diff options
22 files changed, 319 insertions, 112 deletions
diff --git a/compiler/rustc_borrowck/src/type_check/relate_tys.rs b/compiler/rustc_borrowck/src/type_check/relate_tys.rs index 00296aa38da..85f63371659 100644 --- a/compiler/rustc_borrowck/src/type_check/relate_tys.rs +++ b/compiler/rustc_borrowck/src/type_check/relate_tys.rs @@ -483,61 +483,59 @@ impl<'bccx, 'tcx> TypeRelation<'tcx> for NllTypeRelating<'_, 'bccx, 'tcx> { return Ok(ty::Binder::dummy(a)); } - if self.ambient_covariance() { - // Covariance, so we want `for<..> A <: for<..> B` -- - // therefore we compare any instantiation of A (i.e., A - // instantiated with existentials) against every - // instantiation of B (i.e., B instantiated with - // universals). - - // Reset the ambient variance to covariant. This is needed - // to correctly handle cases like - // - // for<'a> fn(&'a u32, &'a u32) == for<'b, 'c> fn(&'b u32, &'c u32) - // - // Somewhat surprisingly, these two types are actually - // **equal**, even though the one on the right looks more - // polymorphic. The reason is due to subtyping. To see it, - // consider that each function can call the other: - // - // - The left function can call the right with `'b` and - // `'c` both equal to `'a` - // - // - The right function can call the left with `'a` set to - // `{P}`, where P is the point in the CFG where the call - // itself occurs. Note that `'b` and `'c` must both - // include P. At the point, the call works because of - // subtyping (i.e., `&'b u32 <: &{P} u32`). - let variance = std::mem::replace(&mut self.ambient_variance, ty::Variance::Covariant); - - // Note: the order here is important. Create the placeholders first, otherwise - // we assign the wrong universe to the existential! - self.enter_forall(b, |this, b| { - let a = this.instantiate_binder_with_existentials(a); - this.relate(a, b) - })?; - - self.ambient_variance = variance; - } + match self.ambient_variance { + ty::Variance::Covariant => { + // Covariance, so we want `for<..> A <: for<..> B` -- + // therefore we compare any instantiation of A (i.e., A + // instantiated with existentials) against every + // instantiation of B (i.e., B instantiated with + // universals). + + // Note: the order here is important. Create the placeholders first, otherwise + // we assign the wrong universe to the existential! + self.enter_forall(b, |this, b| { + let a = this.instantiate_binder_with_existentials(a); + this.relate(a, b) + })?; + } - if self.ambient_contravariance() { - // Contravariance, so we want `for<..> A :> for<..> B` - // -- therefore we compare every instantiation of A (i.e., - // A instantiated with universals) against any - // instantiation of B (i.e., B instantiated with - // existentials). Opposite of above. - - // Reset ambient variance to contravariance. See the - // covariant case above for an explanation. - let variance = - std::mem::replace(&mut self.ambient_variance, ty::Variance::Contravariant); - - self.enter_forall(a, |this, a| { - let b = this.instantiate_binder_with_existentials(b); - this.relate(a, b) - })?; - - self.ambient_variance = variance; + ty::Variance::Contravariant => { + // Contravariance, so we want `for<..> A :> for<..> B` -- + // therefore we compare every instantiation of A (i.e., A + // instantiated with universals) against any + // instantiation of B (i.e., B instantiated with + // existentials). Opposite of above. + + // Note: the order here is important. Create the placeholders first, otherwise + // we assign the wrong universe to the existential! + self.enter_forall(a, |this, a| { + let b = this.instantiate_binder_with_existentials(b); + this.relate(a, b) + })?; + } + + ty::Variance::Invariant => { + // Invariant, so we want `for<..