From 7aa602b84c93c0f2072e0e1638a1cddcd9637ca4 Mon Sep 17 00:00:00 2001 From: Santiago Pastorino Date: Thu, 3 Dec 2020 20:10:55 -0300 Subject: [PATCH 1/4] Revert "Auto merge of #79637 - spastorino:revert-trait-inheritance-self, r=Mark-Simulacrum" This reverts commit b4def89d76896eec73b4af33642ba7e5eb53c567, reversing changes made to 7dc1e852d43cb8c9e77dc1e53014f0eb85d2ebfb. --- compiler/rustc_infer/src/traits/util.rs | 34 +++- compiler/rustc_middle/src/query/mod.rs | 15 +- compiler/rustc_middle/src/ty/context.rs | 38 +++- compiler/rustc_middle/src/ty/query/keys.rs | 24 ++- .../rustc_trait_selection/src/traits/mod.rs | 3 +- compiler/rustc_typeck/src/astconv/mod.rs | 68 +++++-- .../rustc_typeck/src/check/fn_ctxt/mod.rs | 8 +- compiler/rustc_typeck/src/collect.rs | 185 +++++++++++++----- .../rustc_typeck/src/collect/item_bounds.rs | 4 +- .../incremental/cyclic-trait-hierarchy.rs | 10 +- .../ambiguous-associated-type2.rs | 12 ++ .../ambiguous-associated-type2.stderr | 16 ++ .../associated-item-through-where-clause.rs | 21 ++ ...e-predicates-that-can-define-assoc-type.rs | 10 + .../missing-trait-bound-for-assoc-fails.rs | 10 + ...missing-trait-bound-for-assoc-fails.stderr | 16 ++ .../super-trait-referencing-self.rs | 12 ++ .../super-trait-referencing.rs | 19 ++ .../super-trait-where-referencing-self.rs | 27 +++ .../cycle-projection-based-on-where-clause.rs | 24 --- ...le-projection-based-on-where-clause.stderr | 16 -- .../cycle-trait-supertrait-direct.stderr | 11 +- .../cycle-trait-supertrait-indirect.stderr | 18 +- src/test/ui/issues/issue-12511.stderr | 16 +- src/test/ui/issues/issue-20772.stderr | 6 +- src/test/ui/issues/issue-20825.stderr | 6 +- src/test/ui/issues/issue-22673.rs | 5 +- src/test/ui/issues/issue-22673.stderr | 16 -- 28 files changed, 499 insertions(+), 151 deletions(-) create mode 100644 src/test/ui/associated-type-bounds/ambiguous-associated-type2.rs create mode 100644 src/test/ui/associated-type-bounds/ambiguous-associated-type2.stderr create mode 100644 src/test/ui/associated-type-bounds/associated-item-through-where-clause.rs create mode 100644 src/test/ui/associated-type-bounds/handle-predicates-that-can-define-assoc-type.rs create mode 100644 src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.rs create mode 100644 src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.stderr create mode 100644 src/test/ui/associated-type-bounds/super-trait-referencing-self.rs create mode 100644 src/test/ui/associated-type-bounds/super-trait-referencing.rs create mode 100644 src/test/ui/associated-type-bounds/super-trait-where-referencing-self.rs delete mode 100644 src/test/ui/cycle-projection-based-on-where-clause.rs delete mode 100644 src/test/ui/cycle-projection-based-on-where-clause.stderr delete mode 100644 src/test/ui/issues/issue-22673.stderr diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 13cf1e1083f7f..9b928f55c0276 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -1,9 +1,10 @@ use smallvec::smallvec; use crate::traits::{Obligation, ObligationCause, PredicateObligation}; -use rustc_data_structures::fx::FxHashSet; +use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; use rustc_middle::ty::outlives::Component; use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness}; +use rustc_span::symbol::Ident; pub fn anonymize_predicate<'tcx>( tcx: TyCtxt<'tcx>, @@ -282,6 +283,37 @@ pub fn transitive_bounds<'tcx>( elaborate_trait_refs(tcx, bounds).filter_to_traits() } +/// A specialized variant of `elaborate_trait_refs` that only elaborates trait references that may +/// define the given associated type `assoc_name`. It uses the +/// `super_predicates_that_define_assoc_type` query to avoid enumerating super-predicates that +/// aren't related to `assoc_item`. This is used when resolving types like `Self::Item` or +/// `T::Item` and helps to avoid cycle errors (see e.g. #35237). +pub fn transitive_bounds_that_define_assoc_type<'tcx>( + tcx: TyCtxt<'tcx>, + bounds: impl Iterator>, + assoc_name: Ident, +) -> FxIndexSet> { + let mut stack: Vec<_> = bounds.collect(); + let mut trait_refs = FxIndexSet::default(); + + while let Some(trait_ref) = stack.pop() { + if trait_refs.insert(trait_ref) { + let super_predicates = + tcx.super_predicates_that_define_assoc_type((trait_ref.def_id(), Some(assoc_name))); + for (super_predicate, _) in super_predicates.predicates { + let bound_predicate = super_predicate.bound_atom(); + let subst_predicate = super_predicate + .subst_supertrait(tcx, &bound_predicate.rebind(trait_ref.skip_binder())); + if let Some(binder) = subst_predicate.to_opt_poly_trait_ref() { + stack.push(binder.value); + } + } + } + } + + trait_refs +} + /////////////////////////////////////////////////////////////////////////// // Other /////////////////////////////////////////////////////////////////////////// diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs index ca528b2f0914b..a3040f498ce54 100644 --- a/compiler/rustc_middle/src/query/mod.rs +++ b/compiler/rustc_middle/src/query/mod.rs @@ -443,12 +443,23 @@ rustc_queries! { /// full predicates are available (note that supertraits have /// additional acyclicity requirements). query super_predicates_of(key: DefId) -> ty::GenericPredicates<'tcx> { - desc { |tcx| "computing the supertraits of `{}`", tcx.def_path_str(key) } + desc { |tcx| "computing the super predicates of `{}`", tcx.def_path_str(key) } + } + + /// The `Option` is the name of an associated type. If it is `None`, then this query + /// returns the full set of predicates. If `Some`, then the query returns only the + /// subset of super-predicates that reference traits that define the given associated type. + /// This is used to avoid cycles in resolving types like `T::Item`. + query super_predicates_that_define_assoc_type(key: (DefId, Option)) -> ty::GenericPredicates<'tcx> { + desc { |tcx| "computing the super traits of `{}`{}", + tcx.def_path_str(key.0), + if let Some(assoc_name) = key.1 { format!