From 13efaf0481275dba18f1d18f4b59b664b2d2031a Mon Sep 17 00:00:00 2001 From: Niko Matsakis Date: Mon, 17 Jul 2017 16:16:14 -0400 Subject: [PATCH] add universes to type inference variables --- src/librustc/infer/anon_types/mod.rs | 3 +- src/librustc/infer/combine.rs | 4 +-- src/librustc/infer/fudge.rs | 6 +++- src/librustc/infer/lattice.rs | 12 ++++--- src/librustc/infer/mod.rs | 23 ++++++++----- src/librustc/infer/type_variable.rs | 30 ++++++++++++++--- src/librustc/traits/coherence.rs | 4 ++- src/librustc/traits/error_reporting.rs | 17 +++++++--- src/librustc/traits/project.rs | 2 ++ src/librustc/traits/select.rs | 3 +- src/librustc/traits/specialize/mod.rs | 2 +- src/librustc_typeck/check/_match.rs | 11 ++++-- src/librustc_typeck/check/closure.rs | 3 +- src/librustc_typeck/check/coercion.rs | 3 +- src/librustc_typeck/check/dropck.rs | 2 +- src/librustc_typeck/check/method/confirm.rs | 4 +-- src/librustc_typeck/check/method/mod.rs | 2 +- src/librustc_typeck/check/method/probe.rs | 7 ++-- src/librustc_typeck/check/method/suggest.rs | 3 +- src/librustc_typeck/check/mod.rs | 37 +++++++++++++-------- src/librustc_typeck/check/op.rs | 9 +++-- 21 files changed, 132 insertions(+), 55 deletions(-) diff --git a/src/librustc/infer/anon_types/mod.rs b/src/librustc/infer/anon_types/mod.rs index a749d0dddd7ee..eb26f0c1188bf 100644 --- a/src/librustc/infer/anon_types/mod.rs +++ b/src/librustc/infer/anon_types/mod.rs @@ -600,7 +600,8 @@ impl<'a, 'gcx, 'tcx> Instantiator<'a, 'gcx, 'tcx> { return anon_defn.concrete_ty; } let span = tcx.def_span(def_id); - let ty_var = infcx.next_ty_var(TypeVariableOrigin::TypeInference(span)); + let ty_var = infcx.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(span)); let predicates_of = tcx.predicates_of(def_id); let bounds = predicates_of.instantiate(tcx, substs); diff --git a/src/librustc/infer/combine.rs b/src/librustc/infer/combine.rs index 44a848d3cc6e3..469cb4591124e 100644 --- a/src/librustc/infer/combine.rs +++ b/src/librustc/infer/combine.rs @@ -407,7 +407,7 @@ impl<'cx, 'gcx, 'tcx> TypeRelation<'cx, 'gcx, 'tcx> for Generalizer<'cx, 'gcx, ' drop(variables); self.relate(&u, &u) } - TypeVariableValue::Unknown { .. } => { + TypeVariableValue::Unknown { universe } => { match self.ambient_variance { // Invariant: no need to make a fresh type variable. ty::Invariant => return Ok(t), @@ -424,7 +424,7 @@ impl<'cx, 'gcx, 'tcx> TypeRelation<'cx, 'gcx, 'tcx> for Generalizer<'cx, 'gcx, ' } let origin = *variables.var_origin(vid); - let new_var_id = variables.new_var(false, origin); + let new_var_id = variables.new_var(universe, false, origin); let u = self.tcx().mk_var(new_var_id); debug!("generalize: replacing original vid={:?} with new={:?}", vid, u); diff --git a/src/librustc/infer/fudge.rs b/src/librustc/infer/fudge.rs index 961dd70a46852..48eb253415cdf 100644 --- a/src/librustc/infer/fudge.rs +++ b/src/librustc/infer/fudge.rs @@ -141,7 +141,11 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for RegionFudger<'a, 'gcx, 'tcx> { // This variable was created during the // fudging. Recreate it with a fresh variable // here. - self.infcx.next_ty_var(origin) + // + // The ROOT universe is fine because we only + // ever invoke this routine at the + // "item-level" of inference. + self.infcx.next_ty_var(ty::UniverseIndex::ROOT, origin) } } } diff --git a/src/librustc/infer/lattice.rs b/src/librustc/infer/lattice.rs index 28aba51ab3724..c4722f9a7f96c 100644 --- a/src/librustc/infer/lattice.rs +++ b/src/librustc/infer/lattice.rs @@ -88,13 +88,17 @@ pub fn super_lattice_tys<'a, 'gcx, 'tcx, L>(this: &mut L, // is (e.g.) `Box`. A more obvious solution might be to // iterate on the subtype obligations that are returned, but I // think this suffices. -nmatsakis - (&ty::TyInfer(TyVar(..)), _) => { - let v = infcx.next_ty_var(TypeVariableOrigin::LatticeVariable(this.cause().span)); + (&ty::TyInfer(TyVar(a_vid)), _) => { + let universe = infcx.type_variables.borrow_mut().probe(a_vid).universe().unwrap(); + let v = infcx.next_ty_var(universe, + TypeVariableOrigin::LatticeVariable(this.cause().span)); this.relate_bound(v, b, a)?; Ok(v) } - (_, &ty::TyInfer(TyVar(..))) => { - let v = infcx.next_ty_var(TypeVariableOrigin::LatticeVariable(this.cause().span)); + (_, &ty::TyInfer(TyVar(b_vid))) => { + let universe = infcx.type_variables.borrow_mut().probe(b_vid).universe().unwrap(); + let v = infcx.next_ty_var(universe, + TypeVariableOrigin::LatticeVariable(this.cause().span)); this.relate_bound(v, a, b)?; Ok(v) } diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs index 9b856f94c5615..58026007320d0 100644 --- a/src/librustc/infer/mod.rs +++ b/src/librustc/infer/mod.rs @@ -1015,18 +1015,22 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { }) } - pub fn next_ty_var_id(&self, diverging: bool, origin: TypeVariableOrigin) -> TyVid { + pub fn next_ty_var_id(&self, + universe: ty::UniverseIndex, + diverging: bool, + origin: TypeVariableOrigin) + -> TyVid { self.type_variables .borrow_mut() - .new_var(diverging, origin) + .new_var(universe, diverging, origin) } - pub fn next_ty_var(&self, origin: TypeVariableOrigin) -> Ty<'tcx> { - self.tcx.mk_var(self.next_ty_var_id(false, origin)) + pub fn next_ty_var(&self, universe: ty::UniverseIndex, origin: TypeVariableOrigin) -> Ty<'tcx> { + self.tcx.mk_var(self.next_ty_var_id(universe, false, origin)) } - pub fn next_diverging_ty_var(&self, origin: TypeVariableOrigin) -> Ty<'tcx> { - self.tcx.mk_var(self.next_ty_var_id(true, origin)) + pub fn next_diverging_ty_var(&self, universe: ty::UniverseIndex, origin: TypeVariableOrigin) -> Ty<'tcx> { + self.tcx.mk_var(self.next_ty_var_id(universe, true, origin)) } pub fn next_int_var_id(&self) -> IntVid { @@ -1081,12 +1085,14 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { /// use an inference variable for `C` with `[T, U]` /// as the substitutions for the default, `(T, U)`. pub fn type_var_for_def(&self, + universe: ty::UniverseIndex, span: Span, def: &ty::TypeParameterDef) -> Ty<'tcx> { let ty_var_id = self.type_variables .borrow_mut() - .new_var(false, + .new_var(universe, + false, TypeVariableOrigin::TypeParameterDefinition(span, def.name)); self.tcx.mk_var(ty_var_id) @@ -1095,13 +1101,14 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { /// Given a set of generics defined on a type or impl, returns a substitution mapping each /// type/region parameter to a fresh inference variable. pub fn fresh_substs_for_item(&self, + universe: ty::UniverseIndex, span: Span, def_id: DefId) -> &'tcx Substs<'tcx> { Substs::for_item(self.tcx, def_id, |def, _| { self.region_var_for_def(span, def) }, |def, _| { - self.type_var_for_def(span, def) + self.type_var_for_def(universe, span, def) }) } diff --git a/src/librustc/infer/type_variable.rs b/src/librustc/infer/type_variable.rs index 9b9e9fa0015fa..5daac988f80b7 100644 --- a/src/librustc/infer/type_variable.rs +++ b/src/librustc/infer/type_variable.rs @@ -12,6 +12,7 @@ use syntax::ast; use syntax_pos::Span; use ty::{self, Ty}; +use std::cmp; use std::marker::PhantomData; use std::u32; use