diff options
author | lcnr <rust@lcnr.de> | 2022-06-29 09:58:39 +0200 |
---|---|---|
committer | GitHub <noreply@github.com> | 2022-06-29 09:58:39 +0200 |
commit | 03534fa6519685d484cf3694894003a78276c362 (patch) | |
tree | 8fcb8a1f0b844354618dccd7973b50905512613d | |
parent | 116edb6800ea1d6615578e7f65366ae65364b3d8 (diff) | |
download | rust-revert-98576-region-stuff-cool-beans.tar.gz |
Revert "small regions refactoring"revert-98576-region-stuff-cool-beans
21 files changed, 59 insertions, 38 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_name.rs b/compiler/rustc_borrowck/src/diagnostics/region_name.rs index e60e11f11df..8f3699553d9 100644 --- a/compiler/rustc_borrowck/src/diagnostics/region_name.rs +++ b/compiler/rustc_borrowck/src/diagnostics/region_name.rs @@ -879,7 +879,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> { } let mut found = false; - tcx.fold_regions(tcx.type_of(body_parent_did), |r: ty::Region<'tcx>, _| { + tcx.fold_regions(tcx.type_of(body_parent_did), &mut true, |r: ty::Region<'tcx>, _| { if *r == ty::ReEarlyBound(region) { found = true; } diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs index f5c9392948b..0fe3b45bc7c 100644 --- a/compiler/rustc_borrowck/src/region_infer/mod.rs +++ b/compiler/rustc_borrowck/src/region_infer/mod.rs @@ -1009,7 +1009,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { debug!("try_promote_type_test_subject(ty = {:?})", ty); - let ty = tcx.fold_regions(ty, |r, _depth| { + let ty = tcx.fold_regions(ty, &mut false, |r, _depth| { let region_vid = self.to_region_vid(r); // The challenge if this. We have some region variable `r` @@ -1289,7 +1289,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { where T: TypeFoldable<'tcx>, { - tcx.fold_regions(value, |r, _db| { + tcx.fold_regions(value, &mut false, |r, _db| { let vid = self.to_region_vid(r); let scc = self.constraint_sccs.scc(vid); let repr = self.scc_representatives[scc]; diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs index d182c0cf4e8..81073758791 100644 --- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs +++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs @@ -59,7 +59,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { debug!(?concrete_type, ?substs); let mut subst_regions = vec![self.universal_regions.fr_static]; - let universal_substs = infcx.tcx.fold_regions(substs, |region, _| { + let universal_substs = infcx.tcx.fold_regions(substs, &mut false, |region, _| { if let ty::RePlaceholder(..) = region.kind() { // Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs. return region; @@ -91,7 +91,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { subst_regions.dedup(); let universal_concrete_type = - infcx.tcx.fold_regions(concrete_type, |region, _| match *region { + infcx.tcx.fold_regions(concrete_type, &mut false, |region, _| match *region { ty::ReVar(vid) => subst_regions .iter() .find(|ur_vid| self.eval_equal(vid, **ur_vid)) @@ -146,7 +146,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { where T: TypeFoldable<'tcx>, { - tcx.fold_regions(ty, |region, _| match *region { + tcx.fold_regions(ty, &mut false, |region, _| match *region { ty::ReVar(vid) => { // Find something that we can name let upper_bound = self.approx_universal_upper_bound(vid); diff --git a/compiler/rustc_borrowck/src/renumber.rs b/compiler/rustc_borrowck/src/renumber.rs index 7a8ce621c5d..2876d60527f 100644 --- a/compiler/rustc_borrowck/src/renumber.rs +++ b/compiler/rustc_borrowck/src/renumber.rs @@ -31,7 +31,7 @@ pub fn renumber_regions<'tcx, T>(infcx: &InferCtxt<'_, 'tcx>, value: T) -> T where T: