From 2a73553513f393ab00e2da217ff0082403f1985b Mon Sep 17 00:00:00 2001 From: Bryanskiy Date: Fri, 23 Feb 2024 16:39:57 +0300 Subject: Support ?Trait bounds in supertraits and dyn Trait under a feature gate --- compiler/rustc_hir_analysis/src/check/wfcheck.rs | 2 +- .../rustc_hir_analysis/src/collect/resolve_bound_vars.rs | 2 +- .../rustc_hir_analysis/src/hir_ty_lowering/bounds.rs | 16 +++++++++++----- .../rustc_hir_analysis/src/hir_ty_lowering/errors.rs | 8 ++++---- compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs | 4 ++-- .../src/hir_ty_lowering/object_safety.rs | 9 ++++++--- 6 files changed, 25 insertions(+), 16 deletions(-) (limited to 'compiler/rustc_hir_analysis/src') diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs index 0316ef69bf8..456dc4e4e07 100644 --- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs +++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs @@ -831,7 +831,7 @@ impl<'tcx> TypeVisitor> for GATArgsCollector<'tcx> { fn could_be_self(trait_def_id: LocalDefId, ty: &hir::Ty<'_>) -> bool { match ty.kind { - hir::TyKind::TraitObject([trait_ref], ..) => match trait_ref.trait_ref.path.segments { + hir::TyKind::TraitObject([(trait_ref, _)], ..) => match trait_ref.trait_ref.path.segments { [s] => s.res.opt_def_id() == Some(trait_def_id.to_def_id()), _ => false, }, diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs index 349dc9ad00e..02ea95852f0 100644 --- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs +++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs @@ -652,7 +652,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> { debug!(?bounds, ?lifetime, "TraitObject"); let scope = Scope::TraitRefBoundary { s: self.scope }; self.with(scope, |this| { - for bound in bounds { + for (bound, _) in bounds { this.visit_poly_trait_ref_inner( bound, NonLifetimeBinderAllowed::Deny("trait object types"), diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs index 6f9c481650b..f05884f8912 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs @@ -9,7 +9,7 @@ use rustc_middle::bug; use rustc_middle::ty::print::PrintTraitRefExt as _; use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TyCtxt}; use rustc_span::symbol::Ident; -use rustc_span::{ErrorGuaranteed, Span, Symbol}; +use rustc_span::{sym, ErrorGuaranteed, Span, Symbol}; use rustc_trait_selection::traits; use rustc_type_ir::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor}; use smallvec::SmallVec; @@ -75,10 +75,16 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } } - if unbounds.len() > 1 { - self.dcx().emit_err(errors::MultipleRelaxedDefaultBounds { - spans: unbounds.iter().map(|ptr| ptr.span).collect(), - }); + if unbounds.len() > 1 && !tcx.features().more_maybe_bounds { + self.tcx() + .sess + .create_feature_err( + errors::MultipleRelaxedDefaultBounds { + spans: unbounds.iter().map(|ptr| ptr.span).collect(), + }, + sym::more_maybe_bounds, + ) + .emit(); } let mut seen_sized_unbound = false; diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs index 8ff6ced8b39..e9ec2466089 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs @@ -698,7 +698,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { &self, associated_types: FxIndexMap>, potential_assoc_types: Vec, - trait_bounds: &[hir::PolyTraitRef<'_>], + trait_bounds: &[(hir::PolyTraitRef<'_>, hir::TraitBoundModifier)], ) { if associated_types.values().all(|v| v.is_empty()) { return; @@ -744,12 +744,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // related to issue #91997, turbofishes added only when in an expr or pat let mut in_expr_or_pat = false; if let ([], [bound]) = (&potential_assoc_types[..], &trait_bounds) { - let grandparent = tcx.parent_hir_node(tcx.parent_hir_id(bound.trait_ref.hir_ref_id)); + let grandparent = tcx.parent_hir_node(tcx.parent_hir_id(bound.0.trait_ref.hir_ref_id)); in_expr_or_pat = match grandparent { Node::Expr(_) | Node::Pat(_) => true, _ => false, }; - match bound.trait_ref.path.segments { + match bound.0.trait_ref.path.segments { // FIXME: `trait_ref.path.span` can point to a full path with multiple // segments, even