Remove lifetimes from BorrowckDomain.

They are only present because it's currently defined in terms of the
domains of `Borrows` and `MaybeUninitializedPlaces` and
`EverInitializedPlaces` via associated types. This commit introduces
typedefs for those domains, avoiding the lifetimes.

Author: nnethercote

compiler/rustc_borrowck/src/dataflow.rs

@@ -8,7 +8,10 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::{RegionVid, TyCtxt};
 use rustc_mir_dataflow::fmt::DebugWithContext;
-use rustc_mir_dataflow::impls::{EverInitializedPlaces, MaybeUninitializedPlaces};
+use rustc_mir_dataflow::impls::{
+    EverInitializedPlaces, EverInitializedPlacesDomain, MaybeUninitializedPlaces,
+    MaybeUninitializedPlacesDomain,
+};
 use rustc_mir_dataflow::{Analysis, GenKill, JoinSemiLattice, SwitchIntEdgeEffects};
 use tracing::debug;
 
@@ -24,7 +27,7 @@ pub(crate) struct Borrowck<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> Analysis<'tcx> for Borrowck<'a, 'tcx> {
-    type Domain = BorrowckDomain<'a, 'tcx>;
+    type Domain = BorrowckDomain;
 
     const NAME: &'static str = "borrowck";
 
@@ -110,14 +113,14 @@ impl<'a, 'tcx> Analysis<'tcx> for Borrowck<'a, 'tcx> {
     }
 }
 
-impl JoinSemiLattice for BorrowckDomain<'_, '_> {
+impl JoinSemiLattice for BorrowckDomain {
     fn join(&mut self, _other: &Self) -> bool {
         // This is only reachable from `iterate_to_fixpoint`, which this analysis doesn't use.
         unreachable!();
     }
 }
 
-impl<'tcx, C> DebugWithContext<C> for BorrowckDomain<'_, 'tcx>
+impl<'tcx, C> DebugWithContext<C> for BorrowckDomain
 where
     C: rustc_mir_dataflow::move_paths::HasMoveData<'tcx>,
 {
@@ -160,10 +163,10 @@ where
 
 /// The transient state of the dataflow analyses used by the borrow checker.
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct BorrowckDomain<'a, 'tcx> {
-    pub(crate) borrows: <Borrows<'a, 'tcx> as Analysis<'tcx>>::Domain,
-    pub(crate) uninits: <MaybeUninitializedPlaces<'a, 'tcx> as Analysis<'tcx>>::Domain,
-    pub(crate) ever_inits: <EverInitializedPlaces<'a, 'tcx> as Analysis<'tcx>>::Domain,
+pub(crate) struct BorrowckDomain {
+    pub(crate) borrows: BorrowsDomain,
+    pub(crate) uninits: MaybeUninitializedPlacesDomain,
+    pub(crate) ever_inits: EverInitializedPlacesDomain,
 }
 
 rustc_index::newtype_index! {
@@ -566,6 +569,8 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     }
 }
 
+type BorrowsDomain = BitSet<BorrowIndex>;
+
 /// Forward dataflow computation of the set of borrows that are in scope at a particular location.
 /// - we gen the introduced loans
 /// - we kill loans on locals going out of (regular) scope
@@ -574,7 +579,7 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
 /// - we also kill loans of conflicting places when overwriting a shared path: e.g. borrows of
 ///   `a.b.c` when `a` is overwritten.
 impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
-    type Domain = BitSet<BorrowIndex>;
+    type Domain = BorrowsDomain;
 
     const NAME: &'static str = "borrows";
 

compiler/rustc_borrowck/src/lib.rs

@@ -603,7 +603,7 @@ impl<'a, 'tcx> ResultsVisitor<'a, 'tcx, Borrowck<'a, 'tcx>> for MirBorrowckCtxt<
     fn visit_statement_before_primary_effect(
         &mut self,
         _results: &mut Results<'tcx, Borrowck<'a, 'tcx>>,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
         stmt: &'a Statement<'tcx>,
         location: Location,
     ) {
@@ -677,7 +677,7 @@ impl<'a, 'tcx> ResultsVisitor<'a, 'tcx, Borrowck<'a, 'tcx>> for MirBorrowckCtxt<
     fn visit_terminator_before_primary_effect(
         &mut self,
         _results: &mut Results<'tcx, Borrowck<'a, 'tcx>>,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
         term: &'a Terminator<'tcx>,
         loc: Location,
     ) {
@@ -790,7 +790,7 @@ impl<'a, 'tcx> ResultsVisitor<'a, 'tcx, Borrowck<'a, 'tcx>> for MirBorrowckCtxt<
     fn visit_terminator_after_primary_effect(
         &mut self,
         _results: &mut Results<'tcx, Borrowck<'a, 'tcx>>,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
         term: &'a Terminator<'tcx>,
         loc: Location,
     ) {
@@ -983,7 +983,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         place_span: (Place<'tcx>, Span),
         kind: (AccessDepth, ReadOrWrite),
         is_local_mutation_allowed: LocalMutationIsAllowed,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         let (sd, rw) = kind;
 
@@ -1032,7 +1032,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         place_span: (Place<'tcx>, Span),
         sd: AccessDepth,
         rw: ReadOrWrite,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) -> bool {
         let mut error_reported = false;
 
