From 4e2d420ac5f23bb9853410098b4f686704c0a6c2 Mon Sep 17 00:00:00 2001 From: lcnr Date: Thu, 7 Aug 2025 10:57:51 +0200 Subject: avoid duplicate error string --- compiler/rustc_borrowck/src/diagnostics/mod.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'compiler/rustc_borrowck/src') diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs index b67dba3af96..995c953fda9 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mod.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs @@ -676,7 +676,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { }); if let Some(span) = predicate_span { - err.span_note(span, "due to current limitations in the borrow checker, this implies a `'static` lifetime"); + err.span_note(span, fluent::borrowck_limitations_implies_static); } } -- cgit 1.4.1-3-g733a5 From d62e8578c5dcf08a4b5766ea63ea921f68c9de99 Mon Sep 17 00:00:00 2001 From: lcnr Date: Thu, 7 Aug 2025 11:24:46 +0200 Subject: also consider HR bounds --- .../rustc_borrowck/src/diagnostics/region_errors.rs | 20 +++++++++++++++++--- .../extended/lending_iterator.stderr | 6 ++++++ 2 files changed, 23 insertions(+), 3 deletions(-) (limited to 'compiler/rustc_borrowck/src') diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs index 2b74f1a48f7..cd03daad593 100644 --- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs @@ -215,7 +215,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { diag: &mut Diag<'_>, lower_bound: RegionVid, ) { - let mut suggestions = vec![]; let tcx = self.infcx.tcx; // find generic associated types in the given region 'lower_bound' @@ -239,7 +238,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { // find higher-ranked trait bounds bounded to the generic associated types let mut hrtb_bounds = vec![]; - gat_id_and_generics.iter().flatten().for_each(|(gat_hir_id, generics)| { + gat_id_and_generics.iter().flatten().for_each(|&(gat_hir_id, generics)| { for pred in generics.predicates { let BoundPredicate(WhereBoundPredicate { bound_generic_params, bounds, .. }) = pred.kind @@ -248,17 +247,32 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { }; if bound_generic_params .iter() - .rfind(|bgp| tcx.local_def_id_to_hir_id(bgp.def_id) == *gat_hir_id) + .rfind(|bgp| tcx.local_def_id_to_hir_id(bgp.def_id) == gat_hir_id) .is_some() { for bound in *bounds { hrtb_bounds.push(bound); } + } else { + for bound in *bounds { + if let Trait(trait_bound) = bound { + if trait_bound + .bound_generic_params + .iter() + .rfind(|bgp| tcx.local_def_id_to_hir_id(bgp.def_id) == gat_hir_id) + .is_some() + { + hrtb_bounds.push(bound); + return; + } + } + } } } }); debug!(?hrtb_bounds); + let mut suggestions = vec![]; hrtb_bounds.iter().for_each(|bound| { let Trait(PolyTraitRef { trait_ref, span: trait_span, .. }) = bound else { return; diff --git a/tests/ui/generic-associated-types/extended/lending_iterator.stderr b/tests/ui/generic-associated-types/extended/lending_iterator.stderr index 84f5ed07bda..dc349c6ceb9 100644 --- a/tests/ui/generic-associated-types/extended/lending_iterator.stderr +++ b/tests/ui/generic-associated-types/extended/lending_iterator.stderr @@ -12,6 +12,12 @@ error: `Self` does not live long enough | LL | >::from_iter(self) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: due to current limitations in the borrow checker, this implies a `'static` lifetime + --> $DIR/lending_iterator.rs:4:21 + | +LL | fn from_iter LendingIterator = A>>(iter: T) -> Self; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 2 previous errors -- cgit 1.4.1-3-g733a5 From a95a2ac476ef04ccf8cfabd35e6fcdb9569f053d Mon Sep 17 00:00:00 2001 From: lcnr Date: Thu, 7 Aug 2025 11:30:24 +0200 Subject: rework `add_placeholder_from_predicate_note` --- compiler/rustc_borrowck/src/diagnostics/mod.rs | 58 ++++++++++++++++++---- ...ementation-not-general-enough-ice-133252.stderr | 6 --- .../bugs/hrtb-implied-1.stderr | 4 +- .../bugs/hrtb-implied-2.stderr | 6 ++- .../bugs/hrtb-implied-3.stderr | 4 +- .../normalization-placeholder-leak.fail.stderr | 12 +++++ tests/ui/issues/issue-26217.stderr | 4 +- tests/ui/nll/local-outlives-static-via-hrtb.stderr | 8 +-- ...tion-insensitive-scopes-issue-117146.nll.stderr | 4 +- ...insensitive-scopes-issue-117146.polonius.stderr | 4 +- tests/ui/nll/type-test-universe.stderr | 4 +- .../references/reject_lifetime_extension.stderr | 4 +- 12 files changed, 84 insertions(+), 34 deletions(-) (limited to 'compiler/rustc_borrowck/src') diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs index 995c953fda9..7d7d0abc3f4 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mod.