diff --git a/compiler/rustc_infer/src/infer/canonical/query_response.rs b/compiler/rustc_infer/src/infer/canonical/query_response.rs index 8938ed78a94d7..7120d5ad93455 100644 --- a/compiler/rustc_infer/src/infer/canonical/query_response.rs +++ b/compiler/rustc_infer/src/infer/canonical/query_response.rs @@ -128,7 +128,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { let region_constraints = self.with_region_constraints(|region_constraints| { make_query_region_constraints( tcx, - region_obligations.iter().map(|(_, r_o)| (r_o.sup_type, r_o.sub_region)), + region_obligations.iter().map(|r_o| (r_o.sup_type, r_o.sub_region)), region_constraints, ) }); diff --git a/compiler/rustc_infer/src/infer/free_regions.rs b/compiler/rustc_infer/src/infer/free_regions.rs index 082eb1bf11101..fad949a3bc6a1 100644 --- a/compiler/rustc_infer/src/infer/free_regions.rs +++ b/compiler/rustc_infer/src/infer/free_regions.rs @@ -4,7 +4,6 @@ //! and use that to decide when one free region outlives another, and so forth. use rustc_data_structures::transitive_relation::TransitiveRelation; -use rustc_hir::def_id::DefId; use rustc_middle::ty::{self, Lift, Region, TyCtxt}; /// Combines a `FreeRegionMap` and a `TyCtxt`. @@ -14,16 +13,13 @@ use rustc_middle::ty::{self, Lift, Region, TyCtxt}; pub(crate) struct RegionRelations<'a, 'tcx> { pub tcx: TyCtxt<'tcx>, - /// The context used for debug messages - pub context: DefId, - /// Free-region relationships. pub free_regions: &'a FreeRegionMap<'tcx>, } impl<'a, 'tcx> RegionRelations<'a, 'tcx> { - pub fn new(tcx: TyCtxt<'tcx>, context: DefId, free_regions: &'a FreeRegionMap<'tcx>) -> Self { - Self { tcx, context, free_regions } + pub fn new(tcx: TyCtxt<'tcx>, free_regions: &'a FreeRegionMap<'tcx>) -> Self { + Self { tcx, free_regions } } pub fn lub_free_regions(&self, r_a: Region<'tcx>, r_b: Region<'tcx>) -> Region<'tcx> { 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 68c709a2e24d3..87fa22b3835ef 100644 --- a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs +++ b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs @@ -120,13 +120,9 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> { ) -> LexicalRegionResolutions<'tcx> { let mut var_data = self.construct_var_data(self.tcx()); - // Dorky hack to cause `dump_constraints` to only get called - // if debug mode is enabled: - debug!( - "----() End constraint listing (context={:?}) {:?}---", - self.region_rels.context, - self.dump_constraints(self.region_rels) - ); + if cfg!(debug_assertions) { + self.dump_constraints(); + } let graph = self.construct_graph(); self.expand_givens(&graph); @@ -156,8 +152,8 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> { } } - fn dump_constraints(&self, free_regions: &RegionRelations<'_, 'tcx>) { - debug!("----() Start constraint listing (context={:?}) ()----", free_regions.context); + #[instrument(level = "debug", skip(self))] + fn dump_constraints(&self) { for (idx, (constraint, _)) in self.data.constraints.iter().enumerate() { debug!("Constraint {} => {:?}", idx, constraint); } diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs index 6f88b83a47321..c73302c7e415a 100644 --- a/compiler/rustc_infer/src/infer/mod.rs +++ b/compiler/rustc_infer/src/infer/mod.rs @@ -15,7 +15,6 @@ use rustc_data_structures::sync::Lrc; use rustc_data_structures::undo_log::Rollback; use rustc_data_structures::unify as ut; use rustc_errors::{DiagnosticBuilder, ErrorGuaranteed}; -use rustc_hir as hir; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_middle::infer::canonical::{Canonical, CanonicalVarValues}; use rustc_middle::infer::unify_key::{ConstVarValue, ConstVariableValue}; @@ -147,7 +146,7 @@ pub struct InferCtxtInner<'tcx> { /// for each body-id in this map, which will process the /// obligations within. This is expected to be done 'late enough' /// that all type inference variables have been bound and so forth. - region_obligations: Vec<(hir::HirId, RegionObligation<'tcx>)>, + region_obligations: Vec>, undo_log: InferCtxtUndoLogs<'tcx>, @@ -171,7 +170,7 @@ impl<'tcx> InferCtxtInner<'tcx> { } #[inline] - pub fn region_obligations(&self) -> &[(hir::HirId, RegionObligation<'tcx>)] { + pub fn region_obligations(&self) -> &[RegionObligation<'tcx>] { &self.region_obligations } @@ -1267,7 +1266,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { /// `resolve_vars_if_possible` as well as `fully_resolve`. pub fn resolve_regions( &self, - region_context: DefId, outlives_env: &OutlivesEnvironment<'tcx>, ) -> Vec> { let (var_infos, data) = { @@ -1286,8 +1284,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { .into_infos_and_data() }; - let region_rels = - &RegionRelations::new(self.tcx, region_context, outlives_env.free_region_map()); + let region_rels = &RegionRelations::new(self.tcx, outlives_env.free_region_map()); let (lexical_region_resolutions, errors) = lexical_region_resolve::resolve(outlives_env.param_env, region_rels, var_infos, data); @@ -1302,12 +1299,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { /// result. After this, no more unification operations should be /// done -- or the compiler will panic -- but it is legal to use /// `resolve_vars_if_possible` as well as `fully_resolve`. - pub fn resolve_regions_and_report_errors( - &self, - region_context: DefId, - outlives_env: &OutlivesEnvironment<'tcx>, - ) { - let errors = self.resolve_regions(region_context, outlives_env); + pub fn resolve_regions_and_report_errors(&self, outlives_env: &OutlivesEnvironment<'tcx>) { + let errors = self.resolve_regions(outlives_env); if !self.is_tainted_by_errors() { // As a heuristic, just skip reporting region errors diff --git a/compiler/rustc_infer/src/infer/outlives/env.rs b/compiler/rustc_infer/src/infer/outlives/env.rs index 9ddda7b92eb5a..b897de7315a02 100644 --- a/compiler/rustc_infer/src/infer/outlives/env.rs +++ b/compiler/rustc_infer/src/infer/outlives/env.rs @@ -1,8 +1,6 @@ use crate::infer::free_regions::FreeRegionMap; use crate::infer::{GenericKind, InferCtxt}; use crate::traits::query::OutlivesBound; -use rustc_data_structures::fx::FxHashMap; -use rustc_hir as hir; use rustc_middle::ty::{self, ReEarlyBound, ReFree, ReVar, Region}; use super::explicit_outlives_bounds; @@ -31,9 +29,7 @@ pub struct OutlivesEnvironment<'tcx> { pub param_env: ty::ParamEnv<'tcx>, free_region_map: FreeRegionMap<'tcx>, - // Contains, for each body B that we are checking (that is, the fn - // item, but also any nested closures), the set of implied region - // bounds that are in scope in that particular body. + // Contains the implied region bounds in scope for our current body. // // Example: // @@ -43,24 +39,15 @@ pub struct OutlivesEnvironment<'tcx> { // } // body B0 // ``` // - // Here, for body B0, the list would be `[T: 'a]`, because we + // Here, when checking the body B0, the list would be `[T: 'a]`, because we // infer that `T` must outlive `'a` from the implied bounds on the // fn declaration. // - // For the body B1, the list would be `[T: 'a, T: 'b]`, because we + // For the body B1 however, the list would be `[T: 'a, T: 'b]`, because we // also can see that -- within the closure body! -- `T` must // outlive `'b`. This is not necessarily true outside the closure // body, since the closure may never be called. - // - // We collect this map as we descend the tree. We then use the - // results when proving outlives obligations like `T: 'x` later - // (e.g., if `T: 'x` must be proven within the body B1, then we - // know it is true if either `'a: 'x` or `'b: 'x`). - region_bound_pairs_map: FxHashMap>, - - // Used to compute `region_bound_pairs_map`: contains the set of - // in-scope region-bound pairs thus far. - region_bound_pairs_accum: RegionBoundPairs<'tcx>, + region_bound_pairs: RegionBoundPairs<'tcx>, } /// "Region-bound pairs" tracks outlives relations that are known to @@ -73,8 +60,7 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> { let mut env = OutlivesEnvironment { param_env, free_region_map: Default::default(), - region_bound_pairs_map: Default::default(), - region_bound_pairs_accum: vec![], + region_bound_pairs: Default::default(), }; env.add_outlives_bounds(None, explicit_outlives_bounds(param_env)); @@ -87,62 +73,9 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> { &self.free_region_map } - /// Borrows current value of the `region_bound_pairs`. - pub fn region_bound_pairs_map(&self) -> &FxHashMap> { - &self.region_bound_pairs_map - } - - /// This is a hack to support the old-school regionck, which - /// processes region constraints from the main function and the - /// closure together. In that context, when we enter a closure, we - /// want to be able to "save" the state of the surrounding a - /// function. We can then add implied bounds and the like from the - /// closure arguments into the environment -- these should only - /// apply in the closure body, so once we exit, we invoke - /// `pop_snapshot_post_typeck_child` to