui/drop/drop_order.rs): exhaustive temporary drop order test for various Rust constructs, including let chains
[`scope.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/scope.rs): match guard scoping test
[`drop-scope.rs`](4adafcf40a/tests/ui/rfcs/rfc-2294-if-let-guard/drop-scope.rs): another match guard scoping test, ensuring that temporaries in if-let guards live for the arm
[`drop_order_if_let_rescope.rs`](4adafcf40a/tests/ui/drop/drop_order_if_let_rescope.rs): if let rescoping on edition 2024, including chains
[`mir_let_chains_drop_order.rs`](4adafcf40a/tests/ui/mir/mir_let_chains_drop_order.rs): comprehensive drop order test for let chains, distinguishes editions 2021 and 2024.
[`issue-99938.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/issue-99938.rs), [`issue-99852.rs`](4adafcf40a/tests/ui/mir/issue-99852.rs) both bad MIR ICEs fixed by #102394

### Linting

[`irrefutable-lets.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/irrefutable-lets.rs): trailing and leading irrefutable let patterns get linted for, others don't. The lint is turned off for `else if`.
[`issue-121070-let-range.rs`](4adafcf40a/tests/ui/lint/issue-121070-let-range.rs): regression test for false positive of the unused parens lint, precedence requires the `()`s here

### Parser: intentional restrictions

[`disallowed-positions.rs`](2128d8df0e/tests/ui/rfcs/rfc-2497-if-let-chains/disallowed-positions.rs): `let` in expression context is rejected everywhere except at the top level
[`invalid-let-in-a-valid-let-context.rs`](4adafcf40a/tests/ui/rfcs/rfc-2497-if-let-chains/invalid-let-in-a-valid-let-context.rs): nested `let` is not allowed (let's are no legal expressions just because they are allowed in `if` and `while`).

### Parser: recovery

[`issue-103381.rs`](4adafcf40a/tests/ui/parser/issues/issue-103381.rs): Graceful recovery of incorrect chaining of `if` and `if let`
[`semi-in-let-chain.rs`](4adafcf40a/tests/ui/parser/semi-in-let-chain.rs): Ensure that stray `;`s in let chains give nice errors (`if_chain!` users might be accustomed to `;`s)
[`deli-ident-issue-1.rs`](4adafcf40a/tests/ui/parser/deli-ident-issue-1.rs), [`brace-in-let-chain.rs`](4adafcf40a/tests/ui/parser/brace-in-let-chain.rs): Ensure that stray unclosed `{`s in let chains give nice errors and hints

### Misc

[`conflicting_bindings.rs`](4adafcf40a/tests/ui/pattern/usefulness/conflicting_bindings.rs): the conflicting bindings check also works in let chains. Personally, I'd extend it to chains with multiple let's as well.
[`let-chains-attr.rs`](4adafcf40a/tests/ui/expr/if/attrs/let-chains-attr.rs): attributes work on let chains

### Tangential tests with `#![feature(let_chains)]`

[`if-let.rs`](4adafcf40a/tests/coverage/branch/if-let.rs): MC/DC coverage tests for let chains
[`logical_or_in_conditional.rs`](4adafcf40a/tests/mir-opt/building/logical_or_in_conditional.rs): not really about let chains, more about dropping/scoping behaviour of `||`
[`stringify.rs`](4adafcf40a/tests/ui/macros/stringify.rs): exhaustive test of the `stringify` macro
[`expanded-interpolation.rs`](4adafcf40a/tests/ui/unpretty/expanded-interpolation.rs), [`expanded-exhaustive.rs`](4adafcf40a/tests/ui/unpretty/expanded-exhaustive.rs): Exhaustive test of `-Zunpretty`
[`diverges-not.rs`](4adafcf40a/tests/ui/rfcs/rfc-0000-never_patterns/diverges-not.rs): Never type, mostly tangential to let chains

</details>

## Possible future work

* There is proposals to allow `if let Pat(bindings) = expr {}` to be written as `if expr is Pat(bindings) {}` ([RFC 3573]). `if let` chains are a natural extension of the already existing `if let` syntax, and I'd argue orthogonal towards `is` syntax.
  * https://github.com/rust-lang/lang-team/issues/297
* One could have similar chaining inside `let ... else` statements. There is no proposed RFC for this however, nor is it implemented on nightly.
* Match guards have the `if` keyword as well, but on stable Rust, they don't support `let`. The functionality is available via an unstable feature ([`if_let_guard` tracking issue]). Stabilization of let chains affects this feature in so far as match guards containing let chains now only need the `if_let_guard` feature gate be present instead of also the `let_chains` feature (NOTE: this PR doesn't implement this simplification, it's left for future work).

