Minimize use of GenKill.

Thanks to the previous couple of commits, many uses of the `GenKill`
trait can be replaced with a concrete type.

Author: nnethercote

compiler/rustc_borrowck/src/dataflow.rs

@@ -427,7 +427,7 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     /// That means they went out of a nonlexical scope
     fn kill_loans_out_of_scope_at_location(
         &self,
-        trans: &mut impl GenKill<BorrowIndex>,
+        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
         location: Location,
     ) {
         // NOTE: The state associated with a given `location`
@@ -447,7 +447,11 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     }
 
     /// Kill any borrows that conflict with `place`.
-    fn kill_borrows_on_place(&self, trans: &mut impl GenKill<BorrowIndex>, place: Place<'tcx>) {
+    fn kill_borrows_on_place(
+        &self,
+        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
+        place: Place<'tcx>,
+    ) {
         debug!("kill_borrows_on_place: place={:?}", place);
 
         let other_borrows_of_local = self

compiler/rustc_mir_dataflow/src/framework/mod.rs

@@ -305,11 +305,11 @@ pub trait GenKillAnalysis<'tcx>: Analysis<'tcx> {
     );
 
     /// See `Analysis::apply_switch_int_edge_effects`.
-    fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
+    fn switch_int_edge_effects(
         &mut self,
         _block: BasicBlock,
         _discr: &mir::Operand<'tcx>,
-        _edge_effects: &mut impl SwitchIntEdgeEffects<G>,
+        _edge_effects: &mut impl SwitchIntEdgeEffects<Self::Domain>,
     ) {
     }
 }

compiler/rustc_mir_dataflow/src/impls/initialized.rs

@@ -270,7 +270,7 @@ impl<'tcx> HasMoveData<'tcx> for EverInitializedPlaces<'_, 'tcx> {
 
 impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
     fn update_bits(
-        trans: &mut impl GenKill<MovePathIndex>,
+        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
         path: MovePathIndex,
         state: DropFlagState,
     ) {
@@ -283,7 +283,7 @@ impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
 
 impl<'tcx> MaybeUninitializedPlaces<'_, 'tcx> {
     fn update_bits(
-        trans: &mut impl GenKill<MovePathIndex>,
+        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
         path: MovePathIndex,
         state: DropFlagState,
     ) {
@@ -296,7 +296,7 @@ impl<'tcx> MaybeUninitializedPlaces<'_, 'tcx> {
 
 impl<'a, 'tcx> DefinitelyInitializedPlaces<'a, 'tcx> {
     fn update_bits(
-        trans: &mut impl GenKill<MovePathIndex>,
+        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
         path: MovePathIndex,
         state: DropFlagState,
     ) {
@@ -399,11 +399,11 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
         });
     }
 
-    fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
+    fn switch_int_edge_effects(
         &mut self,
         block: mir::BasicBlock,
         discr: &mir::Operand<'tcx>,
-        edge_effects: &mut impl SwitchIntEdgeEffects<G>,
+        edge_effects: &mut impl SwitchIntEdgeEffects<Self::Domain>,
     ) {
         if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration {
             return;
@@ -524,11 +524,11 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
         });
     }
 
-    fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
+    fn switch_int_edge_effects(
         &mut self,
         block: mir::BasicBlock,
         discr: &mir::Operand<'tcx>,
-        edge_effects: &mut impl SwitchIntEdgeEffects<G>,
+        edge_effects: &mut impl SwitchIntEdgeEffects<Self::Domain>,
     ) {
         if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration {
             return;

compiler/rustc_mir_dataflow/src/impls/liveness.rs

@@ -89,12 +89,9 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeLiveLocals {
     }
 }
 
-pub struct TransferFunction<'a, T>(pub &'a mut T);
+pub struct TransferFunction<'a>(pub &'a mut BitSet<Local>);
 
