diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
index 61c8113d05287..43aa8a6efcec4 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
@@ -2,7 +2,7 @@
use crate::infer::error_reporting::nice_region_error::NiceRegionError;
use crate::infer::lexical_region_resolve::RegionResolutionError;
-use crate::infer::{Subtype, ValuePairs};
+use crate::infer::{SubregionOrigin, Subtype, ValuePairs};
use crate::traits::ObligationCauseCode::CompareImplMethodObligation;
use rustc_errors::ErrorReported;
use rustc_hir as hir;
@@ -11,44 +11,53 @@ use rustc_hir::def_id::DefId;
use rustc_hir::intravisit::Visitor;
use rustc_middle::ty::error::ExpectedFound;
use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_span::{MultiSpan, Span};
+use rustc_span::{MultiSpan, Span, Symbol};
impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
/// Print the error message for lifetime errors when the `impl` doesn't conform to the `trait`.
pub(super) fn try_report_impl_not_conforming_to_trait(&self) -> Option<ErrorReported> {
- if let Some(ref error) = self.error {
- debug!("try_report_impl_not_conforming_to_trait {:?}", error);
- if let RegionResolutionError::SubSupConflict(
- _,
- var_origin,
- sub_origin,
- _sub,
- sup_origin,
- _sup,
- ) = error.clone()
- {
- if let (&Subtype(ref sup_trace), &Subtype(ref sub_trace)) =
- (&sup_origin, &sub_origin)
+ let error = self.error.as_ref()?;
+ debug!("try_report_impl_not_conforming_to_trait {:?}", error);
+ if let RegionResolutionError::SubSupConflict(
+ _,
+ var_origin,
+ sub_origin,
+ _sub,
+ sup_origin,
+ _sup,
+ ) = error.clone()
+ {
+ if let (&Subtype(ref sup_trace), &Subtype(ref sub_trace)) = (&sup_origin, &sub_origin) {
+ if let (
+ ValuePairs::Types(sub_expected_found),
+ ValuePairs::Types(sup_expected_found),
+ CompareImplMethodObligation { trait_item_def_id, .. },
+ ) = (&sub_trace.values, &sup_trace.values, &sub_trace.cause.code)
{
- if let (
- ValuePairs::Types(sub_expected_found),
- ValuePairs::Types(sup_expected_found),
- CompareImplMethodObligation { trait_item_def_id, .. },
- ) = (&sub_trace.values, &sup_trace.values, &sub_trace.cause.code)
- {
- if sup_expected_found == sub_expected_found {
- self.emit_err(
- var_origin.span(),
- sub_expected_found.expected,
- sub_expected_found.found,
- *trait_item_def_id,
- );
- return Some(ErrorReported);
- }
+ if sup_expected_found == sub_expected_found {
+ self.emit_err(
+ var_origin.span(),
+ sub_expected_found.expected,
+ sub_expected_found.found,
+ *trait_item_def_id,
+ );
+ return Some(ErrorReported);
}
}
}
}
+ if let RegionResolutionError::ConcreteFailure(origin, _, _) = error.clone() {
+ if let SubregionOrigin::CompareImplTypeObligation {
+ span,
+ item_name,
+ impl_item_def_id,
+ trait_item_def_id,
+ } = origin
+ {
+ self.emit_associated_type_err(span, item_name, impl_item_def_id, trait_item_def_id);
+ return Some(ErrorReported);
+ }
+ }
None
}
@@ -107,6 +116,25 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
}
err.emit();
}
+
+ fn emit_associated_type_err(
+ &self,
+ span: Span,
+ item_name: Symbol,
+ impl_item_def_id: DefId,
+ trait_item_def_id: DefId,
+ ) {
+ let impl_sp = self.tcx().def_span(impl_item_def_id);
+ let trait_sp = self.tcx().def_span(trait_item_def_id);
+ let mut err = self
+ .tcx()
+ .sess
+ .struct_span_err(span, &format!("`impl` associated type signature for `{}` doesn't match `trait` associated type signature", item_name));