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs @@ -6,7 +6,9 @@ use rustc_abi::{FieldIdx, VariantIdx}; use rustc_data_structures::fx::FxIndexMap; use rustc_errors::{Applicability, Diag, EmissionGuarantee, MultiSpan, listify}; use rustc_hir::def::{CtorKind, Namespace}; -use rustc_hir::{self as hir, CoroutineKind, LangItem}; +use rustc_hir::{ + self as hir, CoroutineKind, GenericBound, LangItem, WhereBoundPredicate, WherePredicateKind, +}; use rustc_index::{IndexSlice, IndexVec}; use rustc_infer::infer::{BoundRegionConversionTime, NllRegionVariableOrigin}; use rustc_infer::traits::SelectionError; @@ -658,25 +660,63 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { /// Add a note to region errors and borrow explanations when higher-ranked regions in predicates /// implicitly introduce an "outlives `'static`" constraint. + /// + /// This is very similar to `fn suggest_static_lifetime_for_gat_from_hrtb` which handles this + /// note for failed type tests instead of outlives errors. fn add_placeholder_from_predicate_note( &self, - err: &mut Diag<'_, G>, + diag: &mut Diag<'_, G>, path: &[OutlivesConstraint<'tcx>], ) { - let predicate_span = path.iter().find_map(|constraint| { + let tcx = self.infcx.tcx; + let Some((gat_hir_id, generics)) = path.iter().find_map(|constraint| { let outlived = constraint.sub; if let Some(origin) = self.regioncx.definitions.get(outlived) - && let NllRegionVariableOrigin::Placeholder(_) = origin.origin - && let ConstraintCategory::Predicate(span) = constraint.category + && let NllRegionVariableOrigin::Placeholder(placeholder) = origin.origin + && let Some(id) = placeholder.bound.kind.get_id() + && let Some(placeholder_id) = id.as_local() + && let gat_hir_id = tcx.local_def_id_to_hir_id(placeholder_id) + && let Some(generics_impl) = + tcx.parent_hir_node(tcx.parent_hir_id(gat_hir_id)).generics() { - Some(span) + Some((gat_hir_id, generics_impl)) } else { None } - }); + }) else { + return; + }; - if let Some(span) = predicate_span { - err.span_note(span, fluent::borrowck_limitations_implies_static); + for pred in generics.predicates { + let WherePredicateKind::BoundPredicate(WhereBoundPredicate { + bound_generic_params, + bounds, + .. + }) = pred.kind + else { + continue; + }; + if bound_generic_params + .iter() + .rfind(|bgp| tcx.local_def_id_to_hir_id(bgp.def_id) == gat_hir_id) + .is_some() + { + diag.span_note(pred.span, fluent::borrowck_limitations_implies_static); + return; + } + for bound in bounds.iter() { + if let GenericBound::Trait(bound) = bound { + if bound + .bound_generic_params + .iter() + .rfind(|bgp| tcx.local_def_id_to_hir_id(bgp.def_id) == gat_hir_id) + .is_some() + { + diag.span_note(bound.span, fluent::borrowck_limitations_implies_static); + return; + } + } + } } } diff --git a/tests/ui/borrowck/implementation-not-general-enough-ice-133252.stderr b/tests/ui/borrowck/implementation-not-general-enough-ice-133252.stderr index 4ec4d2138db..5389226f7a7 100644 --- a/tests/ui/borrowck/implementation-not-general-enough-ice-133252.stderr +++ b/tests/ui/borrowck/implementation-not-general-enough-ice-133252.stderr @@ -22,12 +22,6 @@ LL | force_send(async_load(¬_static)); ... LL | } | - `not_static` dropped here while still borrowed - | -note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/implementation-not-general-enough-ice-133252.rs:16:18 - | -LL | fn force_send(_: T) {} - | ^^^^ error: aborting due to 2 previous errors diff --git a/tests/ui/generic-associated-types/bugs/hrtb-implied-1.stderr b/tests/ui/generic-associated-types/bugs/hrtb-implied-1.stderr index 5dfc42bc873..9e925c33e58 100644 --- a/tests/ui/generic-associated-types/bugs/hrtb-implied-1.stderr +++ b/tests/ui/generic-associated-types/bugs/hrtb-implied-1.stderr @@ -10,10 +10,10 @@ LL | } | - temporary value is freed at the end of this statement | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/hrtb-implied-1.rs:26:26 + --> $DIR/hrtb-implied-1.rs:26:5 | LL | for<'a> I::Item<'a>: Debug, - | ^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/generic-associated-types/bugs/hrtb-implied-2.stderr b/tests/ui/generic-associated-types/bugs/hrtb-implied-2.stderr index 9a1a09b29df..e28b4d7b9ca 100644 --- a/tests/ui/generic-associated-types/bugs/hrtb-implied-2.stderr +++ b/tests/ui/generic-associated-types/bugs/hrtb-implied-2.stderr @@ -15,7 +15,11 @@ LL | let _next = iter2.next(); = note: requirement occurs because of a mutable reference to `Eat<&mut I, F>` = note: mutable references are invariant over their type parameter = help: see for more information about variance - = note: due to current limitations in the borrow checker, this implies a `'static` lifetime +note: due to current limitations in the borrow checker, this implies a `'static` lifetime + --> $DIR/hrtb-implied-2.rs:31:8 + | +LL | F: FnMut(I::Item<'_>), + | ^^^^^^^^^^^^^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/generic-associated-types/bugs/hrtb-implied-3.stderr b/tests/ui/generic-associated-types/bugs/hrtb-implied-3.stderr index 77f363ee87d..36197317b95 100644 --- a/tests/ui/generic-associated-types/bugs/hrtb-implied-3.stderr +++ b/tests/ui/generic-associated-types/bugs/hrtb-implied-3.stderr @@ -12,10 +12,10 @@ LL | trivial_bound(iter); | argument requires that `'1` must outlive `'static` | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/hrtb-implied-3.rs:14:26 + --> $DIR/hrtb-implied-3.rs:14:5 | LL | for<'a> I::Item<'a>: Sized, - | ^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/implied-bounds/normalization-placeholder-leak.fail.stderr b/tests/ui/implied-bounds/normalization-placeholder-leak.fail.stderr index 8919919d04e..8ef77eed5ee 100644 --- a/tests/ui/implied-bounds/normalization-placeholder-leak.fail.stderr +++ b/tests/ui/implied-bounds/normalization-placeholder-leak.fail.stderr @@ -30,6 +30,12 @@ LL | fn test_lifetime<'lt, T: Trait>(_: Foo<&'lt u8>) {} | | | | | lifetime `'lt` defined here | requires that `'lt` must outlive `'static` + | +note: due to current limitations in the borrow checker, this implies a `'static` lifetime + --> $DIR/normalization-placeholder-leak.rs:19:5 + | +LL | for<'x> T::Ty<'x>: Sized; + | ^^^^^^^^^^^^^^^^^^^^^^^^ error: lifetime may not live long enough --> $DIR/normalization-placeholder-leak.rs:38:5 @@ -39,6 +45,12 @@ LL | fn test_alias<'lt, T: AnotherTrait>(_: Foo>) {} | | | | | lifetime `'lt` defined here | requires that `'lt` must outlive `'static` + | +note: due to current limitations in the borrow checker, this implies a `'static` lifetime + --> $DIR/normalization-placeholder-leak.rs:19:5 + | +LL | for<'x> T::Ty<'x>: Sized; + | ^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 6 previous errors diff --git a/tests/ui/issues/issue-26217.stderr b/tests/ui/issues/issue-26217.stderr index 0b153ad7490..dd7e645341a 100644 --- a/tests/ui/issues/issue-26217.stderr +++ b/tests/ui/issues/issue-26217.stderr @@ -7,10 +7,10 @@ LL | foo::<&'a i32>(); | ^^^^^^^^^^^^^^ requires that `'a` must outlive `'static` | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/issue-26217.rs:1:30 + --> $DIR/issue-26217.rs:1:19 | LL | fn foo() where for<'a> T: 'a {} - | ^^ + | ^^^^^^^^^^^^^ error: aborting due to 1 previous error diff --git a/tests/ui/nll/local-outlives-static-via-hrtb.stderr b/tests/ui/nll/local-outlives-static-via-hrtb.stderr index a6b3328b5a2..6aa3fda45e0 100644 --- a/tests/ui/nll/local-outlives-static-via-hrtb.stderr +++ b/tests/ui/nll/local-outlives-static-via-hrtb.stderr @@ -13,10 +13,10 @@ LL | } | - `local` dropped here while still borrowed | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/local-outlives-static-via-hrtb.rs:15:53 + --> $DIR/local-outlives-static-via-hrtb.rs:15:42 | LL | fn assert_static_via_hrtb(_: G) where for<'a> G: Outlives<'a> {} - | ^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^ error[E0597]: `local` does not live long enough --> $DIR/local-outlives-static-via-hrtb.rs:25:45 @@ -33,10 +33,10 @@ LL | } | - `local` dropped here while still borrowed | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/local-outlives-static-via-hrtb.rs:19:20 + --> $DIR/local-outlives-static-via-hrtb.rs:19:5 | LL | for<'a> &'a T: Reference, - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 2 previous errors diff --git a/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.nll.stderr