remove them. - /// - /// Example: - /// - /// ```ignore (pseudo-rust) - /// fn foo() { - /// callback(for<'a> |x: &'a T| { - /// // ^^^^^^^ not legal syntax, but probably should be - /// // within this closure body, `T: 'a` holds - /// }) - /// } - /// ``` - /// - /// This "containment" of closure's effects only works so well. In - /// particular, we (intentionally) leak relationships between free - /// regions that are created by the closure's bounds. The case - /// where this is useful is when you have (e.g.) a closure with a - /// signature like `for<'a, 'b> fn(x: &'a &'b u32)` -- in this - /// case, we want to keep the relationship `'b: 'a` in the - /// free-region-map, so that later if we have to take `LUB('b, - /// 'a)` we can get the result `'b`. - /// - /// I have opted to keep **all modifications** to the - /// free-region-map, however, and not just those that concern free - /// variables bound in the closure. The latter seems more correct, - /// but it is not the existing behavior, and I could not find a - /// case where the existing behavior went wrong. In any case, it - /// seems like it'd be readily fixed if we wanted. There are - /// similar leaks around givens that seem equally suspicious, to - /// be honest. --nmatsakis - pub fn push_snapshot_pre_typeck_child(&self) -> usize { - self.region_bound_pairs_accum.len() - } - - /// See `push_snapshot_pre_typeck_child`. - pub fn pop_snapshot_post_typeck_child(&mut self, len: usize) { - self.region_bound_pairs_accum.truncate(len); - } - - /// Save the current set of region-bound pairs under the given `body_id`. - pub fn save_implied_bounds(&mut self, body_id: hir::HirId) { - let old = - self.region_bound_pairs_map.insert(body_id, self.region_bound_pairs_accum.clone()); - assert!(old.is_none()); + /// Borrows current `region_bound_pairs`. + pub fn region_bound_pairs(&self) -> &RegionBoundPairs<'tcx> { + &self.region_bound_pairs } /// Processes outlives bounds that are known to hold, whether from implied or other sources. @@ -164,11 +97,10 @@ impl<'a, 'tcx> OutlivesEnvironment<'tcx> { debug!("add_outlives_bounds: outlives_bound={:?}", outlives_bound); match outlives_bound { OutlivesBound::RegionSubParam(r_a, param_b) => { - self.region_bound_pairs_accum.push((r_a, GenericKind::Param(param_b))); + self.region_bound_pairs.push((r_a, GenericKind::Param(param_b))); } OutlivesBound::RegionSubProjection(r_a, projection_b) => { - self.region_bound_pairs_accum - .push((r_a, GenericKind::Projection(projection_b))); + self.region_bound_pairs.push((r_a, GenericKind::Projection(projection_b))); } OutlivesBound::RegionSubRegion(r_a, r_b) => { if let (ReEarlyBound(_) | ReFree(_), ReVar(vid_b)) = (r_a.kind(), r_b.kind()) { diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs index 1c1906f3375af..b839566bec99f 100644 --- a/compiler/rustc_infer/src/infer/outlives/obligations.rs +++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs @@ -60,18 +60,16 @@ //! imply that `'b: 'a`. use crate::infer::outlives::components::{push_outlives_components, Component}; +use crate::infer::outlives::env::OutlivesEnvironment; use crate::infer::outlives::env::RegionBoundPairs; use crate::infer::outlives::verify::VerifyBoundCx; use crate::infer::{ self, GenericKind, InferCtxt, RegionObligation, SubregionOrigin, UndoLog, VerifyBound, }; use crate::traits::{ObligationCause, ObligationCauseCode}; +use rustc_data_structures::undo_log::UndoLogs; use rustc_middle::ty::subst::GenericArgKind; use rustc_middle::ty::{self, Region, Ty, TyCtxt, TypeFoldable}; - -use rustc_data_structures::fx::FxHashMap; -use rustc_data_structures::undo_log::UndoLogs; -use rustc_hir as hir; use smallvec::smallvec; impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { @@ -80,16 +78,11 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { /// and later processed by regionck, when full type information is /// available (see `region_obligations` field for more /// information). - pub fn register_region_obligation( - &self, - body_id: hir::HirId, - obligation: RegionObligation<'tcx>, - ) { - debug!("register_region_obligation(body_id={:?}, obligation={:?})", body_id, obligation); - + #[instrument(level = "debug", skip(self))] + pub fn register_region_obligation(&self, obligation: RegionObligation<'tcx>) { let mut inner = self.inner.borrow_mut(); inner.undo_log.push(UndoLog::PushRegionObligation); - inner.region_obligations.push((body_id, obligation)); + inner.region_obligations.push(obligation); } pub fn register_region_obligation_with_cause( @@ -109,14 +102,11 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { ) }); - self.register_region_obligation( - cause.body_id, - RegionObligation { sup_type, sub_region, origin }, - ); + self.register_region_obligation(RegionObligation { sup_type, sub_region, origin }); } /// Trait queries just want to pass back type obligations "as is" - pub fn take_registered_region_obligations(&self) -> Vec<(hir::HirId, RegionObligation<'tcx>)> { + pub fn take_registered_region_obligations(&self) -> Vec> { std::mem::take(&mut self.inner.borrow_mut().region_obligations) } @@ -144,10 +134,10 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { /// - `param_env` is the parameter environment for the enclosing function. /// - `body_id` is the body-id whose region obligations are being /// processed. - #[instrument(level = "debug", skip(self, region_bound_pairs_map))] + #[instrument(level = "debug", skip(self, region_bound_pairs))] pub fn process_registered_region_obligations( &self, - region_bound_pairs_map: &FxHashMap>, + region_bound_pairs: &RegionBoundPairs<'tcx>, param_env: ty::ParamEnv<'tcx>, ) { assert!( @@ -157,7 +147,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> { let my_region_obligations = self.take_registered_region_obligations(); - for (body_id, RegionObligation { sup_type, sub_region, origin }) in my_region_obligations { + for RegionObligation { sup_type, sub_region, origin } in my_region_obligations { debug!( "process_registered_region_obligations: sup_type={:?} sub_region={:?} origin={:?}", sup_type, sub_region, origin @@ -165,18 +155,23 @@ 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); - outlives.type_must_outlive(origin, sup_type, sub_region); - } else { - self.tcx.sess.delay_span_bug( - origin.span(), - &format!("no region-bound-pairs for {:?}", body_id), - ); - } + let outlives = + &mut TypeOutlives::new(self, self.tcx, ®ion_bound_pairs, None, param_env); + outlives.type_must_outlive(origin, sup_type, sub_region); } } + + pub fn check_region_obligations_and_report_errors( + &self, + outlives_env: &OutlivesEnvironment<'tcx>, + ) { + self.process_registered_region_obligations( + outlives_env.region_bound_pairs(), + outlives_env.param_env, + ); + + self.resolve_regions_and_report_errors(outlives_env) + } } /// The `TypeOutlives` struct has the job of "lowering" a `T: 'a` diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 90ff07cba026a..49434ec142828 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -212,15 +212,7 @@ impl<'tcx> AutoTraitFinder<'tcx> { panic!("Unable to fulfill trait {:?} for '{:?}': {:?}", trait_did, ty, errors); } - let body_id_map: FxHashMap<_, _> = infcx - .inner - .borrow() - .region_obligations() - .iter() - .map(|&(id, _)| (id, vec![])) - .collect(); - - infcx.process_registered_region_obligations(&body_id_map, full_env); + infcx.process_registered_region_obligations(&Default::default(), 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 2b26b916d3289..ae69f2f7eb324 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -16,7 +16,6 @@ use crate::traits::{ //use rustc_data_structures::fx::FxHashMap; use rustc_errors::Diagnostic; use rustc_hir::def_id::{DefId, LOCAL_CRATE}; -use rustc_hir::CRATE_HIR_ID; use rustc_infer::infer::{InferCtxt, TyCtxtInferExt}; use rustc_infer::traits::{util, TraitEngine}; use rustc_middle::traits::specialization_graph::OverlapMode; @@ -317,14 +316,13 @@ fn negative_impl<'cx, 'tcx>( let (subject2, obligations) = impl_subject_and_oblig(selcx, impl_env, impl2_def_id, impl2_substs); - !equate(&infcx, impl_env, impl1_def_id, subject1, subject2, obligations) + !equate(&infcx, impl_env, subject1, subject2, obligations) }) } fn equate<'cx, 'tcx>( infcx: &InferCtxt<'cx, 'tcx>, impl_env: ty::ParamEnv<'tcx>, - impl1_def_id: DefId, subject1: ImplSubject<'tcx>, subject2: ImplSubject<'tcx>, obligations: impl Iterator>, @@ -341,7 +339,7 @@ fn equate<'cx, 'tcx>( let opt_failing_obligation = obligations .into_iter() .chain(more_obligations) - .find(|o| negative_impl_exists(selcx, impl_env, impl1_def_id, o)); + .find(|o| negative_impl_exists(selcx, impl_env, o)); if let Some(failing_obligation) = opt_failing_obligation { debug!("overlap: obligation unsatisfiable {:?