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-rw-r--r--compiler/rustc_borrowck/src/constraint_generation.rs248
1 files changed, 0 insertions, 248 deletions
diff --git a/compiler/rustc_borrowck/src/constraint_generation.rs b/compiler/rustc_borrowck/src/constraint_generation.rs
deleted file mode 100644
index 1f642099f..000000000
--- a/compiler/rustc_borrowck/src/constraint_generation.rs
+++ /dev/null
@@ -1,248 +0,0 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-use rustc_infer::infer::InferCtxt;
-use rustc_middle::mir::visit::TyContext;
-use rustc_middle::mir::visit::Visitor;
-use rustc_middle::mir::{
- Body, Local, Location, Place, PlaceRef, ProjectionElem, Rvalue, SourceInfo, Statement,
- StatementKind, Terminator, TerminatorKind, UserTypeProjection,
-};
-use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::GenericArgsRef;
-use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt};
-
-use crate::{
- borrow_set::BorrowSet, facts::AllFacts, location::LocationTable, places_conflict,
- region_infer::values::LivenessValues,
-};
-
-pub(super) fn generate_constraints<'tcx>(
- infcx: &InferCtxt<'tcx>,
- liveness_constraints: &mut LivenessValues<RegionVid>,
- all_facts: &mut Option<AllFacts>,
- location_table: &LocationTable,
- body: &Body<'tcx>,
- borrow_set: &BorrowSet<'tcx>,
-) {
- let mut cg = ConstraintGeneration {
- borrow_set,
- infcx,
- liveness_constraints,
- location_table,
- all_facts,
- body,
- };
-
- for (bb, data) in body.basic_blocks.iter_enumerated() {
- cg.visit_basic_block_data(bb, data);
- }
-}
-
-/// 'cg = the duration of the constraint generation process itself.
-struct ConstraintGeneration<'cg, 'tcx> {
- infcx: &'cg InferCtxt<'tcx>,
- all_facts: &'cg mut Option<AllFacts>,
- location_table: &'cg LocationTable,
- liveness_constraints: &'cg mut LivenessValues<RegionVid>,
- borrow_set: &'cg BorrowSet<'tcx>,
- body: &'cg Body<'tcx>,
-}
-
-impl<'cg, 'tcx> Visitor<'tcx> for ConstraintGeneration<'cg, 'tcx> {
- /// We sometimes have `args` within an rvalue, or within a
- /// call. Make them live at the location where they appear.
- fn visit_args(&mut self, args: &GenericArgsRef<'tcx>, location: Location) {
- self.add_regular_live_constraint(*args, location);
- self.super_args(args);
- }
-
- /// We sometimes have `region` within an rvalue, or within a
- /// call. Make them live at the location where they appear.
- fn visit_region(&mut self, region: ty::Region<'tcx>, location: Location) {
- self.add_regular_live_constraint(region, location);
- self.super_region(region);
- }
-
- /// We sometimes have `ty` within an rvalue, or within a
- /// call. Make them live at the location where they appear.
- fn visit_ty(&mut self, ty: Ty<'tcx>, ty_context: TyContext) {
- match ty_context {
- TyContext::ReturnTy(SourceInfo { span, .. })
- | TyContext::YieldTy(SourceInfo { span, .. })
- | TyContext::UserTy(span)
- | TyContext::LocalDecl { source_info: SourceInfo { span, .. }, .. } => {
- span_bug!(span, "should not be visiting outside of the CFG: {:?}", ty_context);
- }
- TyContext::Location(location) => {
- self.add_regular_live_constraint(ty, location);
- }
- }
-
- self.super_ty(ty);
- }
-
- fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
- if let Some(all_facts) = self.all_facts {
- let _prof_timer = self.infcx.tcx.prof.generic_activity("polonius_fact_generation");
- all_facts.cfg_edge.push((
- self.location_table.start_index(location),
- self.location_table.mid_index(location),
- ));
-
- all_facts.cfg_edge.push((
- self.location_table.mid_index(location),
- self.location_table.start_index(location.successor_within_block()),
- ));
-
- // If there are borrows on this now dead local, we need to record them as `killed`.
- if let StatementKind::StorageDead(local) = statement.kind {
- record_killed_borrows_for_local(
- all_facts,
- self.borrow_set,
- self.location_table,
- local,
- location,
- );
- }
- }
-
- self.super_statement(statement, location);
- }
-
- fn visit_assign(&mut self, place: &Place<'tcx>, rvalue: &Rvalue<'tcx>, location: Location) {
- // When we see `X = ...`, then kill borrows of
- // `(*X).foo` and so forth.