+ err.span_label(impl_sp, &format!("found"));
+ err.span_label(trait_sp, &format!("expected"));
+
+ err.emit();
+ }
}
struct TypeParamSpanVisitor<'tcx> {
diff --git a/compiler/rustc_infer/src/infer/error_reporting/note.rs b/compiler/rustc_infer/src/infer/error_reporting/note.rs
index 4bc59a4baf5ca..5f99a23f86e88 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/note.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/note.rs
@@ -99,6 +99,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
"...so that the definition in impl matches the definition from the trait",
);
}
+ infer::CompareImplTypeObligation { span, .. } => {
+ label_or_note(
+ span,
+ "...so that the definition in impl matches the definition from the trait",
+ );
+ }
}
}
@@ -356,6 +362,18 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
trait_item_def_id,
&format!("`{}: {}`", sup, sub),
),
+ infer::CompareImplTypeObligation {
+ span,
+ item_name,
+ impl_item_def_id,
+ trait_item_def_id,
+ } => self.report_extra_impl_obligation(
+ span,
+ item_name,
+ impl_item_def_id,
+ trait_item_def_id,
+ &format!("`{}: {}`", sup, sub),
+ ),
}
}
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index bc98a3aa3f95e..354b8e26d53d5 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -427,6 +427,15 @@ pub enum SubregionOrigin<'tcx> {
impl_item_def_id: DefId,
trait_item_def_id: DefId,
},
+
+ /// Comparing the signature and requirements of an impl associated type
+ /// against the containing trait
+ CompareImplTypeObligation {
+ span: Span,
+ item_name: Symbol,
+ impl_item_def_id: DefId,
+ trait_item_def_id: DefId,
+ },
}
// `SubregionOrigin` is used a lot. Make sure it doesn't unintentionally get bigger.
@@ -1810,6 +1819,7 @@ impl<'tcx> SubregionOrigin<'tcx> {
ReferenceOutlivesReferent(_, a) => a,
CallReturn(a) => a,
CompareImplMethodObligation { span, .. } => span,
+ CompareImplTypeObligation { span, .. } => span,
}
}
@@ -1833,6 +1843,17 @@ impl<'tcx> SubregionOrigin<'tcx> {
trait_item_def_id,
},
+ traits::ObligationCauseCode::CompareImplTypeObligation {
+ item_name,
+ impl_item_def_id,
+ trait_item_def_id,
+ } => SubregionOrigin::CompareImplTypeObligation {
+ span: cause.span,
+ item_name,
+ impl_item_def_id,
+ trait_item_def_id,
+ },
+
_ => default(),
}
}
diff --git a/src/test/ui/generic-associated-types/impl_bounds.rs b/src/test/ui/generic-associated-types/impl_bounds.rs
index 01edad00a89f1..27c135cb7cf82 100644
--- a/src/test/ui/generic-associated-types/impl_bounds.rs
+++ b/src/test/ui/generic-associated-types/impl_bounds.rs
@@ -15,7 +15,7 @@ impl<T> Foo for Fooy<T> {
type A<'a> where Self: 'static = (&'a ());
//~^ ERROR the parameter type `T` may not live long enough
type B<'a, 'b> where 'b: 'a = (&'a(), &'b ());
- //~^ ERROR lifetime bound not satisfied
+ //~^ ERROR `impl` associated type
//~| ERROR lifetime bound not satisfied
type C where Self: Copy = String;
//~^ ERROR the trait bound `T: Copy` is not satisfied
diff --git a/src/test/ui/generic-associated-types/impl_bounds.stderr b/src/test/ui/generic-associated-types/impl_bounds.stderr
index 8cf923ca3ac0c..73415e0faac88 100644
--- a/src/test/ui/generic-associated-types/impl_bounds.stderr
+++ b/src/test/ui/generic-associated-types/impl_bounds.stderr
@@ -5,24 +5,16 @@ LL | type A<'a> where Self: 'static = (&'a ());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: consider adding an explicit lifetime bound `T: 'static`...