-impl<'tcx, T> Visitor<'tcx> for TransferFunction<'_, T>
-where
-    T: GenKill<Local>,
-{
+impl<'tcx> Visitor<'tcx> for TransferFunction<'_> {
     fn visit_place(&mut self, place: &mir::Place<'tcx>, context: PlaceContext, location: Location) {
         if let PlaceContext::MutatingUse(MutatingUseContext::Yield) = context {
             // The resume place is evaluated and assigned to only after coroutine resumes, so its
@@ -108,10 +105,10 @@ where
                     MutatingUseContext::Call | MutatingUseContext::AsmOutput,
                 ) = context
                 {
-                    // For the associated terminators, this is only a `Def` when the terminator returns
-                    // "successfully." As such, we handle this case separately in `call_return_effect`
-                    // above. However, if the place looks like `*_5`, this is still unconditionally a use of
-                    // `_5`.
+                    // For the associated terminators, this is only a `Def` when the terminator
+                    // returns "successfully." As such, we handle this case separately in
+                    // `call_return_effect` above. However, if the place looks like `*_5`, this is
+                    // still unconditionally a use of `_5`.
                 } else {
                     self.0.kill(place.local);
                 }
@@ -128,12 +125,9 @@ where
     }
 }
 
-struct YieldResumeEffect<'a, T>(&'a mut T);
+struct YieldResumeEffect<'a>(&'a mut BitSet<Local>);
 
-impl<'tcx, T> Visitor<'tcx> for YieldResumeEffect<'_, T>
-where
-    T: GenKill<Local>,
-{
+impl<'tcx> Visitor<'tcx> for YieldResumeEffect<'_> {
     fn visit_place(&mut self, place: &mir::Place<'tcx>, context: PlaceContext, location: Location) {
         DefUse::apply(self.0, *place, context);
         self.visit_projection(place.as_ref(), context, location);
@@ -151,7 +145,7 @@ enum DefUse {
 }
 
 impl DefUse {
-    fn apply(trans: &mut impl GenKill<Local>, place: Place<'_>, context: PlaceContext) {
+    fn apply(trans: &mut BitSet<Local>, place: Place<'_>, context: PlaceContext) {
         match DefUse::for_place(place, context) {
             Some(DefUse::Def) => trans.kill(place.local),
             Some(DefUse::Use) => trans.gen_(place.local),

compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs

@@ -5,7 +5,7 @@ use rustc_middle::mir::visit::{NonMutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
 
 use super::MaybeBorrowedLocals;
-use crate::{GenKill, ResultsCursor};
+use crate::{AnalysisDomain, GenKill, ResultsCursor};
 
 pub struct MaybeStorageLive<'a> {
     always_live_locals: Cow<'a, BitSet<Local>>,
@@ -330,22 +330,23 @@ impl<'tcx> crate::GenKillAnalysis<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
 
 impl<'tcx> MaybeRequiresStorage<'_, 'tcx> {
     /// Kill locals that are fully moved and have not been borrowed.
-    fn check_for_move(&mut self, trans: &mut impl GenKill<Local>, loc: Location) {
+    fn check_for_move(
+        &mut self,
+        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
+        loc: Location,
+    ) {
         let body = self.borrowed_locals.body();
         let mut visitor = MoveVisitor { trans, borrowed_locals: &mut self.borrowed_locals };
         visitor.visit_location(body, loc);
     }
 }
 
-struct MoveVisitor<'a, 'mir, 'tcx, T> {
+struct MoveVisitor<'a, 'mir, 'tcx> {
     borrowed_locals: &'a mut BorrowedLocalsResults<'mir, 'tcx>,
-    trans: &'a mut T,
+    trans: &'a mut BitSet<Local>,
 }
 
-impl<'tcx, T> Visitor<'tcx> for MoveVisitor<'_, '_, 'tcx, T>
-where
-    T: GenKill<Local>,
-{
+impl<'tcx> Visitor<'tcx> for MoveVisitor<'_, '_, 'tcx> {
     fn visit_local(&mut self, local: Local, context: PlaceContext, loc: Location) {
         if PlaceContext::NonMutatingUse(NonMutatingUseContext::Move) == context {
             self.borrowed_locals.seek_before_primary_effect(loc);