@@ -1172,7 +1172,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         location: Location,
         place_span: (Place<'tcx>, Span),
         kind: AccessDepth,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         // Write of P[i] or *P requires P init'd.
         self.check_if_assigned_path_is_moved(location, place_span, state);
@@ -1190,7 +1190,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         &mut self,
         location: Location,
         (rvalue, span): (&'a Rvalue<'tcx>, Span),
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         match rvalue {
             &Rvalue::Ref(_ /*rgn*/, bk, place) => {
@@ -1448,7 +1448,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         &mut self,
         location: Location,
         (operand, span): (&'a Operand<'tcx>, Span),
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         match *operand {
             Operand::Copy(place) => {
@@ -1568,12 +1568,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         }
     }
 
-    fn check_activations(
-        &mut self,
-        location: Location,
-        span: Span,
-        state: &BorrowckDomain<'a, 'tcx>,
-    ) {
+    fn check_activations(&mut self, location: Location, span: Span, state: &BorrowckDomain) {
         // Two-phase borrow support: For each activation that is newly
         // generated at this statement, check if it interferes with
         // another borrow.
@@ -1731,7 +1726,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         location: Location,
         desired_action: InitializationRequiringAction,
         place_span: (PlaceRef<'tcx>, Span),
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         let maybe_uninits = &state.uninits;
 
@@ -1836,7 +1831,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         location: Location,
         desired_action: InitializationRequiringAction,
         place_span: (PlaceRef<'tcx>, Span),
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         let maybe_uninits = &state.uninits;
 
@@ -1935,7 +1930,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         &mut self,
         location: Location,
         (place, span): (Place<'tcx>, Span),
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
     ) {
         debug!("check_if_assigned_path_is_moved place: {:?}", place);
 
@@ -2001,7 +1996,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
             location: Location,
             base: PlaceRef<'tcx>,
             span: Span,
-            state: &BorrowckDomain<'a, 'tcx>,
+            state: &BorrowckDomain,
         ) {
             // rust-lang/rust#21232: Until Rust allows reads from the
             // initialized parts of partially initialized structs, we
@@ -2092,7 +2087,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         (place, span): (Place<'tcx>, Span),
         kind: ReadOrWrite,
         is_local_mutation_allowed: LocalMutationIsAllowed,
-        state: &BorrowckDomain<'a, 'tcx>,
+        state: &BorrowckDomain,
         location: Location,
     ) -> bool {
         debug!(
@@ -2206,18 +2201,14 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
         }
     }
 
-    fn is_local_ever_initialized(
-        &self,
-        local: Local,
-        state: &BorrowckDomain<'a, 'tcx>,
-    ) -> Option<InitIndex> {
+    fn is_local_ever_initialized(&self, local: Local, state: &BorrowckDomain) -> Option<InitIndex> {
         let mpi = self.move_data.rev_lookup.find_local(local)?;
         let ii = &self.move_data.init_path_map[mpi];
         ii.into_iter().find(|&&index| state.ever_inits.contains(index)).copied()
     }
 
     /// Adds the place into the used mutable variables set
-    fn add_used_mut(&mut self, root_place: RootPlace<'tcx>, state: &BorrowckDomain<'a, 'tcx>) {
+    fn add_used_mut(&mut self, root_place: RootPlace<'tcx>, state: &BorrowckDomain) {
         match root_place {
             RootPlace { place_local: local, place_projection: [], is_local_mutation_allowed } => {
                 // If the local may have been initialized, and it is now currently being

compiler/rustc_mir_dataflow/src/impls/initialized.rs

@@ -369,10 +369,12 @@ impl<'tcx> Analysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
     }
 }
 
+/// There can be many more `MovePathIndex` than there are locals in a MIR body.
+/// We use a mixed bitset to avoid paying too high a memory footprint.
+pub type MaybeUninitializedPlacesDomain = MixedBitSet<MovePathIndex>;
+
 impl<'tcx> Analysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
-    /// There can be many more `MovePathIndex` than there are locals in a MIR body.
-    /// We use a mixed bitset to avoid paying too high a memory footprint.
-    type Domain = MixedBitSet<MovePathIndex>;
+    type Domain = MaybeUninitializedPlacesDomain;
 
     const NAME: &'static str = "maybe_uninit";
 
@@ -490,10 +492,12 @@ impl<'tcx> Analysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
     }
 }
 
+/// There can be many more `InitIndex` than there are locals in a MIR body.
+/// We use a mixed bitset to avoid paying too high a memory footprint.
+pub type EverInitializedPlacesDomain = MixedBitSet<InitIndex>;
+
 impl<'tcx> Analysis<'tcx> for EverInitializedPlaces<'_, 'tcx> {
-    /// There can be many more `InitIndex` than there are locals in a MIR body.
-    /// We use a mixed bitset to avoid paying too high a memory footprint.
-    type Domain = MixedBitSet<InitIndex>;
+    type Domain = EverInitializedPlacesDomain;
 
     const NAME: &'static str = "ever_init";
 

compiler/rustc_mir_dataflow/src/impls/mod.rs

@@ -9,7 +9,8 @@ mod storage_liveness;
 
 pub use self::borrowed_locals::{MaybeBorrowedLocals, borrowed_locals};
 pub use self::initialized::{
-    EverInitializedPlaces, MaybeInitializedPlaces, MaybeUninitializedPlaces,
+    EverInitializedPlaces, EverInitializedPlacesDomain, MaybeInitializedPlaces,
+    MaybeUninitializedPlaces, MaybeUninitializedPlacesDomain,
 };
 pub use self::liveness::{
     MaybeLiveLocals, MaybeTransitiveLiveLocals, TransferFunction as LivenessTransferFunction,