diff options
6 files changed, 89 insertions, 17 deletions
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index 7e5fd82b80c..f844930ad26 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -2671,17 +2671,17 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> { // Store all seen lifetimes names from outer scopes. let mut seen_lifetimes = FxHashSet::default(); - // We also can't shadow bindings from the parent item - if let RibKind::AssocItem = kind { - let mut add_bindings_for_ns = |ns| { - let parent_rib = self.ribs[ns] - .iter() - .rfind(|r| matches!(r.kind, RibKind::Item(..))) - .expect("associated item outside of an item"); + // We also can't shadow bindings from associated parent items. + for ns in [ValueNS, TypeNS] { + for parent_rib in self.ribs[ns].iter().rev() { seen_bindings.extend(parent_rib.bindings.keys().map(|ident| (*ident, ident.span))); - }; - add_bindings_for_ns(ValueNS); - add_bindings_for_ns(TypeNS); + + // Break at mod level, to account for nested items which are + // allowed to shadow generic param names. + if matches!(parent_rib.kind, RibKind::Module(..)) { + break; + } + } } // Forbid shadowing lifetime bindings diff --git a/tests/crashes/119716-2.rs b/tests/crashes/119716-2.rs index 9cdc4417f5b..47bffb5c1de 100644 --- a/tests/crashes/119716-2.rs +++ b/tests/crashes/119716-2.rs @@ -1,4 +1,4 @@ //@ known-bug: #119716 #![feature(non_lifetime_binders)] trait Trait<T> {} -fn f<T>() -> impl for<T> Trait<impl Trait<T>> {} +fn f() -> impl for<T> Trait<impl Trait<T>> {} diff --git a/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.rs b/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.rs index 4ba696f4ae0..9f20cf08579 100644 --- a/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.rs +++ b/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.rs @@ -9,9 +9,10 @@ fn bug<const N: Nat>(&self) where for<const N: usize = 3, T = u32> [(); COT::BYTES]:, //~^ ERROR only lifetime parameters can be used in this context - //~^^ ERROR defaults for generic parameters are not allowed in `for<...>` binders - //~^^^ ERROR defaults for generic parameters are not allowed in `for<...>` binders - //~^^^^ ERROR failed to resolve: use of undeclared type `COT` + //~| ERROR defaults for generic parameters are not allowed in `for<...>` binders + //~| ERROR defaults for generic parameters are not allowed in `for<...>` binders + //~| ERROR failed to resolve: use of undeclared type `COT` + //~| ERROR the name `N` is already used for a generic parameter in this item's generic parameters { } diff --git a/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.stderr b/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.stderr index ee0ec38ab06..6037e685e44 100644 --- a/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.stderr +++ b/tests/ui/const-generics/generic_const_exprs/ice-predicates-of-no-entry-found-for-key-119275.stderr @@ -6,6 +6,15 @@ LL | fn bug<const N: Nat>(&self) | = note: associated functions are those in `impl` or `trait` definitions +error[E0403]: the name `N` is already used for a generic parameter in this item's generic parameters + --> $DIR/ice-predicates-of-no-entry-found-for-key-119275.rs:10:15 + | +LL | fn bug<const N: Nat>(&self) + | - first use of `N` +... +LL | for<const N: usize = 3, T = u32> [(); COT::BYTES]:, + | ^ already used + error[E0412]: cannot find type `Nat` in this scope --> $DIR/ice-predicates-of-no-entry-found-for-key-119275.rs:6:17 | @@ -40,7 +49,7 @@ error[E0433]: failed to resolve: use of undeclared type `COT` LL | for<const N: usize = 3, T = u32> [(); COT::BYTES]:, | ^^^ use of undeclared type `COT` -error: aborting due to 6 previous errors +error: aborting due to 7 previous errors -Some errors have detailed explanations: E0412, E0433, E0658. -For more information about an error, try `rustc --explain E0412`. +Some errors have detailed explanations: E0403, E0412, E0433, E0658. +For more information about an error, try `rustc --explain E0403`. diff --git a/tests/ui/traits/non_lifetime_binders/shadowed.rs b/tests/ui/traits/non_lifetime_binders/shadowed.rs new file mode 100644 index 00000000000..1c480e3940b --- /dev/null +++ b/tests/ui/traits/non_lifetime_binders/shadowed.rs @@ -0,0 +1,18 @@ +#![feature(non_lifetime_binders)] +//~^ WARN the feature `non_lifetime_binders` is incomplete + +fn function<T>() where for<T> (): Sized {} +//~^ ERROR the name `T` is already used for a generic parameter + +struct Struct<T>(T) where for<T> (): Sized; +//~^ ERROR the name `T` is already used for a generic parameter + +impl<T> Struct<T> { + fn method() where for<T> (): Sized {} + //~^ ERROR the name `T` is already used for a generic parameter +} + +fn repeated() where for<T, T> (): Sized {} +//~^ ERROR the name `T` is already used for a generic parameter + +fn main() {} diff --git a/tests/ui/traits/non_lifetime_binders/shadowed.stderr b/tests/ui/traits/non_lifetime_binders/shadowed.stderr new file mode 100644 index 00000000000..59a073aefc9 --- /dev/null +++ b/tests/ui/traits/non_lifetime_binders/shadowed.stderr @@ -0,0 +1,44 @@ +error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters + --> $DIR/shadowed.rs:4:28 + | +LL | fn function<T>() where for<T> (): Sized {} + | - ^ already used + | | + | first use of `T` + +error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters + --> $DIR/shadowed.rs:7:31 + | +LL | struct Struct<T>(T) where for<T> (): Sized; + | - ^ already used + | | + | first use of `T` + +error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters + --> $DIR/shadowed.rs:11:27 + | +LL | impl<T> Struct<T> { + | - first use of `T` +LL | fn method() where for<T> (): Sized {} + | ^ already used + +error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters + --> $DIR/shadowed.rs:15:28 + | +LL | fn repeated() where for<T, T> (): Sized {} + | - ^ already used + | | + | first use of `T` + +warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/shadowed.rs:1:12 + | +LL | #![feature(non_lifetime_binders)] + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information + = note: `#[warn(incomplete_features)]` on by default + +error: aborting due to 4 previous errors; 1 warning emitted + +For more information about this error, try `rustc --explain E0403`. |