> A == for<..> B` -- + // therefore we want `exists<..> A == for<..> B` and + // `exists<..> B == for<..> A`. + // + // See the comment in `fn Equate::binders` for more details. + + // Note: the order here is important. Create the placeholders first, otherwise + // we assign the wrong universe to the existential! + self.enter_forall(b, |this, b| { + let a = this.instantiate_binder_with_existentials(a); + this.relate(a, b) + })?; + // Note: the order here is important. Create the placeholders first, otherwise + // we assign the wrong universe to the existential! + self.enter_forall(a, |this, a| { + let b = this.instantiate_binder_with_existentials(b); + this.relate(a, b) + })?; + } + + ty::Variance::Bivariant => {} } Ok(a) diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs index 3b7a7817279..6e9b4236e20 100644 --- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs +++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs @@ -169,6 +169,7 @@ pub fn check_intrinsic_type( let bound_vars = tcx.mk_bound_variable_kinds(&[ ty::BoundVariableKind::Region(ty::BrAnon), + ty::BoundVariableKind::Region(ty::BrAnon), ty::BoundVariableKind::Region(ty::BrEnv), ]); let mk_va_list_ty = |mutbl| { @@ -181,7 +182,7 @@ pub fn check_intrinsic_type( let env_region = ty::Region::new_bound( tcx, ty::INNERMOST, - ty::BoundRegion { var: ty::BoundVar::from_u32(1), kind: ty::BrEnv }, + ty::BoundRegion { var: ty::BoundVar::from_u32(2), kind: ty::BrEnv }, ); let va_list_ty = tcx.type_of(did).instantiate(tcx, &[region.into()]); (Ty::new_ref(tcx, env_region, ty::TypeAndMut { ty: va_list_ty, mutbl }), va_list_ty) @@ -493,9 +494,12 @@ pub fn check_intrinsic_type( sym::raw_eq => { let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon }; - let param_ty = + let param_ty_lhs = + Ty::new_imm_ref(tcx, ty::Region::new_bound(tcx, ty::INNERMOST, br), param(0)); + let br = ty::BoundRegion { var: ty::BoundVar::from_u32(1), kind: ty::BrAnon }; + let param_ty_rhs = Ty::new_imm_ref(tcx, ty::Region::new_bound(tcx, ty::INNERMOST, br), param(0)); - (1, 0, vec![param_ty; 2], tcx.types.bool) + (1, 0, vec![param_ty_lhs, param_ty_rhs], tcx.types.bool) } sym::black_box => (1, 0, vec![param(0)], param(0)), diff --git a/compiler/rustc_infer/src/infer/relate/equate.rs b/compiler/rustc_infer/src/infer/relate/equate.rs index 43d6aef3e15..1617a062ea0 100644 --- a/compiler/rustc_infer/src/infer/relate/equate.rs +++ b/compiler/rustc_infer/src/infer/relate/equate.rs @@ -1,12 +1,13 @@ use super::combine::{CombineFields, ObligationEmittingRelation}; use super::StructurallyRelateAliases; +use crate::infer::BoundRegionConversionTime::HigherRankedType; use crate::infer::{DefineOpaqueTypes, SubregionOrigin}; use crate::traits::PredicateObligations; use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation}; use rustc_middle::ty::GenericArgsRef; use rustc_middle::ty::TyVar; -use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt}; +use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_hir::def_id::DefId; use rustc_span::Span; @@ -167,12 +168,34 @@ impl<'tcx> TypeRelation<'tcx> for Equate<'_, '_, 'tcx> { return Ok(a); } - if a.skip_binder().has_escaping_bound_vars() || b.skip_binder().has_escaping_bound_vars() { - self.fields.higher_ranked_sub(a, b, self.a_is_expected)?; - self.fields.higher_ranked_sub(b, a, self.a_is_expected)?; - } else { + if let (Some(a), Some(b)) = (a.no_bound_vars(), b.no_bound_vars()) { // Fast path for the common case. - self.relate(a.skip_binder(), b.skip_binder())?; + self.relate(a, b)?; + } else { + // When equating binders, we check that there is a 1-to-1 + // correspondence between the bound vars in both types. + // + // We do so by separately instantiating one of the binders with + // placeholders and the other with inference variables and then + // equating the instantiated types. + // + // We want `for<..