rustc_data_structures::fx::FxHashMap; @@ -81,10 +82,18 @@ struct TypeVariableData { #[derive(Copy, Clone, Debug)] pub enum TypeVariableValue<'tcx> { Known { value: Ty<'tcx> }, - Unknown, + Unknown { universe: ty::UniverseIndex }, +} + +#[derive(Copy, Clone, Debug)] +pub enum ProbeTyValue<'tcx> { + Ty(Ty<'tcx>), + Vid(ty::TyVid), } impl<'tcx> TypeVariableValue<'tcx> { + /// If this value is known, returns the type it is known to be. + /// Otherwise, `None`. pub fn known(&self) -> Option> { match *self { TypeVariableValue::Unknown { .. } => None, @@ -92,6 +101,14 @@ impl<'tcx> TypeVariableValue<'tcx> { } } + /// If this value is unknown, returns the universe, otherwise `None`. + pub fn universe(&self) -> Option { + match *self { + TypeVariableValue::Unknown { universe } => Some(universe), + TypeVariableValue::Known { .. } => None, + } + } + pub fn is_unknown(&self) -> bool { match *self { TypeVariableValue::Unknown { .. } => true, @@ -178,10 +195,11 @@ impl<'tcx> TypeVariableTable<'tcx> { /// The code in this module doesn't care, but it can be useful /// for improving error messages. pub fn new_var(&mut self, + universe: ty::UniverseIndex, diverging: bool, origin: TypeVariableOrigin) -> ty::TyVid { - let eq_key = self.eq_relations.new_key(TypeVariableValue::Unknown); + let eq_key = self.eq_relations.new_key(TypeVariableValue::Unknown { universe }); let sub_key = self.sub_relations.new_key(()); assert_eq!(eq_key.vid, sub_key); @@ -388,8 +406,12 @@ impl<'tcx> ut::UnifyValue for TypeVariableValue<'tcx> { (&TypeVariableValue::Known { .. }, &TypeVariableValue::Unknown { .. }) => Ok(*value1), (&TypeVariableValue::Unknown { .. }, &TypeVariableValue::Known { .. }) => Ok(*value2), - // If both sides are *unknown*, it hardly matters, does it? - (&TypeVariableValue::Unknown, &TypeVariableValue::Unknown) => Ok(*value1), + // If both sides are unknown, we need to pick the most restrictive universe. + (&TypeVariableValue::Unknown { universe: universe1 }, + &TypeVariableValue::Unknown { universe: universe2 }) => { + let universe = cmp::min(universe1, universe2); + Ok(TypeVariableValue::Unknown { universe }) + } } } } diff --git a/src/librustc/traits/coherence.rs b/src/librustc/traits/coherence.rs index a9f1c8750f4be..183b1a5470e5a 100644 --- a/src/librustc/traits/coherence.rs +++ b/src/librustc/traits/coherence.rs @@ -92,7 +92,9 @@ fn with_fresh_ty_vars<'cx, 'gcx, 'tcx>(selcx: &mut SelectionContext<'cx, 'gcx, ' -> ty::ImplHeader<'tcx> { let tcx = selcx.tcx(); - let impl_substs = selcx.infcx().fresh_substs_for_item(DUMMY_SP, impl_def_id); + let impl_substs = selcx.infcx().fresh_substs_for_item(param_env.universe, + DUMMY_SP, + impl_def_id); let header = ty::ImplHeader { impl_def_id, diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs index 118d4ddd4457b..dba23c22647f8 100644 --- a/src/librustc/traits/error_reporting.rs +++ b/src/librustc/traits/error_reporting.rs @@ -292,7 +292,9 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { self.tcx.for_each_relevant_impl( trait_ref.def_id, trait_self_ty, |def_id| { - let impl_substs = self.fresh_substs_for_item(obligation.cause.span, def_id); + let impl_substs = self.fresh_substs_for_item(param_env.universe, + obligation.cause.span, + def_id); let impl_trait_ref = tcx .impl_trait_ref(def_id) .unwrap() @@ -1194,6 +1196,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { -> bool { struct ParamToVarFolder<'a, 'gcx: 'a+'tcx, 'tcx: 'a> { infcx: &'a InferCtxt<'a, 'gcx, 'tcx>, + param_env: ty::ParamEnv<'tcx>, var_map: FxHashMap, Ty<'tcx>> } @@ -1203,9 +1206,14 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> { if let ty::TyParam(ty::ParamTy {name, ..