diff --git a/src/librustc/ich/impls_ty.rs b/src/librustc/ich/impls_ty.rs index 844250f51a099..433076bb8342c 100644 --- a/src/librustc/ich/impls_ty.rs +++ b/src/librustc/ich/impls_ty.rs @@ -92,9 +92,6 @@ impl<'a> HashStable> for ty::RegionKind { ty::ReFree(ref free_region) => { free_region.hash_stable(hcx, hasher); } - ty::ReClosureBound(vid) => { - vid.hash_stable(hcx, hasher); - } ty::ReVar(..) | ty::RePlaceholder(..) => { bug!("StableHasher: unexpected region {:?}", *self) } diff --git a/src/librustc/mir/query.rs b/src/librustc/mir/query.rs index 824cdfe55bfb6..8c81f5227d260 100644 --- a/src/librustc/mir/query.rs +++ b/src/librustc/mir/query.rs @@ -88,34 +88,35 @@ pub struct ConstQualifs { /// requirements are then verified and proved by the closure's /// creating function. This struct encodes those requirements. /// -/// The requirements are listed as being between various -/// `RegionVid`. The 0th region refers to `'static`; subsequent region -/// vids refer to the free regions that appear in the closure (or -/// generator's) type, in order of appearance. (This numbering is -/// actually defined by the `UniversalRegions` struct in the NLL -/// region checker. See for example -/// `UniversalRegions::closure_mapping`.) Note that we treat the free -/// regions in the closure's type "as if" they were erased, so their -/// precise identity is not important, only their position. +/// The requirements are listed as being between various `RegionVid`. The 0th +/// region refers to `'static`; subsequent region vids refer to the free +/// regions that appear in the closure (or generator's) type, in order of +/// appearance. (This numbering is actually defined by the `UniversalRegions` +/// struct in the NLL region checker. See for example +/// `UniversalRegions::closure_mapping`.) Note the free regions in the +/// closure's signature and captures are erased. /// /// Example: If type check produces a closure with the closure substs: /// /// ```text /// ClosureSubsts = [ -/// i8, // the "closure kind" -/// for<'x> fn(&'a &'x u32) -> &'x u32, // the "closure signature" -/// &'a String, // some upvar +/// 'a, // From the parent. +/// 'b, +/// i8, // the "closure kind" +/// for<'x> fn(&' &'x u32) -> &'x u32, // the "closure signature" +/// &' String, // some upvar /// ] /// ``` /// -/// here, there is one unique free region (`'a`) but it appears -/// twice. We would "renumber" each occurrence to a unique vid, as follows: +/// We would "renumber" each free region to a unique vid, as follows: /// /// ```text /// ClosureSubsts = [ -/// i8, // the "closure kind" -/// for<'x> fn(&'1 &'x u32) -> &'x u32, // the "closure signature" -/// &'2 String, // some upvar +/// '1, // From the parent. +/// '2, +/// i8, // the "closure kind" +/// for<'x> fn(&'3 &'x u32) -> &'x u32, // the "closure signature" +/// &'4 String, // some upvar /// ] /// ``` /// @@ -124,14 +125,12 @@ pub struct ConstQualifs { /// can be extracted from its type and constrained to have the given /// outlives relationship. /// -/// In some cases, we have to record outlives requirements between -/// types and regions as well. In that case, if those types include -/// any regions, those regions are recorded as `ReClosureBound` -/// instances assigned one of these same indices. Those regions will -/// be substituted away by the creator. We use `ReClosureBound` in -/// that case because the regions must be allocated in the global -/// `TyCtxt`, and hence we cannot use `ReVar` (which is what we use -/// internally within the rest of the NLL code). +/// In some cases, we have to record outlives requirements between types and +/// regions as well. In that case, if those types include any regions, those +/// regions are recorded using their external names (`ReStatic`, +/// `ReEarlyBound`, `ReFree`). We use these because in a query response we +/// cannot use `ReVar` (which is what we use internally within the rest of the +/// NLL code). #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] pub struct ClosureRegionRequirements<'tcx> { /// The number of external regions defined on the closure. In our diff --git a/src/librustc/ty/print/pretty.rs b/src/librustc/ty/print/pretty.rs index cb01d821c1871..301254d4f0ded 100644 --- a/src/librustc/ty/print/pretty.rs +++ b/src/librustc/ty/print/pretty.rs @@ -1547,7 +1547,7 @@ impl PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> { ty::ReVar(_) | ty::ReScope(_) | ty::ReErased => false, - ty::ReStatic | ty::ReEmpty(_) | ty::ReClosureBound(_) => true, + ty::ReStatic | ty::ReEmpty(_) => true, } } @@ -1659,12 +1659,6 @@ impl FmtPrinter<'_, '_, F> { p!