diff options
5 files changed, 84 insertions, 3 deletions
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs index f57456949bb..bd017b213b6 100644 --- a/compiler/rustc_borrowck/src/region_infer/mod.rs +++ b/compiler/rustc_borrowck/src/region_infer/mod.rs @@ -1726,9 +1726,10 @@ impl<'tcx> RegionInferenceContext<'tcx> { // `BoringNoLocation` constraints can point to user-written code, but are less // specific, and are not used for relations that would make sense to blame. ConstraintCategory::BoringNoLocation => 6, - // Do not blame internal constraints. - ConstraintCategory::OutlivesUnnameablePlaceholder(_) => 7, - ConstraintCategory::Internal => 8, + // Do not blame internal constraints if we can avoid it. Never blame + // the `'region: 'static` constraints introduced by placeholder outlives. + ConstraintCategory::Internal => 7, + ConstraintCategory::OutlivesUnnameablePlaceholder(_) => 8, }; debug!("constraint {constraint:?} category: {category:?}, interest: {interest:?}"); diff --git a/tests/ui/associated-inherent-types/hr-do-not-blame-outlives-static-ice.rs b/tests/ui/associated-inherent-types/hr-do-not-blame-outlives-static-ice.rs new file mode 100644 index 00000000000..e5c1f47b9e0 --- /dev/null +++ b/tests/ui/associated-inherent-types/hr-do-not-blame-outlives-static-ice.rs @@ -0,0 +1,17 @@ +//@ compile-flags: -Zdeduplicate-diagnostics=yes + +// Regression test for #146467. +#![feature(inherent_associated_types)] +//~^ WARN the feature `inherent_associated_types` is incomplete + +struct Foo<T>(T); + +impl<'a> Foo<fn(&())> { + //~^ ERROR the lifetime parameter `'a` is not constrained by the impl trait + type Assoc = &'a (); +} + +fn foo(_: for<'a> fn(Foo<fn(&'a ())>::Assoc)) {} +//~^ ERROR mismatched types +//~| ERROR higher-ranked subtype error +fn main() {} diff --git a/tests/ui/associated-inherent-types/hr-do-not-blame-outlives-static-ice.stderr b/tests/ui/associated-inherent-types/hr-do-not-blame-outlives-static-ice.stderr new file mode 100644 index 00000000000..4c0726d4ddc --- /dev/null +++ b/tests/ui/associated-inherent-types/hr-do-not-blame-outlives-static-ice.stderr @@ -0,0 +1,34 @@ +warning: the feature `inherent_associated_types` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/hr-do-not-blame-outlives-static-ice.rs:4:12 + | +LL | #![feature(inherent_associated_types)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #8995 <https://github.com/rust-lang/rust/issues/8995> for more information + = note: `#[warn(incomplete_features)]` on by default + +error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates + --> $DIR/hr-do-not-blame-outlives-static-ice.rs:9:6 + | +LL | impl<'a> Foo<fn(&())> { + | ^^ unconstrained lifetime parameter + +error[E0308]: mismatched types + --> $DIR/hr-do-not-blame-outlives-static-ice.rs:14:11 + | +LL | fn foo(_: for<'a> fn(Foo<fn(&'a ())>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected struct `Foo<for<'a> fn(&'a ())>` + found struct `Foo<for<'a> fn(&'a ())>` + +error: higher-ranked subtype error + --> $DIR/hr-do-not-blame-outlives-static-ice.rs:14:1 + | +LL | fn foo(_: for<'a> fn(Foo<fn(&'a ())>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 3 previous errors; 1 warning emitted + +Some errors have detailed explanations: E0207, E0308. +For more information about an error, try `rustc --explain E0207`. diff --git a/tests/ui/higher-ranked/do-not-blame-outlives-static-ice.rs b/tests/ui/higher-ranked/do-not-blame-outlives-static-ice.rs new file mode 100644 index 00000000000..dfdb816652c --- /dev/null +++ b/tests/ui/higher-ranked/do-not-blame-outlives-static-ice.rs @@ -0,0 +1,12 @@ +//@ compile-flags: -Zdeduplicate-diagnostics=yes + +// Regression test for #146467. +trait Trait { type Assoc; } + +impl Trait for fn(&()) { type Assoc = (); } + +fn f(_: for<'a> fn(<fn(&'a ()) as Trait>::Assoc)) {} +//~^ ERROR implementation of `Trait` is not general enough +//~| ERROR higher-ranked subtype error + +fn main() {} diff --git a/tests/ui/higher-ranked/do-not-blame-outlives-static-ice.stderr b/tests/ui/higher-ranked/do-not-blame-outlives-static-ice.stderr new file mode 100644 index 00000000000..c75a063e45f --- /dev/null +++ b/tests/ui/higher-ranked/do-not-blame-outlives-static-ice.stderr @@ -0,0 +1,17 @@ +error: implementation of `Trait` is not general enough + --> $DIR/do-not-blame-outlives-static-ice.rs:8:9 + | +LL | fn f(_: for<'a> fn(<fn(&'a ()) as Trait>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Trait` is not general enough + | + = note: `for<'a> fn(&'a ())` must implement `Trait`, for any lifetime `'0`... + = note: ...but `Trait` is actually implemented for the type `for<'a> fn(&'a ())` + +error: higher-ranked subtype error + --> $DIR/do-not-blame-outlives-static-ice.rs:8:1 + | +LL | fn f(_: for<'a> fn(<fn(&'a ()) as Trait>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 2 previous errors + |