diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs index 0df5a57bc2c..4823472cf96 100644 --- a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs +++ b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs @@ -144,6 +144,7 @@ impl<'tcx> InherentCollect<'tcx> { let id = id.owner_id.def_id; let item_span = self.tcx.def_span(id); let self_ty = self.tcx.type_of(id).instantiate_identity(); + let self_ty = peel_off_weak_aliases(self.tcx, self_ty); match *self_ty.kind() { ty::Adt(def, _) => self.check_def_id(id, self_ty, def.did()), ty::Foreign(did) => self.check_def_id(id, self_ty, did), @@ -166,7 +167,7 @@ impl<'tcx> InherentCollect<'tcx> { | ty::Never | ty::FnPtr(_) | ty::Tuple(..) => self.check_primitive_impl(id, self_ty), - ty::Alias(..) | ty::Param(_) => { + ty::Alias(ty::Projection | ty::Inherent | ty::Opaque, _) | ty::Param(_) => { Err(self.tcx.dcx().emit_err(errors::InherentNominal { span: item_span })) } ty::FnDef(..) @@ -174,6 +175,7 @@ impl<'tcx> InherentCollect<'tcx> { | ty::CoroutineClosure(..) | ty::Coroutine(..) | ty::CoroutineWitness(..) + | ty::Alias(ty::Weak, _) | ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) => { @@ -184,3 +186,30 @@ impl<'tcx> InherentCollect<'tcx> { } } } + +/// Peel off all weak alias types in this type until there are none left. +/// +///
+/// +/// This assumes that `ty` gets normalized later and that any overflows occurring +/// during said normalization get reported. +/// +///
+fn peel_off_weak_aliases<'tcx>(tcx: TyCtxt<'tcx>, mut ty: Ty<'tcx>) -> Ty<'tcx> { + let ty::Alias(ty::Weak, _) = ty.kind() else { return ty }; + + let limit = tcx.recursion_limit(); + let mut depth = 0; + + while let ty::Alias(ty::Weak, alias) = ty.kind() { + if !limit.value_within_limit(depth) { + let guar = tcx.dcx().delayed_bug("overflow expanding weak alias type"); + return Ty::new_error(tcx, guar); + } + + ty = tcx.type_of(alias.def_id).instantiate(tcx, alias.args); + depth += 1; + } + + ty +} diff --git a/tests/ui/lazy-type-alias/inherent-impls-conflicting.rs b/tests/ui/lazy-type-alias/inherent-impls-conflicting.rs new file mode 100644 index 00000000000..2adb04839ae --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-conflicting.rs @@ -0,0 +1,10 @@ +#![feature(lazy_type_alias)] +#![allow(incomplete_features)] + +type Alias = Local; +struct Local; + +impl Alias { fn method() {} } //~ ERROR duplicate definitions with name `method` +impl Local { fn method() {} } + +fn main() {} diff --git a/tests/ui/lazy-type-alias/inherent-impls-conflicting.stderr b/tests/ui/lazy-type-alias/inherent-impls-conflicting.stderr new file mode 100644 index 00000000000..3f8dcef857f --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-conflicting.stderr @@ -0,0 +1,11 @@ +error[E0592]: duplicate definitions with name `method` + --> $DIR/inherent-impls-conflicting.rs:7:14 + | +LL | impl Alias { fn method() {} } + | ^^^^^^^^^^^ duplicate definitions for `method` +LL | impl Local { fn method() {} } + | ----------- other definition for `method` + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0592`. diff --git a/tests/ui/lazy-type-alias/inherent-impls-not-nominal.rs b/tests/ui/lazy-type-alias/inherent-impls-not-nominal.rs new file mode 100644 index 00000000000..0ec23bb7fb7 --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-not-nominal.rs @@ -0,0 +1,12 @@ +#![feature(lazy_type_alias)] +#![allow(incomplete_features)] + +type Alias = <() as Trait>::Out; + +trait Trait { type Out; } +impl Trait for () { type Out = Local; } +struct Local; + +impl Alias {} //~ ERROR no nominal type found for inherent implementation + +fn main() {} diff --git a/tests/ui/lazy-type-alias/inherent-impls-not-nominal.stderr b/tests/ui/lazy-type-alias/inherent-impls-not-nominal.stderr new file mode 100644 index 00000000000..2936e70f5b4 --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-not-nominal.stderr @@ -0,0 +1,11 @@ +error[E0118]: no nominal type found for inherent implementation + --> $DIR/inherent-impls-not-nominal.rs:10:1 + | +LL | impl Alias {} + | ^^^^^^^^^^ impl requires a nominal type + | + = note: either implement a trait on it or create a newtype to wrap it instead + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0118`. diff --git a/tests/ui/lazy-type-alias/inherent-impls-overflow.classic.stderr b/tests/ui/lazy-type-alias/inherent-impls-overflow.classic.stderr new file mode 100644 index 00000000000..1cace470627 --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-overflow.classic.stderr @@ -0,0 +1,43 @@ +error[E0275]: overflow evaluating the requirement `Loop` + --> $DIR/inherent-impls-overflow.rs:7:13 + | +LL | type Loop = Loop; + | ^^^^ + | + = note: in case this is a recursive type alias, consider using a struct, enum, or union instead + +error[E0275]: overflow evaluating the requirement `Loop` + --> $DIR/inherent-impls-overflow.rs:9:1 + | +LL | impl Loop {} + | ^^^^^^^^^^^^ + | + = note: in case this is a recursive type alias, consider using a struct, enum, or union instead + +error[E0275]: overflow evaluating the requirement `Poly0<((((((...,),),),),),)>` + --> $DIR/inherent-impls-overflow.rs:11:17 + | +LL | type Poly0 = Poly1<(T,)>; + | ^^^^^^^^^^^ + | + = note: in case this is a recursive type alias, consider using a struct, enum, or union instead + +error[E0275]: overflow evaluating the requirement `Poly1<((((((...,),),),),),)>` + --> $DIR/inherent-impls-overflow.rs:14:17 + | +LL | type Poly1 = Poly0<(T,)>; + | ^^^^^^^^^^^ + | + = note: in case this is a recursive type alias, consider using a struct, enum, or union instead + +error[E0275]: overflow evaluating the requirement `Poly1<((((((...,),),),),),)>` + --> $DIR/inherent-impls-overflow.rs:18:1 + | +LL | impl Poly0<()> {} + | ^^^^^^^^^^^^^^^^^ + | + = note: in case this is a recursive type alias, consider using a struct, enum, or union instead + +error: aborting due to 5 previous errors + +For more information about this error, try `rustc --explain E0275`. diff --git a/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr b/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr new file mode 100644 index 00000000000..1a6259b5cf9 --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr @@ -0,0 +1,38 @@ +error[E0275]: overflow evaluating the requirement `Loop == _` + --> $DIR/inherent-impls-overflow.rs:9:6 + | +LL | impl Loop {} + | ^^^^ + | + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inherent_impls_overflow`) + +error[E0392]: type parameter `T` is never used + --> $DIR/inherent-impls-overflow.rs:11:12 + | +LL | type Poly0 = Poly1<(T,)>; + | ^ unused type parameter + | + = help: consider removing `T` or referring to it in the body of the type alias + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead + +error[E0392]: type parameter `T` is never used + --> $DIR/inherent-impls-overflow.rs:14:12 + | +LL | type Poly1 = Poly0<(T,)>; + | ^ unused type parameter + | + = help: consider removing `T` or referring to it in the body of the type alias + = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead + +error[E0275]: overflow evaluating the requirement `Poly0<()> == _` + --> $DIR/inherent-impls-overflow.rs:18:6 + | +LL | impl Poly0<()> {} + | ^^^^^^^^^ + | + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inherent_impls_overflow`) + +error: aborting due to 4 previous errors + +Some errors have detailed explanations: E0275, E0392. +For more information about an error, try `rustc --explain E0275`. diff --git a/tests/ui/lazy-type-alias/inherent-impls-overflow.rs b/tests/ui/lazy-type-alias/inherent-impls-overflow.rs new file mode 100644 index 00000000000..b260dedeb07 --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls-overflow.rs @@ -0,0 +1,20 @@ +//@ revisions: classic next +//@[next] compile-flags: -Znext-solver + +#![feature(lazy_type_alias)] +#![allow(incomplete_features)] + +type Loop = Loop; //[classic]~ ERROR overflow evaluating the requirement + +impl Loop {} //~ ERROR overflow evaluating the requirement + +type Poly0 = Poly1<(T,)>; +//[classic]~^ ERROR overflow evaluating the requirement +//[next]~^^ ERROR type parameter `T` is never used +type Poly1 = Poly0<(T,)>; +//[classic]~^ ERROR overflow evaluating the requirement +//[next]~^^ ERROR type parameter `T` is never used + +impl Poly0<()> {} //~ ERROR overflow evaluating the requirement + +fn main() {} diff --git a/tests/ui/lazy-type-alias/inherent-impls.rs b/tests/ui/lazy-type-alias/inherent-impls.rs new file mode 100644 index 00000000000..835b70bf67a --- /dev/null +++ b/tests/ui/lazy-type-alias/inherent-impls.rs @@ -0,0 +1,18 @@ +//@ check-pass + +#![feature(lazy_type_alias)] +#![allow(incomplete_features)] + +type Alias = Local; +struct Local; + +impl Alias { + fn method(self) {} +} + +fn main() { + let _ = Local.method(); + let _ = Local::method; + let _ = Alias {}.method(); + let _ = Alias::method; +}