(" with associated type name `{}`", assoc_name) } else { "".to_string() }, + } } /// To avoid cycles within the predicates of a single item we compute /// per-type-parameter predicates for resolving `T::AssocTy`. - query type_param_predicates(key: (DefId, LocalDefId)) -> ty::GenericPredicates<'tcx> { + query type_param_predicates(key: (DefId, LocalDefId, rustc_span::symbol::Ident)) -> ty::GenericPredicates<'tcx> { desc { |tcx| "computing the bounds for type parameter `{}`", { let id = tcx.hir().local_def_id_to_hir_id(key.1); tcx.hir().ty_param_name(id) diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index 1255302f74384..ea1484aa37cde 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -52,7 +52,7 @@ use rustc_session::config::{BorrowckMode, CrateType, OutputFilenames}; use rustc_session::lint::{Level, Lint}; use rustc_session::Session; use rustc_span::source_map::MultiSpan; -use rustc_span::symbol::{kw, sym, Symbol}; +use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{Span, DUMMY_SP}; use rustc_target::abi::{Layout, TargetDataLayout, VariantIdx}; use rustc_target::spec::abi; @@ -2053,6 +2053,42 @@ impl<'tcx> TyCtxt<'tcx> { self.mk_fn_ptr(sig.map_bound(|sig| ty::FnSig { unsafety: hir::Unsafety::Unsafe, ..sig })) } + /// Given the def_id of a Trait `trait_def_id` and the name of an associated item `assoc_name` + /// returns true if the `trait_def_id` defines an associated item of name `assoc_name`. + pub fn trait_may_define_assoc_type(self, trait_def_id: DefId, assoc_name: Ident) -> bool { + self.super_traits_of(trait_def_id).any(|trait_did| { + self.associated_items(trait_did) + .find_by_name_and_kind(self, assoc_name, ty::AssocKind::Type, trait_did) + .is_some() + }) + } + + /// Computes the def-ids of the transitive super-traits of `trait_def_id`. This (intentionally) + /// does not compute the full elaborated super-predicates but just the set of def-ids. It is used + /// to identify which traits may define a given associated type to help avoid cycle errors. + /// Returns a `DefId` iterator. + fn super_traits_of(self, trait_def_id: DefId) -> impl Iterator + 'tcx { + let mut set = FxHashSet::default(); + let mut stack = vec![trait_def_id]; + + set.insert(trait_def_id); + + iter::from_fn(move || -> Option { + let trait_did = stack.pop()?; + let generic_predicates = self.super_predicates_of(trait_did); + + for (predicate, _) in generic_predicates.predicates { + if let ty::PredicateAtom::Trait(data, _) = predicate.skip_binders() { + if set.insert(data.def_id()) { + stack.push(data.def_id()); + } + } + } + + Some(trait_did) + }) + } + /// Given a closure signature, returns an equivalent fn signature. Detuples /// and so forth -- so e.g., if we have a sig with `Fn<(u32, i32)>` then /// you would get a `fn(u32, i32)`. diff --git a/compiler/rustc_middle/src/ty/query/keys.rs b/compiler/rustc_middle/src/ty/query/keys.rs index bfa1581aaae29..6b4714b1bb8c8 100644 --- a/compiler/rustc_middle/src/ty/query/keys.rs +++ b/compiler/rustc_middle/src/ty/query/keys.rs @@ -7,7 +7,7 @@ use crate::ty::subst::{GenericArg, SubstsRef}; use crate::ty::{self, Ty, TyCtxt}; use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE}; use rustc_query_system::query::DefaultCacheSelector; -use rustc_span::symbol::Symbol; +use rustc_span::symbol::{Ident, Symbol}; use rustc_span::{Span, DUMMY_SP}; /// The `Key` trait controls what types can legally be used as the key @@ -160,6 +160,28 @@ impl Key for (LocalDefId, DefId) { } } +impl Key for (DefId, Option) { + type CacheSelector = DefaultCacheSelector; + + fn query_crate(&self) -> CrateNum { + self.0.krate + } + fn default_span(&self, tcx: TyCtxt<'_>) -> Span { + tcx.def_span(self.0) + } +} + +impl Key for (DefId, LocalDefId, Ident) { + type CacheSelector = DefaultCacheSelector; + + fn query_crate(&self) -> CrateNum { + self.0.krate + } + fn default_span(&self, tcx: TyCtxt<'_>) -> Span { + self.1.default_span(tcx) + } +} + impl Key for (CrateNum, DefId) { type CacheSelector = DefaultCacheSelector; diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index f7c0bafff05b4..0a81b6e105dff 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -65,7 +65,8 @@ pub use self::util::{ get_vtable_index_of_object_method, impl_item_is_final, predicate_for_trait_def, upcast_choices, }; pub use self::util::{ - supertrait_def_ids, supertraits, transitive_bounds, SupertraitDefIds, Supertraits, + supertrait_def_ids, supertraits, transitive_bounds, transitive_bounds_that_define_assoc_type, + SupertraitDefIds, Supertraits, }; pub use self::chalk_fulfill::FulfillmentContext as ChalkFulfillmentContext; diff --git a/compiler/rustc_typeck/src/astconv/mod.rs b/compiler/rustc_typeck/src/astconv/mod.rs index 5659345f0ff9c..244eba8ad5e02 100644 --- a/compiler/rustc_typeck/src/astconv/mod.rs +++ b/compiler/rustc_typeck/src/astconv/mod.rs @@ -49,9 +49,10 @@ pub trait AstConv<'tcx> { fn default_constness_for_trait_bounds(&self) -> Constness; - /// Returns predicates in scope of the form `X: Foo`, where `X` is - /// a type parameter `X` with the given id `def_id`. This is a - /// subset of the full set of predicates. + /// Returns predicates in scope of the form `X: Foo`, where `X` + /// is a type parameter `X` with the given id `def_id` and T + /// matches `assoc_name`. This is a subset of the full set of + /// predicates. /// /// This is used for one specific purpose: resolving "short-hand" /// associated type references like `T::Item`. In principle, we @@ -60,7 +61,12 @@ pub trait AstConv<'tcx> { /// but this can lead to cycle errors. The problem is that we have /// to do this resolution *in order to create the predicates in /// the first place*. Hence, we have this "special pass". - fn get_type_parameter_bounds(&self, span: Span, def_id: DefId) -> ty::GenericPredicates<'tcx>; + fn get_type_parameter_bounds( + &self, + span: Span, + def_id: DefId, + assoc_name: Ident, + ) -> ty::GenericPredicates<'tcx>; /// Returns the lifetime to use when a lifetime is