}", failing_obligation); @@ -356,18 +354,17 @@ fn equate<'cx, 'tcx>( fn negative_impl_exists<'cx, 'tcx>( selcx: &SelectionContext<'cx, 'tcx>, param_env: ty::ParamEnv<'tcx>, - region_context: DefId, o: &PredicateObligation<'tcx>, ) -> bool { let infcx = &selcx.infcx().fork(); - if resolve_negative_obligation(infcx, param_env, region_context, o) { + if resolve_negative_obligation(infcx, param_env, o) { return true; } // Try to prove a negative obligation exists for super predicates for o in util::elaborate_predicates(infcx.tcx, iter::once(o.predicate)) { - if resolve_negative_obligation(infcx, param_env, region_context, &o) { + if resolve_negative_obligation(infcx, param_env, &o) { return true; } } @@ -379,7 +376,6 @@ fn negative_impl_exists<'cx, 'tcx>( fn resolve_negative_obligation<'cx, 'tcx>( infcx: &InferCtxt<'cx, 'tcx>, param_env: ty::ParamEnv<'tcx>, - region_context: DefId, o: &PredicateObligation<'tcx>, ) -> bool { let tcx = infcx.tcx; @@ -397,19 +393,11 @@ fn resolve_negative_obligation<'cx, 'tcx>( return false; } - let mut outlives_env = OutlivesEnvironment::new(param_env); - // FIXME -- add "assumed to be well formed" types into the `outlives_env` - - // "Save" the accumulated implied bounds into the outlives environment - // (due to the FIXME above, there aren't any, but this step is still needed). - // The "body id" is given as `CRATE_HIR_ID`, which is the same body-id used - // by the "dummy" causes elsewhere (body-id is only relevant when checking - // 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); + // FIXME -- also add "assumed to be well formed" types into the `outlives_env` + let outlives_env = OutlivesEnvironment::new(param_env); + infcx.process_registered_region_obligations(outlives_env.region_bound_pairs(), param_env); - let errors = infcx.resolve_regions(region_context, &outlives_env); + let errors = infcx.resolve_regions(&outlives_env); if !errors.is_empty() { return false; diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index 34b0f431b8e2d..b45f72e8748d6 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -198,17 +198,13 @@ pub fn type_known_to_meet_bound_modulo_regions<'a, 'tcx>( } } +#[instrument(level = "debug", skip(tcx, elaborated_env))] fn do_normalize_predicates<'tcx>( tcx: TyCtxt<'tcx>, - region_context: DefId, cause: ObligationCause<'tcx>, elaborated_env: ty::ParamEnv<'tcx>, predicates: Vec>, ) -> Result>, ErrorGuaranteed> { - debug!( - "do_normalize_predicates(predicates={:?}, region_context={:?}, cause={:?})", - predicates, region_context, cause, - ); let span = cause.span; tcx.infer_ctxt().enter(|infcx| { // FIXME. We should really... do something with these region @@ -240,7 +236,7 @@ fn do_normalize_predicates<'tcx>( // cares about declarations like `'a: 'b`. let outlives_env = OutlivesEnvironment::new(elaborated_env); - infcx.resolve_regions_and_report_errors(region_context, &outlives_env); + infcx.resolve_regions_and_report_errors(&outlives_env); let predicates = match infcx.fully_resolve(predicates) { Ok(predicates) => predicates, @@ -269,9 +265,9 @@ fn do_normalize_predicates<'tcx>( // FIXME: this is gonna need to be removed ... /// Normalizes the parameter environment, reporting errors if they occur. +#[instrument(level = "debug", skip(tcx))] pub fn normalize_param_env_or_error<'tcx>( tcx: TyCtxt<'tcx>, - region_context: DefId, unnormalized_env: ty::ParamEnv<'tcx>, cause: ObligationCause<'tcx>, ) -> ty::ParamEnv<'tcx> { @@ -289,12 +285,6 @@ pub fn normalize_param_env_or_error<'tcx>( // parameter environments once for every fn as it goes, // and errors will get reported then; so outside of type inference we // can be sure that no errors should occur. - - debug!( - "normalize_param_env_or_error(region_context={:?}, unnormalized_env={:?}, cause={:?})", - region_context, unnormalized_env, cause - ); - let mut predicates: Vec<_> = util::elaborate_predicates(tcx, unnormalized_env.caller_bounds().into_iter()) .map(|obligation| obligation.predicate) @@ -338,7 +328,6 @@ pub fn normalize_param_env_or_error<'tcx>( ); let Ok(non_outlives_predicates) = do_normalize_predicates( tcx, - region_context, cause.clone(), elaborated_env, predicates, @@ -362,7 +351,6 @@ pub fn normalize_param_env_or_error<'tcx>( ); let Ok(outlives_predicates) = do_normalize_predicates( tcx, - region_context, cause, outlives_env, outlives_predicates, diff --git a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs index 25cc6e9f9f2f1..aad3c37f84e5a 100644 --- a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs +++ b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs @@ -1,73 +1,7 @@ -use crate::infer::at::At; -use crate::infer::canonical::OriginalQueryValues; -use crate::infer::InferOk; - -use rustc_middle::ty::subst::GenericArg; use rustc_middle::ty::{self, Ty, TyCtxt}; pub use rustc_middle::traits::query::{DropckConstraint, DropckOutlivesResult}; -pub trait AtExt<'tcx> { - fn dropck_outlives(&self, ty: Ty<'tcx>) -> InferOk<'tcx, Vec>>; -} - -impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx> { - /// Given a type `ty` of some value being dropped, computes a set - /// of "kinds" (types, regions) that must be outlive the execution - /// of the destructor. These basically correspond to data that the - /// destructor might access. This is used during regionck to - /// impose "outlives" constraints on any lifetimes referenced - /// within. - /// - /// The rules here are given by the "dropck" RFCs, notably [#1238] - /// and [#1327]. This is a fixed-point computation, where we - /// explore all the data that will be dropped (transitively) when - /// a value of type `ty` is dropped. For each type T that will be - /// dropped and which has a destructor, we must assume that all - /// the types/regions of T are live during the destructor, unless - /// they are marked with a special attribute (`#[may_dangle]`). - /// - /// [#1238]: https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md - /// [#1327]: https://github.com/rust-lang/rfcs/blob/master/text/1327-dropck-param-eyepatch.md - fn dropck_outlives(&self, ty: Ty<'tcx>) -> InferOk<'tcx, Vec>> { - debug!("dropck_outlives(ty={:?}, param_env={:?})", ty, self.param_env,); - - // Quick check: there are a number of cases that we know do not require - // any destructor. - let tcx = self.infcx.tcx; - if trivial_dropck_outlives(tcx, ty) { - return InferOk { value: vec![], obligations: vec![] }; - } - - let mut orig_values = OriginalQueryValues::default(); - let c_ty = self.infcx.canonicalize_query(self.param_env.and(ty), &mut orig_values); - let span = self.cause.span; - debug!("c_ty = {:?}", c_ty); - if let Ok(result) = tcx.dropck_outlives(c_ty) - && result.is_proven() - && let Ok(InferOk { value, obligations }) = - self.infcx.instantiate_query_response_and_region_obligations( - self.cause, - self.param_env, - &orig_values, - result, - ) - { - let ty = self.infcx.resolve_vars_if_possible(ty); - let kinds = value.into_kinds_reporting_overflows(tcx, span, ty); - return InferOk { value: kinds, obligations }; - } - - // Errors and ambiguity in dropck occur in two cases: - // - unresolved inference variables at the end of typeck - // - non well-formed types where projections cannot be resolved - // Either of these should have created an error before. - tcx.sess.delay_span_bug(span, "dtorck encountered internal error"); - - InferOk { value: vec![], obligations: vec![] } - } -} - /// This returns true if the type `ty` is "trivial" for /// dropck-outlives -- that is, if it doesn't require any types to /// outlive. This is similar but not *quite* the same as the @@ -79,6 +13,8 @@ impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx> { /// /// Note also that `needs_drop` requires a "global" type (i.e., one /// with erased regions), but this function does not. +/// +// FIXME(@lcnr): remove this module and move this function somewhere else. pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool { match ty.kind() { // None of these types have a destructor and hence they do not @@ -105,7 +41,7 @@ pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool { ty::Array(ty, _) | ty::Slice(ty) => trivial_dropck_outlives(tcx, *ty), // (T1..Tn) and closures have same properties as T1..Tn -- - // check if *any* of those are trivial. + // check if *all* of them are trivial. ty::Tuple(tys) => tys.iter().all(|t| trivial_dropck_outlives(tcx, t)), ty::Closure(_, ref substs) => { trivial_dropck_outlives(tcx, substs.as_closure().tupled_upvars_ty()) diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs index 605c9ace5ed06..c9d46b2810ddb 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs @@ -95,7 +95,7 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( infcx.tcx, region_obligations .iter() - .map(|(_, r_o)| (r_o.sup_type, r_o.sub_region)) + .map(|r_o| (r_o.sup_type, r_o.sub_region)) .map(|(ty, r)| (infcx.resolve_vars_if_possible(ty), r)), ®ion_constraint_data, ); diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs index 38ae6a25b1806..1d345caf69971 100644 --- a/compiler/rustc_ty_utils/src/ty.rs +++ b/compiler/rustc_ty_utils/src/ty.rs @@ -211,7 +211,7 @@ fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> { tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id) }); let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id); - traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause) + traits::normalize_param_env_or_error(tcx, unnormalized_env, cause) } /// Elaborate the environment. diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs index 6222dbb40741c..ef74214781e5d 100644 --- a/compiler/rustc_typeck/src/check/check.rs +++ b/compiler/rustc_typeck/src/check/check.rs @@ -13,6 +13,7 @@ use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::Visitor; use rustc_hir::lang_items::LangItem; use rustc_hir::{ItemKind, Node, PathSegment}; +use rustc_infer::infer::outlives::env::OutlivesEnvironment; use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt}; use rustc_infer::traits::Obligation; @@ -736,10 +737,8 @@ fn check_opaque_meets_bounds<'tcx>( hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => {} // Can have different predicates to their defining use hir::OpaqueTyOrigin::TyAlias => { - // Finally, resolve all regions. This catches wily misuses of - // lifetime parameters. - let fcx = FnCtxt::new(&inh, param_env, hir_id); - fcx.regionck_item(hir_id, span, FxHashSet::default()); + let outlives_environment = OutlivesEnvironment::new(param_env); + infcx.check_region_obligations_and_report_errors(&outlives_environment); } } diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs index 95c82a7d2c3d8..0a9b6863ef577 100644 --- a/compiler/rustc_typeck/src/check/compare_method.rs +++ b/compiler/rustc_typeck/src/check/compare_method.rs @@ -1,3 +1,4 @@ +use crate::check::regionck::OutlivesEnvironmentExt; use crate::errors::LifetimesOrBoundsMismatchOnTrait; use rustc_data_structures::stable_set::FxHashSet; use rustc_errors::{pluralize, struct_span_err, Applicability, DiagnosticId, ErrorGuaranteed}; @@ -5,6 +6,7 @@ use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::intravisit; use rustc_hir::{GenericParamKind, ImplItemKind, TraitItemKind}; +use rustc_infer::infer::outlives::env::OutlivesEnvironment; use rustc_infer::infer::{self, InferOk, TyCtxtInferExt}; use rustc_infer::traits::util; use rustc_middle::ty::error::{ExpectedFound, TypeError}; @@ -78,10 +80,11 @@ fn compare_predicate_entailment<'tcx>( let trait_to_impl_substs = impl_trait_ref.substs; // This node-id should be used for the `body_id` field on each - // `ObligationCause` (and the `FnCtxt`). This is what - // `regionck_item` expects. + // `ObligationCause` (and the `FnCtxt`). + // + // FIXME(@lcnr): remove that after removing `cause.body_id` from + // obligations. let impl_m_hir_id = tcx.hir().local_def_id_to_hir_id(impl_m.def_id.expect_local()); - // We sometimes modify the span further down. let mut cause = ObligationCause::new( impl_m_span, @@ -208,8 +211,7 @@ fn compare_predicate_entailment<'tcx>( Reveal::UserFacing, hir::Constness::NotConst, ); - let param_env = - traits::normalize_param_env_or_error(tcx, impl_m.def_id, param_env, normalize_cause); + let param_env = traits::normalize_param_env_or_error(tcx, param_env, normalize_cause); tcx.infer_ctxt().enter(|infcx| { let inh = Inherited::new(infcx, impl_m.def_id.expect_local()); @@ -399,8 +401,9 @@ fn compare_predicate_entailment<'tcx>( // Finally, resolve all regions. This catches wily misuses of // lifetime parameters. - let fcx = FnCtxt::new(&inh, param_env, impl_m_hir_id); - fcx.regionck_item(impl_m_hir_id, impl_m_span, wf_tys); + let mut outlives_environment = OutlivesEnvironment::new(param_env); + outlives_environment.add_implied_bounds(infcx, wf_tys, impl_m_hir_id); + infcx.check_region_obligations_and_report_errors(&outlives_environment); Ok(()) }) @@ -1155,8 +1158,8 @@ pub(crate) fn compare_const_impl<'tcx>( return; } - let fcx = FnCtxt::new(&inh, param_env, impl_c_hir_id); - fcx.regionck_item(impl_c_hir_id, impl_c_span, FxHashSet::default()); + let outlives_environment = OutlivesEnvironment::new(param_env); + infcx.resolve_regions_and_report_errors(&outlives_environment); }); } @@ -1247,12 +1250,7 @@ fn compare_type_predicate_entailment<'tcx>( Reveal::UserFacing, hir::Constness::NotConst, ); - let param_env = traits::normalize_param_env_or_error( - tcx, - impl_ty.def_id, - param_env, - normalize_cause.clone(), - ); + let param_env = traits::normalize_param_env_or_error(tcx, param_env, normalize_cause.clone()); tcx.infer_ctxt().enter(|infcx| { let inh = Inherited::new(infcx, impl_ty.def_id.expect_local()); let infcx = &inh.infcx; @@ -1279,8 +1277,8 @@ fn compare_type_predicate_entailment<'tcx>( // Finally, resolve all regions. This catches wily misuses of // lifetime parameters. - let fcx = FnCtxt::new(&inh, param_env, impl_ty_hir_id); - fcx.regionck_item(impl_ty_hir_id, impl_ty_span, FxHashSet::default()); + let outlives_environment = OutlivesEnvironment::new(param_env); + infcx.check_region_obligations_and_report_errors(&outlives_environment); Ok(()) }) @@ -1504,12 +1502,16 @@ pub fn check_type_bounds<'tcx>( // Finally, resolve all regions. This catches wily misuses of // lifetime parameters. + // + // FIXME: Remove that `FnCtxt`. let fcx = FnCtxt::new(&inh, param_env, impl_ty_hir_id); let implied_bounds = match impl_ty.container { ty::TraitContainer(_) => FxHashSet::default(), ty::ImplContainer(def_id) => fcx.impl_implied_bounds(def_id, impl_ty_span), }; - fcx.regionck_item(impl_ty_hir_id, impl_ty_span, implied_bounds); + let mut outlives_environment = OutlivesEnvironment::new(param_env); + outlives_environment.add_implied_bounds(infcx, implied_bounds, impl_ty_hir_id); + infcx.check_region_obligations_and_report_errors(&outlives_environment); Ok(()) }) diff --git a/compiler/rustc_typeck/src/check/dropck.rs b/compiler/rustc_typeck/src/check/dropck.rs index a4013e10525ee..72095c408075c 100644 --- a/compiler/rustc_typeck/src/check/dropck.rs +++ b/compiler/rustc_typeck/src/check/dropck.rs @@ -1,5 +1,6 @@ -use crate::check::regionck::RegionCtxt; -use crate::hir; +// FIXME(@lcnr): Move this module out of `rustc_typeck`. +// +// We don't do any drop checking during hir typeck. use crate::hir::def_id::{DefId, LocalDefId}; use rustc_errors::{struct_span_err, ErrorGuaranteed}; use rustc_middle::ty::error::TypeError; @@ -7,7 +8,6 @@ use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation}; use rustc_middle::ty::subst::SubstsRef; use rustc_middle::ty::util::IgnoreRegions; use rustc_middle::ty::{self, Predicate, Ty, TyCtxt}; -use rustc_span::Span; /// This function confirms that the `Drop` implementation identified by /// `drop_impl_did` is not any more specialized than the type it is @@ -229,19 +229,6 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>( result } -/// This function is not only checking that the dropck obligations are met for -/// the given type, but it's also currently preventing non-regular recursion in -/// types from causing stack overflows (dropck_no_diverge_on_nonregular_*.rs). -/// -/// FIXME: Completely rip out dropck and regionck. -pub(crate) fn check_drop_obligations<'a, 'tcx>( - _rcx: &mut RegionCtxt<'a, 'tcx>, - _ty: Ty<'tcx>, - _span: Span, - _body_id: hir::HirId, -) { -} - // This is an implementation of the TypeRelation trait with the // aim of simply comparing for equality (without side-effects). // It is not intended to be used anywhere else other than here. diff --git a/compiler/rustc_typeck/src/check/mod.rs b/compiler/rustc_typeck/src/check/mod.rs index 0ede9ef775631..dee58791cec18 100644 --- a/compiler/rustc_typeck/src/check/mod.rs +++ b/compiler/rustc_typeck/src/check/mod.rs @@ -368,7 +368,7 @@ fn typeck_with_fallback<'tcx>( let typeck_results = Inherited::build(tcx, def_id).enter(|inh| { let param_env = tcx.param_env(def_id); - let (fcx, wf_tys) = if let Some(hir::FnSig { header, decl, .. }) = fn_sig { + let fcx = if let Some(hir::FnSig { header, decl, .. }) = fn_sig { let fn_sig = if crate::collect::get_infer_ret_ty(&decl.output).is_some() { let fcx = FnCtxt::new(&inh, param_env, body.value.hir_id); >::ty_of_fn(&fcx, id, header.unsafety, header.abi, decl, None, None) @@ -378,13 +378,7 @@ fn typeck_with_fallback<'tcx>( check_abi(tcx, id, span, fn_sig.abi()); - // When normalizing the function signature, we assume all types are - // well-formed. So, we don't need to worry about the obligations - // from normalization. We could just discard these, but to align with - // compare_method and elsewhere, we just add implied bounds for - // these types. - let mut wf_tys = FxHashSet::default(); - // Compute the fty from point of view of inside the fn. + // Compute the function signature from point of view of inside the fn. let fn_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), fn_sig); let fn_sig = inh.normalize_associated_types_in( body.value.span, @@ -392,10 +386,7 @@ fn typeck_with_fallback<'tcx>( param_env, fn_sig, ); - wf_tys.extend(fn_sig.inputs_and_output.iter()); - - let fcx = check_fn(&inh, param_env, fn_sig, decl, id, body, None, true).0; - (fcx, wf_tys) + check_fn(&inh, param_env, fn_sig, decl, id, body, None, true).0 } else { let fcx = FnCtxt::new(&inh, param_env, body.value.hir_id); let expected_type = body_ty @@ -458,7 +449,7 @@ fn typeck_with_fallback<'tcx>( fcx.write_ty(id, expected_type); - (fcx, FxHashSet::default()) + fcx }; let fallback_has_occurred = fcx.type_inference_fallback(); @@ -490,11 +481,7 @@ fn typeck_with_fallback<'tcx>( fcx.check_asms(); - if fn_sig.is_some() { - fcx.regionck_fn(id, body, span, wf_tys); - } else { - fcx.regionck_expr(body); - } + fcx.infcx.skip_region_resolution(); fcx.resolve_type_vars_in_body(body) }); diff --git a/compiler/rustc_typeck/src/check/regionck.rs b/compiler/rustc_typeck/src/check/regionck.rs index 0ce6392209894..1c3c5f999bca8 100644 --- a/compiler/rustc_typeck/src/check/regionck.rs +++ b/compiler/rustc_typeck/src/check/regionck.rs @@ -1,106 +1,9 @@ -//! The region check is a final pass that runs over the AST after we have -//! inferred the type constraints but before we have actually finalized -//! the types. Its purpose is to embed a variety of region constraints. -//! Inserting these constraints as a separate pass is good because (1) it -//! localizes the code that has to do with region inference and (2) often -//! we cannot know what constraints are needed until the basic types have -//! been inferred. -//! -//! ### Interaction with the borrow checker -//! -//! In general, the job of the borrowck module (which runs later) is to -//! check that all soundness criteria are met, given a particular set of -//! regions. The job of *this* module is to anticipate the needs of the -//! borrow checker and infer regions that will satisfy its requirements. -//! It is generally true that the inference doesn't need to be sound, -//! meaning that if there is a bug and we inferred bad regions, the borrow -//! checker should catch it. This is not entirely true though; for -//! example, the borrow checker doesn't check subtyping, and it doesn't -//! check that region pointers are always live when they are used. It -//! might be worthwhile to fix this so that borrowck serves as a kind of -//! verification step -- that would add confidence in the overall -//! correctness of the compiler, at the cost of duplicating some type -//! checks and effort. -//! -//! ### Inferring the duration of borrows, automatic and otherwise -//! -//! Whenever we introduce a borrowed pointer, for example as the result of -//! a borrow expression `let x = &data`, the lifetime of the pointer `x` -//! is always specified as a region inference variable. `regionck` has the -//! job of adding constraints such that this inference variable is as -//! narrow as possible while still accommodating all uses (that is, every -//! dereference of the resulting pointer must be within the lifetime). -//! -//! #### Reborrows -//! -//! Generally speaking, `regionck` does NOT try to ensure that the data -//! `data` will outlive the pointer `x`. That is the job of borrowck. The -//! one exception is when "re-borrowing" the contents of another borrowed -//! pointer. For example, imagine you have a borrowed pointer `b` with -//! lifetime `L1` and you have an expression `&*b`. The result of this -//! expression will be another borrowed pointer with lifetime `L2` (which is -//! an inference variable). The borrow checker is going to enforce the -//! constraint that `L2 < L1`, because otherwise you are re-borrowing data -//! for a lifetime larger than the original loan. However, without the -//! routines in this module, the region inferencer would not know of this -//! dependency and thus it might infer the lifetime of `L2` to be greater -//! than `L1` (issue #3148). -//! -//! There are a number of troublesome scenarios in the tests -//! `region-dependent-*.rs`, but here is one example: -//! -//! struct Foo { i: i32 } -//! struct Bar { foo: Foo } -//! fn get_i<'a>(x: &'a Bar) -> &'a i32 { -//! let foo = &x.foo; // Lifetime L1 -//! &foo.i // Lifetime L2 -//! } -//! -//! Note that this comes up either with `&` expressions, `ref` -//! bindings, and `autorefs`, which are the three ways to introduce -//! a borrow. -//! -//! The key point here is that when you are borrowing a value that -//! is "guaranteed" by a borrowed pointer, you must link the -//! lifetime of that borrowed pointer (`L1`, here) to the lifetime of -//! the borrow itself (`L2`). What do I mean by "guaranteed" by a -//! borrowed pointer? I mean any data that is reached by first -//! dereferencing a borrowed pointer and then either traversing -//! interior offsets or boxes. We say that the guarantor -//! of such data is the region of the borrowed pointer that was -//! traversed. This is essentially the same as the ownership -//! relation, except that a borrowed pointer never owns its -//! contents. - -use crate::check::dropck; -use crate::check::FnCtxt; -use crate::mem_categorization as mc; use crate::outlives::outlives_bounds::InferCtxtExt as _; use rustc_data_structures::stable_set::FxHashSet; use rustc_hir as hir; -use rustc_hir::def_id::LocalDefId; -use rustc_hir::intravisit::{self, Visitor}; -use rustc_hir::PatKind; use rustc_infer::infer::outlives::env::OutlivesEnvironment; -use rustc_infer::infer::{self, InferCtxt, RegionObligation}; -use rustc_middle::hir::place::{PlaceBase, PlaceWithHirId}; -use rustc_middle::ty::adjustment; -use rustc_middle::ty::{self, Ty}; -use rustc_span::Span; -use std::ops::Deref; - -// a variation on try that just returns unit -macro_rules! ignore_err { - ($e:expr) => { - match $e { - Ok(e) => e, - Err(_) => { - debug!("ignoring mem-categorization error!"); - return (); - } - } - }; -} +use rustc_infer::infer::InferCtxt; +use rustc_middle::ty::Ty; pub(crate) trait OutlivesEnvironmentExt<'tcx> { fn add_implied_bounds( @@ -108,7 +11,6 @@ pub(crate) trait OutlivesEnvironmentExt<'tcx> { infcx: &InferCtxt<'_, 'tcx>, fn_sig_tys: FxHashSet>, body_id: hir::HirId, - span: Span, ); } @@ -135,750 +37,11 @@ impl<'tcx> OutlivesEnvironmentExt<'tcx> for OutlivesEnvironment<'tcx> { infcx: &InferCtxt<'a, 'tcx>, fn_sig_tys: FxHashSet>, body_id: hir::HirId, - span: Span, ) { for ty in fn_sig_tys { let ty = infcx.resolve_vars_if_possible(ty); - let implied_bounds = infcx.implied_outlives_bounds(self.param_env, body_id, ty, span); + let implied_bounds = infcx.implied_outlives_bounds(self.param_env, body_id, ty); self.add_outlives_bounds(Some(infcx), implied_bounds) } } } - -/////////////////////////////////////////////////////////////////////////// -// PUBLIC ENTRY POINTS - -impl<'a, 'tcx> FnCtxt<'a, 'tcx> { - pub fn regionck_expr(&self, body: &'tcx hir::Body<'tcx>) { - let subject = self.tcx.hir().body_owner_def_id(body.id()); - let id = body.value.hir_id; - let mut rcx = RegionCtxt::new(self, id, Subject(subject), self.param_env); - - // There are no add'l implied bounds when checking a - // standalone expr (e.g., the `E` in a type like `[u32; E]`). - rcx.outlives_environment.save_implied_bounds(id); - - if !self.errors_reported_since_creation() { - // regionck assumes typeck succeeded - rcx.visit_body(body); - rcx.visit_region_obligations(id); - } - // Checked by NLL - rcx.fcx.skip_region_resolution(); - } - - /// Region checking during the WF phase for items. `wf_tys` are the - /// types from which we should derive implied bounds, if any. - #[instrument(level = "debug", skip(self))] - pub fn regionck_item(&self, item_id: hir::HirId, span: Span, wf_tys: FxHashSet>) { - let subject = self.tcx.hir().local_def_id(item_id); - let mut rcx = RegionCtxt::new(self, item_id, Subject(subject), self.param_env); - rcx.outlives_environment.add_implied_bounds(self, wf_tys, item_id, span); - rcx.outlives_environment.save_implied_bounds(item_id); - rcx.visit_region_obligations(item_id); - rcx.resolve_regions_and_report_errors(); - } - - /// Region check a function body. Not invoked on closures, but - /// only on the "root" fn item (in which closures may be - /// embedded). Walks the function body and adds various add'l - /// constraints that are needed for region inference. This is - /// separated both to isolate "pure" region constraints from the - /// rest of type check and because sometimes we need type - /// inference to have completed before we can determine which - /// constraints to add. - pub(crate) fn regionck_fn( - &self, - fn_id: hir::HirId, - body: &'tcx hir::Body<'tcx>, - span: Span, - wf_tys: FxHashSet>, - ) { - debug!