clean up translate_outlives_facts

- remove dependency on `TypeChecker`
- move to legacy fact generation module
- group facts emitted during typeck together

Author: lqd

compiler/rustc_borrowck/src/polonius/legacy/mod.rs

@@ -3,14 +3,19 @@
 //! Will be removed in the future, once the in-tree `-Zpolonius=next` implementation reaches feature
 //! parity.
 
+use std::iter;
+
+use either::Either;
 use rustc_middle::mir::{Body, Local, LocalKind, Location, START_BLOCK};
 use rustc_middle::ty::{GenericArg, TyCtxt};
 use rustc_mir_dataflow::move_paths::{InitKind, InitLocation, MoveData};
 use tracing::debug;
 
 use crate::borrow_set::BorrowSet;
+use crate::constraints::OutlivesConstraint;
 use crate::facts::{AllFacts, PoloniusRegionVid};
 use crate::location::LocationTable;
+use crate::type_check::MirTypeckRegionConstraints;
 use crate::type_check::free_region_relations::UniversalRegionRelations;
 use crate::universal_regions::UniversalRegions;
 
@@ -205,3 +210,31 @@ pub(crate) fn emit_drop_facts<'tcx>(
         });
     }
 }
+
+/// Emit facts about the outlives constraints: the `subset` base relation, i.e. not a transitive
+/// closure.
+pub(crate) fn emit_outlives_facts<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    constraints: &MirTypeckRegionConstraints<'tcx>,
+    location_table: &LocationTable,
+    all_facts: &mut Option<AllFacts>,
+) {
+    if let Some(facts) = all_facts {
+        let _prof_timer = tcx.prof.generic_activity("polonius_fact_generation");
+        facts.subset_base.extend(constraints.outlives_constraints.outlives().iter().flat_map(
+            |constraint: &OutlivesConstraint<'_>| {
+                if let Some(from_location) = constraint.locations.from_location() {
+                    Either::Left(iter::once((
+                        constraint.sup.into(),
+                        constraint.sub.into(),
+                        location_table.mid_index(from_location),
+                    )))
+                } else {
+                    Either::Right(location_table.all_points().map(move |location| {
+                        (constraint.sup.into(), constraint.sub.into(), location)
+                    }))
+                }
+            },
+        ));
+    }
+}

compiler/rustc_borrowck/src/type_check/liveness/mod.rs

@@ -13,7 +13,6 @@ use tracing::debug;
 
 use super::TypeChecker;
 use crate::constraints::OutlivesConstraintSet;
-use crate::polonius;
 use crate::region_infer::values::LivenessValues;
 use crate::universal_regions::UniversalRegions;
 
@@ -45,15 +44,6 @@ pub(super) fn generate<'a, 'tcx>(
     let (relevant_live_locals, boring_locals) =
         compute_relevant_live_locals(typeck.tcx(), &free_regions, body);
 
-    polonius::legacy::emit_access_facts(
-        typeck.tcx(),
-        body,
-        move_data,
-        typeck.universal_regions,
-        typeck.location_table,
-        typeck.all_facts,
-    );
-
     trace::trace(
         typeck,
         body,

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -3,7 +3,6 @@
 use std::rc::Rc;
 use std::{fmt, iter, mem};
 
-use either::Either;
 use rustc_abi::{FIRST_VARIANT, FieldIdx};
 use rustc_data_structures::frozen::Frozen;
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
@@ -60,7 +59,7 @@ use crate::renumber::RegionCtxt;
 use crate::session_diagnostics::{MoveUnsized, SimdIntrinsicArgConst};
 use crate::type_check::free_region_relations::{CreateResult, UniversalRegionRelations};
 use crate::universal_regions::{DefiningTy, UniversalRegions};
-use crate::{BorrowckInferCtxt, path_utils};
+use crate::{BorrowckInferCtxt, path_utils, polonius};
 
 macro_rules! span_mirbug {
     ($context:expr, $elem:expr, $($message:tt)*) => ({
@@ -182,7 +181,20 @@ pub(crate) fn type_check<'a, 'tcx>(
 
     liveness::generate(&mut checker, body, &elements, flow_inits, move_data);
 
-    translate_outlives_facts(&mut checker);
+    polonius::legacy::emit_access_facts(
+        infcx.tcx,
+        body,
+        move_data,
+        &universal_region_relations.universal_regions,
+        location_table,
+        checker.all_facts,
+    );
+    polonius::legacy::emit_outlives_facts(
+        infcx.tcx,
+        checker.constraints,
+        location_table,
+        checker.all_facts,
+    );
     let opaque_type_values = infcx.take_opaque_types();
 
     let opaque_type_values = opaque_type_values
@@ -234,30 +246,6 @@ pub(crate) fn type_check<'a, 'tcx>(
     MirTypeckResults { constraints, universal_region_relations, opaque_type_values }
 }
 
-fn translate_outlives_facts(typeck: &mut TypeChecker<'_, '_>) {
-    if let Some(facts) = typeck.all_facts {
-        let _prof_timer = typeck.infcx.tcx.prof.generic_activity("polonius_fact_generation");
-        let location_table = typeck.location_table;
-        facts.subset_base.extend(
-            typeck.constraints.outlives_constraints.outlives().iter().flat_map(
-                |constraint: &OutlivesConstraint<'_>| {
-                    if let Some(from_location) = constraint.locations.from_location() {
-                        Either::Left(iter::once((
-                            constraint.sup.into(),
-                            constraint.sub.into(),
-                            location_table.mid_index(from_location),
-                        )))
-                    } else {
-                        Either::Right(location_table.all_points().map(move |location| {
-                            (constraint.sup.into(), constraint.sub.into(), location)
-                        }))
-                    }
-                },
-            ),
-        );
-    }
-}
-
 #[track_caller]
 fn mirbug(tcx: TyCtxt<'_>, span: Span, msg: String) {
     // We sometimes see MIR failures (notably predicate failures) due to