omitted (and not elided). fn re_infer(&self, param: Option<&ty::GenericParamDef>, span: Span) @@ -792,7 +798,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { } // Returns `true` if a bounds list includes `?Sized`. - pub fn is_unsized(&self, ast_bounds: &[hir::GenericBound<'_>], span: Span) -> bool { + pub fn is_unsized(&self, ast_bounds: &[&hir::GenericBound<'_>], span: Span) -> bool { let tcx = self.tcx(); // Try to find an unbound in bounds. @@ -850,7 +856,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { fn add_bounds( &self, param_ty: Ty<'tcx>, - ast_bounds: &[hir::GenericBound<'_>], + ast_bounds: &[&hir::GenericBound<'_>], bounds: &mut Bounds<'tcx>, ) { let constness = self.default_constness_for_trait_bounds(); @@ -865,7 +871,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { hir::GenericBound::Trait(_, hir::TraitBoundModifier::Maybe) => {} hir::GenericBound::LangItemTrait(lang_item, span, hir_id, args) => self .instantiate_lang_item_trait_ref( - lang_item, span, hir_id, args, param_ty, bounds, + *lang_item, *span, *hir_id, args, param_ty, bounds, ), hir::GenericBound::Outlives(ref l) => bounds .region_bounds @@ -896,6 +902,42 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { ast_bounds: &[hir::GenericBound<'_>], sized_by_default: SizedByDefault, span: Span, + ) -> Bounds<'tcx> { + let ast_bounds: Vec<_> = ast_bounds.iter().collect(); + self.compute_bounds_inner(param_ty, &ast_bounds, sized_by_default, span) + } + + /// Convert the bounds in `ast_bounds` that refer to traits which define an associated type + /// named `assoc_name` into ty::Bounds. Ignore the rest. + pub fn compute_bounds_that_match_assoc_type( + &self, + param_ty: Ty<'tcx>, + ast_bounds: &[hir::GenericBound<'_>], + sized_by_default: SizedByDefault, + span: Span, + assoc_name: Ident, + ) -> Bounds<'tcx> { + let mut result = Vec::new(); + + for ast_bound in ast_bounds { + if let Some(trait_ref) = ast_bound.trait_ref() { + if let Some(trait_did) = trait_ref.trait_def_id() { + if self.tcx().trait_may_define_assoc_type(trait_did, assoc_name) { + result.push(ast_bound); + } + } + } + } + + self.compute_bounds_inner(param_ty, &result, sized_by_default, span) + } + + fn compute_bounds_inner( + &self, + param_ty: Ty<'tcx>, + ast_bounds: &[&hir::GenericBound<'_>], + sized_by_default: SizedByDefault, + span: Span, ) -> Bounds<'tcx> { let mut bounds = Bounds::default(); @@ -1098,7 +1140,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { // parameter to have a skipped binder. let param_ty = tcx.mk_projection(assoc_ty.def_id, projection_ty.skip_binder().substs); - self.add_bounds(param_ty, ast_bounds, bounds); + let ast_bounds: Vec<_> = ast_bounds.iter().collect(); + self.add_bounds(param_ty, &ast_bounds, bounds); } } Ok(()) @@ -1413,8 +1456,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { ty_param_def_id, assoc_name, span, ); - let predicates = - &self.get_type_parameter_bounds(span, ty_param_def_id.to_def_id()).predicates; + let predicates = &self + .get_type_parameter_bounds(span, ty_param_def_id.to_def_id(), assoc_name) + .predicates; debug!("find_bound_for_assoc_item: predicates={:#?}", predicates); @@ -1422,12 +1466,14 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { let param_name = tcx.hir().ty_param_name(param_hir_id); self.one_bound_for_assoc_type( || { - traits::transitive_bounds( + traits::transitive_bounds_that_define_assoc_type( tcx, predicates.iter().filter_map(|(p, _)| { p.to_opt_poly_trait_ref().map(|trait_ref| trait_ref.value) }), + assoc_name, ) + .into_iter() }, || param_name.to_string(), assoc_name, diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs b/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs index e9223f700dcc7..4da4835f7cfbb 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/mod.rs @@ -20,6 +20,7 @@ use rustc_middle::ty::fold::TypeFoldable; use rustc_middle::ty::subst::GenericArgKind; use rustc_middle::ty::{self, Const, Ty, TyCtxt}; use rustc_session::Session; +use rustc_span::symbol::Ident; use rustc_span::{self, Span}; use rustc_trait_selection::traits::{ObligationCause, ObligationCauseCode}; @@ -183,7 +184,12 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> { } } - fn get_type_parameter_bounds(&self, _: Span, def_id: DefId) -> ty::GenericPredicates<'tcx> { + fn get_type_parameter_bounds( + &self, + _: Span, + def_id: DefId, + _: Ident, + ) -> ty::GenericPredicates<'tcx> { let tcx = self.tcx; let hir_id = tcx.hir().local_def_id_to_hir_id(def_id.expect_local()); let item_id = tcx.hir().ty_param_owner(hir_id); diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index b1d98d75196d5..1d2449baee4fe 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -1,3 +1,4 @@ +// ignore-tidy-filelength //! "Collection" is the process of determining the type and other external //! details of each item in Rust. Collection is specifically concerned //! with *inter-procedural* things -- for example, for a function @@ -77,6 +78,7 @@ pub fn provide(providers: &mut Providers) { projection_ty_from_predicates, explicit_predicates_of, super_predicates_of, + super_predicates_that_define_assoc_type, trait_explicit_predicates_and_bounds, type_param_predicates, trait_def, @@ -308,8 +310,17 @@ impl AstConv<'tcx> for ItemCtxt<'tcx> { } } - fn get_type_parameter_bounds(&self, span: Span, def_id: DefId) -> ty::GenericPredicates<'tcx> { - self.tcx.at(span).type_param_predicates((self.item_def_id, def_id.expect_local())) + fn get_type_parameter_bounds( + &self, + span: Span, + def_id: DefId, + assoc_name: Ident, + ) -> ty::GenericPredicates<'tcx> { + self.tcx.at(span).type_param_predicates(( + self.item_def_id, + def_id.expect_local(), + assoc_name, + )) } fn re_infer(&self, _: Option<&ty::GenericParamDef>, _: Span) -> Option> { @@ -490,7 +501,7 @@ fn get_new_lifetime_name<'tcx>( /// `X: Foo` where `X` is the type parameter `def_id`. fn type_param_predicates( tcx: TyCtxt<'_>, - (item_def_id, def_id): (DefId, LocalDefId), + (item_def_id, def_id, assoc_name): (DefId, LocalDefId, Ident), ) -> ty::GenericPredicates<'_> { use rustc_hir::*; @@ -515,7 +526,7 @@ fn type_param_predicates( let mut result = parent .map(|parent| { let icx = ItemCtxt::new(tcx, parent); - icx.get_type_parameter_bounds(DUMMY_SP, def_id.to_def_id()) + icx.get_type_parameter_bounds(DUMMY_SP, def_id.to_def_id(), assoc_name) }) .unwrap_or_default(); let mut extend = None; @@ -558,12 +569,18 @@ fn type_param_predicates( let icx = ItemCtxt::new(tcx, item_def_id); let extra_predicates = extend.into_iter().chain( - icx.type_parameter_bounds_in_generics(ast_generics, param_id, ty, OnlySelfBounds(true)) - .into_iter() - .filter(|(predicate, _)| match predicate.kind().skip_binder() { - ty::PredicateKind::Trait(data, _) => data.self_ty().is_param(index), - _ => false, - }), + icx.type_parameter_bounds_in_generics( + ast_generics, + param_id, + ty, + OnlySelfBounds(true), + Some(assoc_name), + ) + .into_iter() + .filter(|(predicate, _)| match predicate.kind().skip_binder() { + ty::PredicateAtom::Trait(data, _) => data.self_ty().is_param(index), + _ => false, + }), ); result.predicates = tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(extra_predicates)); @@ -581,6 +598,7 @@ impl ItemCtxt<'tcx> { param_id: hir::HirId, ty: Ty<'tcx>, only_self_bounds: OnlySelfBounds, + assoc_name: Option, ) -> Vec<(ty::Predicate<'tcx>, Span)> { let constness = self.default_constness_for_trait_bounds(); let from_ty_params = ast_generics @@ -591,6 +609,10 @@ impl ItemCtxt<'tcx> { _ => None, }) .flat_map(|bounds| bounds.iter()) + .filter(|b| match assoc_name { + Some(assoc_name) => self.bound_defines_assoc_item(b, assoc_name), + None => true, + }) .flat_map(|b| predicates_from_bound(self, ty, b, constness)); let from_where_clauses = ast_generics @@ -609,12 +631,34 @@ impl ItemCtxt<'tcx> { } else { None }; - bp.bounds.iter().filter_map(move |b| bt.map(|bt| (bt, b))) + bp.bounds + .iter() + .filter(|b| match assoc_name { + Some(assoc_name) => self.bound_defines_assoc_item(b, assoc_name), + None => true, + }) + .filter_map(move |b| bt.map(|bt| (bt, b))) }) .flat_map(|(bt, b)| predicates_from_bound(self, bt, b, constness)); from_ty_params.chain(from_where_clauses).collect() } + + fn bound_defines_assoc_item(&self, b: &hir::GenericBound<'_>, assoc_name: Ident) -> bool { + debug!("bound_defines_assoc_item(b={:?}, assoc_name={:?})", b, assoc_name); + + match b { + hir::GenericBound::Trait(poly_trait_ref, _) => { + let trait_ref = &poly_trait_ref.trait_ref; + if let Some(trait_did) = trait_ref.trait_def_id() { + self.tcx.trait_may_define_assoc_type(trait_did, assoc_name) + } else { + false + } + } + _ => false, + } + } } /// Tests whether this is the AST for a reference to the type @@ -983,54 +1027,91 @@ fn adt_def(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::AdtDef { /// the transitive super-predicates are converted. fn super_predicates_of(tcx: TyCtxt<'_>, trait_def_id: DefId) -> ty::GenericPredicates<'_> { debug!("super_predicates(trait_def_id={:?})", trait_def_id); - let trait_hir_id = tcx.hir().local_def_id_to_hir_id(trait_def_id.expect_local()); + tcx.super_predicates_that_define_assoc_type((trait_def_id, None)) +} - let item = match tcx.hir().get(trait_hir_id) { - Node::Item(item) => item, - _ => bug!("trait_node_id {} is not an item", trait_hir_id), - }; +/// Ensures that the super-predicates of the trait with a `DefId` +/// of `trait_def_id` are converted and stored. This also ensures that +/// the transitive super-predicates are converted. +fn super_predicates_that_define_assoc_type( + tcx: TyCtxt<'_>, + (trait_def_id, assoc_name): (DefId, Option), +) -> ty::GenericPredicates<'_> { + debug!( + "super_predicates_that_define_assoc_type(trait_def_id={:?}, assoc_name={:?})", + trait_def_id, assoc_name + ); + if trait_def_id.is_local() { + debug!("super_predicates_that_define_assoc_type: local trait_def_id={:?}", trait_def_id); + let trait_hir_id = tcx.hir().local_def_id_to_hir_id(trait_def_id.expect_local()); - let (generics, bounds) = match item.kind { - hir::ItemKind::Trait(.., ref generics, ref supertraits, _) => (generics, supertraits), - hir::ItemKind::TraitAlias(ref generics, ref supertraits) => (generics, supertraits), - _ => span_bug!(item.span, "super_predicates invoked on non-trait"), - }; + let item = match tcx.hir().get(trait_hir_id) { + Node::Item(item) => item, + _ => bug!("trait_node_id {} is not an item", trait_hir_id), + }; - let icx = ItemCtxt::new(tcx, trait_def_id); - - // Convert the bounds that follow the colon, e.g., `Bar + Zed` in `trait Foo: Bar + Zed`. - let self_param_ty = tcx.types.self_param; - let superbounds1 = - AstConv::compute_bounds(&icx, self_param_ty, bounds, SizedByDefault::No, item.span); - - let superbounds1 = superbounds1.predicates(tcx, self_param_ty); - - // Convert any explicit superbounds in the where-clause, - // e.g., `trait Foo where Self: Bar`. - // In the case of trait aliases, however, we include all bounds in the where-clause, - // so e.g., `trait Foo = where u32: PartialEq` would include `u32: PartialEq` - // as one of its "superpredicates". - let is_trait_alias = tcx.is_trait_alias(trait_def_id); - let superbounds2 = icx.type_parameter_bounds_in_generics( - generics, - item.hir_id, - self_param_ty, - OnlySelfBounds(!is_trait_alias), - ); + let (generics, bounds) = match item.kind { + hir::ItemKind::Trait(.., ref generics, ref supertraits, _) => (generics, supertraits), + hir::ItemKind::TraitAlias(ref generics, ref supertraits) => (generics, supertraits), + _ => span_bug!