("regionck_fn(id={})", fn_id); - let subject = self.tcx.hir().body_owner_def_id(body.id()); - let hir_id = body.value.hir_id; - let mut rcx = RegionCtxt::new(self, hir_id, Subject(subject), self.param_env); - // We need to add the implied bounds from the function signature - rcx.outlives_environment.add_implied_bounds(self, wf_tys, fn_id, span); - rcx.outlives_environment.save_implied_bounds(fn_id); - - if !self.errors_reported_since_creation() { - // regionck assumes typeck succeeded - rcx.visit_fn_body(fn_id, body, self.tcx.hir().span(fn_id)); - } - - // Checked by NLL - rcx.fcx.skip_region_resolution(); - } -} - -/////////////////////////////////////////////////////////////////////////// -// INTERNALS - -pub struct RegionCtxt<'a, 'tcx> { - pub fcx: &'a FnCtxt<'a, 'tcx>, - - outlives_environment: OutlivesEnvironment<'tcx>, - - // id of innermost fn body id - body_id: hir::HirId, - body_owner: LocalDefId, - - // id of AST node being analyzed (the subject of the analysis). - subject_def_id: LocalDefId, -} - -impl<'a, 'tcx> Deref for RegionCtxt<'a, 'tcx> { - type Target = FnCtxt<'a, 'tcx>; - fn deref(&self) -> &Self::Target { - self.fcx - } -} - -pub struct Subject(LocalDefId); - -impl<'a, 'tcx> RegionCtxt<'a, 'tcx> { - pub fn new( - fcx: &'a FnCtxt<'a, 'tcx>, - initial_body_id: hir::HirId, - Subject(subject): Subject, - param_env: ty::ParamEnv<'tcx>, - ) -> RegionCtxt<'a, 'tcx> { - let outlives_environment = OutlivesEnvironment::new(param_env); - RegionCtxt { - fcx, - body_id: initial_body_id, - body_owner: subject, - subject_def_id: subject, - outlives_environment, - } - } - - /// Try to resolve the type for the given node, returning `t_err` if an error results. Note that - /// we never care about the details of the error, the same error will be detected and reported - /// in the writeback phase. - /// - /// Note one important point: we do not attempt to resolve *region variables* here. This is - /// because regionck is essentially adding constraints to those region variables and so may yet - /// influence how they are resolved. - /// - /// Consider this silly example: - /// - /// ```ignore UNSOLVED (does replacing @i32 with Box preserve the desired semantics for the example?) - /// fn borrow(x: &i32) -> &i32 {x} - /// fn foo(x: @i32) -> i32 { // block: B - /// let b = borrow(x); // region: - /// *b - /// } - /// ``` - /// - /// Here, the region of `b` will be ``. `` is constrained to be some subregion of the - /// block B and some superregion of the call. If we forced it now, we'd choose the smaller - /// region (the call). But that would make the *b illegal. Since we don't resolve, the type - /// of b will be `&.i32` and then `*b` will require that `` be bigger than the let and - /// the `*b` expression, so we will effectively resolve `` to be the block B. - pub fn resolve_type(&self, unresolved_ty: Ty<'tcx>) -> Ty<'tcx> { - self.resolve_vars_if_possible(unresolved_ty) - } - - /// Try to resolve the type for the given node. - fn resolve_node_type(&self, id: hir::HirId) -> Ty<'tcx> { - let t = self.node_ty(id); - self.resolve_type(t) - } - - /// This is the "main" function when region-checking a function item or a - /// closure within a function item. It begins by updating various fields - /// (e.g., `outlives_environment`) to be appropriate to the function and - /// then adds constraints derived from the function body. - /// - /// Note that it does **not** restore the state of the fields that - /// it updates! This is intentional, since -- for the main - /// function -- we wish to be able to read the final - /// `outlives_environment` and other fields from the caller. For - /// closures, however, we save and restore any "scoped state" - /// before we invoke this function. (See `visit_fn` in the - /// `intravisit::Visitor` impl below.) - fn visit_fn_body( - &mut self, - id: hir::HirId, // the id of the fn itself - body: &'tcx hir::Body<'tcx>, - span: Span, - ) { - // When we enter a function, we can derive - debug!("visit_fn_body(id={:?})", id); - - let body_id = body.id(); - self.body_id = body_id.hir_id; - self.body_owner = self.tcx.hir().body_owner_def_id(body_id); - - let Some(fn_sig) = self.typeck_results.borrow().liberated_fn_sigs().get(id) else { - bug!("No fn-sig entry for id={:?}", id); - }; - - // Collect the types from which we create inferred bounds. - // For the return type, if diverging, substitute `bool` just - // because it will have no effect. - // - // FIXME(#27579) return types should not be implied bounds - let fn_sig_tys: FxHashSet<_> = - fn_sig.inputs().iter().cloned().chain(Some(fn_sig.output())).collect(); - - self.outlives_environment.add_implied_bounds(self.fcx, fn_sig_tys, body_id.hir_id, span); - self.outlives_environment.save_implied_bounds(body_id.hir_id); - self.link_fn_params(body.params); - self.visit_body(body); - self.visit_region_obligations(body_id.hir_id); - } - - fn visit_inline_const(&mut self, id: hir::HirId, body: &'tcx hir::Body<'tcx>) { - debug!("visit_inline_const(id={:?})", id); - - // Save state of current function. We will restore afterwards. - let old_body_id = self.body_id; - let old_body_owner = self.body_owner; - let env_snapshot = self.outlives_environment.push_snapshot_pre_typeck_child(); - - let body_id = body.id(); - self.body_id = body_id.hir_id; - self.body_owner = self.tcx.hir().body_owner_def_id(body_id); - - self.outlives_environment.save_implied_bounds(body_id.hir_id); - - self.visit_body(body); - self.visit_region_obligations(body_id.hir_id); - - // Restore state from previous function. - self.outlives_environment.pop_snapshot_post_typeck_child(env_snapshot); - self.body_id = old_body_id; - self.body_owner = old_body_owner; - } - - fn visit_region_obligations(&mut self, hir_id: hir::HirId) { - debug!("visit_region_obligations: hir_id={:?}", hir_id); - - // region checking can introduce new pending obligations - // which, when processed, might generate new region - // obligations. So make sure we process those. - self.select_all_obligations_or_error(); - } - - fn resolve_regions_and_report_errors(&self) { - self.infcx.process_registered_region_obligations( - self.outlives_environment.region_bound_pairs_map(), - self.param_env, - ); - - self.fcx.resolve_regions_and_report_errors( - self.subject_def_id.to_def_id(), - &self.outlives_environment, - ); - } - - fn constrain_bindings_in_pat(&mut self, pat: &hir::Pat<'_>) { - debug!("regionck::visit_pat(pat={:?})", pat); - pat.each_binding(|_, hir_id, span, _| { - let typ = self.resolve_node_type(hir_id); - let body_id = self.body_id; - dropck::check_drop_obligations(self, typ, span, body_id); - }) - } -} - -impl<'a, 'tcx> Visitor<'tcx> for RegionCtxt<'a, 'tcx> { - // (..) FIXME(#3238) should use visit_pat, not visit_arm/visit_local, - // However, right now we run into an issue whereby some free - // regions are not properly related if they appear within the - // types of arguments that must be inferred. This could be - // addressed by deferring the construction of the region - // hierarchy, and in particular the relationships between free - // regions, until regionck, as described in #3238. - - fn visit_fn( - &mut self, - fk: intravisit::FnKind<'tcx>, - _: &'tcx hir::FnDecl<'tcx>, - body_id: hir::BodyId, - span: Span, - hir_id: hir::HirId, - ) { - assert!( - matches!(fk, intravisit::FnKind::Closure), - "visit_fn invoked for something other than a closure" - ); - - // Save state of current function before invoking - // `visit_fn_body`. We will restore afterwards. - let old_body_id = self.body_id; - let old_body_owner = self.body_owner; - let env_snapshot = self.outlives_environment.push_snapshot_pre_typeck_child(); - - let body = self.tcx.hir().body(body_id); - self.visit_fn_body(hir_id, body, span); - - // Restore state from previous function. - self.outlives_environment.pop_snapshot_post_typeck_child(env_snapshot); - self.body_id = old_body_id; - self.body_owner = old_body_owner; - } - - //visit_pat: visit_pat, // (..) see above - - fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) { - // see above - self.constrain_bindings_in_pat(arm.pat); - intravisit::walk_arm(self, arm); - } - - fn visit_local(&mut self, l: &'tcx hir::Local<'tcx>) { - // see above - self.constrain_bindings_in_pat(l.pat); - self.link_local(l); - intravisit::walk_local(self, l); - } - - fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { - // Check any autoderefs or autorefs that appear. - let cmt_result = self.constrain_adjustments(expr); - - // If necessary, constrain destructors in this expression. This will be - // the adjusted form if there is an adjustment. - match cmt_result { - Ok(head_cmt) => { - self.check_safety_of_rvalue_destructor_if_necessary(&head_cmt, expr.span); - } - Err(..) => { - self.tcx.sess.delay_span_bug(expr.span, "cat_expr Errd"); - } - } - - match expr.kind { - hir::ExprKind::AddrOf(hir::BorrowKind::Ref, m, ref base) => { - self.link_addr_of(expr, m, base); - - intravisit::walk_expr(self, expr); - } - - hir::ExprKind::Match(ref discr, arms, _) => { - self.link_match(discr, arms); - - intravisit::walk_expr(self, expr); - } - - hir::ExprKind::ConstBlock(anon_const) => { - let body = self.tcx.hir().body(anon_const.body); - self.visit_inline_const(anon_const.hir_id, body); - } - - _ => intravisit::walk_expr(self, expr), - } - } -} - -impl<'a, 'tcx> RegionCtxt<'a, 'tcx> { - /// Creates a temporary `MemCategorizationContext` and pass it to the closure. - fn with_mc(&self, f: F) -> R - where - F: for<'b> FnOnce(mc::MemCategorizationContext<'b, 'tcx>) -> R, - { - f(mc::MemCategorizationContext::new( - &self.infcx, - self.outlives_environment.param_env, - self.body_owner, - &self.typeck_results.borrow(), - )) - } - - /// Invoked on any adjustments that occur. Checks that if this is a region pointer being - /// dereferenced, the lifetime of the pointer includes the deref expr. - fn constrain_adjustments( - &mut self, - expr: &hir::Expr<'_>, - ) -> mc::McResult> { - debug!