}) = ty.sty { let infcx = self.infcx; - self.var_map.entry(ty).or_insert_with(|| - infcx.next_ty_var( - TypeVariableOrigin::TypeParameterDefinition(DUMMY_SP, name))) + let param_env = self.param_env; + self.var_map + .entry(ty) + .or_insert_with(|| { + let origin = TypeVariableOrigin::TypeParameterDefinition(DUMMY_SP, + name); + infcx.next_ty_var(param_env.universe, origin) + }) } else { ty.super_fold_with(self) } @@ -1217,6 +1225,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { let cleaned_pred = pred.fold_with(&mut ParamToVarFolder { infcx: self, + param_env, var_map: FxHashMap() }); diff --git a/src/librustc/traits/project.rs b/src/librustc/traits/project.rs index 1cf92d5a78669..3fe72344e8fea 100644 --- a/src/librustc/traits/project.rs +++ b/src/librustc/traits/project.rs @@ -469,6 +469,7 @@ pub fn normalize_projection_type<'a, 'b, 'gcx, 'tcx>( let tcx = selcx.infcx().tcx; let def_id = projection_ty.item_def_id; let ty_var = selcx.infcx().next_ty_var( + param_env.universe, TypeVariableOrigin::NormalizeProjectionType(tcx.def_span(def_id))); let projection = ty::Binder(ty::ProjectionPredicate { projection_ty, @@ -789,6 +790,7 @@ fn normalize_to_error<'a, 'gcx, 'tcx>(selcx: &mut SelectionContext<'a, 'gcx, 'tc let tcx = selcx.infcx().tcx; let def_id = projection_ty.item_def_id; let new_value = selcx.infcx().next_ty_var( + param_env.universe, TypeVariableOrigin::NormalizeProjectionType(tcx.def_span(def_id))); Normalized { value: new_value, diff --git a/src/librustc/traits/select.rs b/src/librustc/traits/select.rs index e5f05f30fd8a8..9e24a4e6afacf 100644 --- a/src/librustc/traits/select.rs +++ b/src/librustc/traits/select.rs @@ -3111,7 +3111,8 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> { snapshot); let skol_obligation_trait_ref = skol_obligation.trait_ref; - let impl_substs = self.infcx.fresh_substs_for_item(obligation.cause.span, + let impl_substs = self.infcx.fresh_substs_for_item(obligation.param_env.universe, + obligation.cause.span, impl_def_id); let impl_trait_ref = impl_trait_ref.subst(self.tcx(), diff --git a/src/librustc/traits/specialize/mod.rs b/src/librustc/traits/specialize/mod.rs index 72d9dd9012ca9..5dfeb1bb42928 100644 --- a/src/librustc/traits/specialize/mod.rs +++ b/src/librustc/traits/specialize/mod.rs @@ -221,7 +221,7 @@ fn fulfill_implication<'a, 'gcx, 'tcx>(infcx: &InferCtxt<'a, 'gcx, 'tcx>, target_impl: DefId) -> Result<&'tcx Substs<'tcx>, ()> { let selcx = &mut SelectionContext::new(&infcx); - let target_substs = infcx.fresh_substs_for_item(DUMMY_SP, target_impl); + let target_substs = infcx.fresh_substs_for_item(param_env.universe, DUMMY_SP, target_impl); let (target_trait_ref, mut obligations) = impl_trait_ref_and_oblig(selcx, param_env, target_impl, diff --git a/src/librustc_typeck/check/_match.rs b/src/librustc_typeck/check/_match.rs index 427641aaf0951..da66a2e52e81f 100644 --- a/src/librustc_typeck/check/_match.rs +++ b/src/librustc_typeck/check/_match.rs @@ -329,6 +329,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let element_tys_iter = (0..max_len).map(|_| self.next_ty_var( // FIXME: MiscVariable for now, obtaining the span and name information // from all tuple elements isn't trivial. + ty::UniverseIndex::ROOT, TypeVariableOrigin::TypeInference(pat.span))); let element_tys = tcx.mk_type_list(element_tys_iter); let pat_ty = tcx.mk_ty(ty::TyTuple(element_tys, false)); @@ -339,7 +340,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { pat_ty } PatKind::Box(ref inner) => { - let inner_ty = self.next_ty_var(TypeVariableOrigin::TypeInference(inner.span)); + let inner_ty = self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(inner.span)); let uniq_ty = tcx.mk_box(inner_ty); if self.check_dereferencable(pat.span, expected, &inner) { @@ -372,6 +374,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { } _ => { let inner_ty = self.next_ty_var( + ty::UniverseIndex::ROOT, TypeVariableOrigin::TypeInference(inner.span)); let mt = ty::TypeAndMut { ty: inner_ty, mutbl: mutbl }; let region = self.next_region_var(infer::PatternRegion(pat.span)); @@ -630,7 +633,8 @@ https://doc.rust-lang.org/reference/types.html#trait-objects"); // ...but otherwise we want to use any supertype of the // discriminant. This is sort of a workaround, see note (*) in // `check_pat` for some details. - discrim_ty = self.next_ty_var(TypeVariableOrigin::TypeInference(discrim.span)); + discrim_ty = self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(discrim.span)); self.check_expr_has_type_or_error(discrim, discrim_ty); }; @@ -691,7 +695,8 @@ https://doc.rust-lang.org/reference/types.html#trait-objects"); // arm for inconsistent arms or to the whole match when a `()` type // is required). Expectation::ExpectHasType(ety) if ety != self.tcx.mk_nil() => ety, - _ => self.next_ty_var(TypeVariableOrigin::MiscVariable(expr.span)), + _ => self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(expr.span)), }; CoerceMany::with_coercion_sites(coerce_first, arms) }; diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs index 794d466ee7cdb..5e0c47f18bf5a 100644 --- a/src/librustc_typeck/check/closure.rs +++ b/src/librustc_typeck/check/closure.rs @@ -110,7 +110,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { |_, _| span_bug!(expr.span, "closure has region param"), |_, _| { self.infcx - .next_ty_var(TypeVariableOrigin::ClosureSynthetic(expr.span)) + .next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::ClosureSynthetic(expr.span)) }, ); let substs = ty::ClosureSubsts { substs }; diff --git a/src/librustc_typeck/check/coercion.rs b/src/librustc_typeck/check/coercion.rs index 47e4b0272bed4..e2d6817697e8f 100644 --- a/src/librustc_typeck/check/coercion.rs +++ b/src/librustc_typeck/check/coercion.rs @@ -177,6 +177,7 @@ impl<'f, 'gcx, 'tcx> Coerce<'f, 'gcx, 'tcx> { // micro-optimization: no need for this if `b` is // already resolved in some way. let diverging_ty = self.next_diverging_ty_var( + ty::UniverseIndex::ROOT, TypeVariableOrigin::AdjustmentType(self.cause.span)); self.unify_and(&b, &diverging_ty, simple(Adjust::NeverToAny)) } else { @@ -510,7 +511,7 @@ impl<'f, 'gcx, 'tcx> Coerce<'f, 'gcx, 'tcx> { // We only have the latter, so we use an inference variable // for the former and let type inference do the rest. let origin = TypeVariableOrigin::MiscVariable(self.cause.span); - let coerce_target = self.next_ty_var(origin); + let coerce_target = self.next_ty_var(ty::UniverseIndex::ROOT, origin); let mut coercion = self.unify_and(coerce_target, target, |target| { let unsize = Adjustment { kind: Adjust::Unsize, diff --git a/src/librustc_typeck/check/dropck.rs b/src/librustc_typeck/check/dropck.rs index 039669a62e104..165cfe6604e8b 100644 --- a/src/librustc_typeck/check/dropck.rs +++ b/src/librustc_typeck/check/dropck.rs @@ -90,7 +90,7 @@ fn ensure_drop_params_and_item_params_correspond<'a, 'tcx>( let drop_impl_span = tcx.def_span(drop_impl_did); let fresh_impl_substs = - infcx.fresh_substs_for_item(drop_impl_span, drop_impl_did); + infcx.fresh_substs_for_item(ty::UniverseIndex::ROOT, drop_impl_span, drop_impl_did); let fresh_impl_self_ty = drop_impl_ty.subst(tcx, fresh_impl_substs); let cause = &ObligationCause::misc(drop_impl_span, drop_impl_node_id); diff --git a/src/librustc_typeck/check/method/confirm.rs b/src/librustc_typeck/check/method/confirm.rs index a3233c8d86599..b777ac30920cd 100644 --- a/src/librustc_typeck/check/method/confirm.rs +++ b/src/librustc_typeck/check/method/confirm.rs @@ -259,7 +259,7 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> { // the process we will unify the transformed-self-type // of the method with the actual type in order to // unify some of these variables. - self.fresh_substs_for_item(self.span, trait_def_id) + self.fresh_substs_for_item(ty::UniverseIndex::ROOT, self.span, trait_def_id) } probe::WhereClausePick(ref poly_trait_ref) => { @@ -336,7 +336,7 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> { { self.to_ty(ast_ty) } else { - self.type_var_for_def(self.span, def) + self.type_var_for_def(ty::UniverseIndex::ROOT, self.span, def) } }) } diff --git a/src/librustc_typeck/check/method/mod.rs b/src/librustc_typeck/check/method/mod.rs index 4a122fbc4c195..af86570309dfd 100644 --- a/src/librustc_typeck/check/method/mod.rs +++ b/src/librustc_typeck/check/method/mod.rs @@ -255,7 +255,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { } else if let Some(ref input_types) = opt_input_types { input_types[def.index as usize - 1] } else { - self.type_var_for_def(span, def) + self.type_var_for_def(ty::UniverseIndex::ROOT, span, def) } }); diff --git a/src/librustc_typeck/check/method/probe.rs b/src/librustc_typeck/check/method/probe.rs index 0a20af23e2e9d..c95ead285594b 100644 --- a/src/librustc_typeck/check/method/probe.rs +++ b/src/librustc_typeck/check/method/probe.rs @@ -730,7 +730,9 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { Def::Method(def_id) => { let fty = self.tcx.fn_sig(def_id); self.probe(|_| { - let substs = self.fresh_substs_for_item(self.span, method.def_id); + let substs = self.fresh_substs_for_item(ty::UniverseIndex::ROOT, + self.span, + method.def_id); let fty = fty.subst(self.tcx, substs); let (fty, _) = self.replace_late_bound_regions_with_fresh_var( self.span, infer::FnCall, &fty); @@ -1309,7 +1311,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { if i < substs.len() { substs.type_at(i) } else { - self.type_var_for_def(self.span, def) + self.type_var_for_def(ty::UniverseIndex::ROOT, self.span, def) } }); xform_fn_sig.subst(self.tcx, substs) @@ -1326,6 +1328,7 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { def_id, |_, _| self.tcx.types.re_erased, |_, _| self.next_ty_var( + ty::UniverseIndex::ROOT, TypeVariableOrigin::SubstitutionPlaceholder( self.tcx.def_span(def_id)))) } diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs index 4556b5a42b3d6..5c20490f82303 100644 --- a/src/librustc_typeck/check/method/suggest.rs +++ b/src/librustc_typeck/check/method/suggest.rs @@ -54,7 +54,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { self.autoderef(span, ty).any(|(ty, _)| { self.probe(|_| { let fn_once_substs = tcx.mk_substs_trait(ty, - &[self.next_ty_var(TypeVariableOrigin::MiscVariable(span))]); + &[self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(span))]); let trait_ref = ty::TraitRef::new(fn_once, fn_once_substs); let poly_trait_ref = trait_ref.to_poly_trait_ref(); let obligation = diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 4fa48d96d36c4..a7001acc495a3 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -362,7 +362,8 @@ impl<'a, 'gcx, 'tcx> Expectation<'tcx> { /// hard constraint exists, creates a fresh type variable. fn coercion_target_type(self, fcx: &FnCtxt<'a, 'gcx, 'tcx>, span: Span) -> Ty<'tcx> { self.only_has_type(fcx) - .unwrap_or_else(|| fcx.next_ty_var(TypeVariableOrigin::MiscVariable(span))) + .unwrap_or_else(|| fcx.