though `trait_ref.path.segments` is of length `1`. Work // around that bug here, even though it should be fixed elsewhere. @@ -790,7 +790,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // and we can then use their span to indicate this to the user. let bound_names = trait_bounds .iter() - .filter_map(|poly_trait_ref| { + .filter_map(|(poly_trait_ref, _)| { let path = poly_trait_ref.trait_ref.path.segments.last()?; let args = path.args?; diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs index 29c71c3fa50..e7aad0a29c5 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs @@ -34,7 +34,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { .ok() .is_some_and(|s| s.trim_end().ends_with('<')); - let is_global = poly_trait_ref.trait_ref.path.is_global(); + let is_global = poly_trait_ref.0.trait_ref.path.is_global(); let mut sugg = vec![( self_ty.span.shrink_to_lo(), @@ -176,7 +176,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let mut is_downgradable = true; let is_object_safe = match self_ty.kind { hir::TyKind::TraitObject(objects, ..) => { - objects.iter().all(|o| match o.trait_ref.path.res { + objects.iter().all(|(o, _)| match o.trait_ref.path.res { Res::Def(DefKind::Trait, id) => { if Some(id) == owner { // For recursive traits, don't downgrade the error. (#119652) diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs index aafadc7f9cb..b3c7a1ff8a8 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/object_safety.rs @@ -27,7 +27,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { &self, span: Span, hir_id: hir::HirId, - hir_trait_bounds: &[hir::PolyTraitRef<'tcx>], + hir_trait_bounds: &[(hir::PolyTraitRef<'tcx>, hir::TraitBoundModifier)], lifetime: &hir::Lifetime, borrowed: bool, representation: DynKind, @@ -37,7 +37,10 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let mut bounds = Bounds::default(); let mut potential_assoc_types = Vec::new(); let dummy_self = self.tcx().types.trait_object_dummy_self; - for trait_bound in hir_trait_bounds.iter().rev() { + for (trait_bound, modifier) in hir_trait_bounds.iter().rev() { + if *modifier == hir::TraitBoundModifier::Maybe { + continue; + } if let GenericArgCountResult { correct: Err(GenericArgCountMismatch { invalid_args: cur_potential_assoc_types, .. }), @@ -249,7 +252,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let args = tcx.mk_args(&args); let span = i.bottom().1; - let empty_generic_args = hir_trait_bounds.iter().any(|hir_bound| { + let empty_generic_args = hir_trait_bounds.iter().any(|(hir_bound, _)| { hir_bound.trait_ref.path.res == Res::Def(DefKind::Trait, trait_ref.def_id) && hir_bound.span.contains(span) }); -- cgit 1.4.1-3-g733a5 From fd9d0bfbacc2d5af183ba394ca16cb2581dab02d Mon Sep 17 00:00:00 2001 From: Bryanskiy Date: Fri, 26 Jul 2024 16:33:30 +0300 Subject: Forbid `?Trait` bounds repetitions --- .../src/hir_ty_lowering/bounds.rs | 26 +++++++++++++--------- .../feature-gate-more-maybe-bounds.rs | 7 ++++++ .../feature-gate-more-maybe-bounds.stderr | 20 ++++++++++++++++- tests/ui/traits/maybe-polarity-repeated.rs | 9 ++++++++ tests/ui/traits/maybe-polarity-repeated.stderr | 21 +++++++++++++++++ 5 files changed, 72 insertions(+), 11 deletions(-) create mode 100644 tests/ui/traits/maybe-polarity-repeated.rs create mode 100644 tests/ui/traits/maybe-polarity-repeated.stderr (limited to 'compiler/rustc_hir_analysis/src') diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs index f05884f8912..9d839908559 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/bounds.rs @@ -75,16 +75,22 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { } } - if unbounds.len() > 1 && !tcx.features().more_maybe_bounds { - self.tcx() - .sess - .create_feature_err( - errors::MultipleRelaxedDefaultBounds { - spans: unbounds.iter().map(|ptr| ptr.span).collect(), - }, - sym::more_maybe_bounds, - ) - .emit(); + let mut unique_bounds = FxIndexSet::default(); + let mut seen_repeat = false; + for unbound in &unbounds { + if let Res::Def(DefKind::Trait, unbound_def_id) = unbound.trait_ref.path.res { + seen_repeat |= !unique_bounds.insert(unbound_def_id); + } + } + if unbounds.len() > 1 { + let err = errors::MultipleRelaxedDefaultBounds { + spans: unbounds.iter().map(|ptr| ptr.span).collect(), + }; + if seen_repeat { + self.dcx().emit_err(err); + } else if !tcx.features().more_maybe_bounds { + self.tcx().sess.create_feature_err(err, sym::more_maybe_bounds).emit(); + }; } let mut seen_sized_unbound = false; diff --git a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs index 4541499b7c7..debe143b091 100644 --- a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs +++ b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.rs @@ -14,4 +14,11 @@ fn bar(_: T) {} //~| WARN relaxing a default bound only does something for `?Sized`; all other traits are not bound by default //~| WARN relaxing a default bound only does something for `?Sized`; all other traits are not bound by default +trait Trait {} +// Do not suggest `#![feature(more_maybe_bounds)]` for repetitions +fn baz(_ : T) {} +//~^ ERROR type parameter has more than one relaxed default bound, only one is supported +//~| WARN relaxing a default bound only does something for `?Sized`; all other traits are not bound by default +//~| WARN relaxing a default bound only does something for `?Sized`; all other traits are not bound by default + fn main() {} diff --git a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr index 2b7a353020a..e6d65e05997 100644 --- a/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr +++ b/tests/ui/feature-gates/feature-gate-more-maybe-bounds.stderr @@ -47,7 +47,25 @@ warning: relaxing a default bound only does something for `?Sized`; all other tr LL | fn bar(_: T) {} | ^^^^^^^ -error: aborting due to 4 previous errors; 2 warnings emitted +error[E0203]: type parameter has more than one relaxed default bound, only one is supported + --> $DIR/feature-gate-more-maybe-bounds.rs:19:11 + | +LL | fn baz(_ : T) {} + | ^^^^^^ ^^^^^^ + +warning: relaxing a default bound only does something for `?Sized`; all other traits are not bound by default + --> $DIR/feature-gate-more-maybe-bounds.rs:19:11 + | +LL | fn baz(_ : T) {} + | ^^^^^^ + +warning: relaxing a default bound only does something for `?Sized`; all other traits are not bound by default + --> $DIR/feature-gate-more-maybe-bounds.rs:19:20 + | +LL | fn baz(_ : T) {} + | ^^^^^^ + +error: aborting due to 5 previous errors; 4 warnings emitted Some errors have detailed explanations: E0203, E0658. For more information about an error, try `rustc --explain E0203`. diff --git a/tests/ui/traits/maybe-polarity-repeated.rs b/tests/ui/traits/maybe-polarity-repeated.rs new file mode 100644 index 00000000000..4b5ec83fffa --- /dev/null +++ b/tests/ui/traits/maybe-polarity-repeated.rs @@ -0,0 +1,9 @@ +#![feature(more_maybe_bounds)] + +trait Trait {} +fn foo(_: T) {} +//~^ ERROR type parameter has more than one relaxed default bound, only one is supported +//~| WARN relaxing a default bound only does something for `?Sized`; all other traits are not bound by default +//~| WARN relaxing a default bound only does something for `?Sized`; all other traits are not bound by default + +fn main() {} diff --git a/tests/ui/traits/maybe-polarity-repeated.stderr b/tests/ui/traits/maybe-polarity-repeated.stderr new file mode 100644 index 00000000000..610c484fbec --- /dev/null +++ b/tests/ui/traits/maybe-polarity-repeated.stderr @@ -0,0 +1,21 @@ +error[E0203]: type parameter has more than one relaxed default bound, only one is supported + --> $DIR/maybe-polarity-repeated.rs:4:11 + | +LL | fn foo(_: T) {} + | ^^^^^^ ^^^^^^ + +warning: relaxing a default bound only does something for `?Sized`; all other traits are not bound by default + --> $DIR/maybe-polarity-repeated.rs:4:11 + | +LL | fn foo(_: T) {} + | ^^^^^^ + +warning: relaxing a default bound only does something for `?Sized`; all other traits are not bound by default + --> $DIR/maybe-polarity-repeated.rs:4:20 + | +LL | fn foo(_: T) {} + | ^^^^^^ + +error: aborting due to 1 previous error; 2 warnings emitted + +For more information about this error, try `rustc --explain E0203`. -- cgit 1.4.1-3-g733a5