Merging upstream version 1.73.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 6 insertions, 751 deletions

diff --git a/compiler/rustc_mir_dataflow/src/impls/mod.rs b/compiler/rustc_mir_dataflow/src/impls/mod.rs
index 98cec1c67..f8db18fc1 100644
--- a/compiler/rustc_mir_dataflow/src/impls/mod.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/mod.rs
@@ -2,763 +2,18 @@
 //! bitvectors attached to each basic block, represented via a
 //! zero-sized structure.
 
-use rustc_index::bit_set::{BitSet, ChunkedBitSet};
-use rustc_index::Idx;
-use rustc_middle::mir::visit::{MirVisitable, Visitor};
-use rustc_middle::mir::{self, Body, Location};
-use rustc_middle::ty::{self, TyCtxt};
-
-use crate::drop_flag_effects_for_function_entry;
-use crate::drop_flag_effects_for_location;
-use crate::elaborate_drops::DropFlagState;
-use crate::framework::{CallReturnPlaces, SwitchIntEdgeEffects};
-use crate::move_paths::{HasMoveData, InitIndex, InitKind, LookupResult, MoveData, MovePathIndex};
-use crate::on_lookup_result_bits;
-use crate::MoveDataParamEnv;
-use crate::{drop_flag_effects, on_all_children_bits};
-use crate::{lattice, AnalysisDomain, GenKill, GenKillAnalysis};
-
 mod borrowed_locals;
+mod initialized;
 mod liveness;
 mod storage_liveness;
 
 pub use self::borrowed_locals::borrowed_locals;
 pub use self::borrowed_locals::MaybeBorrowedLocals;
+pub use self::initialized::{
+    DefinitelyInitializedPlaces, EverInitializedPlaces, MaybeInitializedPlaces,
+    MaybeUninitializedPlaces,
+};
 pub use self::liveness::MaybeLiveLocals;
 pub use self::liveness::MaybeTransitiveLiveLocals;
+pub use self::liveness::TransferFunction as LivenessTransferFunction;
 pub use self::storage_liveness::{MaybeRequiresStorage, MaybeStorageDead, MaybeStorageLive};
-
-/// `MaybeInitializedPlaces` tracks all places that might be
-/// initialized upon reaching a particular point in the control flow
-/// for a function.
-///
-/// For example, in code like the following, we have corresponding
-/// dataflow information shown in the right-hand comments.
-///
-/// ```rust
-/// struct S;
-/// fn foo(pred: bool) {                        // maybe-init:
-///                                             // {}
-///     let a = S; let mut b = S; let c; let d; // {a, b}
-///
-///     if pred {
-///         drop(a);                            // {   b}
-///         b = S;                              // {   b}
-///
-///     } else {
-///         drop(b);                            // {a}
-///         d = S;                              // {a,       d}
-///
-///     }                                       // {a, b,    d}
-///
-///     c = S;                                  // {a, b, c, d}
-/// }
-/// ```
-///
-/// To determine whether a place *must* be initialized at a
-/// particular control-flow point, one can take the set-difference
-/// between this data and the data from `MaybeUninitializedPlaces` at the
-/// corresponding control-flow point.
-///
-/// Similarly, at a given `drop` statement, the set-intersection
-/// between this data and `MaybeUninitializedPlaces` yields the set of
-/// places that would require a dynamic drop-flag at that statement.
-pub struct MaybeInitializedPlaces<'a, 'tcx> {
-    tcx: TyCtxt<'tcx>,
-    body: &'a Body<'tcx>,
-    mdpe: &'a MoveDataParamEnv<'tcx>,
-}
-
-impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, mdpe: &'a MoveDataParamEnv<'tcx>) -> Self {
-        MaybeInitializedPlaces { tcx, body, mdpe }
-    }
-}
-
-impl<'a, 'tcx> HasMoveData<'tcx> for MaybeInitializedPlaces<'a, 'tcx> {
-    fn move_data(&self) -> &MoveData<'tcx> {
-        &self.mdpe.move_data
-    }
-}
-
-/// `MaybeUninitializedPlaces` tracks all places that might be
-/// uninitialized upon reaching a particular point in the control flow
-/// for a function.
-///
-/// For example, in code like the following, we have corresponding
-/// dataflow information shown in the right-hand comments.