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(span))) } } @@ -921,7 +922,8 @@ impl<'a, 'gcx, 'tcx> GatherLocalsVisitor<'a, 'gcx, 'tcx> { match ty_opt { None => { // infer the variable's type - let var_ty = self.fcx.next_ty_var(TypeVariableOrigin::TypeInference(span)); + let var_ty = self.fcx.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(span)); self.fcx.locals.borrow_mut().insert(nid, var_ty); var_ty } @@ -1025,7 +1027,8 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>, let span = body.value.span; if body.is_generator && can_be_generator.is_some() { - let yield_ty = fcx.next_ty_var(TypeVariableOrigin::TypeInference(span)); + let yield_ty = fcx.next_ty_var(fcx.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(span))); fcx.require_type_is_sized(yield_ty, span, traits::SizedYieldType); fcx.yield_ty = Some(yield_ty); } @@ -1058,7 +1061,8 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>, // This ensures that all nested generators appear before the entry of this generator. // resolve_generator_interiors relies on this property. let gen_ty = if can_be_generator.is_some() && body.is_generator { - let witness = fcx.next_ty_var(TypeVariableOrigin::MiscVariable(span)); + let witness = fcx.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(span)); let interior = ty::GeneratorInterior { witness, movable: can_be_generator.unwrap() == hir::GeneratorMovability::Movable, @@ -1096,6 +1100,7 @@ fn check_fn<'a, 'gcx, 'tcx>(inherited: &'a Inherited<'a, 'gcx, 'tcx>, let mut actual_return_ty = coercion.complete(&fcx); if actual_return_ty.is_never() { actual_return_ty = fcx.next_diverging_ty_var( + ty::UniverseIndex::ROOT, TypeVariableOrigin::DivergingFn(span)); } fcx.demand_suptype(span, ret_ty, actual_return_ty); @@ -1687,13 +1692,14 @@ impl<'a, 'gcx, 'tcx> AstConv<'gcx, 'tcx> for FnCtxt<'a, 'gcx, 'tcx> { } fn ty_infer(&self, span: Span) -> Ty<'tcx> { - self.next_ty_var(TypeVariableOrigin::TypeInference(span)) + self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(span)) } fn ty_infer_for_def(&self, ty_param_def: &ty::TypeParameterDef, span: Span) -> Ty<'tcx> { - self.type_var_for_def(span, ty_param_def) + self.type_var_for_def(ty::UniverseIndex::ROOT, span, ty_param_def) } fn projected_ty_from_poly_trait_ref(&self, @@ -2315,7 +2321,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // If some lookup succeeds, write callee into table and extract index/element // type from the method signature. // If some lookup succeeded, install method in table - let input_ty = self.next_ty_var(TypeVariableOrigin::AutoDeref(base_expr.span)); + let input_ty = self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::AutoDeref(base_expr.span)); let method = self.try_overloaded_place_op( expr.span, self_ty, &[input_ty], needs, PlaceOp::Index); @@ -2754,6 +2761,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { assert!(!self.tables.borrow().adjustments().contains_key(expr.hir_id), "expression with never type wound up being adjusted"); let adj_ty = self.next_diverging_ty_var( + ty::UniverseIndex::ROOT, TypeVariableOrigin::AdjustmentType(expr.span)); self.apply_adjustments(expr, vec![Adjustment { kind: Adjust::NeverToAny, @@ -2831,7 +2839,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let ity = self.tcx.type_of(did); debug!