diff --git a/compiler/rustc_resolve/messages.ftl b/compiler/rustc_resolve/messages.ftl
index 02847a0f5f91..769c469a5ab2 100644
--- a/compiler/rustc_resolve/messages.ftl
+++ b/compiler/rustc_resolve/messages.ftl
@@ -292,6 +292,9 @@ resolve_underscore_lifetime_name_cannot_be_used_here =
resolve_unexpected_res_change_ty_to_const_param_sugg =
you might have meant to write a const parameter here
+resolve_unexpected_res_use_at_op_in_slice_pat_with_range_sugg =
+ if you meant to collect the rest of the slice in `{$ident}`, use the at operator
+
resolve_unreachable_label =
use of unreachable label `{$name}`
.label = unreachable label `{$name}`
diff --git a/compiler/rustc_resolve/src/errors.rs b/compiler/rustc_resolve/src/errors.rs
index 655fc9812d74..49a0e597dbc7 100644
--- a/compiler/rustc_resolve/src/errors.rs
+++ b/compiler/rustc_resolve/src/errors.rs
@@ -800,3 +800,17 @@ pub(crate) struct UnexpectedResChangeTyToConstParamSugg {
#[applicability]
pub applicability: Applicability,
}
+
+#[derive(Subdiagnostic)]
+#[suggestion(
+ resolve_unexpected_res_use_at_op_in_slice_pat_with_range_sugg,
+ code = "{snippet}",
+ applicability = "maybe-incorrect",
+ style = "verbose"
+)]
+pub(crate) struct UnexpectedResUseAtOpInSlicePatWithRangeSugg {
+ #[primary_span]
+ pub span: Span,
+ pub ident: Ident,
+ pub snippet: String,
+}
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 310c126213ad..5d712461993d 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1077,24 +1077,34 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
err: &mut Diagnostic,
path: &[Segment],
) {
- if let Some(pat) = self.diagnostic_metadata.current_pat
- && let ast::PatKind::Range(Some(start), None, range) = &pat.kind
- && let ExprKind::Path(None, range_path) = &start.kind
+ let Some(pat) = self.diagnostic_metadata.current_pat else { return };
+ let (bound, side, range) = match &pat.kind {
+ ast::PatKind::Range(Some(bound), None, range) => (bound, Side::Start, range),
+ ast::PatKind::Range(None, Some(bound), range) => (bound, Side::End, range),
+ _ => return,
+ };
+ if let ExprKind::Path(None, range_path) = &bound.kind
&& let [segment] = &range_path.segments[..]
&& let [s] = path
&& segment.ident == s.ident
+ && segment.ident.span.eq_ctxt(range.span)
{
- // We've encountered `[first, rest..]` where the user might have meant
- // `[first, rest @ ..]` (#88404).
- err.span_suggestion_verbose(
- segment.ident.span.between(range.span),
- format!(
- "if you meant to collect the rest of the slice in `{}`, use the at operator",
- segment.ident,
- ),
- " @ ",
- Applicability::MaybeIncorrect,
- );
+ // We've encountered `[first, rest..]` (#88404) or `[first, ..rest]` (#120591)
+ // where the user might have meant `[first, rest @ ..]`.