(write("'", ui)); return Ok(self); } - - // The user should never encounter these in unsubstituted form. - ty::ReClosureBound(vid) => { - p!(write("{:?}", vid)); - return Ok(self); - } } p!(write("'_")); diff --git a/src/librustc/ty/structural_impls.rs b/src/librustc/ty/structural_impls.rs index e2fa03139110c..81be5b11143af 100644 --- a/src/librustc/ty/structural_impls.rs +++ b/src/librustc/ty/structural_impls.rs @@ -81,8 +81,6 @@ impl fmt::Debug for ty::RegionKind { match *self { ty::ReEarlyBound(ref data) => write!(f, "ReEarlyBound({}, {})", data.index, data.name), - ty::ReClosureBound(ref vid) => write!(f, "ReClosureBound({:?})", vid), - ty::ReLateBound(binder_id, ref bound_region) => { write!(f, "ReLateBound({:?}, {:?})", binder_id, bound_region) } diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs index e265a2f8257fb..7f0ee1a86197b 100644 --- a/src/librustc/ty/sty.rs +++ b/src/librustc/ty/sty.rs @@ -1442,12 +1442,6 @@ pub enum RegionKind { /// Erased region, used by trait selection, in MIR and during codegen. ReErased, - - /// These are regions bound in the "defining type" for a - /// closure. They are used ONLY as part of the - /// `ClosureRegionRequirements` that are produced by MIR borrowck. - /// See `ClosureRegionRequirements` for more details. - ReClosureBound(RegionVid), } impl<'tcx> rustc_serialize::UseSpecializedDecodable for Region<'tcx> {} @@ -1689,7 +1683,6 @@ impl RegionKind { RegionKind::RePlaceholder(placeholder) => placeholder.name.is_named(), RegionKind::ReEmpty(_) => false, RegionKind::ReErased => false, - RegionKind::ReClosureBound(..) => false, } } @@ -1770,9 +1763,6 @@ impl RegionKind { ty::ReEmpty(_) | ty::ReStatic => { flags = flags | TypeFlags::HAS_FREE_REGIONS; } - ty::ReClosureBound(..) => { - flags = flags | TypeFlags::HAS_FREE_REGIONS; - } ty::ReLateBound(..) => { flags = flags | TypeFlags::HAS_RE_LATE_BOUND; } diff --git a/src/librustc_infer/infer/canonical/canonicalizer.rs b/src/librustc_infer/infer/canonical/canonicalizer.rs index 964e378f7abc8..ad23ecc1e3647 100644 --- a/src/librustc_infer/infer/canonical/canonicalizer.rs +++ b/src/librustc_infer/infer/canonical/canonicalizer.rs @@ -336,10 +336,6 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for Canonicalizer<'cx, 'tcx> { | ty::ReEmpty(_) | ty::RePlaceholder(..) | ty::ReErased => self.canonicalize_region_mode.canonicalize_free_region(self, r), - - ty::ReClosureBound(..) => { - bug!("closure bound region encountered during canonicalization"); - } } } diff --git a/src/librustc_infer/infer/combine.rs b/src/librustc_infer/infer/combine.rs index 9d06e26d9bb3c..0f5d4d30a2385 100644 --- a/src/librustc_infer/infer/combine.rs +++ b/src/librustc_infer/infer/combine.rs @@ -581,10 +581,6 @@ impl TypeRelation<'tcx> for Generalizer<'_, 'tcx> { return Ok(r); } - ty::ReClosureBound(..) => { - span_bug!(self.span, "encountered unexpected ReClosureBound: {:?}", r,); - } - ty::RePlaceholder(..) | ty::ReVar(..) | ty::ReEmpty(_) diff --git a/src/librustc_infer/infer/error_reporting/mod.rs b/src/librustc_infer/infer/error_reporting/mod.rs index a544381f33da1..239b67a1da3ff 100644 --- a/src/librustc_infer/infer/error_reporting/mod.rs +++ b/src/librustc_infer/infer/error_reporting/mod.rs @@ -152,11 +152,6 @@ pub(super) fn note_and_explain_region( ty::ReVar(_) | ty::ReLateBound(..) | ty::ReErased => { (format!("lifetime {:?}", region), None) } - - // We shouldn't encounter an error message with ReClosureBound. - ty::ReClosureBound(..) => { - bug!