(item.span, "super_predicates invoked on non-trait"), + }; + + let icx = ItemCtxt::new(tcx, trait_def_id); + + // Convert the bounds that follow the colon, e.g., `Bar + Zed` in `trait Foo: Bar + Zed`. + let self_param_ty = tcx.types.self_param; + let superbounds1 = if let Some(assoc_name) = assoc_name { + AstConv::compute_bounds_that_match_assoc_type( + &icx, + self_param_ty, + &bounds, + SizedByDefault::No, + item.span, + assoc_name, + ) + } else { + AstConv::compute_bounds(&icx, self_param_ty, &bounds, SizedByDefault::No, item.span) + }; - // Combine the two lists to form the complete set of superbounds: - let superbounds = &*tcx.arena.alloc_from_iter(superbounds1.into_iter().chain(superbounds2)); + let superbounds1 = superbounds1.predicates(tcx, self_param_ty); + + // Convert any explicit superbounds in the where-clause, + // e.g., `trait Foo where Self: Bar`. + // In the case of trait aliases, however, we include all bounds in the where-clause, + // so e.g., `trait Foo = where u32: PartialEq` would include `u32: PartialEq` + // as one of its "superpredicates". + let is_trait_alias = tcx.is_trait_alias(trait_def_id); + let superbounds2 = icx.type_parameter_bounds_in_generics( + generics, + item.hir_id, + self_param_ty, + OnlySelfBounds(!is_trait_alias), + assoc_name, + ); - // Now require that immediate supertraits are converted, - // which will, in turn, reach indirect supertraits. - for &(pred, span) in superbounds { - debug!("superbound: {:?}", pred); - if let ty::PredicateKind::Trait(bound, _) = pred.kind().skip_binder() { - tcx.at(span).super_predicates_of(bound.def_id()); + // Combine the two lists to form the complete set of superbounds: + let superbounds = &*tcx.arena.alloc_from_iter(superbounds1.into_iter().chain(superbounds2)); + + // Now require that immediate supertraits are converted, + // which will, in turn, reach indirect supertraits. + if assoc_name.is_none() { + // Now require that immediate supertraits are converted, + // which will, in turn, reach indirect supertraits. + for &(pred, span) in superbounds { + debug!("superbound: {:?}", pred); + if let ty::PredicateKind::Trait(bound, _) = pred.kind().skip_binder() { + tcx.at(span).super_predicates_of(bound.def_id()); + } + } } - } - ty::GenericPredicates { parent: None, predicates: superbounds } + ty::GenericPredicates { parent: None, predicates: superbounds } + } else { + // if `assoc_name` is None, then the query should've been redirected to an + // external provider + assert!(assoc_name.is_some()); + tcx.super_predicates_of(trait_def_id) + } } fn trait_def(tcx: TyCtxt<'_>, def_id: DefId) -> ty::TraitDef { diff --git a/compiler/rustc_typeck/src/collect/item_bounds.rs b/compiler/rustc_typeck/src/collect/item_bounds.rs index 537a58328942b..fe18dc5ed0c69 100644 --- a/compiler/rustc_typeck/src/collect/item_bounds.rs +++ b/compiler/rustc_typeck/src/collect/item_bounds.rs @@ -28,7 +28,7 @@ fn associated_type_bounds<'tcx>( let bounds = AstConv::compute_bounds( &ItemCtxt::new(tcx, assoc_item_def_id), item_ty, - bounds, + &bounds, SizedByDefault::Yes, span, ); @@ -69,7 +69,7 @@ fn opaque_type_bounds<'tcx>( let bounds = AstConv::compute_bounds( &ItemCtxt::new(tcx, opaque_def_id), item_ty, - bounds, + &bounds, SizedByDefault::Yes, span, ) diff --git a/src/test/incremental/cyclic-trait-hierarchy.rs b/src/test/incremental/cyclic-trait-hierarchy.rs index 03bb5eea765cc..b502e7207d561 100644 --- a/src/test/incremental/cyclic-trait-hierarchy.rs +++ b/src/test/incremental/cyclic-trait-hierarchy.rs @@ -3,11 +3,11 @@ // revisions: rpass1 cfail2 #[cfg(rpass1)] -pub trait T2 { } +pub trait T2 {} #[cfg(cfail2)] -pub trait T2: T1 { } -//[cfail2]~^ ERROR cycle detected when computing the supertraits of `T2` +pub trait T2: T1 {} +//[cfail2]~^ ERROR cycle detected when computing the super predicates of `T2` -pub trait T1: T2 { } +pub trait T1: T2 {} -fn main() { } +fn main() {} diff --git a/src/test/ui/associated-type-bounds/ambiguous-associated-type2.rs b/src/test/ui/associated-type-bounds/ambiguous-associated-type2.rs new file mode 100644 index 0000000000000..1b6d6d0ff599f --- /dev/null +++ b/src/test/ui/associated-type-bounds/ambiguous-associated-type2.rs @@ -0,0 +1,12 @@ +// ignore-tidy-linelength + +trait Foo { + type Item; +} +trait Bar { + type Item; +} +trait Baz: Foo + Bar {} +//~^ ERROR cycle detected when computing the super traits of `Baz` with associated type name `Item` [E0391] + +fn main() {} diff --git a/src/test/ui/associated-type-bounds/ambiguous-associated-type2.stderr b/src/test/ui/associated-type-bounds/ambiguous-associated-type2.stderr new file mode 100644 index 0000000000000..bda1debeac0d6 --- /dev/null +++ b/src/test/ui/associated-type-bounds/ambiguous-associated-type2.stderr @@ -0,0 +1,16 @@ +error[E0391]: cycle detected when computing the super traits of `Baz` with associated type name `Item` + --> $DIR/ambiguous-associated-type2.rs:9:1 + | +LL | trait Baz: Foo + Bar {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: ...which again requires computing the super traits of `Baz` with associated type name `Item`, completing the cycle +note: cycle used when computing the super traits of `Baz` + --> $DIR/ambiguous-associated-type2.rs:9:1 + | +LL | trait Baz: Foo + Bar {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0391`. diff --git a/src/test/ui/associated-type-bounds/associated-item-through-where-clause.rs b/src/test/ui/associated-type-bounds/associated-item-through-where-clause.rs new file mode 100644 index 0000000000000..3eb50ab554735 --- /dev/null +++ b/src/test/ui/associated-type-bounds/associated-item-through-where-clause.rs @@ -0,0 +1,21 @@ +// check-pass + +trait Foo { + type Item; +} + +trait Bar +where + Self: Foo, +{ +} + +#[allow(dead_code)] +fn foo(_m: M) +where + M: Bar, + M::Item: Send, +{ +} + +fn main() {} diff --git a/src/test/ui/associated-type-bounds/handle-predicates-that-can-define-assoc-type.rs b/src/test/ui/associated-type-bounds/handle-predicates-that-can-define-assoc-type.rs new file mode 100644 index 0000000000000..b1e54ec04493b --- /dev/null +++ b/src/test/ui/associated-type-bounds/handle-predicates-that-can-define-assoc-type.rs @@ -0,0 +1,10 @@ +// check-pass + +trait Foo {} +trait Bar { + type A; + type B; +} +trait Baz: Bar + Foo {} + +fn main() {} diff --git a/src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.rs b/src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.rs