+ let (span, snippet) = match side {
+ Side::Start => (segment.ident.span.between(range.span), " @ ".into()),
+ Side::End => (range.span.to(segment.ident.span), format!("{} @ ..", segment.ident)),
+ };
+ err.subdiagnostic(errors::UnexpectedResUseAtOpInSlicePatWithRangeSugg {
+ span,
+ ident: segment.ident,
+ snippet,
+ });
+ }
+
+ enum Side {
+ Start,
+ End,
}
}
diff --git a/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.rs b/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.rs
index a619fcafc861..1eba7aeb4d64 100644
--- a/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.rs
+++ b/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.rs
@@ -1,9 +1,23 @@
fn main() {
match &[1, 2, 3][..] {
- [1, rest..] => println!("{rest:?}"),
+ [1, rest..] => println!("{rest}"),
//~^ ERROR cannot find value `rest` in this scope
//~| ERROR cannot find value `rest` in this scope
//~| ERROR `X..` patterns in slices are experimental
_ => {}
}
+ match &[4, 5, 6][..] {
+ [] => {}
+ [_, ..tail] => println!("{tail}"),
+ //~^ ERROR cannot find value `tail` in this scope
+ //~| ERROR cannot find value `tail` in this scope
+ //~| ERROR exclusive range pattern syntax is experimental
+ }
+ match &[7, 8, 9][..] {
+ [] => {}
+ [_, ...tail] => println!("{tail}"),
+ //~^ ERROR cannot find value `tail` in this scope
+ //~| ERROR cannot find value `tail` in this scope
+ //~| ERROR range-to patterns with `...` are not allowed
+ }
}
diff --git a/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.stderr b/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.stderr
index c3c9131b63eb..3a19517c85bd 100644
--- a/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.stderr
+++ b/tests/ui/pattern/range-pattern-meant-to-be-slice-rest-pattern.stderr
@@ -1,31 +1,82 @@
+error: range-to patterns with `...` are not allowed
+ --> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:18:13
+ |
+LL | [_, ...tail] => println!("{tail}"),
+ | ^^^ help: use `..=` instead
+
error[E0425]: cannot find value `rest` in this scope
--> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:3:13
|
-LL | [1, rest..] => println!("{rest:?}"),
+LL | [1, rest..] => println!("{rest}"),
| ^^^^ not found in this scope
|
help: if you meant to collect the rest of the slice in `rest`, use the at operator
|
-LL | [1, rest @ ..] => println!("{rest:?}"),
+LL | [1, rest @ ..] => println!("{rest}"),
| +
error[E0425]: cannot find value `rest` in this scope
--> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:3:35
|
-LL | [1, rest..] => println!("{rest:?}"),
+LL | [1, rest..] => println!("{rest}"),
+ | ^^^^ not found in this scope
+
+error[E0425]: cannot find value `tail` in this scope
+ --> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:11:15
+ |
+LL | [_, ..tail] => println!("{tail}"),
+ | ^^^^ not found in this scope
+ |
+help: if you meant to collect the rest of the slice in `tail`, use the at operator
+ |
+LL | [_, tail @ ..] => println!("{tail}"),
+ | ~~~~~~~~~
+
+error[E0425]: cannot find value `tail` in this scope
+ --> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:11:35
+ |
+LL | [_, ..tail] => println!("{tail}"),
| ^^^^ not found in this scope
+error[E0425]: cannot find value `tail` in this scope
+ --> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:18:16
+ |
+LL | [_, ...tail] => println!("{tail}"),
+ | ^^^^ not found in this scope
+ |
+help: if you meant to collect the rest of the slice in `tail`, use the at operator
+ |
+LL | [_, tail @ ..] => println!("{tail}"),
+ | ~~~~~~~~~
+
+error[E0425]: cannot find value `tail` in this scope
+ --> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:18:36
+ |
+LL | [_, ...tail] => println!("{tail}"),
+ | ^^^^ not found in this scope
+
error[E0658]: `X..` patterns in slices are experimental
--> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:3:13
|
-LL | [1, rest..] => println!("{rest:?}"),
+LL | [1, rest..] => println!("{rest}"),
| ^^^^^^
|
= note: see issue #67264 <https://github.com/rust-lang/rust/issues/67264> for more information
= help: add `#![feature(half_open_range_patterns_in_slices)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-error: aborting due to 3 previous errors
+error[E0658]: exclusive range pattern syntax is experimental
+ --> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:11:13
+ |
+LL | [_, ..tail] => println!("{tail}"),
+ | ^^^^^^
+ |
+ = note: see issue #37854 <https://github.com/rust-lang/rust/issues/37854> for more information
+ = help: add `#![feature(exclusive_range_pattern)]` to the crate attributes to enable
+ = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+ = help: use an inclusive range pattern, like N..=M
+
+error: aborting due to 9 previous errors
Some errors have detailed explanations: E0425, E0658.
For more information about an error, try `rustc --explain E0425`.