("encountered unexpected ReClosureBound: {:?}", region,); - } }; emit_msg_span(err, prefix, description, span, suffix); diff --git a/src/librustc_infer/infer/freshen.rs b/src/librustc_infer/infer/freshen.rs index a454feea36b70..fa28cf5b45464 100644 --- a/src/librustc_infer/infer/freshen.rs +++ b/src/librustc_infer/infer/freshen.rs @@ -135,10 +135,6 @@ impl<'a, 'tcx> TypeFolder<'tcx> for TypeFreshener<'a, 'tcx> { // replace all free regions with 'erased self.tcx().lifetimes.re_erased } - - ty::ReClosureBound(..) => { - bug!("encountered unexpected region: {:?}", r,); - } } } diff --git a/src/librustc_infer/infer/lexical_region_resolve/mod.rs b/src/librustc_infer/infer/lexical_region_resolve/mod.rs index b7278ecd5e407..dfad3d8e26f3d 100644 --- a/src/librustc_infer/infer/lexical_region_resolve/mod.rs +++ b/src/librustc_infer/infer/lexical_region_resolve/mod.rs @@ -464,12 +464,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> { /// term "concrete regions"). fn lub_concrete_regions(&self, a: Region<'tcx>, b: Region<'tcx>) -> Region<'tcx> { let r = match (a, b) { - (&ty::ReClosureBound(..), _) - | (_, &ty::ReClosureBound(..)) - | (&ReLateBound(..), _) - | (_, &ReLateBound(..)) - | (&ReErased, _) - | (_, &ReErased) => { + (&ReLateBound(..), _) | (_, &ReLateBound(..)) | (&ReErased, _) | (_, &ReErased) => { bug!("cannot relate region: LUB({:?}, {:?})", a, b); } diff --git a/src/librustc_infer/infer/region_constraints/mod.rs b/src/librustc_infer/infer/region_constraints/mod.rs index 868b95043796b..e9ad7313ea0e2 100644 --- a/src/librustc_infer/infer/region_constraints/mod.rs +++ b/src/librustc_infer/infer/region_constraints/mod.rs @@ -798,7 +798,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> { | ty::ReEarlyBound(..) => ty::UniverseIndex::ROOT, ty::ReEmpty(ui) => ui, ty::RePlaceholder(placeholder) => placeholder.universe, - ty::ReClosureBound(vid) | ty::ReVar(vid) => self.var_universe(vid), + ty::ReVar(vid) => self.var_universe(vid), ty::ReLateBound(..) => bug!("universe(): encountered bound region {:?}", region), } } diff --git a/src/librustc_mir/borrow_check/diagnostics/region_name.rs b/src/librustc_mir/borrow_check/diagnostics/region_name.rs index 7103fc596c922..2d0ccd4a98869 100644 --- a/src/librustc_mir/borrow_check/diagnostics/region_name.rs +++ b/src/librustc_mir/borrow_check/diagnostics/region_name.rs @@ -292,8 +292,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> { | ty::ReVar(..) | ty::RePlaceholder(..) | ty::ReEmpty(_) - | ty::ReErased - | ty::ReClosureBound(..) => None, + | ty::ReErased => None, } } diff --git a/src/librustc_mir/borrow_check/region_infer/mod.rs b/src/librustc_mir/borrow_check/region_infer/mod.rs index fe96b3e34a2a8..c8b0e59ebb117 100644 --- a/src/librustc_mir/borrow_check/region_infer/mod.rs +++ b/src/librustc_mir/borrow_check/region_infer/mod.rs @@ -940,8 +940,9 @@ impl<'tcx> RegionInferenceContext<'tcx> { /// inference variables with some region from the closure /// signature -- this is not always possible, so this is a /// fallible process. Presuming we do find a suitable region, we - /// will represent it with a `ReClosureBound`, which is a - /// `RegionKind` variant that can be allocated in the gcx. + /// will use it's *external name*, which will be a `RegionKind` + /// variant that can be used in query responses such as + /// `ReEarlyBound`. fn try_promote_type_test_subject( &self, infcx: &InferCtxt<'_, 'tcx>, @@ -991,14 +992,14 @@ impl<'tcx> RegionInferenceContext<'tcx> { // find an equivalent. let upper_bound = self.non_local_universal_upper_bound(region_vid); if self.region_contains(region_vid, upper_bound) { - tcx.mk_region(ty::ReClosureBound(upper_bound)) + self.definitions[upper_bound].external_name.unwrap_or(r) } else { - // In the case of a failure, use a `ReVar` - // result. This will cause the `lift` later on to - // fail. + // In the case of a failure, use a `ReVar` result. This will + // cause the `has_local_value` later on to return `None`. r } }); + debug!("try_promote_type_test_subject: folded ty = {:?