-///
-/// ```rust
-/// struct S;
-/// fn foo(pred: bool) {                        // maybe-uninit:
-///                                             // {a, b, c, d}
-///     let a = S; let mut b = S; let c; let d; // {      c, d}
-///
-///     if pred {
-///         drop(a);                            // {a,    c, d}
-///         b = S;                              // {a,    c, d}
-///
-///     } else {
-///         drop(b);                            // {   b, c, d}
-///         d = S;                              // {   b, c   }
-///
-///     }                                       // {a, b, c, d}
-///
-///     c = S;                                  // {a, b,    d}
-/// }
-/// ```
-///
-/// To determine whether a place *must* be uninitialized at a
-/// particular control-flow point, one can take the set-difference
-/// between this data and the data from `MaybeInitializedPlaces` at the
-/// corresponding control-flow point.
-///
-/// Similarly, at a given `drop` statement, the set-intersection
-/// between this data and `MaybeInitializedPlaces` yields the set of
-/// places that would require a dynamic drop-flag at that statement.
-pub struct MaybeUninitializedPlaces<'a, 'tcx> {
-    tcx: TyCtxt<'tcx>,
-    body: &'a Body<'tcx>,
-    mdpe: &'a MoveDataParamEnv<'tcx>,
-
-    mark_inactive_variants_as_uninit: bool,
-}
-
-impl<'a, 'tcx> MaybeUninitializedPlaces<'a, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, mdpe: &'a MoveDataParamEnv<'tcx>) -> Self {
-        MaybeUninitializedPlaces { tcx, body, mdpe, mark_inactive_variants_as_uninit: false }
-    }
-
-    /// Causes inactive enum variants to be marked as "maybe uninitialized" after a switch on an
-    /// enum discriminant.
-    ///
-    /// This is correct in a vacuum but is not the default because it causes problems in the borrow
-    /// checker, where this information gets propagated along `FakeEdge`s.
-    pub fn mark_inactive_variants_as_uninit(mut self) -> Self {
-        self.mark_inactive_variants_as_uninit = true;
-        self
-    }
-}
-
-impl<'a, 'tcx> HasMoveData<'tcx> for MaybeUninitializedPlaces<'a, 'tcx> {
-    fn move_data(&self) -> &MoveData<'tcx> {
-        &self.mdpe.move_data
-    }
-}
-
-/// `DefinitelyInitializedPlaces` tracks all places that are definitely
-/// initialized upon reaching a particular point in the control flow
-/// for a function.
-///
-/// For example, in code like the following, we have corresponding
-/// dataflow information shown in the right-hand comments.
-///
-/// ```rust
-/// struct S;
-/// fn foo(pred: bool) {                        // definite-init:
-///                                             // {          }
-///     let a = S; let mut b = S; let c; let d; // {a, b      }
-///
-///     if pred {
-///         drop(a);                            // {   b,     }
-///         b = S;                              // {   b,     }
-///
-///     } else {
-///         drop(b);                            // {a,        }
-///         d = S;                              // {a,       d}
-///
-///     }                                       // {          }
-///
-///     c = S;                                  // {       c  }
-/// }
-/// ```
-///
-/// To determine whether a place *may* be uninitialized at a
-/// particular control-flow point, one can take the set-complement
-/// of this data.
-///
-/// Similarly, at a given `drop` statement, the set-difference between
-/// this data and `MaybeInitializedPlaces` yields the set of places
-/// that would require a dynamic drop-flag at that statement.
-pub struct DefinitelyInitializedPlaces<'a, 'tcx> {
-    tcx: TyCtxt<'tcx>,
-    body: &'a Body<'tcx>,
-    mdpe: &'a MoveDataParamEnv<'tcx>,
-}
-
-impl<'a, 'tcx> DefinitelyInitializedPlaces<'a, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, mdpe: &'a MoveDataParamEnv<'tcx>) -> Self {
-        DefinitelyInitializedPlaces { tcx, body, mdpe }
-    }
-}
-
-impl<'a, 'tcx> HasMoveData<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
-    fn move_data(&self) -> &MoveData<'tcx> {
-        &self.mdpe.move_data
-    }
-}
-
-/// `EverInitializedPlaces` tracks all places that might have ever been
-/// initialized upon reaching a particular point in the control flow
-/// for a function, without an intervening `StorageDead`.
-///
-/// This dataflow is used to determine if an immutable local variable may
-/// be assigned to.
-///
-/// For example, in code like the following, we have corresponding
-/// dataflow information shown in the right-hand comments.
