From 364475b281519695da69736ac2ee38c254b30c4f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Thu, 16 Jan 2025 20:56:37 +0000 Subject: [PATCH 1/4] Add tests for some cases mentioned in #135589 --- .../missing-lifetime-in-assoc-type-1.rs | 16 +++++++++++++ .../missing-lifetime-in-assoc-type-1.stderr | 15 ++++++++++++ .../missing-lifetime-in-assoc-type-2.rs | 14 +++++++++++ .../missing-lifetime-in-assoc-type-2.stderr | 24 +++++++++++++++++++ .../missing-lifetime-in-assoc-type-3.rs | 14 +++++++++++ .../missing-lifetime-in-assoc-type-3.stderr | 20 ++++++++++++++++ .../missing-lifetime-in-assoc-type-4.rs | 14 +++++++++++ .../missing-lifetime-in-assoc-type-4.stderr | 15 ++++++++++++ 8 files changed, 132 insertions(+) create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.rs create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.rs create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs new file mode 100644 index 0000000000000..28e86635b1b79 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs @@ -0,0 +1,16 @@ +struct S; +struct T; + +impl<'a> IntoIterator for &S { + //~^ ERROR E0207 + //~| NOTE unconstrained lifetime parameter + type Item = &T; + //~^ ERROR in the trait associated type + //~| NOTE this lifetime must come from the implemented type + type IntoIter = std::collections::btree_map::Values<'a, i32, T>; + + fn into_iter(self) -> Self::IntoIter { + todo!() + } +} +fn main() {} diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr new file mode 100644 index 0000000000000..0796f65b9b2d1 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr @@ -0,0 +1,15 @@ +error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type + --> $DIR/missing-lifetime-in-assoc-type-1.rs:7:17 + | +LL | type Item = &T; + | ^ this lifetime must come from the implemented type + +error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates + --> $DIR/missing-lifetime-in-assoc-type-1.rs:4:6 + | +LL | impl<'a> IntoIterator for &S { + | ^^ unconstrained lifetime parameter + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0207`. diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.rs new file mode 100644 index 0000000000000..dd720f075ac46 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.rs @@ -0,0 +1,14 @@ +struct S; +struct T; + +impl IntoIterator for &S { + type Item = &T; + //~^ ERROR in the trait associated type + type IntoIter = std::collections::btree_map::Values<'a, i32, T>; + //~^ ERROR use of undeclared lifetime name `'a` + + fn into_iter(self) -> Self::IntoIter { + todo!() + } +} +fn main() {} diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr new file mode 100644 index 0000000000000..77916b651b13c --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr @@ -0,0 +1,24 @@ +error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type + --> $DIR/missing-lifetime-in-assoc-type-2.rs:5:17 + | +LL | type Item = &T; + | ^ this lifetime must come from the implemented type + +error[E0261]: use of undeclared lifetime name `'a` + --> $DIR/missing-lifetime-in-assoc-type-2.rs:7:57 + | +LL | type IntoIter = std::collections::btree_map::Values<'a, i32, T>; + | ^^ undeclared lifetime + | +help: consider introducing lifetime `'a` here + | +LL | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; + | ++++ +help: consider introducing lifetime `'a` here + | +LL | impl<'a> IntoIterator for &S { + | ++++ + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0261`. diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.rs new file mode 100644 index 0000000000000..60d1f0f8fe571 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.rs @@ -0,0 +1,14 @@ +struct S; +struct T; + +impl IntoIterator for &S { + type Item = &T; + //~^ ERROR in the trait associated type + type IntoIter = std::collections::btree_map::Values; + //~^ ERROR missing lifetime specifier + + fn into_iter(self) -> Self::IntoIter { + todo!