diff options
| -rw-r--r-- | src/librustc_traits/lowering.rs | 109 |
1 files changed, 59 insertions, 50 deletions
diff --git a/src/librustc_traits/lowering.rs b/src/librustc_traits/lowering.rs index 36e60cee788..ca785e5e058 100644 --- a/src/librustc_traits/lowering.rs +++ b/src/librustc_traits/lowering.rs @@ -8,14 +8,14 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -use rustc::hir::{self, ImplPolarity}; use rustc::hir::def_id::DefId; use rustc::hir::intravisit::{self, NestedVisitorMap, Visitor}; -use rustc::ty::{self, Slice, TyCtxt}; +use rustc::traits::{Clause, DomainGoal, Goal, PolyDomainGoal, ProgramClause, WhereClauseAtom}; use rustc::ty::subst::Substs; -use rustc::traits::{WhereClauseAtom, PolyDomainGoal, DomainGoal, ProgramClause, Clause, Goal}; -use syntax::ast; +use rustc::ty::{self, Slice, TyCtxt}; use rustc_data_structures::sync::Lrc; +use syntax::ast; +use syntax::ast; use std::iter; @@ -24,7 +24,10 @@ trait Lower<T> { fn lower(&self) -> T; } -impl<T, U> Lower<Vec<U>> for Vec<T> where T: Lower<U> { +impl<T, U> Lower<Vec<U>> for Vec<T> +where + T: Lower<U>, +{ fn lower(&self) -> Vec<U> { self.iter().map(|item| item.lower()).collect() } @@ -42,7 +45,10 @@ impl<'tcx> Lower<WhereClauseAtom<'tcx>> for ty::ProjectionPredicate<'tcx> { } } -impl<'tcx, T> Lower<DomainGoal<'tcx>> for T where T: Lower<WhereClauseAtom<'tcx>> { +impl<'tcx, T> Lower<DomainGoal<'tcx>> for T +where + T: Lower<WhereClauseAtom<'tcx>>, +{ fn lower(&self) -> DomainGoal<'tcx> { DomainGoal::Holds(self.lower()) } @@ -67,7 +73,8 @@ impl<'tcx> Lower<DomainGoal<'tcx>> for ty::TypeOutlivesPredicate<'tcx> { /// `forall<'a> { T: Fn(&'a i32) }` which corresponds to something like /// `Binder<Holds(Implemented(TraitPredicate))>`. impl<'tcx, T> Lower<PolyDomainGoal<'tcx>> for ty::Binder<T> - where T: Lower<DomainGoal<'tcx>> + ty::fold::TypeFoldable<'tcx> +where + T: Lower<DomainGoal<'tcx>> + ty::fold::TypeFoldable<'tcx>, { fn lower(&self) -> PolyDomainGoal<'tcx> { self.map_bound_ref(|p| p.lower()) @@ -84,10 +91,9 @@ impl<'tcx> Lower<PolyDomainGoal<'tcx>> for ty::Predicate<'tcx> { TypeOutlives(predicate) => predicate.lower(), Projection(predicate) => predicate.lower(), WellFormed(ty) => ty::Binder::dummy(DomainGoal::WellFormedTy(*ty)), - ObjectSafe(..) | - ClosureKind(..) | - Subtype(..) | - ConstEvaluatable(..) => unimplemented!(), + ObjectSafe(..) | ClosureKind(..) | Subtype(..) | ConstEvaluatable(..) => { + unimplemented!() + } } } } @@ -104,20 +110,16 @@ impl<'tcx> IntoFromEnvGoal for DomainGoal<'tcx> { use self::DomainGoal::*; match self { Holds(wc_atom) => FromEnv(wc_atom), - WellFormed(..) | - FromEnv(..) | - WellFormedTy(..) | - FromEnvTy(..) | - Normalize(..) | - RegionOutlives(..) | - TypeOutlives(..) => self, + WellFormed(..) | FromEnv(..) | WellFormedTy(..) | FromEnvTy(..) | Normalize(..) + | RegionOutlives(..) | TypeOutlives(..) => self, } } } -crate fn program_clauses_for<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) - -> Lrc<&'tcx Slice<Clause<'tcx>>> -{ +crate fn program_clauses_for<'a, 'tcx>( + tcx: TyCtxt<'a, 'tcx, 'tcx>, + def_id: DefId, +) -> Lrc<&'tcx Slice<Clause<'tcx>>> { let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); let node = tcx.hir.find(node_id).unwrap(); match node { @@ -125,23 +127,24 @@ crate fn program_clauses_for<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefI hir::ItemTrait(..) => program_clauses_for_trait(tcx, def_id), hir::ItemImpl(..) => program_clauses_for_impl(tcx, def_id), _ => Lrc::new(tcx.mk_clauses(iter::empty::<Clause>())), - } + }, hir::map::Node::NodeImplItem(item) => { if let hir::ImplItemKind::Type(..) = item.node { program_clauses_for_associated_type_value(tcx, def_id) } else { Lrc::new(tcx.mk_clauses(iter::empty::<Clause>())) } - }, + } // FIXME: other constructions e.g. traits, associated types... _ => Lrc::new(tcx.mk_clauses(iter::empty::<Clause>())), } } -fn program_clauses_for_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) - -> Lrc<&'tcx Slice<Clause<'tcx>>> -{ +fn program_clauses_for_trait<'a, 'tcx>( + tcx: TyCtxt<'a, 'tcx, 'tcx>, + def_id: DefId, +) -> Lrc<&'tcx Slice<Clause<'tcx>>> { // `trait Trait<P1..Pn> where WC { .. } // P0 == Self` // Rule Implemented-From-Env (see rustc guide) @@ -156,8 +159,8 @@ fn