From 4dbf9ba0aba366a08e0be5427fbd7ad900b0db7c Mon Sep 17 00:00:00 2001 From: lcnr Date: Mon, 27 Jun 2022 15:48:54 +0200 Subject: [PATCH] outside of borrowck, do not provide an implicit_region_bound see comment added to the field in `VerifyBoundCx`. --- .../src/type_check/constraint_conversion.rs | 6 +++--- .../src/type_check/free_region_relations.rs | 4 ++-- .../rustc_borrowck/src/type_check/input_output.rs | 2 +- compiler/rustc_borrowck/src/type_check/mod.rs | 4 ++-- .../rustc_infer/src/infer/outlives/obligations.rs | 13 ++----------- compiler/rustc_infer/src/infer/outlives/verify.rs | 5 +++++ .../rustc_trait_selection/src/traits/auto_trait.rs | 2 +- .../rustc_trait_selection/src/traits/coherence.rs | 6 +----- compiler/rustc_typeck/src/check/regionck.rs | 1 - compiler/rustc_typeck/src/check/wfcheck.rs | 8 +------- 10 files changed, 18 insertions(+), 33 deletions(-) diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs index 3c9e3870aeac..6f7adc218b2e 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: Option>, + implicit_region_bound: 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: Option>, + implicit_region_bound: ty::Region<'tcx>, param_env: ty::ParamEnv<'tcx>, locations: Locations, span: Span, @@ -120,7 +120,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> { &mut *self, tcx, region_bound_pairs, - implicit_region_bound, + Some(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 813307356c4c..421ef5be8128 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: Option>, + implicit_region_bound: ty::Region<'tcx>, universal_regions: &Rc>, 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>, - implicit_region_bound: Option>, + implicit_region_bound: 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 2259a59e1956..2a6ca5246daa 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, - Some(self.implicit_region_bound), + 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 355254fe9429..542fc6b0f485 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, - Some(implicit_region_bound), + 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, - Some(self.implicit_region_bound), + self.implicit_region_bound, self.param_env, locations, locations.span(self.body), diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs index a268493b28f6..1c1906f3375a 100644 --- a/compiler/rustc_infer/src/infer/outlives/obligations.rs +++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs @@ -141,9 +141,6 @@ 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. @@ -151,7 +148,6 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { pub fn process_registered_region_obligations( &self, region_bound_pairs_map: &FxHashMap>, - implicit_region_bound: Option>, param_env: ty::ParamEnv<'tcx>, ) { assert!( @@ -170,13 +166,8 @@ 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, - implicit_region_bound, - param_env, - ); + let outlives = + &mut TypeOutlives::new(self, self.tcx, ®ion_bound_pairs, None, 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 191f5f18ec2a..1ffa070687f4 100644 --- a/compiler/rustc_infer/src/infer/outlives/verify.rs +++ b/compiler/rustc_infer/src/infer/outlives/verify.rs @@ -16,6 +16,11 @@ 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>, param_env: ty::ParamEnv<'tcx>, } diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index a63790b594d8..90ff07cba026 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, None, full_env); + infcx.process_registered_region_obligations(&body_id_map, 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 b37db4b9e182..2b26b916d328 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -407,11 +407,7 @@ 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(), - Some(tcx.lifetimes.re_root_empty), - param_env, - ); + infcx.process_registered_region_obligations(outlives_env.region_bound_pairs_map(), param_env); let errors = infcx.resolve_regions(region_context, &outlives_env); diff --git a/compiler/rustc_typeck/src/check/regionck.rs b/compiler/rustc_typeck/src/check/regionck.rs index 161ec31793dd..0ce639220989 100644 --- a/compiler/rustc_typeck/src/check/regionck.rs +++ b/compiler/rustc_typeck/src/check/regionck.rs @@ -366,7 +366,6 @@ 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 793121538957..ae478842c3ab 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -596,13 +596,7 @@ 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, - Some(infcx.tcx.lifetimes.re_root_empty), - param_env, - ); + let outlives = &mut TypeOutlives::new(infcx, tcx, region_bound_pairs, None, param_env); outlives.type_must_outlive(origin, ty, region); }) }