TypeFoldable<'tcx>, { - infcx.tcx.fold_regions(value, |_region, _depth| { + infcx.tcx.fold_regions(value, &mut false, |_region, _depth| { let origin = NllRegionVariableOrigin::Existential { from_forall: false }; infcx.next_nll_region_var(origin) }) diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs index 5e33d9d25c2..3c9e3870aea 100644 --- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs +++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs @@ -23,7 +23,7 @@ pub(crate) struct ConstraintConversion<'a, 'tcx> { tcx: TyCtxt<'tcx>, universal_regions: &'a UniversalRegions<'tcx>, region_bound_pairs: &'a RegionBoundPairs<'tcx>, - implicit_region_bound: ty::Region<'tcx>, + implicit_region_bound: Option<ty::Region<'tcx>>, param_env: ty::ParamEnv<'tcx>, locations: Locations, span: Span, @@ -36,7 +36,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> { infcx: &'a InferCtxt<'a, 'tcx>, universal_regions: &'a UniversalRegions<'tcx>, region_bound_pairs: &'a RegionBoundPairs<'tcx>, - implicit_region_bound: ty::Region<'tcx>, + implicit_region_bound: Option<ty::Region<'tcx>>, param_env: ty::ParamEnv<'tcx>, locations: Locations, span: Span, @@ -108,7 +108,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> { // create new region variables, which can't be done later when // verifying these bounds. if t1.has_placeholders() { - t1 = tcx.fold_regions(t1, |r, _| match *r { + t1 = tcx.fold_regions(t1, &mut false, |r, _| match *r { ty::RePlaceholder(placeholder) => { self.constraints.placeholder_region(self.infcx, placeholder) } @@ -120,7 +120,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> { &mut *self, tcx, region_bound_pairs, - Some(implicit_region_bound), + implicit_region_bound, param_env, ) .type_must_outlive(origin, t1, r2); diff --git a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs index 421ef5be812..813307356c4 100644 --- a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs +++ b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs @@ -61,7 +61,7 @@ pub(crate) struct CreateResult<'tcx> { pub(crate) fn create<'tcx>( infcx: &InferCtxt<'_, 'tcx>, param_env: ty::ParamEnv<'tcx>, - implicit_region_bound: ty::Region<'tcx>, + implicit_region_bound: Option<ty::Region<'tcx>>, universal_regions: &Rc<UniversalRegions<'tcx>>, constraints: &mut MirTypeckRegionConstraints<'tcx>, ) -> CreateResult<'tcx> { @@ -223,7 +223,7 @@ struct UniversalRegionRelationsBuilder<'this, 'tcx> { infcx: &'this InferCtxt<'this, 'tcx>, param_env: ty::ParamEnv<'tcx>, universal_regions: Rc<UniversalRegions<'tcx>>, - implicit_region_bound: ty::Region<'tcx>, + implicit_region_bound: Option<ty::Region<'tcx>>, constraints: &'this mut MirTypeckRegionConstraints<'tcx>, // outputs: diff --git a/compiler/rustc_borrowck/src/type_check/input_output.rs b/compiler/rustc_borrowck/src/type_check/input_output.rs index 2a6ca5246da..2259a59e195 100644 --- a/compiler/rustc_borrowck/src/type_check/input_output.rs +++ b/compiler/rustc_borrowck/src/type_check/input_output.rs @@ -230,7 +230,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { self.infcx, &self.borrowck_context.universal_regions, &self.region_bound_pairs, - self.implicit_region_bound, + Some(self.implicit_region_bound), self.param_env, Locations::All(DUMMY_SP), DUMMY_SP, diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index 542fc6b0f48..355254fe942 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -157,7 +157,7 @@ pub(crate) fn type_check<'mir, 'tcx>( } = free_region_relations::create( infcx, param_env, - implicit_region_bound, + Some(implicit_region_bound), universal_regions, &mut constraints, ); @@ -1142,7 +1142,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { self.infcx, self.borrowck_context.universal_regions, self.region_bound_pairs, - self.implicit_region_bound, + Some(self.implicit_region_bound), self.param_env, locations, locations.span(self.body), diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs index 89d84fcf09c..c2c093f9f2f 100644 --- a/compiler/rustc_borrowck/src/universal_regions.rs +++ b/compiler/rustc_borrowck/src/universal_regions.rs @@ -725,7 +725,7 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> { where T: TypeFoldable<'tcx>, { - self.tcx.fold_regions(value, |_region, _depth| self.next_nll_region_var(origin)) + self.tcx.fold_regions(value, &mut false, |_region, _depth| self.next_nll_region_var(origin)) } #[instrument(level = "debug", skip(self, indices))] @@ -817,7 +817,9 @@ impl<'tcx> UniversalRegionIndices<'tcx> { where T: TypeFoldable<'tcx>, { - tcx.fold_regions(value, |region, _| tcx.mk_region(ty::ReVar(self.to_region_vid(region)))) + tcx.fold_regions(value, &mut false, |region, _| { + tcx.mk_region(ty::ReVar(self.to_region_vid(region))) + }) } } diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs index 42d52446ab6..b9596cd10ed 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs @@ -79,7 +79,7 @@ pub fn find_param_with_region<'tcx>( // May return None; sometimes the tables are not yet populated. let ty = fn_sig.inputs()[index]; let mut found_anon_region = false; - let new_param_ty = tcx.fold_regions(ty, |r, _| { + let new_param_ty = tcx.fold_regions(ty, &mut false, |r, _| { if r == anon_region { found_anon_region = true; replace_region diff --git a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs index 68c709a2e24..455de47acef 100644 --- a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs +++ b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs @@ -868,7 +868,7 @@ impl<'tcx> LexicalRegionResolutions<'tcx> { where T: TypeFoldable<'tcx>, { - tcx.fold_regions(value, |r, _db| match *r { + tcx.fold_regions(value, &mut false, |r, _db| match *r { ty::ReVar(rid) => self.resolve_var(rid), _ => r, }) diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs index 1c1906f3375..a268493b28f 100644 --- a/compiler/rustc_infer/src/infer/outlives/obligations.rs +++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs @@ -141,6 +141,9 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { /// `('a, K)` in this list tells us that the bounds in scope /// indicate that `K: 'a`, where `K` is either a generic /// parameter like `T` or a projection like `T::Item`. + /// - `implicit_region_bound`: if some, this is a region bound + /// that is considered to hold for all type parameters (the + /// function body). /// - `param_env` is the parameter environment for the enclosing function. /// - `body_id` is the body-id whose region obligations are being /// processed. @@ -148,6 +151,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { pub fn process_registered_region_obligations( &self, region_bound_pairs_map: &FxHashMap<hir::HirId, RegionBoundPairs<'tcx>>, + implicit_region_bound: Option<ty::Region<'tcx>>, param_env: ty::ParamEnv<'tcx>, ) { assert!