> A == for<..> B` -- therefore we want + // `exists<..> A == for<..> B` and `exists<..> B == for<..> A`. + + let span = self.fields.trace.cause.span; + let infcx = self.fields.infcx; + + // Check if `exists<..> A == for<..> B` + infcx.enter_forall(b, |b| { + let a = infcx.instantiate_binder_with_fresh_vars(span, HigherRankedType, a); + self.relate(a, b) + })?; + + // Check if `exists<..> B == for<..> A`. + infcx.enter_forall(a, |a| { + let b = infcx.instantiate_binder_with_fresh_vars(span, HigherRankedType, b); + self.relate(a, b) + })?; } Ok(a) } diff --git a/tests/ui/associated-inherent-types/issue-111404-1.rs b/tests/ui/associated-inherent-types/issue-111404-1.rs index dd62e59f07d..3255bf20ebd 100644 --- a/tests/ui/associated-inherent-types/issue-111404-1.rs +++ b/tests/ui/associated-inherent-types/issue-111404-1.rs @@ -8,7 +8,9 @@ impl<'a> Foo<fn(&'a ())> { } fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {} -//~^ ERROR higher-ranked subtype error +//~^ ERROR mismatched types [E0308] +//~| ERROR mismatched types [E0308] +//~| ERROR higher-ranked subtype error //~| ERROR higher-ranked subtype error fn main() {} diff --git a/tests/ui/associated-inherent-types/issue-111404-1.stderr b/tests/ui/associated-inherent-types/issue-111404-1.stderr index cf4d4a5f19b..5074c877a8e 100644 --- a/tests/ui/associated-inherent-types/issue-111404-1.stderr +++ b/tests/ui/associated-inherent-types/issue-111404-1.stderr @@ -1,3 +1,22 @@ +error[E0308]: mismatched types + --> $DIR/issue-111404-1.rs:10:11 + | +LL | fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected struct `Foo<fn(&())>` + found struct `Foo<for<'b> fn(&'b ())>` + +error[E0308]: mismatched types + --> $DIR/issue-111404-1.rs:10:11 + | +LL | fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected struct `Foo<fn(&())>` + found struct `Foo<for<'b> fn(&'b ())>` + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` + error: higher-ranked subtype error --> $DIR/issue-111404-1.rs:10:1 | @@ -12,5 +31,6 @@ LL | fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {} | = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` -error: aborting due to 2 previous errors +error: aborting due to 4 previous errors +For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/closure-expected-type/expect-fn-supply-fn.rs b/tests/ui/closure-expected-type/expect-fn-supply-fn.rs index 7f1c140279c..7599d078351 100644 --- a/tests/ui/closure-expected-type/expect-fn-supply-fn.rs +++ b/tests/ui/closure-expected-type/expect-fn-supply-fn.rs @@ -30,14 +30,16 @@ fn expect_free_supply_bound() { // Here, we are given a function whose region is bound at closure level, // but we expect one bound in the argument. Error results. with_closure_expecting_fn_with_free_region(|x: fn(&u32), y| {}); - //~^ ERROR mismatched types + //~^ ERROR mismatched types [E0308] + //~| ERROR lifetime may not live long enough } fn expect_bound_supply_free_from_fn<'x>(x: &'x u32) { // Here, we are given a `fn(&u32)` but we expect a `fn(&'x // u32)`. In principle, this could be ok, but we demand equality. with_closure_expecting_fn_with_bound_region(|x: fn(&'x u32), y| {}); - //~^ ERROR mismatched types + //~^ ERROR mismatched types [E0308] + //~| ERROR lifetime may not live long