b/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.nll.stderr index 1d086c658df..8ee45b472ea 100644 --- a/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.nll.stderr +++ b/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.nll.stderr @@ -14,10 +14,10 @@ LL | } | - `a` dropped here while still borrowed | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/location-insensitive-scopes-issue-117146.rs:20:22 + --> $DIR/location-insensitive-scopes-issue-117146.rs:20:11 | LL | fn bad &()>(_: F) {} - | ^^^ + | ^^^^^^^^^^^^^^ error: implementation of `Fn` is not general enough --> $DIR/location-insensitive-scopes-issue-117146.rs:13:5 diff --git a/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.polonius.stderr b/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.polonius.stderr index 1d086c658df..8ee45b472ea 100644 --- a/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.polonius.stderr +++ b/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.polonius.stderr @@ -14,10 +14,10 @@ LL | } | - `a` dropped here while still borrowed | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/location-insensitive-scopes-issue-117146.rs:20:22 + --> $DIR/location-insensitive-scopes-issue-117146.rs:20:11 | LL | fn bad &()>(_: F) {} - | ^^^ + | ^^^^^^^^^^^^^^ error: implementation of `Fn` is not general enough --> $DIR/location-insensitive-scopes-issue-117146.rs:13:5 diff --git a/tests/ui/nll/type-test-universe.stderr b/tests/ui/nll/type-test-universe.stderr index 31e17d64b8c..bea18240c35 100644 --- a/tests/ui/nll/type-test-universe.stderr +++ b/tests/ui/nll/type-test-universe.stderr @@ -13,10 +13,10 @@ LL | outlives_forall::>(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static` | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/type-test-universe.rs:6:16 + --> $DIR/type-test-universe.rs:6:5 | LL | for<'u> T: 'u, - | ^^ + | ^^^^^^^^^^^^^ error: aborting due to 2 previous errors diff --git a/tests/ui/transmutability/references/reject_lifetime_extension.stderr b/tests/ui/transmutability/references/reject_lifetime_extension.stderr index a597041c6ca..459e9a02aaa 100644 --- a/tests/ui/transmutability/references/reject_lifetime_extension.stderr +++ b/tests/ui/transmutability/references/reject_lifetime_extension.stderr @@ -68,10 +68,10 @@ LL | unsafe { extend_hrtb(src) } | argument requires that `'a` must outlive `'static` | note: due to current limitations in the borrow checker, this implies a `'static` lifetime - --> $DIR/reject_lifetime_extension.rs:85:25 + --> $DIR/reject_lifetime_extension.rs:85:9 | LL | for<'b> &'b u8: TransmuteFrom<&'a u8>, - | ^^^^^^^^^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 8 previous errors -- cgit 1.4.1-3-g733a5 From 5c716bdc8754a3d919396768fed2ec76110257cd Mon Sep 17 00:00:00 2001 From: lcnr Date: Thu, 7 Aug 2025 12:09:48 +0200 Subject: add comment --- compiler/rustc_borrowck/src/diagnostics/mod.rs | 3 +++ compiler/rustc_borrowck/src/diagnostics/region_errors.rs | 4 +++- 2 files changed, 6 insertions(+), 1 deletion(-) (limited to 'compiler/rustc_borrowck/src') diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs index 7d7d0abc3f4..5642cdf87fd 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mod.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs @@ -687,6 +687,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { return; }; + // Look for the where-bound which introduces the placeholder. + // As we're using the HIR, we need to handle both `for<'a> T: Trait<'a>` + // and `T: for<'a> Trait`<'a>. for pred in generics.predicates { let WherePredicateKind::BoundPredicate(WhereBoundPredicate { bound_generic_params, diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs index cd03daad593..fe4e1b6011e 100644 --- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs @@ -236,7 +236,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { .collect::>(); debug!(?gat_id_and_generics); - // find higher-ranked trait bounds bounded to the generic associated types + // Look for the where-bound which introduces the placeholder. + // As we're using the HIR, we need to handle both `for<'a> T: Trait<'a>` + // and `T: for<'a> Trait`<'a>. let mut hrtb_bounds = vec![]; gat_id_and_generics.iter().flatten().for_each(|&(gat_hir_id, generics)| { for pred in generics.predicates { -- cgit 1.4.1-3-g733a5