-///
-/// ```rust
-/// struct S;
-/// fn foo(pred: bool) {                        // ever-init:
-///                                             // {          }
-///     let a = S; let mut b = S; let c; let d; // {a, b      }
-///
-///     if pred {
-///         drop(a);                            // {a, b,     }
-///         b = S;                              // {a, b,     }
-///
-///     } else {
-///         drop(b);                            // {a, b,      }
-///         d = S;                              // {a, b,    d }
-///
-///     }                                       // {a, b,    d }
-///
-///     c = S;                                  // {a, b, c, d }
-/// }
-/// ```
-pub struct EverInitializedPlaces<'a, 'tcx> {
-    #[allow(dead_code)]
-    tcx: TyCtxt<'tcx>,
-    body: &'a Body<'tcx>,
-    mdpe: &'a MoveDataParamEnv<'tcx>,
-}
-
-impl<'a, 'tcx> EverInitializedPlaces<'a, 'tcx> {
-    pub fn new(tcx: TyCtxt<'tcx>, body: &'a Body<'tcx>, mdpe: &'a MoveDataParamEnv<'tcx>) -> Self {
-        EverInitializedPlaces { tcx, body, mdpe }
-    }
-}
-
-impl<'a, 'tcx> HasMoveData<'tcx> for EverInitializedPlaces<'a, 'tcx> {
-    fn move_data(&self) -> &MoveData<'tcx> {
-        &self.mdpe.move_data
-    }
-}
-
-impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
-    fn update_bits(
-        trans: &mut impl GenKill<MovePathIndex>,
-        path: MovePathIndex,
-        state: DropFlagState,
-    ) {
-        match state {
-            DropFlagState::Absent => trans.kill(path),
-            DropFlagState::Present => trans.gen(path),
-        }
-    }
-}
-
-impl<'a, 'tcx> MaybeUninitializedPlaces<'a, 'tcx> {
-    fn update_bits(
-        trans: &mut impl GenKill<MovePathIndex>,
-        path: MovePathIndex,
-        state: DropFlagState,
-    ) {
-        match state {
-            DropFlagState::Absent => trans.gen(path),
-            DropFlagState::Present => trans.kill(path),
-        }
-    }
-}
-
-impl<'a, 'tcx> DefinitelyInitializedPlaces<'a, 'tcx> {
-    fn update_bits(
-        trans: &mut impl GenKill<MovePathIndex>,
-        path: MovePathIndex,
-        state: DropFlagState,
-    ) {
-        match state {
-            DropFlagState::Absent => trans.kill(path),
-            DropFlagState::Present => trans.gen(path),
-        }
-    }
-}
-
-impl<'tcx> AnalysisDomain<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
-    type Domain = ChunkedBitSet<MovePathIndex>;
-    const NAME: &'static str = "maybe_init";
-
-    fn bottom_value(&self, _: &mir::Body<'tcx>) -> Self::Domain {
-        // bottom = uninitialized
-        ChunkedBitSet::new_empty(self.move_data().move_paths.len())
-    }
-
-    fn initialize_start_block(&self, _: &mir::Body<'tcx>, state: &mut Self::Domain) {
-        drop_flag_effects_for_function_entry(self.tcx, self.body, self.mdpe, |path, s| {
-            assert!(s == DropFlagState::Present);
-            state.insert(path);
-        });
-    }
-}
-
-impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
-    type Idx = MovePathIndex;
-
-    fn statement_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        statement: &mir::Statement<'tcx>,
-        location: Location,
-    ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
-            Self::update_bits(trans, path, s)
-        });
-
-        if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration {
-            return;
-        }
-
-        // Mark all places as "maybe init" if they are mutably borrowed. See #90752.
-        for_each_mut_borrow(statement, location, |place| {
-            let LookupResult::Exact(mpi) = self.move_data().rev_lookup.find(place.as_ref()) else { return };
-            on_all_children_bits(self.tcx, self.body, self.move_data(), mpi, |child| {
-                trans.gen(child);
-            })
-        })
-    }
-
-    fn terminator_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        terminator: &mir::Terminator<'tcx>,
-        location: Location,
-    ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
-            Self::update_bits(trans, path, s)
-        });
-
-        if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration {
-            return;
-        }
-
-        for_each_mut_borrow(terminator, location, |place| {
-            let LookupResult::Exact(mpi) = self.move_data().rev_lookup.find(place.as_ref()) else { return };
-            on_all_children_bits(self.tcx, self.body, self.move_data(), mpi, |child| {
-                trans.gen(child);
-            })
-        })
-    }
-
-    fn call_return_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _block: mir::BasicBlock,
-        return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-        return_places.for_each(|place| {
-            // when a call returns successfully, that means we need to set
-            // the bits for that dest_place to 1 (initialized).