enough } fn expect_bound_supply_free_from_closure() { diff --git a/tests/ui/closure-expected-type/expect-fn-supply-fn.stderr b/tests/ui/closure-expected-type/expect-fn-supply-fn.stderr index e010f0502f8..4215cd0bc11 100644 --- a/tests/ui/closure-expected-type/expect-fn-supply-fn.stderr +++ b/tests/ui/closure-expected-type/expect-fn-supply-fn.stderr @@ -19,6 +19,15 @@ LL | fn expect_free_supply_free_from_fn<'x>(x: &'x u32) { LL | with_closure_expecting_fn_with_free_region(|x: fn(&'x u32), y| {}); | ^ requires that `'x` must outlive `'static` +error: lifetime may not live long enough + --> $DIR/expect-fn-supply-fn.rs:32:49 + | +LL | with_closure_expecting_fn_with_free_region(|x: fn(&u32), y| {}); + | ^ + | | + | has type `fn(&'1 u32)` + | requires that `'1` must outlive `'static` + error[E0308]: mismatched types --> $DIR/expect-fn-supply-fn.rs:32:49 | @@ -29,7 +38,7 @@ LL | with_closure_expecting_fn_with_free_region(|x: fn(&u32), y| {}); found fn pointer `for<'a> fn(&'a _)` error[E0308]: mismatched types - --> $DIR/expect-fn-supply-fn.rs:39:50 + --> $DIR/expect-fn-supply-fn.rs:40:50 | LL | with_closure_expecting_fn_with_bound_region(|x: fn(&'x u32), y| {}); | ^ one type is more general than the other @@ -37,8 +46,17 @@ LL | with_closure_expecting_fn_with_bound_region(|x: fn(&'x u32), y| {}); = note: expected fn pointer `for<'a> fn(&'a _)` found fn pointer `fn(&_)` +error: lifetime may not live long enough + --> $DIR/expect-fn-supply-fn.rs:40:50 + | +LL | fn expect_bound_supply_free_from_fn<'x>(x: &'x u32) { + | -- lifetime `'x` defined here +... +LL | with_closure_expecting_fn_with_bound_region(|x: fn(&'x u32), y| {}); + | ^ requires that `'x` must outlive `'static` + error[E0308]: mismatched types - --> $DIR/expect-fn-supply-fn.rs:48:50 + --> $DIR/expect-fn-supply-fn.rs:50:50 | LL | with_closure_expecting_fn_with_bound_region(|x: Foo<'_>, y| { | ^ one type is more general than the other @@ -46,6 +64,6 @@ LL | with_closure_expecting_fn_with_bound_region(|x: Foo<'_>, y| { = note: expected fn pointer `for<'a> fn(&'a _)` found fn pointer `fn(&_)` -error: aborting due to 5 previous errors +error: aborting due to 7 previous errors For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.rs b/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.rs index 99f805f7f0f..fb706ba1352 100644 --- a/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.rs +++ b/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.rs @@ -1,10 +1,15 @@ -// Test that impls for these two types are considered ovelapping: +//@ check-pass + +// These types were previously considered equal as they are subtypes of each other. +// This has been changed in #118247 and we now consider them to be disjoint. +// +// In our test: // // * `for<'r> fn(fn(&'r u32))` // * `fn(fn(&'a u32)` where `'a` is free // -// This is because, for `'a = 'static`, the two types overlap. -// Effectively for them to be equal to you get: +// These were considered equal as for `'a = 'static` subtyping succeeds in both +// directions: // // * `for<'r> fn(fn(&'r u32)) <: fn(fn(&'static u32))` // * true if `exists<'r> { 'r: 'static }` (obviously true) @@ -15,12 +20,7 @@ trait Trait {} impl Trait for for<'r> fn(fn(&'r ())) {} impl<'a> Trait for fn(fn(&'a ())) {} -//~^ ERROR conflicting implementations -// -// Note in particular that we do NOT get a future-compatibility warning -// here. This is because the new leak-check proposed in [MCP 295] does not -// "error" when these two types are equated. -// -// [MCP 295]: https://github.com/rust-lang/compiler-team/issues/295 +//~^ WARN conflicting implementations of