new file mode 100644 index 0000000000000..07d0f8f8769e5 --- /dev/null +++ b/src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.rs @@ -0,0 +1,10 @@ +#[allow(dead_code)] +fn foo(_m: M) +where + M::Item: Temp, + //~^ ERROR cannot find trait `Temp` in this scope [E0405] + //~| ERROR associated type `Item` not found for `M` [E0220] +{ +} + +fn main() {} diff --git a/src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.stderr b/src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.stderr new file mode 100644 index 0000000000000..bc2807b03961c --- /dev/null +++ b/src/test/ui/associated-type-bounds/missing-trait-bound-for-assoc-fails.stderr @@ -0,0 +1,16 @@ +error[E0405]: cannot find trait `Temp` in this scope + --> $DIR/missing-trait-bound-for-assoc-fails.rs:4:14 + | +LL | M::Item: Temp, + | ^^^^ not found in this scope + +error[E0220]: associated type `Item` not found for `M` + --> $DIR/missing-trait-bound-for-assoc-fails.rs:4:8 + | +LL | M::Item: Temp, + | ^^^^ associated type `Item` not found + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0220, E0405. +For more information about an error, try `rustc --explain E0220`. diff --git a/src/test/ui/associated-type-bounds/super-trait-referencing-self.rs b/src/test/ui/associated-type-bounds/super-trait-referencing-self.rs new file mode 100644 index 0000000000000..c82ec01f4d61d --- /dev/null +++ b/src/test/ui/associated-type-bounds/super-trait-referencing-self.rs @@ -0,0 +1,12 @@ +// check-pass +trait Foo { + type Bar; +} +trait Qux: Foo + AsRef {} +trait Foo2 {} + +trait Qux2: Foo2 + AsRef { + type Bar; +} + +fn main() {} diff --git a/src/test/ui/associated-type-bounds/super-trait-referencing.rs b/src/test/ui/associated-type-bounds/super-trait-referencing.rs new file mode 100644 index 0000000000000..2e97535157fd2 --- /dev/null +++ b/src/test/ui/associated-type-bounds/super-trait-referencing.rs @@ -0,0 +1,19 @@ +// check-pass + +// The goal of this test is to ensure that T: Bar +// in the where clause does not cycle + +trait Foo { + type Item; +} + +trait Bar {} + +fn baz() +where + T: Foo, + T: Bar, +{ +} + +fn main() {} diff --git a/src/test/ui/associated-type-bounds/super-trait-where-referencing-self.rs b/src/test/ui/associated-type-bounds/super-trait-where-referencing-self.rs new file mode 100644 index 0000000000000..72a6be9ffc388 --- /dev/null +++ b/src/test/ui/associated-type-bounds/super-trait-where-referencing-self.rs @@ -0,0 +1,27 @@ +// check-pass + +// Test that we do not get a cycle due to +// resolving `Self::Bar` in the where clauses +// on a trait definition (in particular, in +// a where clause that is defining a superpredicate). + +trait Foo { + type Bar; +} +trait Qux +where + Self: Foo, + Self: AsRef, +{ +} +trait Foo2 {} + +trait Qux2 +where + Self: Foo2, + Self: AsRef, +{ + type Bar; +} + +fn main() {} diff --git a/src/test/ui/cycle-projection-based-on-where-clause.rs b/src/test/ui/cycle-projection-based-on-where-clause.rs deleted file mode 100644 index d3609acfdff63..0000000000000 --- a/src/test/ui/cycle-projection-based-on-where-clause.rs +++ /dev/null @@ -1,24 +0,0 @@ -// Example cycle where a bound on `T` uses a shorthand for `T`. This -// creates a cycle because we have to know the bounds on `T` to figure -// out what trait defines `Item`, but we can't know the bounds on `T` -// without knowing how to handle `T::Item`. -// -// Note that in the future cases like this could perhaps become legal, -// if we got more fine-grained about our cycle detection or changed -// how we handle `T::Item` resolution. - -use std::ops::Add; - -// Preamble. -trait Trait { type Item; } - -struct A - where T : Trait, - T : Add - //~^ ERROR cycle detected -{ - data: T -} - -fn main() { -} diff --git a/src/test/ui/cycle-projection-based-on-where-clause.stderr b/src/test/ui/cycle-projection-based-on-where-clause.stderr deleted file mode 100644 index 2c337cc6bf903..0000000000000 --- a/src/test/ui/cycle-projection-based-on-where-clause.stderr +++ /dev/null @@ -1,16 +0,0 @@ -error[E0391]: cycle detected when computing the bounds for type parameter `T` - --> $DIR/cycle-projection-based-on-where-clause.rs:17:19 - | -LL | T : Add - | ^^^^^^^ - | - = note: ...which again requires computing the bounds for type parameter `T`, completing the cycle -note: cycle used when computing explicit predicates of `A` - --> $DIR/cycle-projection-based-on-where-clause.rs:17:19 - | -LL | T : Add - | ^^^^^^^ - -error: aborting due to previous error - -For more information about this error, try `rustc --explain E0391`. diff --git a/src/test/ui/cycle-trait/cycle-trait-supertrait-direct.stderr b/src/test/ui/cycle-trait/cycle-trait-supertrait-direct.stderr index 8aa3ac8abf52c..ee54b2fd151d7 100644 --- a/src/test/ui/cycle-trait/cycle-trait-supertrait-direct.stderr +++ b/src/test/ui/cycle-trait/cycle-trait-supertrait-direct.stderr @@ -1,10 +1,15 @@ -error[E0391]: cycle detected when computing the supertraits of `Chromosome` +error[E0391]: cycle detected when computing the super predicates of `Chromosome` + --> $DIR/cycle-trait-supertrait-direct.rs:3:1 + | +LL | trait Chromosome: Chromosome { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: ...which requires computing the super traits of `Chromosome`... --> $DIR/cycle-trait-supertrait-direct.rs:3:19 | LL | trait Chromosome: Chromosome { | ^^^^^^^^^^ - | - = note: ...which again requires computing the supertraits of `Chromosome`, completing the cycle + = note: ...which again requires computing the super predicates of `Chromosome`, completing the cycle note: cycle used when collecting item types in top-level module --> $DIR/cycle-trait-supertrait-direct.rs:3:1 | diff --git a/src/test/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr b/src/test/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr index 9740f43a4ba97..0a2284e0efbca 100644 --- a/src/test/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr +++ b/src/test/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr @@ -1,16 +1,26 @@ -error[E0391]: cycle detected when computing the supertraits of `B` +error[E0391]: cycle detected when computing the super predicates of `B` + --> $DIR/cycle-trait-supertrait-indirect.rs:7:1 + | +LL | trait B: C { + | ^^^^^^^^^^ + | +note: ...which requires computing the super traits of `B`... --> $DIR/cycle-trait-supertrait-indirect.rs:7:10 | LL | trait B: C { | ^ +note: ...which requires computing the super predicates of `C`... + --> $DIR/cycle-trait-supertrait-indirect.rs:11:1 | -note: ...which requires computing the supertraits of `C`... +LL | trait C: B { } + | ^^^^^^^^^^ +note: ...which requires computing the super traits of `C`... --> $DIR/cycle-trait-supertrait-indirect.rs:11:10 | LL | trait C: B { } | ^ - = note: ...which again requires computing the supertraits of `B`, completing the cycle -note: cycle used when computing the supertraits of `A` + = note: ...which again requires computing the super predicates of `B`, completing the cycle +note: cycle used when computing the super traits of `A` --> $DIR/cycle-trait-supertrait-indirect.rs:4:10 | LL | trait A: B { diff --git a/src/test/ui/issues/issue-12511.stderr b/src/test/ui/issues/issue-12511.stderr index 37e38ff60ae4b..5f2b98c5237db 100644 --- a/src/test/ui/issues/issue-12511.stderr +++ b/src/test/ui/issues/issue-12511.stderr @@ -1,15 +1,25 @@ -error[E0391]: cycle detected when computing the supertraits of `T1` +error[E0391]: cycle detected when computing the super predicates of `T1` + --> $DIR/issue-12511.rs:1:1 + | +LL | trait T1 : T2 { + | ^^^^^^^^^^^^^ + | +note: ...which requires computing the super traits of `T1`... --> $DIR/issue-12511.rs:1:12 | LL | trait T1 : T2 { | ^^ +note: ...which requires computing the super predicates of `T2`... + --> $DIR/issue-12511.rs:5:1 | -note: ...which requires computing the supertraits of `T2`... +LL | trait T2 : T1 { + | ^^^^^^^^^^^^^ +note: ...which requires computing the super traits of `T2`... --> $DIR/issue-12511.rs:5:12 | LL | trait T2 : T1 { | ^^ - = note: ...which again requires computing the supertraits of `T1`, completing the cycle + = note: ...which again requires computing the super predicates of `T1`, completing the cycle note: cycle used when collecting item types in top-level module --> $DIR/issue-12511.rs:1:1 | diff --git a/src/test/ui/issues/issue-20772.stderr b/src/test/ui/issues/issue-20772.stderr index d64636310a368..4aecc7eab4628 100644 --- a/src/test/ui/issues/issue-20772.stderr +++ b/src/test/ui/issues/issue-20772.stderr @@ -1,4 +1,4 @@ -error[E0391]: cycle detected when computing the supertraits of `T` +error[E0391]: cycle detected when computing the super traits of `T` with associated type name `Item` --> $DIR/issue-20772.rs:1:1 | LL | / trait T : Iterator @@ -6,8 +6,8 @@ LL | | LL | | {} | |__^ | - = note: ...which again requires computing the supertraits of `T`, completing the cycle -note: cycle used when collecting item types in top-level module + = note: ...which again requires computing the super traits of `T` with associated type name `Item`, completing the cycle +note: cycle used when computing the super traits of `T` --> $DIR/issue-20772.rs:1:1 | LL | / trait T : Iterator diff --git a/src/test/ui/issues/issue-20825.stderr b/src/test/ui/issues/issue-20825.stderr index 5f9709d1c649b..ccbe06d9c0d56 100644 --- a/src/test/ui/issues/issue-20825.stderr +++ b/src/test/ui/issues/issue-20825.stderr @@ -1,11 +1,11 @@ -error[E0391]: cycle detected when computing the supertraits of `Processor` +error[E0391]: cycle detected when computing the super traits of `Processor` with associated type name `Input` --> $DIR/issue-20825.rs:5:1 | LL | pub trait Processor: Subscriber { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | - = note: ...which again requires computing the supertraits of `Processor`, completing the cycle -note: cycle used when collecting item types in top-level module + = note: ...which again requires computing the super traits of `Processor` with associated type name `Input`, completing the cycle +note: cycle used when computing the super traits of `Processor` --> $DIR/issue-20825.rs:5:1 | LL | pub trait Processor: Subscriber { diff --git a/src/test/ui/issues/issue-22673.rs b/src/test/ui/issues/issue-22673.rs index ba8057b684de8..4b9b4d6b23da4 100644 --- a/src/test/ui/issues/issue-22673.rs +++ b/src/test/ui/issues/issue-22673.rs @@ -1,5 +1,6 @@ -trait Expr : PartialEq { - //~^ ERROR: cycle detected +// check-pass + +trait Expr: PartialEq { type Item; } diff --git a/src/test/ui/issues/issue-22673.stderr b/src/test/ui/issues/issue-22673.stderr deleted file mode 100644 index 9e7e4b218b1c6..0000000000000 --- a/src/test/ui/issues/issue-22673.stderr +++ /dev/null @@ -1,16 +0,0 @@ -error[E0391]: cycle detected when computing the supertraits of `Expr` - --> $DIR/issue-22673.rs:1:1 - | -LL | trait Expr : PartialEq { - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | - = note: ...which again requires computing the supertraits of `Expr`, completing the cycle -note: cycle used when collecting item types in top-level module - --> $DIR/issue-22673.rs:1:1 - | -LL | trait Expr : PartialEq { - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -error: aborting due to previous error - -For more information about this error, try `rustc --explain E0391`. From 7b6998798548a4b87a0c65655522802d81387fba Mon Sep 17 00:00:00 2001 From: Santiago Pastorino Date: Tue, 2 Feb 2021 13:34:08 -0300 Subject: [PATCH 2/4] Add regression test for ICE that happened on incr comp An ICE happened when certain code is compiled in incremental compilation mode and there are two `Ident`s that have the same `StableHash` value but are considered different by `Eq` and `Hash`. The `Ident` issue is now fixed. --- .../traits-assoc-type-macros.rs | 43 +++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 src/test/ui/associated-type-bounds/traits-assoc-type-macros.rs diff --git