("constrain_adjustments(expr={:?})", expr); - - let mut place = self.with_mc(|mc| mc.cat_expr_unadjusted(expr))?; - - let typeck_results = self.typeck_results.borrow(); - let adjustments = typeck_results.expr_adjustments(expr); - if adjustments.is_empty() { - return Ok(place); - } - - debug!("constrain_adjustments: adjustments={:?}", adjustments); - - // If necessary, constrain destructors in the unadjusted form of this - // expression. - self.check_safety_of_rvalue_destructor_if_necessary(&place, expr.span); - - for adjustment in adjustments { - debug!("constrain_adjustments: adjustment={:?}, place={:?}", adjustment, place); - - if let adjustment::Adjust::Deref(Some(deref)) = adjustment.kind { - self.link_region( - expr.span, - deref.region, - ty::BorrowKind::from_mutbl(deref.mutbl), - &place, - ); - } - - if let adjustment::Adjust::Borrow(ref autoref) = adjustment.kind { - self.link_autoref(expr, &place, autoref); - } - - place = self.with_mc(|mc| mc.cat_expr_adjusted(expr, place, adjustment))?; - } - - Ok(place) - } - - fn check_safety_of_rvalue_destructor_if_necessary( - &mut self, - place_with_id: &PlaceWithHirId<'tcx>, - span: Span, - ) { - if let PlaceBase::Rvalue = place_with_id.place.base { - if place_with_id.place.projections.is_empty() { - let typ = self.resolve_type(place_with_id.place.ty()); - let body_id = self.body_id; - dropck::check_drop_obligations(self, typ, span, body_id); - } - } - } - /// Adds constraints to inference such that `T: 'a` holds (or - /// reports an error if it cannot). - /// - /// # Parameters - /// - /// - `origin`, the reason we need this constraint - /// - `ty`, the type `T` - /// - `region`, the region `'a` - pub fn type_must_outlive( - &self, - origin: infer::SubregionOrigin<'tcx>, - ty: Ty<'tcx>, - region: ty::Region<'tcx>, - ) { - self.infcx.register_region_obligation( - self.body_id, - RegionObligation { sub_region: region, sup_type: ty, origin }, - ); - } - - /// Computes the guarantor for an expression `&base` and then ensures that the lifetime of the - /// resulting pointer is linked to the lifetime of its guarantor (if any). - fn link_addr_of( - &mut self, - expr: &hir::Expr<'_>, - mutability: hir::Mutability, - base: &hir::Expr<'_>, - ) { - debug!("link_addr_of(expr={:?}, base={:?})", expr, base); - - let cmt = ignore_err!(self.with_mc(|mc| mc.cat_expr(base))); - - debug!("link_addr_of: cmt={:?}", cmt); - - self.link_region_from_node_type(expr.span, expr.hir_id, mutability, &cmt); - } - - /// Computes the guarantors for any ref bindings in a `let` and - /// then ensures that the lifetime of the resulting pointer is - /// linked to the lifetime of the initialization expression. - fn link_local(&self, local: &hir::Local<'_>) { - debug!("regionck::for_local()"); - let init_expr = match local.init { - None => { - return; - } - Some(expr) => &*expr, - }; - let discr_cmt = ignore_err!(self.with_mc(|mc| mc.cat_expr(init_expr))); - self.link_pattern(discr_cmt, local.pat); - } - - /// Computes the guarantors for any ref bindings in a match and - /// then ensures that the lifetime of the resulting pointer is - /// linked to the lifetime of its guarantor (if any). - fn link_match(&self, discr: &hir::Expr<'_>, arms: &[hir::Arm<'_>]) { - debug!("regionck::for_match()"); - let discr_cmt = ignore_err!(self.with_mc(|mc| mc.cat_expr(discr))); - debug!("discr_cmt={:?}", discr_cmt); - for arm in arms { - self.link_pattern(discr_cmt.clone(), arm.pat); - } - } - - /// Computes the guarantors for any ref bindings in a match and - /// then ensures that the lifetime of the resulting pointer is - /// linked to the lifetime of its guarantor (if any). - fn link_fn_params(&self, params: &[hir::Param<'_>]) { - for param in params { - let param_ty = self.node_ty(param.hir_id); - let param_cmt = - self.with_mc(|mc| mc.cat_rvalue(param.hir_id, param.pat.span, param_ty)); - debug!("param_ty={:?} param_cmt={:?} param={:?}", param_ty, param_cmt, param); - self.link_pattern(param_cmt, param.pat); - } - } - - /// Link lifetimes of any ref bindings in `root_pat` to the pointers found - /// in the discriminant, if needed. - fn link_pattern(&self, discr_cmt: PlaceWithHirId<'tcx>, root_pat: &hir::Pat<'_>) { - debug!("link_pattern(discr_cmt={:?}, root_pat={:?})", discr_cmt, root_pat); - ignore_err!(self.with_mc(|mc| { - mc.cat_pattern(discr_cmt, root_pat, |sub_cmt, hir::Pat { kind, span, hir_id, .. }| { - // `ref x` pattern - if let PatKind::Binding(..) = kind - && let Some(ty::BindByReference(mutbl)) = mc.typeck_results.extract_binding_mode(self.tcx.sess, *hir_id, *span) { - self.link_region_from_node_type(*span, *hir_id, mutbl, sub_cmt); - } - }) - })); - } - - /// Link lifetime of borrowed pointer resulting from autoref to lifetimes in the value being - /// autoref'd. - fn link_autoref( - &self, - expr: &hir::Expr<'_>, - expr_cmt: &PlaceWithHirId<'tcx>, - autoref: &adjustment::AutoBorrow<'tcx>, - ) { - debug!("link_autoref(autoref={:?}, expr_cmt={:?})", autoref, expr_cmt); - - match *autoref { - adjustment::AutoBorrow::Ref(r, m) => { - self.link_region(expr.span, r, ty::BorrowKind::from_mutbl(m.into()), expr_cmt); - } - - adjustment::AutoBorrow::RawPtr(_) => {} - } - } - - /// Like `link_region()`, except that the region is extracted from the type of `id`, - /// which must be some reference (`&T`, `&str`, etc). - fn link_region_from_node_type( - &self, - span: Span, - id: hir::HirId, - mutbl: hir::Mutability, - cmt_borrowed: &PlaceWithHirId<'tcx>, - ) { - debug!( - "link_region_from_node_type(id={:?}, mutbl={:?}, cmt_borrowed={:?})", - id, mutbl, cmt_borrowed - ); - - let rptr_ty = self.resolve_node_type(id); - if let ty::Ref(r, _, _) = rptr_ty.kind() { - debug!("rptr_ty={}", rptr_ty); - self.link_region(span, *r, ty::BorrowKind::from_mutbl(mutbl), cmt_borrowed); - } - } - - /// Informs the inference engine that `borrow_cmt` is being borrowed with - /// kind `borrow_kind` and lifetime `borrow_region`. - /// In order to ensure borrowck is satisfied, this may create constraints - /// between regions, as explained in `link_reborrowed_region()`. - fn link_region( - &self, - span: Span, - borrow_region: ty::Region<'tcx>, - borrow_kind: ty::BorrowKind, - borrow_place: &PlaceWithHirId<'tcx>, - ) { - let origin = infer::DataBorrowed(borrow_place.place.ty(), span); - self.type_must_outlive(origin, borrow_place.place.ty(), borrow_region); - - for pointer_ty in borrow_place.place.deref_tys() { - debug!( - "link_region(borrow_region={:?}, borrow_kind={:?}, pointer_ty={:?})", - borrow_region, borrow_kind, borrow_place - ); - match *pointer_ty.kind() { - ty::RawPtr(_) => return, - ty::Ref(ref_region, _, ref_mutability) => { - if self.link_reborrowed_region(span, borrow_region, ref_region, ref_mutability) - { - return; - } - } - _ => assert!(pointer_ty.is_box(), "unexpected built-in deref type {}", pointer_ty), - } - } - if let PlaceBase::Upvar(upvar_id) = borrow_place.place.base { - self.link_upvar_region(span, borrow_region, upvar_id); - } - } - - /// This is the most complicated case: the path being borrowed is - /// itself the referent of a borrowed pointer. Let me give an - /// example fragment of code to make clear(er) the situation: - /// - /// ```ignore (incomplete Rust code) - /// let r: &'a mut T = ...; // the original reference "r" has lifetime 'a - /// ... - /// &'z *r // the reborrow has lifetime 'z - /// ``` - /// - /// Now, in this case, our primary job is to add the inference - /// constraint that `'z <= 'a`. Given this setup, let's clarify the - /// parameters in (roughly) terms of the example: - /// - /// ```plain,ignore (pseudo-Rust) - /// A borrow of: `& 'z bk * r` where `r` has type `& 'a bk T` - /// borrow_region ^~ ref_region ^~ - /// borrow_kind ^~ ref_kind ^~ - /// ref_cmt ^ - /// ``` - /// - /// Here `bk` stands for some borrow-kind (e.g., `mut`, `uniq`, etc). - /// - /// There is a complication beyond the simple scenario I just painted: there - /// may in fact be more levels of reborrowing. In the example, I said the - /// borrow was like `&'z *r`, but it might in fact be a borrow like - /// `&'z **q` where `q` has type `&'a &'b mut T`. In that case, we want to - /// ensure that `'z <= 'a` and `'z <= 'b`. - /// - /// The return value of this function indicates whether we *don't* need to - /// the recurse to the next reference up. - /// - /// This is explained more below. - fn link_reborrowed_region( - &self, - span: Span, - borrow_region: ty::Region<'tcx>, - ref_region: ty::Region<'tcx>, - ref_mutability: hir::Mutability, - ) -> bool { - debug!