- self.record_killed_borrows_for_place(*place, location);
-
- self.super_assign(place, rvalue, location);
- }
-
- fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) {
- if let Some(all_facts) = self.all_facts {
- let _prof_timer = self.infcx.tcx.prof.generic_activity("polonius_fact_generation");
- all_facts.cfg_edge.push((
- self.location_table.start_index(location),
- self.location_table.mid_index(location),
- ));
-
- let successor_blocks = terminator.successors();
- all_facts.cfg_edge.reserve(successor_blocks.size_hint().0);
- for successor_block in successor_blocks {
- all_facts.cfg_edge.push((
- self.location_table.mid_index(location),
- self.location_table.start_index(successor_block.start_location()),
- ));
- }
- }
-
- // A `Call` terminator's return value can be a local which has borrows,
- // so we need to record those as `killed` as well.
- if let TerminatorKind::Call { destination, .. } = terminator.kind {
- self.record_killed_borrows_for_place(destination, location);
- }
-
- self.super_terminator(terminator, location);
- }
-
- fn visit_ascribe_user_ty(
- &mut self,
- _place: &Place<'tcx>,
- _variance: ty::Variance,
- _user_ty: &UserTypeProjection,
- _location: Location,
- ) {
- }
-}
-
-impl<'cx, 'tcx> ConstraintGeneration<'cx, 'tcx> {
- /// Some variable with type `live_ty` is "regular live" at
- /// `location` -- i.e., it may be used later. This means that all
- /// regions appearing in the type `live_ty` must be live at
- /// `location`.
- fn add_regular_live_constraint<T>(&mut self, live_ty: T, location: Location)
- where
- T: TypeVisitable<TyCtxt<'tcx>>,
- {
- debug!("add_regular_live_constraint(live_ty={:?}, location={:?})", live_ty, location);
-
- self.infcx.tcx.for_each_free_region(&live_ty, |live_region| {
- let vid = live_region.as_var();
- self.liveness_constraints.add_element(vid, location);
- });
- }
-
- /// When recording facts for Polonius, records the borrows on the specified place
- /// as `killed`. For example, when assigning to a local, or on a call's return destination.
- fn record_killed_borrows_for_place(&mut self, place: Place<'tcx>, location: Location) {
- if let Some(all_facts) = self.all_facts {
- let _prof_timer = self.infcx.tcx.prof.generic_activity("polonius_fact_generation");
-
- // Depending on the `Place` we're killing:
- // - if it's a local, or a single deref of a local,
- // we kill all the borrows on the local.
- // - if it's a deeper projection, we have to filter which
- // of the borrows are killed: the ones whose `borrowed_place`
- // conflicts with the `place`.
- match place.as_ref() {
- PlaceRef { local, projection: &[] }
- | PlaceRef { local, projection: &[ProjectionElem::Deref] } => {
- debug!(
- "Recording `killed` facts for borrows of local={:?} at location={:?}",
- local, location
- );
-
- record_killed_borrows_for_local(
- all_facts,
- self.borrow_set,
- self.location_table,
- local,
- location,
- );
- }
-
- PlaceRef { local, projection: &[.., _] } => {
- // Kill conflicting borrows of the innermost local.
- debug!(
- "Recording `killed` facts for borrows of \
- innermost projected local={:?} at location={:?}",
- local, location
- );
-
- if let Some(borrow_indices) = self.borrow_set.local_map.get(&local) {
- for &borrow_index in borrow_indices {
- let places_conflict = places_conflict::places_conflict(
- self.infcx.tcx,
- self.body,
- self.borrow_set[borrow_index].borrowed_place,
- place,
- places_conflict::PlaceConflictBias::NoOverlap,
- );
-
- if places_conflict {
- let location_index = self.location_table.mid_index(location);
- all_facts.loan_killed_at.push((borrow_index, location_index));
- }
- }
- }
- }
- }
- }
- }
-}
-
-/// When recording facts for Polonius, records the borrows on the specified local as `killed`.
-fn record_killed_borrows_for_local(
- all_facts: &mut AllFacts,
- borrow_set: &BorrowSet<'_>,
- location_table: &LocationTable,
- local: Local,
- location: Location,
-) {
- if let Some(borrow_indices) = borrow_set.local_map.get(&local) {
- all_facts.loan_killed_at.reserve(borrow_indices.len());
- for &borrow_index in borrow_indices {
- let location_index = location_table.mid_index(location);
- all_facts.loan_killed_at.push((borrow_index, location_index));
- }
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-06 23:45:22 +0000