-            on_lookup_result_bits(
-                self.tcx,
-                self.body,
-                self.move_data(),
-                self.move_data().rev_lookup.find(place.as_ref()),
-                |mpi| {
-                    trans.gen(mpi);
-                },
-            );
-        });
-    }
-
-    fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
-        &mut self,
-        block: mir::BasicBlock,
-        discr: &mir::Operand<'tcx>,
-        edge_effects: &mut impl SwitchIntEdgeEffects<G>,
-    ) {
-        if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration {
-            return;
-        }
-
-        let enum_ = discr.place().and_then(|discr| {
-            switch_on_enum_discriminant(self.tcx, &self.body, &self.body[block], discr)
-        });
-
-        let Some((enum_place, enum_def)) = enum_ else {
-            return;
-        };
-
-        let mut discriminants = enum_def.discriminants(self.tcx);
-        edge_effects.apply(|trans, edge| {
-            let Some(value) = edge.value else {
-                return;
-            };
-
-            // MIR building adds discriminants to the `values` array in the same order as they
-            // are yielded by `AdtDef::discriminants`. We rely on this to match each
-            // discriminant in `values` to its corresponding variant in linear time.
-            let (variant, _) = discriminants
-                .find(|&(_, discr)| discr.val == value)
-                .expect("Order of `AdtDef::discriminants` differed from `SwitchInt::values`");
-
-            // Kill all move paths that correspond to variants we know to be inactive along this
-            // particular outgoing edge of a `SwitchInt`.
-            drop_flag_effects::on_all_inactive_variants(
-                self.tcx,
-                self.body,
-                self.move_data(),
-                enum_place,
-                variant,
-                |mpi| trans.kill(mpi),
-            );
-        });
-    }
-}
-
-impl<'tcx> AnalysisDomain<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
-    type Domain = ChunkedBitSet<MovePathIndex>;
-
-    const NAME: &'static str = "maybe_uninit";
-
-    fn bottom_value(&self, _: &mir::Body<'tcx>) -> Self::Domain {
-        // bottom = initialized (start_block_effect counters this at outset)
-        ChunkedBitSet::new_empty(self.move_data().move_paths.len())
-    }
-
-    // sets on_entry bits for Arg places
-    fn initialize_start_block(&self, _: &mir::Body<'tcx>, state: &mut Self::Domain) {
-        // set all bits to 1 (uninit) before gathering counter-evidence
-        state.insert_all();
-
-        drop_flag_effects_for_function_entry(self.tcx, self.body, self.mdpe, |path, s| {
-            assert!(s == DropFlagState::Present);
-            state.remove(path);
-        });
-    }
-}
-
-impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
-    type Idx = MovePathIndex;
-
-    fn statement_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _statement: &mir::Statement<'tcx>,
-        location: Location,
-    ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
-            Self::update_bits(trans, path, s)
-        });
-
-        // Unlike in `MaybeInitializedPlaces` above, we don't need to change the state when a
-        // mutable borrow occurs. Places cannot become uninitialized through a mutable reference.
-    }
-
-    fn terminator_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _terminator: &mir::Terminator<'tcx>,
-        location: Location,
-    ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
-            Self::update_bits(trans, path, s)
-        });
-    }
-
-    fn call_return_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _block: mir::BasicBlock,
-        return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-        return_places.for_each(|place| {
-            // when a call returns successfully, that means we need to set
-            // the bits for that dest_place to 0 (initialized).
-            on_lookup_result_bits(
-                self.tcx,
-                self.body,
-                self.move_data(),
-                self.move_data().rev_lookup.find(place.as_ref()),
-                |mpi| {
-                    trans.kill(mpi);
-                },
-            );
-        });
-    }
-
-    fn switch_int_edge_effects<G: GenKill<Self::Idx>>(
-        &mut self,
-        block: mir::BasicBlock,
-        discr: &mir::Operand<'tcx>,
-        edge_effects: &mut impl SwitchIntEdgeEffects<G>,
-    ) {
-        if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration {
-            return;
-        }
-
-        if !self.mark_inactive_variants_as_uninit {
-            return;
-        }
-
-        let enum_ = discr.place().and_then(|discr| {
-            switch_on_enum_discriminant(self.tcx, &self.body, &self.body[block], discr)
-        });
-
-        let Some((enum_place, enum_def)) = enum_ else {
-            return;
-        };
-
-        let mut discriminants = enum_def.discriminants(self.tcx);
-        edge_effects.apply(|trans, edge| {
-            let Some(value) = edge.value else {
-                return;
-            };
-
-            // MIR building adds discriminants to the `values` array in the same order as they
-            // are yielded by `AdtDef::discriminants`. We rely on this to match each
-            // discriminant in `values` to its corresponding variant in linear time.