("link_reborrowed_region: {:?} <= {:?}", borrow_region, ref_region); - self.sub_regions(infer::Reborrow(span), borrow_region, ref_region); - - // Decide whether we need to recurse and link any regions within - // the `ref_cmt`. This is concerned for the case where the value - // being reborrowed is in fact a borrowed pointer found within - // another borrowed pointer. For example: - // - // let p: &'b &'a mut T = ...; - // ... - // &'z **p - // - // What makes this case particularly tricky is that, if the data - // being borrowed is a `&mut` or `&uniq` borrow, borrowck requires - // not only that `'z <= 'a`, (as before) but also `'z <= 'b` - // (otherwise the user might mutate through the `&mut T` reference - // after `'b` expires and invalidate the borrow we are looking at - // now). - // - // So let's re-examine our parameters in light of this more - // complicated (possible) scenario: - // - // A borrow of: `& 'z bk * * p` where `p` has type `&'b bk & 'a bk T` - // borrow_region ^~ ref_region ^~ - // borrow_kind ^~ ref_kind ^~ - // ref_cmt ^~~ - // - // (Note that since we have not examined `ref_cmt.cat`, we don't - // know whether this scenario has occurred; but I wanted to show - // how all the types get adjusted.) - match ref_mutability { - hir::Mutability::Not => { - // The reference being reborrowed is a shareable ref of - // type `&'a T`. In this case, it doesn't matter where we - // *found* the `&T` pointer, the memory it references will - // be valid and immutable for `'a`. So we can stop here. - true - } - - hir::Mutability::Mut => { - // The reference being reborrowed is either an `&mut T`. This is - // the case where recursion is needed. - false - } - } - } - - /// An upvar may be behind up to 2 references: - /// - /// * One can come from the reference to a "by-reference" upvar. - /// * Another one can come from the reference to the closure itself if it's - /// a `FnMut` or `Fn` closure. - /// - /// This function links the lifetimes of those references to the lifetime - /// of the borrow that's provided. See [RegionCtxt::link_reborrowed_region] for some - /// more explanation of this in the general case. - /// - /// We also supply a *cause*, and in this case we set the cause to - /// indicate that the reference being "reborrowed" is itself an upvar. This - /// provides a nicer error message should something go wrong. - fn link_upvar_region( - &self, - span: Span, - borrow_region: ty::Region<'tcx>, - upvar_id: ty::UpvarId, - ) { - debug!("link_upvar_region(borrorw_region={:?}, upvar_id={:?}", borrow_region, upvar_id); - // A by-reference upvar can't be borrowed for longer than the - // upvar is borrowed from the environment. - let closure_local_def_id = upvar_id.closure_expr_id; - let mut all_captures_are_imm_borrow = true; - for captured_place in self - .typeck_results - .borrow() - .closure_min_captures - .get(&closure_local_def_id.to_def_id()) - .and_then(|root_var_min_cap| root_var_min_cap.get(&upvar_id.var_path.hir_id)) - .into_iter() - .flatten() - { - match captured_place.info.capture_kind { - ty::UpvarCapture::ByRef(upvar_borrow) => { - self.sub_regions( - infer::ReborrowUpvar(span, upvar_id), - borrow_region, - captured_place.region.unwrap(), - ); - if let ty::ImmBorrow = upvar_borrow { - debug!("link_upvar_region: capture by shared ref"); - } else { - all_captures_are_imm_borrow = false; - } - } - ty::UpvarCapture::ByValue => { - all_captures_are_imm_borrow = false; - } - } - } - if all_captures_are_imm_borrow { - return; - } - let fn_hir_id = self.tcx.hir().local_def_id_to_hir_id(closure_local_def_id); - let ty = self.resolve_node_type(fn_hir_id); - debug!("link_upvar_region: ty={:?}", ty); - - // A closure capture can't be borrowed for longer than the - // reference to the closure. - if let ty::Closure(_, substs) = ty.kind() { - match self.infcx.closure_kind(substs) { - Some(ty::ClosureKind::Fn | ty::ClosureKind::FnMut) => { - // Region of environment pointer - let env_region = self.tcx.mk_region(ty::ReFree(ty::FreeRegion { - scope: upvar_id.closure_expr_id.to_def_id(), - bound_region: ty::BrEnv, - })); - self.sub_regions( - infer::ReborrowUpvar(span, upvar_id), - borrow_region, - env_region, - ); - } - Some(ty::ClosureKind::FnOnce) => {} - None => { - span_bug!(span, "Have not inferred closure kind before regionck"); - } - } - } - } -} diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs index 7fe36781cf494..c76c3a4c7baee 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -62,7 +62,10 @@ impl<'tcx> CheckWfFcxBuilder<'tcx> { } let wf_tys = f(&fcx); fcx.select_all_obligations_or_error(); - fcx.regionck_item(id, span, wf_tys); + + let mut outlives_environment = OutlivesEnvironment::new(param_env); + outlives_environment.add_implied_bounds(&fcx.infcx, wf_tys, id); + fcx.infcx.check_region_obligations_and_report_errors(&outlives_environment); }); } } @@ -655,13 +658,12 @@ fn resolve_regions_with_wf_tys<'tcx>( // call individually. tcx.infer_ctxt().enter(|infcx| { let mut outlives_environment = OutlivesEnvironment::new(param_env); - outlives_environment.add_implied_bounds(&infcx, wf_tys.clone(), id, DUMMY_SP); - outlives_environment.save_implied_bounds(id); - let region_bound_pairs = outlives_environment.region_bound_pairs_map().get(&id).unwrap(); + outlives_environment.add_implied_bounds(&infcx, wf_tys.clone(), id); + let region_bound_pairs = outlives_environment.region_bound_pairs(); add_constraints(&infcx, region_bound_pairs); - let errors = infcx.resolve_regions(id.expect_owner().to_def_id(), &outlives_environment); + let errors = infcx.resolve_regions(&outlives_environment); debug!(?errors, "errors"); diff --git a/compiler/rustc_typeck/src/coherence/builtin.rs b/compiler/rustc_typeck/src/coherence/builtin.rs index c647c2a4c1baa..ec4fe3c420323 100644 --- a/compiler/rustc_typeck/src/coherence/builtin.rs +++ b/compiler/rustc_typeck/src/coherence/builtin.rs @@ -349,7 +349,7 @@ fn visit_implementation_of_dispatch_from_dyn<'tcx>(tcx: TyCtxt<'tcx>, impl_did: // Finally, resolve all regions. let outlives_env = OutlivesEnvironment::new(param_env); - infcx.resolve_regions_and_report_errors(impl_did.to_def_id(), &outlives_env); + infcx.resolve_regions_and_report_errors(&outlives_env); } } _ => { @@ -606,7 +606,7 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUn // Finally, resolve all regions. let outlives_env = OutlivesEnvironment::new(param_env); - infcx.resolve_regions_and_report_errors(impl_did.to_def_id(), &outlives_env); + infcx.resolve_regions_and_report_errors(&outlives_env); CoerceUnsizedInfo { custom_kind: kind } }) diff --git a/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs b/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs index 4d22e168bb64c..66b121d75c523 100644 --- a/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs +++ b/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs @@ -150,7 +150,7 @@ fn get_impl_substs<'tcx>( // Conservatively use an empty `ParamEnv`. let outlives_env = OutlivesEnvironment::new(ty::ParamEnv::empty()); - infcx.resolve_regions_and_report_errors(impl1_def_id.to_def_id(), &outlives_env); + infcx.resolve_regions_and_report_errors(&outlives_env); let Ok(impl2_substs) = infcx.fully_resolve(impl2_substs) else { let span = tcx.def_span(impl1_def_id); tcx.sess.emit_err(SubstsOnOverriddenImpl { span }); diff --git a/compiler/rustc_typeck/src/outlives/outlives_bounds.rs b/compiler/rustc_typeck/src/outlives/outlives_bounds.rs index 3bf697e768269..70b8bcd02208d 100644 --- a/compiler/rustc_typeck/src/outlives/outlives_bounds.rs +++ b/compiler/rustc_typeck/src/outlives/outlives_bounds.rs @@ -1,6 +1,5 @@ use rustc_hir as hir; use rustc_middle::ty::{self, Ty}; -use rustc_span::source_map::Span; use rustc_trait_selection::infer::InferCtxt; use rustc_trait_selection::traits::query::type_op::{self, TypeOp, TypeOpOutput}; use rustc_trait_selection::traits::query::NoSolution; @@ -14,7 +13,6 @@ pub trait InferCtxtExt<'tcx> { param_env: ty::ParamEnv<'tcx>, body_id: hir::HirId, ty: Ty<'tcx>, - span: Span, ) -> Vec>; } @@ -38,16 +36,14 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> { /// Note that this may cause outlives obligations to be injected /// into the inference context with this body-id. /// - `ty`, the type that we are supposed to assume is WF. - /// - `span`, a span to use when normalizing, hopefully not important, - /// might be useful if a `bug!` occurs. - #[instrument(level = "debug", skip(self, param_env, body_id, span))] + #[instrument(level = "debug", skip(self, param_env, body_id))] fn implied_outlives_bounds( &self, param_env: ty::ParamEnv<'tcx>, body_id: hir::HirId, ty: Ty<'tcx>, - span: Span, ) -> Vec> { + let span = self.tcx.hir().span(body_id); let result = param_env .and(type_op::implied_outlives_bounds::ImpliedOutlivesBounds { ty }) .fully_perform(self);