() + } +} +fn main() {} diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr new file mode 100644 index 0000000000000..50012ac72d22f --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr @@ -0,0 +1,20 @@ +error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type + --> $DIR/missing-lifetime-in-assoc-type-3.rs:5:17 + | +LL | type Item = &T; + | ^ this lifetime must come from the implemented type + +error[E0106]: missing lifetime specifier + --> $DIR/missing-lifetime-in-assoc-type-3.rs:7:56 + | +LL | type IntoIter = std::collections::btree_map::Values; + | ^ expected named lifetime parameter + | +help: consider introducing a named lifetime parameter + | +LL | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; + | ++++ +++ + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0106`. diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs new file mode 100644 index 0000000000000..b01c59f3ee6d2 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs @@ -0,0 +1,14 @@ +struct S; +struct T; + +impl IntoIterator for &S { + type Item = &T; + //~^ ERROR in the trait associated type + type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; + //~^ ERROR lifetime parameters or bounds on type `IntoIter` do not match the trait declaration + + fn into_iter(self) -> Self::IntoIter { + todo!() + } +} +fn main() {} diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr new file mode 100644 index 0000000000000..f17c098ab6d04 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr @@ -0,0 +1,15 @@ +error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type + --> $DIR/missing-lifetime-in-assoc-type-4.rs:5:17 + | +LL | type Item = &T; + | ^ this lifetime must come from the implemented type + +error[E0195]: lifetime parameters or bounds on type `IntoIter` do not match the trait declaration + --> $DIR/missing-lifetime-in-assoc-type-4.rs:7:18 + | +LL | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; + | ^^^^ lifetimes do not match type in trait + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0195`. From 31556877de42e30a27edabb40014535932137cc9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Thu, 16 Jan 2025 21:02:23 +0000 Subject: [PATCH 2/4] Detect case of missing lifetime in assoc type When an associated type is missing a lifetime, point at its enclosing `impl`, whether it has or doesn't have lifetimes defined. If it does have a lifetime, suggest using it. ``` error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/missing-lifetime-in-assoc-type-1.rs:8:17 | LL | impl<'a> IntoIterator for &S { | ---- there is a named lifetime specified on the impl block you could use ... LL | type Item = &T; | ^ this lifetime must come from the implemented type | help: consider using the lifetime from the impl block | LL | type Item = &'a T; | ++ ``` ``` error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/missing-lifetime-in-assoc-type-2.rs:5:17 | LL | impl IntoIterator for &S { | - you could add a lifetime on the impl block, if the trait or the self type can have one LL | type Item = &T; | ^ this lifetime must come from the implemented type ``` --- compiler/rustc_resolve/src/late.rs | 54 +++++++++++++++++-- .../assoc-type.stderr | 2 + .../missing-lifetime-in-assoc-type-1.rs | 2 + .../missing-lifetime-in-assoc-type-1.stderr | 10 +++- .../missing-lifetime-in-assoc-type-2.stderr | 2 + .../missing-lifetime-in-assoc-type-3.stderr | 2 + .../missing-lifetime-in-assoc-type-4.rs | 2 +- .../missing-lifetime-in-assoc-type-4.stderr | 6 ++- .../ui/lifetimes/no_lending_iterators.stderr | 2 + 9 files changed, 74 insertions(+), 8 deletions(-) diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index e52cbeb733ac0..cc1eaaa46772e 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -20,7 +20,8 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap}; use rustc_data_structures::unord::{UnordMap, UnordSet}; use rustc_errors::codes::*; use rustc_errors::{ - Applicability, DiagArgValue, ErrorGuaranteed, IntoDiagArg, StashKey, Suggestions, + Applicability, Diag, DiagArgValue, ErrorGuaranteed, IntoDiagArg, StashKey, Suggestions, + pluralize, }; use rustc_hir::def::Namespace::{self, *}; use rustc_hir::def::{self, CtorKind, DefKind, LifetimeRes, NonMacroAttrKind, PartialRes, PerNS}; @@ -1887,9 +1888,13 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> { ty: ty.span, }); } else { - self.r.dcx().emit_err(errors::AnonymousLifetimeNonGatReportError { - lifetime: lifetime.ident.span, - }); + let mut err = self.r.dcx().create_err( + errors::AnonymousLifetimeNonGatReportError { + lifetime: lifetime.ident.span, + }, + ); + self.point_at_impl_lifetimes(&mut err, i, lifetime.ident.span); + err.emit(); } } else { self.r.dcx().emit_err(errors::ElidedAnonymousLifetimeReportError { @@ -1926,6 +1931,47 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> { self.report_missing_lifetime_specifiers(vec![missing_lifetime], None); } + fn point_at_impl_lifetimes(&mut self, err: &mut Diag<'_>, i: usize, lifetime: Span) { + let Some((rib, span)) = self.lifetime_ribs[..i] + .iter() + .rev() + .skip(1) + .filter_map(|rib| match rib.kind { + LifetimeRibKind::Generics { span, kind: LifetimeBinderKind::ImplBlock, .. } => { + Some((rib, span)) + } + _ => None, + }) + .next() + else { + return; + }; + if !rib.bindings.is_empty() { + err.span_label( + span, + format!