diff options
7 files changed, 57 insertions, 6 deletions
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index 5b7a00101e9..ef0f41223ea 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -1512,7 +1512,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { count: 1, }; let elision_candidate = LifetimeElisionCandidate::Missing(missing_lifetime); - for rib in self.lifetime_ribs.iter().rev() { + for (i, rib) in self.lifetime_ribs.iter().enumerate().rev() { debug!(?rib.kind); match rib.kind { LifetimeRibKind::AnonymousCreateParameter { binder, .. } => { @@ -1529,16 +1529,31 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> { } else { ("`'_` cannot be used here", "`'_` is a reserved lifetime name") }; - rustc_errors::struct_span_err!( + let mut diag = rustc_errors::struct_span_err!( self.r.session, lifetime.ident.span, E0637, "{}", msg, - ) - .span_label(lifetime.ident.span, note) - .emit(); - + ); + diag.span_label(lifetime.ident.span, note); + if elided { + for rib in self.lifetime_ribs[i..].iter().rev() { + if let LifetimeRibKind::Generics { + span, + kind: LifetimeBinderKind::PolyTrait | LifetimeBinderKind::WhereBound, + .. + } = &rib.kind + { + diag.span_help( + *span, + "consider introducing a higher-ranked lifetime here with `for<'a>`", + ); + break; + } + } + } + diag.emit(); self.record_lifetime_res(lifetime.id, LifetimeRes::Error, elision_candidate); return; } diff --git a/src/test/ui/error-codes/E0637.stderr b/src/test/ui/error-codes/E0637.stderr index 35a4b34fb0a..78341735e19 100644 --- a/src/test/ui/error-codes/E0637.stderr +++ b/src/test/ui/error-codes/E0637.stderr @@ -21,6 +21,12 @@ error[E0637]: `&` without an explicit lifetime name cannot be used here | LL | T: Into<&u32>, | ^ explicit lifetime name needed here + | +help: consider introducing a higher-ranked lifetime here with `for<'a>` + --> $DIR/E0637.rs:13:8 + | +LL | T: Into<&u32>, + | ^ error: aborting due to 3 previous errors diff --git a/src/test/ui/generics/issue-65285-incorrect-explicit-lifetime-name-needed.stderr b/src/test/ui/generics/issue-65285-incorrect-explicit-lifetime-name-needed.stderr index e45387acaf3..9d859fddf56 100644 --- a/src/test/ui/generics/issue-65285-incorrect-explicit-lifetime-name-needed.stderr +++ b/src/test/ui/generics/issue-65285-incorrect-explicit-lifetime-name-needed.stderr @@ -3,6 +3,12 @@ error[E0637]: `&` without an explicit lifetime name cannot be used here | LL | fn should_error<T>() where T : Into<&u32> {} | ^ explicit lifetime name needed here + | +help: consider introducing a higher-ranked lifetime here with `for<'a>` + --> $DIR/issue-65285-incorrect-explicit-lifetime-name-needed.rs:5:32 + | +LL | fn should_error<T>() where T : Into<&u32> {} + | ^ error[E0106]: missing lifetime specifier --> $DIR/issue-65285-incorrect-explicit-lifetime-name-needed.rs:9:20 diff --git a/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2015.stderr b/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2015.stderr index fe726cb49c7..f4d14b5f87b 100644 --- a/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2015.stderr +++ b/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2015.stderr @@ -3,6 +3,12 @@ error[E0637]: `&` without an explicit lifetime name cannot be used here | LL | T: WithType<&u32> | ^ explicit lifetime name needed here + | +help: consider introducing a higher-ranked lifetime here with `for<'a>` + --> $DIR/where-clause-inherent-impl-ampersand.rs:13:8 + | +LL | T: WithType<&u32> + | ^ error: aborting due to previous error diff --git a/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2018.stderr b/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2018.stderr index fe726cb49c7..f4d14b5f87b 100644 --- a/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2018.stderr +++ b/src/test/ui/underscore-lifetime/where-clause-inherent-impl-ampersand.rust2018.stderr @@ -3,6 +3,12 @@ error[E0637]: `&` without an explicit lifetime name cannot be used here | LL | T: WithType<&u32> | ^ explicit lifetime name needed here + | +help: consider introducing a higher-ranked lifetime here with `for<'a>` + --> $DIR/where-clause-inherent-impl-ampersand.rs:13:8 + | +LL | T: WithType<&u32> + | ^ error: aborting due to previous error diff --git a/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2015.stderr b/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2015.stderr index fbd14de2107..63fc1a19b93 100644 --- a/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2015.stderr +++ b/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2015.stderr @@ -3,6 +3,12 @@ error[E0637]: `&` without an explicit lifetime name cannot be used here | LL | T: WithType<&u32> | ^ explicit lifetime name needed here + | +help: consider introducing a higher-ranked lifetime here with `for<'a>` + --> $DIR/where-clause-trait-impl-region.rs:11:8 + | +LL | T: WithType<&u32> + | ^ error: aborting due to previous error diff --git a/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2018.stderr b/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2018.stderr index fbd14de2107..63fc1a19b93 100644 --- a/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2018.stderr +++ b/src/test/ui/underscore-lifetime/where-clause-trait-impl-region.rust2018.stderr @@ -3,6 +3,12 @@ error[E0637]: `&` without an explicit lifetime name cannot be used here | LL | T: WithType<&u32> | ^ explicit lifetime name needed here + | +help: consider introducing a higher-ranked lifetime here with `for<'a>` + --> $DIR/where-clause-trait-impl-region.rs:11:8 + | +LL | T: WithType<&u32> + | ^ error: aborting due to previous error |