( @@ -166,8 +170,13 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { let sup_type = self.resolve_vars_if_possible(sup_type); if let Some(region_bound_pairs) = region_bound_pairs_map.get(&body_id) { - let outlives = - &mut TypeOutlives::new(self, self.tcx, ®ion_bound_pairs, None, param_env); + let outlives = &mut TypeOutlives::new( + self, + self.tcx, + ®ion_bound_pairs, + implicit_region_bound, + param_env, + ); outlives.type_must_outlive(origin, sup_type, sub_region); } else { self.tcx.sess.delay_span_bug( diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs index 86b025dce5e..191f5f18ec2 100644 --- a/compiler/rustc_infer/src/infer/outlives/verify.rs +++ b/compiler/rustc_infer/src/infer/outlives/verify.rs @@ -16,11 +16,6 @@ use rustc_middle::ty::{self, EarlyBinder, Ty, TyCtxt}; pub struct VerifyBoundCx<'cx, 'tcx> { tcx: TyCtxt<'tcx>, region_bound_pairs: &'cx RegionBoundPairs<'tcx>, - /// During borrowck, if there are no outlives bounds on a generic - /// parameter `T`, we assume that `T: 'in_fn_body` holds. - /// - /// Outside of borrowck the only way to prove `T: '?0` is by - /// setting `'?0` to `'empty`. implicit_region_bound: Option<ty::Region<'tcx>>, param_env: ty::ParamEnv<'tcx>, } @@ -268,8 +263,8 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> { // fn foo<'a, A>(x: &'a A) { x.bar() } // // The problem is that the type of `x` is `&'a A`. To be - // well-formed, then, A must outlive `'a`, but we don't know that - // this holds from first principles. + // well-formed, then, A must be lower-generic by `'a`, but we + // don't know that this holds from first principles. let from_region_bound_pairs = self.region_bound_pairs.iter().filter_map(|&(r, p)| { debug!( "declared_generic_bounds_from_env_for_erased_ty: region_bound_pair = {:?}", diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs index a6310ae5e66..b1b8bc13e2f 100644 --- a/compiler/rustc_middle/src/ty/fold.rs +++ b/compiler/rustc_middle/src/ty/fold.rs @@ -465,12 +465,13 @@ impl<'tcx> TyCtxt<'tcx> { pub fn fold_regions<T>( self, value: T, + skipped_regions: &mut bool, mut f: impl FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>, ) -> T where T: TypeFoldable<'tcx>, { - value.fold_with(&mut RegionFolder::new(self, &mut f)) + value.fold_with(&mut RegionFolder::new(self, skipped_regions, &mut f)) } /// Invoke `callback` on every region appearing free in `value`. @@ -578,6 +579,7 @@ impl<'tcx> TyCtxt<'tcx> { pub struct RegionFolder<'a, 'tcx> { tcx: TyCtxt<'tcx>, + skipped_regions: &'a mut bool, /// Stores the index of a binder *just outside* the stuff we have /// visited. So this begins as INNERMOST; when we pass through a @@ -595,9 +597,10 @@ impl<'a, 'tcx> RegionFolder<'a, 'tcx> { #[inline] pub fn new( tcx: TyCtxt<'tcx>, + skipped_regions: &'a mut bool, fold_region_fn: &'a mut dyn FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>, ) -> RegionFolder<'a, 'tcx> { - RegionFolder { tcx, current_index: ty::INNERMOST, fold_region_fn } + RegionFolder { tcx, skipped_regions, current_index: ty::INNERMOST, fold_region_fn } } } @@ -621,6 +624,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for RegionFolder<'a, 'tcx> { match *r { ty::ReLateBound(debruijn, _) if debruijn < self.current_index => { debug!(?self.current_index, "skipped bound region"); + *self.skipped_regions = true; r } _ => { diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 90ff07cba02..a63790b594d 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -220,7 +220,7 @@ impl<'tcx> AutoTraitFinder<'tcx> { .map(|&(id, _)| (id, vec![])) .collect(); - infcx.process_registered_region_obligations(&body_id_map, full_env); + infcx.process_registered_region_obligations(&body_id_map, None, full_env); let region_data = infcx .inner diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 2b26b916d32..b37db4b9e18 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -407,7 +407,11 @@ fn resolve_negative_obligation<'cx, 'tcx>( // function bodies with