( + "there {} named lifetime{} specified on the impl block you could use", + if rib.bindings.len() == 1 { "is a" } else { "are" }, + pluralize!(rib.bindings.len()), + ), + ); + if rib.bindings.len() == 1 { + err.span_suggestion_verbose( + lifetime.shrink_to_hi(), + "consider using the lifetime from the impl block", + format!("{} ", rib.bindings.keys().next().unwrap()), + Applicability::MaybeIncorrect, + ); + } + } else { + err.span_label( + span, + "you could add a lifetime on the impl block, if the trait or the self type can \ + have one", + ); + } + } + #[instrument(level = "debug", skip(self))] fn resolve_elided_lifetime(&mut self, anchor_id: NodeId, span: Span) { let id = self.r.next_node_id(); diff --git a/tests/ui/impl-header-lifetime-elision/assoc-type.stderr b/tests/ui/impl-header-lifetime-elision/assoc-type.stderr index e650eeca48ad9..72c066426bd99 100644 --- a/tests/ui/impl-header-lifetime-elision/assoc-type.stderr +++ b/tests/ui/impl-header-lifetime-elision/assoc-type.stderr @@ -1,6 +1,8 @@ error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/assoc-type.rs:11:19 | +LL | impl MyTrait for &i32 { + | - you could add a lifetime on the impl block, if the trait or the self type can have one LL | type Output = &i32; | ^ this lifetime must come from the implemented type diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs index 28e86635b1b79..5953466375d4e 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs @@ -3,9 +3,11 @@ struct T; impl<'a> IntoIterator for &S { //~^ ERROR E0207 + //~| NOTE there is a named lifetime specified on the impl block you could use //~| NOTE unconstrained lifetime parameter type Item = &T; //~^ ERROR in the trait associated type + //~| HELP consider using the lifetime from the impl block //~| NOTE this lifetime must come from the implemented type type IntoIter = std::collections::btree_map::Values<'a, i32, T>; diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr index 0796f65b9b2d1..1fbde0cfb3988 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr @@ -1,8 +1,16 @@ error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type - --> $DIR/missing-lifetime-in-assoc-type-1.rs:7:17 + --> $DIR/missing-lifetime-in-assoc-type-1.rs:8:17 | +LL | impl<'a> IntoIterator for &S { + | ---- there is a named lifetime specified on the impl block you could use +... LL | type Item = &T; | ^ this lifetime must come from the implemented type + | +help: consider using the lifetime from the impl block + | +LL | type Item = &'a T; + | ++ error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates --> $DIR/missing-lifetime-in-assoc-type-1.rs:4:6 diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr index 77916b651b13c..8408d37a901fd 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr @@ -1,6 +1,8 @@ error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/missing-lifetime-in-assoc-type-2.rs:5:17 | +LL | impl IntoIterator for &S { + | - you could add a lifetime on the impl block, if the trait or the self type can have one LL | type Item = &T; | ^ this lifetime must come from the implemented type diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr index 50012ac72d22f..d93852aee1bd3 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr @@ -1,6 +1,8 @@ error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/missing-lifetime-in-assoc-type-3.rs:5:17 | +LL | impl IntoIterator for &S { + | - you could add a lifetime on the impl block, if the trait or the self type can have one LL | type Item = &T; | ^ this lifetime must come from the implemented type diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs index b01c59f3ee6d2..0c99e8874c354 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs @@ -5,7 +5,7 @@ impl IntoIterator for &S { type Item = &T; //~^ ERROR in the trait associated type type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; - //~^ ERROR lifetime parameters or bounds on type `IntoIter` do not match the trait declaration + //~^ ERROR lifetime parameters or bounds on associated type `IntoIter` do not match the trait declaration fn into_iter(self) -> Self::IntoIter { todo!() diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr index f17c098ab6d04..ebe051509aad2 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.stderr @@ -1,14 +1,16 @@ error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/missing-lifetime-in-assoc-type-4.rs:5:17 | +LL | impl IntoIterator for &S { + | - you could add a lifetime on the impl block, if the trait or the self type can have one LL | type Item = &T; | ^ this lifetime must come from the implemented type -error[E0195]: lifetime parameters or bounds on type `IntoIter` do not match the trait declaration +error[E0195]: lifetime parameters or bounds on associated type `IntoIter` do not match the trait declaration --> $DIR/missing-lifetime-in-assoc-type-4.rs:7:18 | LL | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; - | ^^^^ lifetimes do not match type in trait + | ^^^^ lifetimes do not match associated type in trait error: aborting due to 2 previous errors diff --git a/tests/ui/lifetimes/no_lending_iterators.stderr b/tests/ui/lifetimes/no_lending_iterators.stderr index 340ef93588515..cadba149c234d 100644 --- a/tests/ui/lifetimes/no_lending_iterators.stderr +++ b/tests/ui/lifetimes/no_lending_iterators.stderr @@ -13,6 +13,8 @@ LL | impl Iterator for Data { error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type --> $DIR/no_lending_iterators.rs:18:17 | +LL | impl Bar for usize { + | - you could add a lifetime on the impl block, if the trait or the self type can have one LL | type Item = &usize; | ^ this lifetime must come from the implemented type From 02b8028cb3b677940a5d3620da79206a9d42dd1e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Thu, 16 Jan 2025 21:38:14 +0000 Subject: [PATCH 3/4] On unconstrained lifetime on `impl` block, suggest using it if there's an implicit borrow in the self type ``` error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates --> $DIR/missing-lifetime-in-assoc-type-1.rs:4:6 | LL | impl<'a> IntoIterator for &S { | ^^ unconstrained lifetime parameter | help: consider using the named lifetime here instead of an implict lifetime | LL | impl<'a> IntoIterator for &'a S { | ++ ``` --- .../rustc_hir_analysis/src/impl_wf_check.rs | 24 +++++++++++++++- .../missing-lifetime-in-assoc-type-1.rs | 1 + .../missing-lifetime-in-assoc-type-1.stderr | 7 ++++- .../missing-lifetime-in-assoc-type-5.rs | 19 +++++++++++++ .../missing-lifetime-in-assoc-type-5.stderr | 28 +++++++++++++++++++ 5 files changed, 77 insertions(+), 2 deletions(-) create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.rs create mode 100644 tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs index cbdc501291bc8..5b8eef0965759 100644 --- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs +++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs @@ -12,11 +12,12 @@ use std::assert_matches::debug_assert_matches; use min_specialization::check_min_specialization; use rustc_data_structures::fx::FxHashSet; +use rustc_errors::Applicability; use rustc_errors::codes::*; use rustc_hir::def::DefKind; use rustc_hir::def_id::LocalDefId; use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt}; -use rustc_span::ErrorGuaranteed; +use rustc_span::{ErrorGuaranteed, kw}; use crate::constrained_generic_params as cgp; use crate::errors::UnconstrainedGenericParameter; @@ -158,6 +159,27 @@ pub(crate) fn enforce_impl_lifetime_params_are_constrained( const_param_note2: false, }); diag.code(E0207); + for p in &impl_generics.own_params { + if p.name == kw::UnderscoreLifetime { + let span = tcx.def_span(p.def_id); + let Ok(snippet) = tcx.sess.source_map().span_to_snippet(span) else { + continue; + }; + + let (span, sugg) = if &snippet == "'_" { + (span, param.name.to_string()) + } else { + (span.shrink_to_hi(), format!