a/src/test/ui/associated-type-bounds/traits-assoc-type-macros.rs b/src/test/ui/associated-type-bounds/traits-assoc-type-macros.rs new file mode 100644 index 0000000000000..ad5c6aed97c2c --- /dev/null +++ b/src/test/ui/associated-type-bounds/traits-assoc-type-macros.rs @@ -0,0 +1,43 @@ +// check-pass +// compile-flags:-Cincremental=tmp/traits-assoc-type-macros + +// This test case makes sure that we can compile with incremental compilation +// enabled when there are macros, traits, inheritance and associated types involved. + +trait Deserializer { + type Error; +} + +trait Deserialize { + fn deserialize(_: D) -> D::Error + where + D: Deserializer; +} + +macro_rules! impl_deserialize { + ($name:ident) => { + impl Deserialize for $name { + fn deserialize(_: D) -> D::Error + where + D: Deserializer, + { + loop {} + } + } + }; +} + +macro_rules! formats { + { + $($name:ident,)* + } => { + $( + pub struct $name; + + impl_deserialize!($name); + )* + } +} +formats! { Foo, Bar, } + +fn main() {} From fd092557ceb36998dc93aa46a797745c58f1969f Mon Sep 17 00:00:00 2001 From: Santiago Pastorino Date: Tue, 2 Feb 2021 13:52:01 -0300 Subject: [PATCH 3/4] Adapt to latest master changes by using PredicateKind --- compiler/rustc_infer/src/traits/util.rs | 2 +- compiler/rustc_middle/src/ty/context.rs | 2 +- compiler/rustc_typeck/src/collect.rs | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 9b928f55c0276..8a1035707fe45 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -301,7 +301,7 @@ pub fn transitive_bounds_that_define_assoc_type<'tcx>( let super_predicates = tcx.super_predicates_that_define_assoc_type((trait_ref.def_id(), Some(assoc_name))); for (super_predicate, _) in super_predicates.predicates { - let bound_predicate = super_predicate.bound_atom(); + let bound_predicate = super_predicate.kind(); let subst_predicate = super_predicate .subst_supertrait(tcx, &bound_predicate.rebind(trait_ref.skip_binder())); if let Some(binder) = subst_predicate.to_opt_poly_trait_ref() { diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index ea1484aa37cde..f83056ebe2a45 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -2078,7 +2078,7 @@ impl<'tcx> TyCtxt<'tcx> { let generic_predicates = self.super_predicates_of(trait_did); for (predicate, _) in generic_predicates.predicates { - if let ty::PredicateAtom::Trait(data, _) = predicate.skip_binders() { + if let ty::PredicateKind::Trait(data, _) = predicate.kind().skip_binder() { if set.insert(data.def_id()) { stack.push(data.def_id()); } diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index 1d2449baee4fe..e5045f906df59 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -578,7 +578,7 @@ fn type_param_predicates( ) .into_iter() .filter(|(predicate, _)| match predicate.kind().skip_binder() { - ty::PredicateAtom::Trait(data, _) => data.self_ty().is_param(index), + ty::PredicateKind::Trait(data, _) => data.self_ty().is_param(index), _ => false, }), ); From 8d17c6a85d6530d446d1cb42ee6636c5c9fbfaaf Mon Sep 17 00:00:00 2001 From: Santiago Pastorino Date: Fri, 5 Feb 2021 15:52:57 -0300 Subject: [PATCH 4/4] Anonymize late bound regions on transitive bounds that define assoc type --- compiler/rustc_infer/src/traits/util.rs | 37 +++++++++++-------- .../traits-assoc-anonymized.rs | 33 +++++++++++++++++ 2 files changed, 55 insertions(+), 15 deletions(-) create mode 100644 src/test/ui/associated-type-bounds/traits-assoc-anonymized.rs diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index 8a1035707fe45..87684c2715f4e 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -292,26 +292,33 @@ pub fn transitive_bounds_that_define_assoc_type<'tcx>( tcx: TyCtxt<'tcx>, bounds: impl Iterator>, assoc_name: Ident, -) -> FxIndexSet> { +) -> impl Iterator> { let mut stack: Vec<_> = bounds.collect(); - let mut trait_refs = FxIndexSet::default(); - - while let Some(trait_ref) = stack.pop() { - if trait_refs.insert(trait_ref) { - let super_predicates = - tcx.super_predicates_that_define_assoc_type((trait_ref.def_id(), Some(assoc_name))); - for (super_predicate, _) in super_predicates.predicates { - let bound_predicate = super_predicate.kind(); - let subst_predicate = super_predicate - .subst_supertrait(tcx, &bound_predicate.rebind(trait_ref.skip_binder())); - if let Some(binder) = subst_predicate.to_opt_poly_trait_ref() { - stack.push(binder.value); + let mut visited = FxIndexSet::default(); + + std::iter::from_fn(move || { + while let Some(trait_ref) = stack.pop() { + let anon_trait_ref = tcx.anonymize_late_bound_regions(trait_ref); + if visited.insert(anon_trait_ref) { + let super_predicates = tcx.super_predicates_that_define_assoc_type(( + trait_ref.def_id(), + Some(assoc_name), + )); + for (super_predicate, _) in super_predicates.predicates { + let bound_predicate = super_predicate.kind(); + let subst_predicate = super_predicate + .subst_supertrait(tcx, &bound_predicate.rebind(trait_ref.skip_binder())); + if let Some(binder) = subst_predicate.to_opt_poly_trait_ref() { + stack.push(binder.value); + } } + + return Some(trait_ref); } } - } - trait_refs + return None; + }) } /////////////////////////////////////////////////////////////////////////// diff --git a/src/test/ui/associated-type-bounds/traits-assoc-anonymized.rs b/src/test/ui/associated-type-bounds/traits-assoc-anonymized.rs new file mode 100644 index 0000000000000..a9d6eed810a6b --- /dev/null +++ b/src/test/ui/associated-type-bounds/traits-assoc-anonymized.rs @@ -0,0 +1,33 @@ +// check-pass + +pub struct LookupInternedStorage; + +impl QueryStorageOps for LookupInternedStorage +where + Q: Query, + for<'d> Q: QueryDb<'d>, +{ + fn fmt_index(&self, db: &>::DynDb) { + <>::DynDb as HasQueryGroup>::group_storage(db); + } +} + +pub trait HasQueryGroup { + fn group_storage(&self); +} + +pub trait QueryStorageOps +where + Q: Query, +{ + fn fmt_index(&self, db: &>::DynDb); +} + +pub trait QueryDb<'d> { + type DynDb: HasQueryGroup + 'd; + type Group; +} + +pub trait Query: for<'d> QueryDb<'d> {} + +fn main() {}