closures). outlives_env.save_implied_bounds(CRATE_HIR_ID); - infcx.process_registered_region_obligations(outlives_env.region_bound_pairs_map(), param_env); + infcx.process_registered_region_obligations( + outlives_env.region_bound_pairs_map(), + Some(tcx.lifetimes.re_root_empty), + param_env, + ); let errors = infcx.resolve_regions(region_context, &outlives_env); diff --git a/compiler/rustc_typeck/src/check/generator_interior.rs b/compiler/rustc_typeck/src/check/generator_interior.rs index 6ee989070b4..f09c7f51f47 100644 --- a/compiler/rustc_typeck/src/check/generator_interior.rs +++ b/compiler/rustc_typeck/src/check/generator_interior.rs @@ -225,7 +225,7 @@ pub fn resolve_interior<'a, 'tcx>( // Note that each region slot in the types gets a new fresh late bound region, // which means that none of the regions inside relate to any other, even if // typeck had previously found constraints that would cause them to be related. - let folded = fcx.tcx.fold_regions(erased, |_, current_depth| { + let folded = fcx.tcx.fold_regions(erased, &mut false, |_, current_depth| { let br = ty::BoundRegion { var: ty::BoundVar::from_u32(counter), kind: ty::BrAnon(counter), diff --git a/compiler/rustc_typeck/src/check/regionck.rs b/compiler/rustc_typeck/src/check/regionck.rs index 0ce63922098..161ec31793d 100644 --- a/compiler/rustc_typeck/src/check/regionck.rs +++ b/compiler/rustc_typeck/src/check/regionck.rs @@ -366,6 +366,7 @@ impl<'a, 'tcx> RegionCtxt<'a, 'tcx> { fn resolve_regions_and_report_errors(&self) { self.infcx.process_registered_region_obligations( self.outlives_environment.region_bound_pairs_map(), + Some(self.tcx.lifetimes.re_root_empty), self.param_env, ); diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs index 7fe36781cf4..240be827f09 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -614,7 +614,13 @@ fn ty_known_to_outlive<'tcx>( ) -> bool { resolve_regions_with_wf_tys(tcx, id, param_env, &wf_tys, |infcx, region_bound_pairs| { let origin = infer::RelateParamBound(DUMMY_SP, ty, None); - let outlives = &mut TypeOutlives::new(infcx, tcx, region_bound_pairs, None, param_env); + let outlives = &mut TypeOutlives::new( + infcx, + tcx, + region_bound_pairs, + Some(infcx.tcx.lifetimes.re_root_empty), + param_env, + ); outlives.type_must_outlive(origin, ty, region); }) } diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index a0cbb7c2c5a..696d8db4e20 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -393,7 +393,7 @@ impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> { } fn ct_infer(&self, ty: Ty<'tcx>, _: Option<&ty::GenericParamDef>, span: Span) -> Const<'tcx> { - let ty = self.tcx.fold_regions(ty, |r, _| match *r { + let ty = self.tcx.fold_regions(ty, &mut false, |r, _| match *r { ty::ReErased => self.tcx.lifetimes.re_static, _ => r, }); @@ -1917,7 +1917,7 @@ fn infer_return_ty_for_fn_sig<'tcx>( Some(ty) => { let fn_sig = tcx.typeck(def_id).liberated_fn_sigs()[hir_id]; // Typeck doesn't expect erased regions to be returned from `type_of`. - let fn_sig = tcx.fold_regions(fn_sig, |r, _| match *r { + let fn_sig = tcx.fold_regions(fn_sig, &mut false, |r, _| match *r { ty::ReErased => tcx.lifetimes.re_static, _ => r, }); diff --git a/compiler/rustc_typeck/src/collect/type_of.rs b/compiler/rustc_typeck/src/collect/type_of.rs index 6ee2b544916..7011dd6e15c 100644 --- a/compiler/rustc_typeck/src/collect/type_of.rs +++ b/compiler/rustc_typeck/src/collect/type_of.rs @@ -772,7 +772,7 @@ fn infer_placeholder_type<'a>( } // Typeck doesn't expect erased regions to be returned from `type_of`. - tcx.fold_regions(ty, |r, _| match *r { + tcx.fold_regions(ty, &mut false, |r, _| match *r { ty::ReErased => tcx.lifetimes.re_static, _ => r, }) |