("impl_self_ty: ity={:?}", ity); - let substs = self.fresh_substs_for_item(span, did); + let substs = self.fresh_substs_for_item(ty::UniverseIndex::ROOT, span, did); let substd_ty = self.instantiate_type_scheme(span, &substs, &ity); TypeAndSubsts { substs: substs, ty: substd_ty } @@ -3971,7 +3979,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let element_ty = if !args.is_empty() { let coerce_to = uty.unwrap_or_else( - || self.next_ty_var(TypeVariableOrigin::TypeInference(expr.span))); + || self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(expr.span))); let mut coerce = CoerceMany::with_coercion_sites(coerce_to, args); assert_eq!(self.diverges.get(), Diverges::Maybe); for e in args { @@ -3981,7 +3990,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { } coerce.complete(self) } else { - self.next_ty_var(TypeVariableOrigin::TypeInference(expr.span)) + self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::TypeInference(expr.span)) }; tcx.mk_array(element_ty, args.len() as u64) } @@ -4011,7 +4021,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { (uty, uty) } None => { - let t: Ty = self.next_ty_var(TypeVariableOrigin::MiscVariable(element.span)); + let t: Ty = self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(element.span)); let element_ty = self.check_expr_has_type_or_error(&element, t); (element_ty, t) } @@ -4792,7 +4803,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // Handle Self first, so we can adjust the index to match the AST. if has_self && i == 0 { return opt_self_ty.unwrap_or_else(|| { - self.type_var_for_def(span, def) + self.type_var_for_def(ty::UniverseIndex::ROOT, span, def) }); } i -= has_self as usize; @@ -4825,7 +4836,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // This can also be reached in some error cases: // We prefer to use inference variables instead of // TyError to let type inference recover somewhat. - self.type_var_for_def(span, def) + self.type_var_for_def(ty::UniverseIndex::ROOT, span, def) } }); diff --git a/src/librustc_typeck/check/op.rs b/src/librustc_typeck/check/op.rs index a28625be2c739..12791107ebb41 100644 --- a/src/librustc_typeck/check/op.rs +++ b/src/librustc_typeck/check/op.rs @@ -174,8 +174,10 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // trait matching creating lifetime constraints that are too strict. // E.g. adding `&'a T` and `&'b T`, given `&'x T: Add<&'x T>`, will result // in `&'a T <: &'x T` and `&'b T <: &'x T`, instead of `'a = 'b = 'x`. - let lhs_ty = self.check_expr_coercable_to_type_with_needs(lhs_expr, - self.next_ty_var(TypeVariableOrigin::MiscVariable(lhs_expr.span)), + let lhs_ty = self.check_expr_coercable_to_type_with_needs( + lhs_expr, + self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(lhs_expr.span)), lhs_needs); let lhs_ty = self.resolve_type_vars_with_obligations(lhs_ty); @@ -185,7 +187,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { // using this variable as the expected type, which sometimes lets // us do better coercions than we would be able to do otherwise, // particularly for things like `String + &String`. - let rhs_ty_var = self.next_ty_var(TypeVariableOrigin::MiscVariable(rhs_expr.span)); + let rhs_ty_var = self.next_ty_var(ty::UniverseIndex::ROOT, + TypeVariableOrigin::MiscVariable(rhs_expr.span)); let result = self.lookup_op_method(lhs_ty, &[rhs_ty_var], Op::Binary(op, is_assign));