}", ty); // `has_local_value` will only be true if we failed to promote some region. @@ -2029,15 +2030,6 @@ pub trait ClosureRegionRequirementsExt<'tcx> { closure_def_id: DefId, closure_substs: SubstsRef<'tcx>, ) -> Vec>; - - fn subst_closure_mapping( - &self, - tcx: TyCtxt<'tcx>, - closure_mapping: &IndexVec>, - value: &T, - ) -> T - where - T: TypeFoldable<'tcx>; } impl<'tcx> ClosureRegionRequirementsExt<'tcx> for ClosureRegionRequirements<'tcx> { @@ -2094,7 +2086,6 @@ impl<'tcx> ClosureRegionRequirementsExt<'tcx> for ClosureRegionRequirements<'tcx } ClosureOutlivesSubject::Ty(ty) => { - let ty = self.subst_closure_mapping(tcx, closure_mapping, &ty); debug!( "apply_requirements: ty={:?} \ outlived_region={:?} \ @@ -2107,22 +2098,4 @@ impl<'tcx> ClosureRegionRequirementsExt<'tcx> for ClosureRegionRequirements<'tcx }) .collect() } - - fn subst_closure_mapping( - &self, - tcx: TyCtxt<'tcx>, - closure_mapping: &IndexVec>, - value: &T, - ) -> T - where - T: TypeFoldable<'tcx>, - { - tcx.fold_regions(value, &mut false, |r, _depth| { - if let ty::ReClosureBound(vid) = r { - closure_mapping[*vid] - } else { - bug!("subst_closure_mapping: encountered non-closure bound free region {:?}", r) - } - }) - } } diff --git a/src/librustc_trait_selection/opaque_types.rs b/src/librustc_trait_selection/opaque_types.rs index 6cf1302783c0b..9367616e71a61 100644 --- a/src/librustc_trait_selection/opaque_types.rs +++ b/src/librustc_trait_selection/opaque_types.rs @@ -823,11 +823,7 @@ impl TypeFolder<'tcx> for ReverseMapper<'tcx> { // The regions that we expect from borrow checking. ty::ReEarlyBound(_) | ty::ReFree(_) | ty::ReEmpty(ty::UniverseIndex::ROOT) => {} - ty::ReEmpty(_) - | ty::RePlaceholder(_) - | ty::ReVar(_) - | ty::ReScope(_) - | ty::ReClosureBound(_) => { + ty::ReEmpty(_) | ty::RePlaceholder(_) | ty::ReVar(_) | ty::ReScope(_) => { // All of the regions in the type should either have been // erased by writeback, or mapped back to named regions by // borrow checking. diff --git a/src/librustc_typeck/outlives/utils.rs b/src/librustc_typeck/outlives/utils.rs index 0cc322f8c2d3d..e1bd78e5113d1 100644 --- a/src/librustc_typeck/outlives/utils.rs +++ b/src/librustc_typeck/outlives/utils.rs @@ -170,7 +170,6 @@ fn is_free_region(tcx: TyCtxt<'_>, region: Region<'_>) -> bool { // These regions don't appear in types from type declarations: RegionKind::ReErased - | RegionKind::ReClosureBound(..) | RegionKind::ReScope(..) | RegionKind::ReVar(..) | RegionKind::RePlaceholder(..) diff --git a/src/librustc_typeck/variance/constraints.rs b/src/librustc_typeck/variance/constraints.rs index 54f84272ae8e0..11612066d44b2 100644 --- a/src/librustc_typeck/variance/constraints.rs +++ b/src/librustc_typeck/variance/constraints.rs @@ -449,7 +449,6 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> { } ty::ReFree(..) - | ty::ReClosureBound(..) | ty::ReScope(..) | ty::ReVar(..) | ty::RePlaceholder(..) diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs index c4ad4554a0048..c16cf9ac10c72 100644 --- a/src/librustdoc/clean/mod.rs +++ b/src/librustdoc/clean/mod.rs @@ -450,7 +450,6 @@ impl Clean> for ty::RegionKind { | ty::ReVar(..) | ty::RePlaceholder(..) | ty::ReEmpty(_) - | ty::ReClosureBound(_) | ty::ReErased => { debug!("cannot clean region {:?}", self); None diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr b/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr index 118a849f98416..2bdb5384800a5 100644 --- a/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr +++ b/src/test/ui/nll/ty-outlives/projection-one-region-closure.stderr @@ -108,7 +108,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T)), ] = note: number of external vids: 4 - = note: where >::AssocType: '_#3r + = note: where >::AssocType: '_#3r note: no external requirements --> $DIR/projection-one-region-closure.rs:62:1 diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr b/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr index 59d8aa484bdac..1ed4c519d2bbd 100644 --- a/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr +++ b/src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-closure.stderr @@ -90,7 +90,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T)), ] = note: number of external vids: 4 - = note: where >::AssocType: '_#3r + = note: where >::AssocType: '_#3r note: no external requirements --> $DIR/projection-one-region-trait-bound-closure.rs:52:1 diff --git a/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr b/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr index ff402f89ae861..b1ee9fac5f973 100644 --- a/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr +++ b/src/test/ui/nll/ty-outlives/projection-two-region-trait-bound-closure.stderr @@ -10,7 +10,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); ] = note: late-bound region is '_#4r = note: number of external vids: 5 - = note: where >::AssocType: '_#3r + = note: where >::AssocType: '_#3r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:34:1 @@ -26,13 +26,13 @@ LL | | } | = note: defining type: no_relationships_late::<'_#1r, '_#2r, T> -error[E0309]: the associated type `>::AssocType` may not live long enough +error[E0309]: the associated type `>::AssocType` may not live long enough --> $DIR/projection-two-region-trait-bound-closure.rs:38:29 | LL | with_signature(cell, t, |cell, t| require(cell, t)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | - = help: consider adding an explicit lifetime bound `>::AssocType: 'a`... + = help: consider adding an explicit lifetime bound `>::AssocType: 'a`... note: external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:48:29 @@ -45,7 +45,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#4r ()>, T)), ] = note: number of external vids: 5 - = note: where >::AssocType: '_#4r + = note: where >::AssocType: '_#4r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:43:1 @@ -61,13 +61,13 @@ LL | | } | = note: defining type: no_relationships_early::<'_#1r, '_#2r, '_#3r, T> -error[E0309]: the associated type `>::AssocType` may not live long enough +error[E0309]: the associated type `>::AssocType` may not live long enough --> $DIR/projection-two-region-trait-bound-closure.rs:48:29 | LL | with_signature(cell, t, |cell, t| require(cell, t)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | - = help: consider adding an explicit lifetime bound `>::AssocType: 'a`... + = help: consider adding an explicit lifetime bound `>::AssocType: 'a`... note: external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:61:29 @@ -80,7 +80,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#4r ()>, T)), ] = note: number of external vids: 5 - = note: where >::AssocType: '_#4r + = note: where >::AssocType: '_#4r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:53:1 @@ -107,7 +107,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#4r ()>, T)), ] = note: number of external vids: 5 - = note: where >::AssocType: '_#4r + = note: where >::AssocType: '_#4r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:65:1 @@ -134,7 +134,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#4r ()>, T)), ] = note: number of external vids: 5 - = note: where >::AssocType: '_#4r + = note: where >::AssocType: '_#4r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:74:1 @@ -162,7 +162,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); ] = note: late-bound region is '_#3r = note: number of external vids: 4 - = note: where >::AssocType: '_#2r + = note: where >::AssocType: '_#2r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:83:1 @@ -202,7 +202,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T)), ] = note: number of external vids: 4 - = note: where >::AssocType: '_#3r + = note: where >::AssocType: '_#3r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:92:1 @@ -229,7 +229,7 @@ LL | with_signature(cell, t, |cell, t| require(cell, t)); extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T)), ] = note: number of external vids: 3 - = note: where >::AssocType: '_#2r + = note: where >::AssocType: '_#2r note: no external requirements --> $DIR/projection-two-region-trait-bound-closure.rs:101:1