program_clauses_for_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefI let trait_pred = ty::TraitPredicate { trait_ref: ty::TraitRef { def_id, - substs: Substs::identity_for_item(tcx, def_id) - } + substs: Substs::identity_for_item(tcx, def_id), + }, }; // `FromEnv(Self: Trait<P1..Pn>)` let from_env = Goal::from(DomainGoal::FromEnv(trait_pred.lower())); @@ -169,9 +172,7 @@ fn program_clauses_for_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefI goal: impl_trait, hypotheses: tcx.mk_goals(iter::once(from_env)), }; - let clauses = iter::once( - Clause::ForAll(ty::Binder::dummy(implemented_from_env)) - ); + let clauses = iter::once(Clause::ForAll(ty::Binder::dummy(implemented_from_env))); // Rule Implied-Bound-From-Trait // @@ -186,8 +187,8 @@ fn program_clauses_for_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefI // FIXME: Remove the [1..] slice; this is a hack because the query // predicates_of currently includes the trait itself (`Self: Trait<P1..Pn>`). let where_clauses = &tcx.predicates_of(def_id).predicates; - let implied_bound_clauses = - where_clauses[1..].into_iter() + let implied_bound_clauses = where_clauses[1..] + .into_iter() .map(|wc| implied_bound_from_trait(tcx, trait_pred, wc)); Lrc::new(tcx.mk_clauses(clauses.chain(implied_bound_clauses))) @@ -203,17 +204,16 @@ fn implied_bound_from_trait<'a, 'tcx>( let impl_trait = DomainGoal::FromEnv(WhereClauseAtom::Implemented(trait_pred)); // `FromEnv(WC) :- FromEnv(Self: Trait<P1..Pn>)` - Clause::ForAll( - where_clause.lower().map_bound(|goal| ProgramClause { - goal: goal.into_from_env_goal(), - hypotheses: tcx.mk_goals(iter::once(Goal::from(impl_trait))), - }) - ) + Clause::ForAll(where_clause.lower().map_bound(|goal| ProgramClause { + goal: goal.into_from_env_goal(), + hypotheses: tcx.mk_goals(iter::once(Goal::from(impl_trait))), + })) } -fn program_clauses_for_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) - -> Lrc<&'tcx Slice<Clause<'tcx>>> -{ +fn program_clauses_for_impl<'a, 'tcx>( + tcx: TyCtxt<'a, 'tcx, 'tcx>, + def_id: DefId, +) -> Lrc<&'tcx Slice<Clause<'tcx>>> { if let ImplPolarity::Negative = tcx.impl_polarity(def_id) { return Lrc::new(tcx.mk_clauses(iter::empty::<Clause>())); } @@ -231,15 +231,17 @@ fn program_clauses_for_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId let trait_ref = tcx.impl_trait_ref(def_id).unwrap(); // `Implemented(A0: Trait<A1..An>)` let trait_pred = ty::TraitPredicate { trait_ref }.lower(); - // `WC` + // `WC` let where_clauses = tcx.predicates_of(def_id).predicates.lower(); - // `Implemented(A0: Trait<A1..An>) :- WC` + // `Implemented(A0: Trait<A1..An>) :- WC` let clause = ProgramClause { goal: trait_pred, hypotheses: tcx.mk_goals( - where_clauses.into_iter().map(|wc| Goal::from_poly_domain_goal(wc, tcx)) - ) + where_clauses + .into_iter() + .map(|wc| Goal::from_poly_domain_goal(wc, tcx)), + ), }; Lrc::new(tcx.mk_clauses(iter::once(Clause::ForAll(ty::Binder::dummy(clause))))) } @@ -290,7 +292,9 @@ pub fn program_clauses_for_associated_type_value<'a, 'tcx>( let clause = ProgramClause { goal: normalize_goal, hypotheses: tcx.mk_goals( - where_clauses.into_iter().map(|wc| Goal::from_poly_domain_goal(wc, tcx)) + where_clauses + .into_iter() + .map(|wc| Goal::from_poly_domain_goal(wc, tcx)), ), }; Lrc::new(tcx.mk_clauses(iter::once(Clause::ForAll(ty::Binder::dummy(clause))))) @@ -302,14 +306,16 @@ pub fn dump_program_clauses<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { } let mut visitor = ClauseDumper { tcx }; - tcx.hir.krate().visit_all_item_likes(&mut visitor.as_deep_visitor()); + tcx.hir + .krate() + .visit_all_item_likes(&mut visitor.as_deep_visitor()); } struct ClauseDumper<'a, 'tcx: 'a> { tcx: TyCtxt<'a, 'tcx, 'tcx>, } -impl<'a, 'tcx> ClauseDumper<'a, 'tcx > { +impl<'a, 'tcx> ClauseDumper<'a, 'tcx> { fn process_attrs(&mut self, node_id: ast::NodeId, attrs: &[ast::Attribute]) { let def_id = self.tcx.hir.local_def_id(node_id); for attr in attrs { @@ -321,7 +327,10 @@ impl<'a, 'tcx> ClauseDumper<'a, 'tcx > { Clause::Implies(program_clause) => program_clause, Clause::ForAll(program_clause) => program_clause.skip_binder(), }; - self.tcx.sess.struct_span_err(attr.span, &format!("{}", program_clause)).emit(); + self.tcx + .sess + .struct_span_err(attr.span, &format!("{}", program_clause)) + .emit(); } } } |