("{} ", param.name)) + }; + diag.span_suggestion_verbose( + span, + "consider using the named lifetime here instead of an implict \ + lifetime", + sugg, + Applicability::MaybeIncorrect, + ); + } + } res = Err(diag.emit()); } } diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs index 5953466375d4e..1ae381ef7bc02 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.rs @@ -5,6 +5,7 @@ impl<'a> IntoIterator for &S { //~^ ERROR E0207 //~| NOTE there is a named lifetime specified on the impl block you could use //~| NOTE unconstrained lifetime parameter + //~| HELP consider using the named lifetime here instead of an implict lifetime type Item = &T; //~^ ERROR in the trait associated type //~| HELP consider using the lifetime from the impl block diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr index 1fbde0cfb3988..bf26ce4a63027 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-1.stderr @@ -1,5 +1,5 @@ error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type - --> $DIR/missing-lifetime-in-assoc-type-1.rs:8:17 + --> $DIR/missing-lifetime-in-assoc-type-1.rs:9:17 | LL | impl<'a> IntoIterator for &S { | ---- there is a named lifetime specified on the impl block you could use @@ -17,6 +17,11 @@ error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, | LL | impl<'a> IntoIterator for &S { | ^^ unconstrained lifetime parameter + | +help: consider using the named lifetime here instead of an implict lifetime + | +LL | impl<'a> IntoIterator for &'a S { + | ++ error: aborting due to 2 previous errors diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.rs b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.rs new file mode 100644 index 0000000000000..ff64d6b900949 --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.rs @@ -0,0 +1,19 @@ +struct S; +struct T; + +impl<'a> IntoIterator for &'_ S { + //~^ ERROR E0207 + //~| NOTE there is a named lifetime specified on the impl block you could use + //~| NOTE unconstrained lifetime parameter + //~| HELP consider using the named lifetime here instead of an implict lifetime + type Item = &T; + //~^ ERROR in the trait associated type + //~| HELP consider using the lifetime from the impl block + //~| NOTE this lifetime must come from the implemented type + type IntoIter = std::collections::btree_map::Values<'a, i32, T>; + + fn into_iter(self) -> Self::IntoIter { + todo!() + } +} +fn main() {} diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr new file mode 100644 index 0000000000000..7a63bd5b05eff --- /dev/null +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr @@ -0,0 +1,28 @@ +error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type + --> $DIR/missing-lifetime-in-assoc-type-5.rs:9:17 + | +LL | impl<'a> IntoIterator for &'_ S { + | ---- there is a named lifetime specified on the impl block you could use +... +LL | type Item = &T; + | ^ this lifetime must come from the implemented type + | +help: consider using the lifetime from the impl block + | +LL | type Item = &'a T; + | ++ + +error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates + --> $DIR/missing-lifetime-in-assoc-type-5.rs:4:6 + | +LL | impl<'a> IntoIterator for &'_ S { + | ^^ unconstrained lifetime parameter + | +help: consider using the named lifetime here instead of an implict lifetime + | +LL | impl<'a> IntoIterator for &'a S { + | ~~ + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0207`. From 6fcc9f5b16526f9c221eba01bacf5ad84cf859f0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Esteban=20K=C3=BCber?= Date: Thu, 16 Jan 2025 22:12:35 +0000 Subject: [PATCH 4/4] Do not suggest introducing lifetime in impl assoc type ``` error[E0261]: use of undeclared lifetime name `'a` --> $DIR/missing-lifetime-in-assoc-type-2.rs:7:57 | LL | impl IntoIterator for &S { | - help: consider introducing lifetime `'a` here: `<'a>` ... LL | type IntoIter = std::collections::btree_map::Values<'a, i32, T>; | ^^ undeclared lifetime ``` ``` error[E0106]: missing lifetime specifier --> $DIR/issue-74918-missing-lifetime.rs:9:30 | LL | type Item = IteratorChunk; | ^ expected named lifetime parameter | help: consider introducing a named lifetime parameter | LL ~ impl<'a, T, S: Iterator> Iterator for ChunkingIterator { LL ~ type Item = IteratorChunk<'a, T, S>; | ``` --- compiler/rustc_resolve/src/late.rs | 4 +++- compiler/rustc_resolve/src/late/diagnostics.rs | 3 +++ tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr | 4 ---- tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr | 7 +++++-- tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr | 5 +++-- .../mismatched_types/issue-74918-missing-lifetime.stderr | 5 +++-- .../ui/nll/user-annotations/region-error-ice-109072.stderr | 4 ---- 7 files changed, 17 insertions(+), 15 deletions(-) diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index cc1eaaa46772e..12c5f7fbc1113 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -378,6 +378,7 @@ enum LifetimeBinderKind { Function, Closure, ImplBlock, + ImplAssocType, } impl LifetimeBinderKind { @@ -388,6 +389,7 @@ impl LifetimeBinderKind { PolyTrait => "bound", WhereBound => "bound", Item | ConstItem => "item", + ImplAssocType => "associated type", ImplBlock => "impl block", Function => "function", Closure => "closure", @@ -3406,7 +3408,7 @@ impl<'a, 'ast, 'ra, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> { &generics.params, RibKind::AssocItem, item.id, - LifetimeBinderKind::Item, + LifetimeBinderKind::ImplAssocType, generics.span, |this| { this.with_lifetime_rib(LifetimeRibKind::AnonymousReportError, |this| { diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index aca251da71d39..f1fde99f1fc12 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -3154,6 +3154,9 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { { continue; } + if let LifetimeBinderKind::ImplAssocType = kind { + continue; + } if !span.can_be_used_for_suggestions() && suggest_note diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr index 8408d37a901fd..7a0246eaac8fd 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-2.stderr @@ -14,10 +14,6 @@ LL | type IntoIter = std::collections::btree_map::Values<'a, i32, T>; | help: consider introducing lifetime `'a` here | -LL | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; - | ++++ -help: consider introducing lifetime `'a` here - | LL | impl<'a> IntoIterator for &S { | ++++ diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr index d93852aee1bd3..408d5bb40664d 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-3.stderr @@ -14,8 +14,11 @@ LL | type IntoIter = std::collections::btree_map::Values; | help: consider introducing a named lifetime parameter | -LL | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>; - | ++++ +++ +LL ~ impl<'a> IntoIterator for &S { +LL | type Item = &T; +LL | +LL ~ type IntoIter = std::collections::btree_map::Values<'a, i32, T>; + | error: aborting due to 2 previous errors diff --git a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr index 7a63bd5b05eff..9c960c67e2502 100644 --- a/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr +++ b/tests/ui/lifetimes/missing-lifetime-in-assoc-type-5.stderr @@ -20,8 +20,9 @@ LL | impl<'a> IntoIterator for &'_ S { | help: consider using the named lifetime here instead of an implict lifetime | -LL | impl<'a> IntoIterator for &'a S { - | ~~ +LL - impl<'a> IntoIterator for &'_ S { +LL + impl<'a> IntoIterator for &'a S { + | error: aborting due to 2 previous errors diff --git a/tests/ui/mismatched_types/issue-74918-missing-lifetime.stderr b/tests/ui/mismatched_types/issue-74918-missing-lifetime.stderr index 5020395eb6aea..dc21c2e3cf9bf 100644 --- a/tests/ui/mismatched_types/issue-74918-missing-lifetime.stderr +++ b/tests/ui/mismatched_types/issue-74918-missing-lifetime.stderr @@ -6,8 +6,9 @@ LL | type Item = IteratorChunk; | help: consider introducing a named lifetime parameter | -LL | type Item<'a> = IteratorChunk<'a, T, S>; - | ++++ +++ +LL ~ impl<'a, T, S: Iterator> Iterator for ChunkingIterator { +LL ~ type Item = IteratorChunk<'a, T, S>; + | error: aborting due to 1 previous error diff --git a/tests/ui/nll/user-annotations/region-error-ice-109072.stderr b/tests/ui/nll/user-annotations/region-error-ice-109072.stderr index 42551b87f6234..026f5b5f80a9b 100644 --- a/tests/ui/nll/user-annotations/region-error-ice-109072.stderr +++ b/tests/ui/nll/user-annotations/region-error-ice-109072.stderr @@ -17,10 +17,6 @@ LL | type T = &'missing (); | help: consider introducing lifetime `'missing` here | -LL | type T<'missing> = &'missing (); - | ++++++++++ -help: consider introducing lifetime `'missing` here - | LL | impl<'missing> Lt<'missing> for () { | ++++++++++