trait `Trait` for type `for<'r> fn(fn(&'r ()))` [coherence_leak_check] +//~| WARN the behavior may change in a future release fn main() {} diff --git a/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.stderr b/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.stderr index 316da26b54d..01694eaf5d1 100644 --- a/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.stderr +++ b/tests/ui/coherence/coherence-fn-covariant-bound-vs-static.stderr @@ -1,13 +1,15 @@ -error[E0119]: conflicting implementations of trait `Trait` for type `for<'r> fn(fn(&'r ()))` - --> $DIR/coherence-fn-covariant-bound-vs-static.rs:17:1 +warning: conflicting implementations of trait `Trait` for type `for<'r> fn(fn(&'r ()))` + --> $DIR/coherence-fn-covariant-bound-vs-static.rs:22:1 | LL | impl Trait for for<'r> fn(fn(&'r ())) {} | ------------------------------------- first implementation here LL | impl<'a> Trait for fn(fn(&'a ())) {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `for<'r> fn(fn(&'r ()))` | + = warning: the behavior may change in a future release + = note: for more information, see issue #56105 <https://github.com/rust-lang/rust/issues/56105> = note: this behavior recently changed as a result of a bug fix; see rust-lang/rust#56105 for details + = note: `#[warn(coherence_leak_check)]` on by default -error: aborting due to 1 previous error +warning: 1 warning emitted -For more information about this error, try `rustc --explain E0119`. diff --git a/tests/ui/coherence/coherence-fn-inputs.rs b/tests/ui/coherence/coherence-fn-inputs.rs index 3afec5c5459..a88a846329d 100644 --- a/tests/ui/coherence/coherence-fn-inputs.rs +++ b/tests/ui/coherence/coherence-fn-inputs.rs @@ -1,11 +1,12 @@ -// Test that we consider these two types completely equal: +//@ check-pass + +// These types were previously considered equal as they are subtypes of each other. +// This has been changed in #118247 and we now consider them to be disjoint. // // * `for<'a, 'b> fn(&'a u32, &'b u32)` // * `for<'c> fn(&'c u32, &'c u32)` // -// For a long time we considered these to be distinct types. But in fact they -// are equivalent, if you work through the implications of subtyping -- this is -// because: +// These types are subtypes of each other as: // // * `'c` can be the intersection of `'a` and `'b` (and there is always an intersection) // * `'a` and `'b` can both be equal to `'c` @@ -13,7 +14,8 @@ trait Trait {} impl Trait for for<'a, 'b> fn(&'a u32, &'b u32) {} impl Trait for for<'c> fn(&'c u32, &'c u32) { - //~^ ERROR conflicting implementations + //~^ WARN conflicting implementations of trait `Trait` for type `for<'a, 'b> fn(&'a u32, &'b u32)` [coherence_leak_check] + //~| WARN the behavior may change in a future release // // Note in particular that we do NOT get a future-compatibility warning // here. This is because the new leak-check proposed in [MCP 295] does not diff --git a/tests/ui/coherence/coherence-fn-inputs.stderr b/tests/ui/coherence/coherence-fn-inputs.stderr index 246ec5947b3..56f3a14833e 100644 --- a/tests/ui/coherence/coherence-fn-inputs.stderr +++ b/tests/ui/coherence/coherence-fn-inputs.stderr @@ -1,13 +1,15 @@ -error[E0119]: conflicting implementations of trait `Trait` for type `for<'a, 'b> fn(&'a u32, &'b u32)` - --> $DIR/coherence-fn-inputs.rs:15:1 +warning: conflicting implementations of trait `Trait` for type `for<'a, 'b> fn(&'a u32, &'b u32)` + --> $DIR/coherence-fn-inputs.rs:16:1 | LL | impl Trait for for<'a, 'b> fn(&'a u32, &'b u32) {} | ----------------------------------------------- first implementation here LL | impl Trait for for<'c> fn(&'c u32, &'c