-            let (variant, _) = discriminants
-                .find(|&(_, discr)| discr.val == value)
-                .expect("Order of `AdtDef::discriminants` differed from `SwitchInt::values`");
-
-            // Mark all move paths that correspond to variants other than this one as maybe
-            // uninitialized (in reality, they are *definitely* uninitialized).
-            drop_flag_effects::on_all_inactive_variants(
-                self.tcx,
-                self.body,
-                self.move_data(),
-                enum_place,
-                variant,
-                |mpi| trans.gen(mpi),
-            );
-        });
-    }
-}
-
-impl<'a, 'tcx> AnalysisDomain<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
-    /// Use set intersection as the join operator.
-    type Domain = lattice::Dual<BitSet<MovePathIndex>>;
-
-    const NAME: &'static str = "definite_init";
-
-    fn bottom_value(&self, _: &mir::Body<'tcx>) -> Self::Domain {
-        // bottom = initialized (start_block_effect counters this at outset)
-        lattice::Dual(BitSet::new_filled(self.move_data().move_paths.len()))
-    }
-
-    // sets on_entry bits for Arg places
-    fn initialize_start_block(&self, _: &mir::Body<'tcx>, state: &mut Self::Domain) {
-        state.0.clear();
-
-        drop_flag_effects_for_function_entry(self.tcx, self.body, self.mdpe, |path, s| {
-            assert!(s == DropFlagState::Present);
-            state.0.insert(path);
-        });
-    }
-}
-
-impl<'tcx> GenKillAnalysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> {
-    type Idx = MovePathIndex;
-
-    fn statement_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _statement: &mir::Statement<'tcx>,
-        location: Location,
-    ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
-            Self::update_bits(trans, path, s)
-        })
-    }
-
-    fn terminator_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _terminator: &mir::Terminator<'tcx>,
-        location: Location,
-    ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
-            Self::update_bits(trans, path, s)
-        })
-    }
-
-    fn call_return_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _block: mir::BasicBlock,
-        return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-        return_places.for_each(|place| {
-            // when a call returns successfully, that means we need to set
-            // the bits for that dest_place to 1 (initialized).
-            on_lookup_result_bits(
-                self.tcx,
-                self.body,
-                self.move_data(),
-                self.move_data().rev_lookup.find(place.as_ref()),
-                |mpi| {
-                    trans.gen(mpi);
-                },
-            );
-        });
-    }
-}
-
-impl<'tcx> AnalysisDomain<'tcx> for EverInitializedPlaces<'_, 'tcx> {
-    type Domain = ChunkedBitSet<InitIndex>;
-
-    const NAME: &'static str = "ever_init";
-
-    fn bottom_value(&self, _: &mir::Body<'tcx>) -> Self::Domain {
-        // bottom = no initialized variables by default
-        ChunkedBitSet::new_empty(self.move_data().inits.len())
-    }
-
-    fn initialize_start_block(&self, body: &mir::Body<'tcx>, state: &mut Self::Domain) {
-        for arg_init in 0..body.arg_count {
-            state.insert(InitIndex::new(arg_init));
-        }
-    }
-}
-
-impl<'tcx> GenKillAnalysis<'tcx> for EverInitializedPlaces<'_, 'tcx> {
-    type Idx = InitIndex;
-
-    #[instrument(skip(self, trans), level = "debug")]
-    fn statement_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        stmt: &mir::Statement<'tcx>,
-        location: Location,
-    ) {
-        let move_data = self.move_data();
-        let init_path_map = &move_data.init_path_map;
-        let init_loc_map = &move_data.init_loc_map;
-        let rev_lookup = &move_data.rev_lookup;
-
-        debug!("initializes move_indexes {:?}", &init_loc_map[location]);
-        trans.gen_all(init_loc_map[location].iter().copied());
-
-        if let mir::StatementKind::StorageDead(local) = stmt.kind {
-            // End inits for StorageDead, so that an immutable variable can
-            // be reinitialized on the next iteration of the loop.
