diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/dataflow.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_borrowck/src/region_infer/mod.rs | 21 |
2 files changed, 14 insertions, 13 deletions
diff --git a/compiler/rustc_borrowck/src/dataflow.rs b/compiler/rustc_borrowck/src/dataflow.rs index 16814950b0d..8676d2ba7c4 100644 --- a/compiler/rustc_borrowck/src/dataflow.rs +++ b/compiler/rustc_borrowck/src/dataflow.rs @@ -273,11 +273,10 @@ impl<'tcx> PoloniusOutOfScopePrecomputer<'_, 'tcx> { ) { let sccs = self.regioncx.constraint_sccs(); let universal_regions = self.regioncx.universal_regions(); - let issuing_region_scc = sccs.scc(issuing_region); // We first handle the cases where the loan doesn't go out of scope, depending on the issuing // region's successors. - for scc in sccs.depth_first_search(issuing_region_scc) { + for successor in self.regioncx.region_graph().depth_first_search(issuing_region) { // 1. Via applied member constraints // // The issuing region can flow into the choice regions, and they are either: @@ -290,6 +289,7 @@ impl<'tcx> PoloniusOutOfScopePrecomputer<'_, 'tcx> { // For additional insurance via fuzzing and crater, we verify that the constraint's min // choice indeed escapes the function. In the future, we could e.g. turn this check into // a debug assert and early return as an optimization. + let scc = sccs.scc(successor); for constraint in self.regioncx.applied_member_constraints(scc) { if universal_regions.is_universal_region(constraint.min_choice) { return; @@ -300,7 +300,7 @@ impl<'tcx> PoloniusOutOfScopePrecomputer<'_, 'tcx> { // // If the issuing region outlives such a region, its loan escapes the function and // cannot go out of scope. We can early return. - if self.regioncx.scc_is_live_at_all_points(scc) { + if self.regioncx.is_region_live_at_all_points(successor) { return; } } diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs index 05c2cbd4969..b1f91a05628 100644 --- a/compiler/rustc_borrowck/src/region_infer/mod.rs +++ b/compiler/rustc_borrowck/src/region_infer/mod.rs @@ -22,11 +22,10 @@ use rustc_middle::traits::ObligationCauseCode; use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt, TypeFoldable, TypeVisitableExt}; use rustc_span::Span; +use crate::constraints::graph::{self, NormalConstraintGraph, RegionGraph}; use crate::dataflow::BorrowIndex; use crate::{ - constraints::{ - graph::NormalConstraintGraph, ConstraintSccIndex, OutlivesConstraint, OutlivesConstraintSet, - }, + constraints::{ConstraintSccIndex, OutlivesConstraint, OutlivesConstraintSet}, diagnostics::{RegionErrorKind, RegionErrors, UniverseInfo}, member_constraints::{MemberConstraintSet, NllMemberConstraintIndex}, nll::PoloniusOutput, @@ -2293,19 +2292,21 @@ impl<'tcx> RegionInferenceContext<'tcx> { self.constraint_sccs.as_ref() } - /// Returns whether the given SCC is live at all points: whether the representative is a + /// Access to the region graph, built from the outlives constraints. + pub(crate) fn region_graph(&self) -> RegionGraph<'_, 'tcx, graph::Normal> { + self.constraint_graph.region_graph(&self.constraints, self.universal_regions.fr_static) + } + + /// Returns whether the given region is considered live at all points: whether it is a /// placeholder or a free region. - pub(crate) fn scc_is_live_at_all_points(&self, scc: ConstraintSccIndex) -> bool { + pub(crate) fn is_region_live_at_all_points(&self, region: RegionVid) -> bool { // FIXME: there must be a cleaner way to find this information. At least, when // higher-ranked subtyping is abstracted away from the borrowck main path, we'll only // need to check whether this is a universal region. - let representative = self.scc_representatives[scc]; - let origin = self.var_infos[representative].origin; + let origin = self.region_definition(region).origin; let live_at_all_points = matches!( origin, - RegionVariableOrigin::Nll( - NllRegionVariableOrigin::Placeholder(_) | NllRegionVariableOrigin::FreeRegion - ) + NllRegionVariableOrigin::Placeholder(_) | NllRegionVariableOrigin::FreeRegion ); live_at_all_points } |