[RFC 3573]: https://github.com/rust-lang/rfcs/pull/3573
[`if_let_guard` tracking issue]: https://github.com/rust-lang/rust/issues/51114

## Open questions / blockers

- [ ] bad recovery if you don't put a `let` (I don't think this is a blocker): [#117977](https://github.com/rust-lang/rust/issues/117977)
- [x] An instance where a temporary lives shorter than with nested ifs, breaking compilation: [#103476](https://github.com/rust-lang/rust/issues/103476). Personally I don't think this is a blocker either, as it's an edge case. Edit: turns out to not reproduce in edition 2025 any more, due to let rescoping. regression test added in #133093
- [x] One should probably extend the tests for `move-guard-if-let-chain.rs` and `conflicting_bindings.rs` to have chains with multiple let's: done in 133093
- [x] Parsing rejection tests: addressed by https://github.com/rust-lang/rust/pull/132828
- [x] [Style](https://rust-lang.zulipchat.com/#narrow/channel/346005-t-style/topic/let.20chains.20stabilization.20and.20formatting): https://github.com/rust-lang/rust/pull/139456
- [x] https://github.com/rust-lang/rust/issues/86730 explicitly mentions `let_else`. I think we can live with `let pat = expr` not evaluating as `expr` for macro_rules macros, especially given that `let pat = expr` is not a legal expression anywhere except inside `if` and `while`.
- [x] Documentation in the reference: https://github.com/rust-lang/reference/pull/1740
- [x] Add chapter to the Rust 2024 [edition guide]: https://github.com/rust-lang/edition-guide/pull/337
- [x] Resolve open questions on desired drop order.

[original reference PR]: https://github.com/rust-lang/reference/pull/1179
[edition guide]: https://github.com/rust-lang/edition-guide
2025-04-22 07:54:10 +00:00
Folkert de Vries
df8a3d5f1d
stabilize naked_functions 2025-04-20 11:18:38 +02:00
Folkert de Vries
41ddf86722
Make #[naked] an unsafe attribute 2025-04-19 00:03:35 +02:00
est31
162daaa2fa Remove let_chains feature gate from even more tests 2025-04-18 15:57:29 +02:00
est31
eb1639bd33 Add tests to check the situation with heterogenous spans
The edition gate is a bit stricter than the drop behaviour,
which is fine. The cases we want to avoid are the opposite:
not gated but 2021 drop behaviour.
2025-04-18 15:57:29 +02:00
Matthias Krüger
4a83f43e63
Rollup merge of #139904 - ferrocene:lw-wkumpwrytvtp, r=nnethercote,jieyouxu
Explicitly annotate edition for `unpretty=expanded` and `unpretty=hir` tests

These emit prelude imports which means they are always edition dependent and so running them with a different `--edition` will fail.
2025-04-17 06:25:17 +02:00
Matthias Krüger
0de803c38d
Rollup merge of #138632 - clubby789:stabilize-cfg-boolean-lit, r=davidtwco,Urgau,traviscross
Stabilize `cfg_boolean_literals`

Closes #131204
`@rustbot` labels +T-lang +I-lang-nominated
This will end up conflicting with the test in #138293 so whichever doesn't land first will need updating

--

# Stabilization Report

## General design

### What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?

[RFC 3695](https://github.com/rust-lang/rfcs/pull/3695), none.

### What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.

None

### Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those?

None

## Has a call-for-testing period been conducted? If so, what feedback was received?

Yes; only positive feedback was received.

## Implementation quality

### Summarize the major parts of the implementation and provide links into the code (or to PRs)

Implemented in [#131034](https://github.com/rust-lang/rust/pull/131034).

### Summarize existing test coverage of this feature

- [Basic usage, including `#[cfg()]`, `cfg!()` and `#[cfg_attr()]`](6d71251cf9/tests/ui/cfg/true-false.rs)
- [`--cfg=true/false` on the command line being accessible via `r#true/r#false`](6d71251cf9/tests/ui/cfg/raw-true-false.rs)
- [Interaction with the unstable `#[doc(cfg(..))]` feature](https://github.com/rust-lang/rust/tree/6d71251/tests/rustdoc-ui/cfg-boolean-literal.rs)
- [Denying `--check-cfg=cfg(true/false)`](https://github.com/rust-lang/rust/tree/6d71251/tests/ui/check-cfg/invalid-arguments.rs)
- Ensuring `--cfg false` on the command line doesn't change the meaning of `cfg(false)`: `tests/ui/cfg/cmdline-false.rs`
- Ensuring both `cfg(true)` and `cfg(false)` on the same item result in it being disabled: `tests/ui/cfg/both-true-false.rs`

### What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?

The above mentioned issue; it should not block as it interacts with another unstable feature.

### What FIXMEs are still in the code for that feature and why is it ok to leave them there?

None

### Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
- `@clubby789` (RFC)
- `@Urgau` (Implementation in rustc)

### Which tools need to be adjusted to support this feature. Has this work been done?

`rustdoc`'s  unstable`#[doc(cfg(..)]` has been updated to respect it. `cargo` has been updated with a forward compatibility lint to enable supporting it in cargo once stabilized.

## Type system and execution rules

### What updates are needed to the reference/specification? (link to PRs when they exist)

A few lines to be added to the reference for configuration predicates, specified in the RFC.
2025-04-17 06:25:15 +02:00
Lukas Wirth
20ab952b4d Explicitly annotate edition for unpretty=expanded and unpretty=hir tests
These emit prelude imports which means they are always edition dependent
2025-04-16 11:10:10 +02:00
Sky
21b7360a9a
Initial UnsafePinned/UnsafeUnpin impl [Part 1: Libs] 2025-04-13 01:11:04 -04:00
Nicholas Nethercote
cdf5b8d4e7 Change how anonymous associated types are printed.
Give them their own symbol `anon_assoc`, as is done for all the other
anonymous `DefPathData` variants.
2025-04-11 20:13:16 +10:00
Vadim Petrochenkov
b3f75353a2 UI tests: add missing diagnostic kinds where possible 2025-04-08 23:06:31 +03:00
clubby789
303c1b45c2 Use cfg(false) in UI tests 2025-04-03 21:41:58 +00:00