-            let move_path_index = rev_lookup.find_local(local);
-            debug!("clears the ever initialized status of {:?}", init_path_map[move_path_index]);
-            trans.kill_all(init_path_map[move_path_index].iter().copied());
-        }
-    }
-
-    #[instrument(skip(self, trans, _terminator), level = "debug")]
-    fn terminator_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        _terminator: &mir::Terminator<'tcx>,
-        location: Location,
-    ) {
-        let (body, move_data) = (self.body, self.move_data());
-        let term = body[location.block].terminator();
-        let init_loc_map = &move_data.init_loc_map;
-        debug!(?term);
-        debug!("initializes move_indexes {:?}", init_loc_map[location]);
-        trans.gen_all(
-            init_loc_map[location]
-                .iter()
-                .filter(|init_index| {
-                    move_data.inits[**init_index].kind != InitKind::NonPanicPathOnly
-                })
-                .copied(),
-        );
-    }
-
-    fn call_return_effect(
-        &mut self,
-        trans: &mut impl GenKill<Self::Idx>,
-        block: mir::BasicBlock,
-        _return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-        let move_data = self.move_data();
-        let init_loc_map = &move_data.init_loc_map;
-
-        let call_loc = self.body.terminator_loc(block);
-        for init_index in &init_loc_map[call_loc] {
-            trans.gen(*init_index);
-        }
-    }
-}
-
-/// Inspect a `SwitchInt`-terminated basic block to see if the condition of that `SwitchInt` is
-/// an enum discriminant.
-///
-/// We expect such blocks to have a call to `discriminant` as their last statement like so:
-///
-/// ```text
-/// ...
-/// _42 = discriminant(_1)
-/// SwitchInt(_42, ..)
-/// ```
-///
-/// If the basic block matches this pattern, this function returns the place corresponding to the
-/// enum (`_1` in the example above) as well as the `AdtDef` of that enum.
-fn switch_on_enum_discriminant<'mir, 'tcx>(
-    tcx: TyCtxt<'tcx>,
-    body: &'mir mir::Body<'tcx>,
-    block: &'mir mir::BasicBlockData<'tcx>,
-    switch_on: mir::Place<'tcx>,
-) -> Option<(mir::Place<'tcx>, ty::AdtDef<'tcx>)> {
-    for statement in block.statements.iter().rev() {
-        match &statement.kind {
-            mir::StatementKind::Assign(box (lhs, mir::Rvalue::Discriminant(discriminated)))
-                if *lhs == switch_on =>
-            {
-                match discriminated.ty(body, tcx).ty.kind() {
-                    ty::Adt(def, _) => return Some((*discriminated, *def)),
-
-                    // `Rvalue::Discriminant` is also used to get the active yield point for a
-                    // generator, but we do not need edge-specific effects in that case. This may
-                    // change in the future.
-                    ty::Generator(..) => return None,
-
-                    t => bug!("`discriminant` called on unexpected type {:?}", t),
-                }
-            }
-            mir::StatementKind::Coverage(_) => continue,
-            _ => return None,
-        }
-    }
-    None
-}
-
-struct OnMutBorrow<F>(F);
-
-impl<F> Visitor<'_> for OnMutBorrow<F>
-where
-    F: FnMut(&mir::Place<'_>),
-{
-    fn visit_rvalue(&mut self, rvalue: &mir::Rvalue<'_>, location: Location) {
-        // FIXME: Does `&raw const foo` allow mutation? See #90413.
-        match rvalue {
-            mir::Rvalue::Ref(_, mir::BorrowKind::Mut { .. }, place)
-            | mir::Rvalue::AddressOf(_, place) => (self.0)(place),
-
-            _ => {}
-        }
-
-        self.super_rvalue(rvalue, location)
-    }
-}
-
-/// Calls `f` for each mutable borrow or raw reference in the program.
-///
-/// This DOES NOT call `f` for a shared borrow of a type with interior mutability. That's okay for
-/// initializedness, because we cannot move from an `UnsafeCell` (outside of `core::cell`), but
-/// other analyses will likely need to check for `!Freeze`.
-fn for_each_mut_borrow<'tcx>(
-    mir: &impl MirVisitable<'tcx>,
-    location: Location,
-    f: impl FnMut(&mir::Place<'_>),
-) {
-    let mut vis = OnMutBorrow(f);
-
-    mir.apply(location, &mut vis);
-}