u32) { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `for<'a, 'b> fn(&'a u32, &'b u32)` | + = warning: the behavior may change in a future release + = note: for more information, see issue #56105 <https://github.com/rust-lang/rust/issues/56105> = note: this behavior recently changed as a result of a bug fix; see rust-lang/rust#56105 for details + = note: `#[warn(coherence_leak_check)]` on by default -error: aborting due to 1 previous error +warning: 1 warning emitted -For more information about this error, try `rustc --explain E0119`. diff --git a/tests/ui/const-generics/generic_const_exprs/typeid-equality-by-subtyping.stderr b/tests/ui/const-generics/generic_const_exprs/typeid-equality-by-subtyping.stderr index 220fcd38b09..26e724c9061 100644 --- a/tests/ui/const-generics/generic_const_exprs/typeid-equality-by-subtyping.stderr +++ b/tests/ui/const-generics/generic_const_exprs/typeid-equality-by-subtyping.stderr @@ -7,5 +7,21 @@ LL | WHAT_A_TYPE => 0, = note: the traits must be derived, manual `impl`s are not sufficient = note: see https://doc.rust-lang.org/stable/std/marker/trait.StructuralPartialEq.html for details -error: aborting due to 1 previous error +error[E0277]: the trait bound `for<'a, 'b> fn(&'a (), &'b ()): WithAssoc<T>` is not satisfied + --> $DIR/typeid-equality-by-subtyping.rs:44:51 + | +LL | fn unsound<T>(x: <One as WithAssoc<T>>::Assoc) -> <Two as WithAssoc<T>>::Assoc + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `WithAssoc<T>` is not implemented for `for<'a, 'b> fn(&'a (), &'b ())` + +error[E0277]: the trait bound `for<'a, 'b> fn(&'a (), &'b ()): WithAssoc<T>` is not satisfied + --> $DIR/typeid-equality-by-subtyping.rs:47:1 + | +LL | / { +LL | | let x: <Two as WithAssoc<T>>::Assoc = generic::<One, T>(x); +LL | | x +LL | | } + | |_^ the trait `WithAssoc<T>` is not implemented for `for<'a, 'b> fn(&'a (), &'b ())` + +error: aborting due to 3 previous errors +For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/higher-ranked/higher-ranked-lifetime-equality.rs b/tests/ui/higher-ranked/higher-ranked-lifetime-equality.rs new file mode 100644 index 00000000000..38abf59d844 --- /dev/null +++ b/tests/ui/higher-ranked/higher-ranked-lifetime-equality.rs @@ -0,0 +1,38 @@ +// A regression test for #97156 + +type One = for<'a> fn(&'a (), &'a ()); +type Two = for<'a, 'b> fn(&'a (), &'b ()); + +mod my_api { + use std::any::Any; + use std::marker::PhantomData; + + pub struct Foo<T: 'static> { + a: &'static dyn Any, + _p: PhantomData<*mut T>, // invariant, the type of the `dyn Any` + } + + impl<T: 'static> Foo<T> { + pub fn deref(&self) -> &'static T { + match self.a.downcast_ref::<T>() { + None => unsafe { std::hint::unreachable_unchecked() }, + Some(a) => a, + } + } + + pub fn new(a: T) -> Foo<T> { + Foo::<T> { a: Box::leak(Box::new(a)), _p: PhantomData } + } + } +} + +use my_api::*; + +fn main() { + let foo = Foo::<One>::new((|_, _| ()) as One); + foo.deref(); + let foo: Foo<Two> = foo; + //~^ ERROR mismatched types [E0308] + //~| ERROR mismatched types [E0308] + foo.deref(); +} diff --git a/tests/ui/higher-ranked/higher-ranked-lifetime-equality.stderr b/tests/ui/higher-ranked/higher-ranked-lifetime-equality.stderr new file mode 100644 index 00000000000..8c0d66bb0bc --- /dev/null +++ b/tests/ui/higher-ranked/higher-ranked-lifetime-equality.stderr @@ -0,0 +1,22 @@ +error[E0308]: mismatched types + --> $DIR/higher-ranked-lifetime-equality.rs:34:25 + | +LL | let foo: Foo<Two> = foo; + | ^^^ one type is more general than the other + | + = note: expected struct `my_api::Foo<for<'a, 'b> fn(&'a (), &'b ())>` + found struct `my_api::Foo<for<'a> fn(&'a (), &'a ())>` + +error[E0308]: mismatched types + --> $DIR/higher-ranked-lifetime-equality.rs:34:25 + | +LL | let foo: Foo<Two> = foo; + | ^^^ one type is more general than the other + | + = note: expected struct `my_api::Foo<for<'a, 'b> fn(&'a (), &'b ())>` + found struct `my_api::Foo<for<'a> fn(&'a (), &'a ())>` + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.rs b/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.rs index 230a0524df4..805fd7f1232 100644 --- a/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.rs +++ b/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.rs @@ -2,8 +2,6 @@ // // In particular, we test this pattern in trait solving, where it is not connected // to any part of the source code. -// -//@ check-pass trait Trait<T> {} @@ -21,17 +19,17 @@ fn main() { // - The impl provides the clause `forall<'a> { (): Trait<fn(fn(&'a u32))> }` // - We instantiate `'a` existentially to get `(): Trait<fn(fn(&?a u32))>` // - We unify `fn(fn(&?a u32))` with `for<'b> fn(fn(&'b u32))` -- this does a - // "bidirectional" subtyping check, so we wind up with: - // - `fn(fn(&?a u32)) <: for<'b> fn(fn(&'b u32))` :- - // - `fn(&!b u32) <: fn(&?a u32)` - // - `&?a u32 <: &!b u32` - // - `?a: !'b` -- solveable if `?a` is inferred to `'static` - // - `for<'b> fn(fn(&'b u32)) <: fn(fn(&?a u32))` :- - // - `fn(&?a u32) <: fn(&?b u32)` - // - `&?b u32 <: &?a u32` - // - `?b: ?a` -- solveable if `?b` is inferred to `'static` - // - So the subtyping check succeeds, somewhat surprisingly. - // This is because we can use `'static`. + // "bidirectional" equality check, so we wind up with: + // - `fn(fn(&?a u32)) == for<'b> fn(fn(&'b u32))` :- + // - `fn(&!b u32) == fn(&?a u32)` + // - `&?a u32 == &!b u32` + // - `?a == !b` -- error. + // - `fn(fn(&?a u32)) == for<'b> fn(fn(&'b u32))` :- + // - `fn(&?b u32) == fn(&?a u32)` + // - `&?a u32 == &?b u32` + // - `?a == ?b` -- OK. + // - So the unification fails. foo::<()>(); + //~^ ERROR implementation of `Trait` is not general enough } diff --git a/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.stderr b/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.stderr new file mode 100644 index 00000000000..385de795b18 --- /dev/null +++ b/tests/ui/higher-ranked/trait-bounds/hrtb-exists-forall-trait-covariant.stderr @@ -0,0 +1,11 @@ +error: implementation of `Trait` is not general enough + --> $DIR/hrtb-exists-forall-trait-covariant.rs:33:5 + | +LL | foo::<()>(); + | ^^^^^^^^^^^ implementation of `Trait` is not general enough + | + = note: `()` must implement `Trait<for<'b> fn(fn(&'b u32))>` + = note: ...but it actually implements `Trait<fn(fn(&'0 u32))>`, for some specific lifetime `'0` + +error: aborting due to 1 previous error + diff --git a/tests/ui/lub-glb/old-lub-glb-hr-eq.rs b/tests/ui/lub-glb/old-lub-glb-hr-eq.rs index 97062ec91af..df288793608 100644 --- a/tests/ui/lub-glb/old-lub-glb-hr-eq.rs +++ b/tests/ui/lub-glb/old-lub-glb-hr-eq.rs @@ -3,8 +3,6 @@ // error. However, now that we handle subtyping correctly, we no // longer get an error, because we recognize these two types as // equivalent! -// -//@ check-pass fn foo(x: fn(&u8, &u8), y: for<'a> fn(&'a u8, &'a u8)) { // The two types above are actually equivalent. With the older @@ -13,6 +11,7 @@ fn foo(x: fn(&u8, &u8), y: for<'a> fn(&'a u8, &'a u8)) { let z = match 22 { 0 => x, _ => y, + //~^ ERROR `match` arms have incompatible types [E0308] }; } diff --git a/tests/ui/lub-glb/old-lub-glb-hr-eq.stderr b/tests/ui/lub-glb/old-lub-glb-hr-eq.stderr new file mode 100644 index 00000000000..ea8e53f2460 --- /dev/null +++ b/tests/ui/lub-glb/old-lub-glb-hr-eq.stderr @@ -0,0 +1,19 @@ +error[E0308]: `match` arms have incompatible types + --> $DIR/old-lub-glb-hr-eq.rs:13:14 + | +LL | let z = match 22 { + | _____________- +LL | | 0 => x, + | | - this is found to be of type `for<'a, 'b> fn(&'a u8, &'b u8)` +LL | | _ => y, + | | ^ one type is more general than the other +LL | | +LL | | }; + | |_____- `match` arms have incompatible types + | + = note: expected fn pointer `for<'a, 'b> fn(&'a _, &'b _)` + found fn pointer `for<'a> fn(&'a _, &'a _)` + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.rs b/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.rs index 039ca1fb58d..52b983cd12f 100644 --- a/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.rs +++ b/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.rs @@ -6,7 +6,6 @@ // another -- effectively, the single lifetime `'a` is just inferred // to be the intersection of the two distinct lifetimes. // -//@ check-pass //@ compile-flags:-Zno-leak-check use std::cell::Cell; @@ -17,7 +16,9 @@ fn make_cell_aa() -> Cell<for<'a> fn(&'a u32, &'a u32)> { fn aa_eq_ab() { let a: Cell<for<'a, 'b> fn(&'a u32, &'b u32)> = make_cell_aa(); + //~^ ERROR mismatched types [E0308] + //~| ERROR mismatched types [E0308] drop(a); } -fn main() { } +fn main() {} diff --git a/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.stderr b/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.stderr new file mode 100644 index 00000000000..9a88ce8756c --- /dev/null +++ b/tests/ui/nll/relate_tys/hr-fn-aau-eq-abu.stderr @@ -0,0 +1,22 @@ +error[E0308]: mismatched types + --> $DIR/hr-fn-aau-eq-abu.rs:18:53 + | +LL | let a: Cell<for<'a, 'b> fn(&'a u32, &'b u32)> = make_cell_aa(); + | ^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected struct `Cell<for<'a, 'b> fn(&'a _, &'b _)>` + found struct `Cell<for<'a> fn(&'a _, &'a _)>` + +error[E0308]: mismatched types + --> $DIR/hr-fn-aau-eq-abu.rs:18:53 + | +LL | let a: Cell<for<'a, 'b> fn(&'a u32, &'b u32)> = make_cell_aa(); + | ^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected struct `Cell<for<'a, 'b> fn(&'a _, &'b _)>` + found struct `Cell<for<'a> fn(&'a _, &'a _)>` + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0308`. diff --git a/tests/ui/traits/next-solver/member-constraints-in-root-universe.rs b/tests/ui/traits/next-solver/member-constraints-in-root-universe.rs index 74164ad2aa2..a5696fc7796 100644 --- a/tests/ui/traits/next-solver/member-constraints-in-root-universe.rs +++ b/tests/ui/traits/next-solver/member-constraints-in-root-universe.rs @@ -1,5 +1,4 @@ //@ compile-flags: -Znext-solver -//@ check-pass trait Trait { type Ty; @@ -11,6 +10,7 @@ impl Trait for for<'a> fn(&'a u8, &'a u8) { // argument is necessary to create universes before registering the hidden type. fn test<'a>(_: <fn(&u8, &u8) as Trait>::Ty) -> impl Sized { + //~^ ERROR the type `<for<'a, 'b> fn(&'a u8, &'b u8) as Trait>::Ty` is not well-formed "hidden type is `&'?0 str` with '?0 member of ['static,]" } diff --git a/tests/ui/traits/next-solver/member-constraints-in-root-universe.stderr b/tests/ui/traits/next-solver/member-constraints-in-root-universe.stderr new file mode 100644 index 00000000000..7a9982f07f6 --- /dev/null +++ b/tests/ui/traits/next-solver/member-constraints-in-root-universe.stderr @@ -0,0 +1,8 @@ +error: the type `<for<'a, 'b> fn(&'a u8, &'b u8) as Trait>::Ty` is not well-formed + --> $DIR/member-constraints-in-root-universe.rs:12:16 + | +LL | fn test<'a>(_: <fn(&u8, &u8) as Trait>::Ty) -> impl Sized { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 1 previous error + |