- = note: ...so that the type `Fooy<T>` will meet its required lifetime bounds
+ = note: ...so that the definition in impl matches the definition from the trait
-error[E0478]: lifetime bound not satisfied
+error: `impl` associated type signature for `B` doesn't match `trait` associated type signature
--> $DIR/impl_bounds.rs:17:5
|
+LL | type B<'a, 'b> where 'a: 'b;
+ | ---------------------------- expected
+...
LL | type B<'a, 'b> where 'b: 'a = (&'a(), &'b ());
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- |
-note: lifetime parameter instantiated with the lifetime `'b` as defined on the associated item at 17:16
- --> $DIR/impl_bounds.rs:17:16
- |
-LL | type B<'a, 'b> where 'b: 'a = (&'a(), &'b ());
- | ^^
-note: but lifetime parameter must outlive the lifetime `'a` as defined on the associated item at 17:12
- --> $DIR/impl_bounds.rs:17:12
- |
-LL | type B<'a, 'b> where 'b: 'a = (&'a(), &'b ());
- | ^^
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found
error[E0478]: lifetime bound not satisfied
--> $DIR/impl_bounds.rs:17:5
diff --git a/src/test/ui/generic-associated-types/issue-86787.stderr b/src/test/ui/generic-associated-types/issue-86787.stderr
index 04cd84b08011c..e1ff772921104 100644
--- a/src/test/ui/generic-associated-types/issue-86787.stderr
+++ b/src/test/ui/generic-associated-types/issue-86787.stderr
@@ -9,7 +9,7 @@ LL | | <Left as HasChildrenOf>::T: 'a,
LL | | <Right as HasChildrenOf>::T: 'a
| | - help: consider adding a where clause: `, <Left as HasChildrenOf>::T: 'a`
LL | | = Either<&'a Left::T, &'a Right::T>;
- | |________________________________________^ ...so that the type `<Left as HasChildrenOf>::T` will meet its required lifetime bounds
+ | |________________________________________^ ...so that the definition in impl matches the definition from the trait
error[E0309]: the associated type `<Right as HasChildrenOf>::T` may not live long enough
--> $DIR/issue-86787.rs:23:5
@@ -22,7 +22,7 @@ LL | | <Left as HasChildrenOf>::T: 'a,
LL | | <Right as HasChildrenOf>::T: 'a
| | - help: consider adding a where clause: `, <Right as HasChildrenOf>::T: 'a`
LL | | = Either<&'a Left::T, &'a Right::T>;
- | |________________________________________^ ...so that the type `<Right as HasChildrenOf>::T` will meet its required lifetime bounds
+ | |________________________________________^ ...so that the definition in impl matches the definition from the trait
error: aborting due to 2 previous errors
diff --git a/src/test/ui/generic-associated-types/missing-where-clause-on-trait.rs b/src/test/ui/generic-associated-types/missing-where-clause-on-trait.rs
new file mode 100644
index 0000000000000..ad9f2e3e4ec4a
--- /dev/null
+++ b/src/test/ui/generic-associated-types/missing-where-clause-on-trait.rs
@@ -0,0 +1,13 @@
+// check-fail
+
+#![feature(generic_associated_types)]
+
+trait Foo {
+ type Assoc<'a, 'b>;
+}
+impl Foo for () {
+ type Assoc<'a, 'b> where 'a: 'b = ();
+ //~^ `impl` associated type
+}
+
+fn main() {}
diff --git a/src/test/ui/generic-associated-types/missing-where-clause-on-trait.stderr b/src/test/ui/generic-associated-types/missing-where-clause-on-trait.stderr
new file mode 100644
index 0000000000000..0e183c8d69a4c
--- /dev/null
+++ b/src/test/ui/generic-associated-types/missing-where-clause-on-trait.stderr
@@ -0,0 +1,11 @@
+error: `impl` associated type signature for `Assoc` doesn't match `trait` associated type signature
+ --> $DIR/missing-where-clause-on-trait.rs:9:5
+ |
+LL | type Assoc<'a, 'b>;
+ | ------------------- expected
+...
+LL | type Assoc<'a, 'b> where 'a: 'b = ();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found
+
+error: aborting due to previous error
+