Remove unused arguments from on_all_children_bits.

`on_all_children_bits` has two arguments that are unused: `tcx` and
`body`. This was not detected by the compiler because it's a recursive
function.

This commit removes them, and removes lots of other arguments and fields
that are no longer necessary.

Author: nnethercote

compiler/rustc_mir_dataflow/src/drop_flag_effects.rs

@@ -1,6 +1,5 @@
 use crate::elaborate_drops::DropFlagState;
 use rustc_middle::mir::{self, Body, Location, Terminator, TerminatorKind};
-use rustc_middle::ty::TyCtxt;
 use rustc_target::abi::VariantIdx;
 
 use super::move_paths::{InitKind, LookupResult, MoveData, MovePathIndex};
@@ -29,8 +28,6 @@ where
 }
 
 pub fn on_lookup_result_bits<'tcx, F>(
-    tcx: TyCtxt<'tcx>,
-    body: &Body<'tcx>,
     move_data: &MoveData<'tcx>,
     lookup_result: LookupResult,
     each_child: F,
@@ -41,22 +38,18 @@ pub fn on_lookup_result_bits<'tcx, F>(
         LookupResult::Parent(..) => {
             // access to untracked value - do not touch children
         }
-        LookupResult::Exact(e) => on_all_children_bits(tcx, body, move_data, e, each_child),
+        LookupResult::Exact(e) => on_all_children_bits(move_data, e, each_child),
     }
 }
 
 pub fn on_all_children_bits<'tcx, F>(
-    tcx: TyCtxt<'tcx>,
-    body: &Body<'tcx>,
     move_data: &MoveData<'tcx>,
     move_path_index: MovePathIndex,
     mut each_child: F,
 ) where
     F: FnMut(MovePathIndex),
 {
     fn on_all_children_bits<'tcx, F>(
-        tcx: TyCtxt<'tcx>,
-        body: &Body<'tcx>,
         move_data: &MoveData<'tcx>,
         move_path_index: MovePathIndex,
         each_child: &mut F,
@@ -67,15 +60,14 @@ pub fn on_all_children_bits<'tcx, F>(
 
         let mut next_child_index = move_data.move_paths[move_path_index].first_child;
         while let Some(child_index) = next_child_index {
-            on_all_children_bits(tcx, body, move_data, child_index, each_child);
+            on_all_children_bits(move_data, child_index, each_child);
             next_child_index = move_data.move_paths[child_index].next_sibling;
         }
     }
-    on_all_children_bits(tcx, body, move_data, move_path_index, &mut each_child);
+    on_all_children_bits(move_data, move_path_index, &mut each_child);
 }
 
 pub fn drop_flag_effects_for_function_entry<'tcx, F>(
-    tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
     ctxt: &MoveDataParamEnv<'tcx>,
     mut callback: F,
@@ -86,14 +78,13 @@ pub fn drop_flag_effects_for_function_entry<'tcx, F>(
     for arg in body.args_iter() {
         let place = mir::Place::from(arg);
         let lookup_result = move_data.rev_lookup.find(place.as_ref());
-        on_lookup_result_bits(tcx, body, move_data, lookup_result, |mpi| {
+        on_lookup_result_bits(move_data, lookup_result, |mpi| {
             callback(mpi, DropFlagState::Present)
         });
     }
 }
 
 pub fn drop_flag_effects_for_location<'tcx, F>(
-    tcx: TyCtxt<'tcx>,
     body: &Body<'tcx>,
     ctxt: &MoveDataParamEnv<'tcx>,
     loc: Location,
@@ -109,32 +100,25 @@ pub fn drop_flag_effects_for_location<'tcx, F>(
         let path = mi.move_path_index(move_data);
         debug!("moving out of path {:?}", move_data.move_paths[path]);
 
-        on_all_children_bits(tcx, body, move_data, path, |mpi| callback(mpi, DropFlagState::Absent))
+        on_all_children_bits(move_data, path, |mpi| callback(mpi, DropFlagState::Absent))
     }
 
     // Drop does not count as a move but we should still consider the variable uninitialized.
     if let Some(Terminator { kind: TerminatorKind::Drop { place, .. }, .. }) =
         body.stmt_at(loc).right()
     {
         if let LookupResult::Exact(mpi) = move_data.rev_lookup.find(place.as_ref()) {
-            on_all_children_bits(tcx, body, move_data, mpi, |mpi| {
-                callback(mpi, DropFlagState::Absent)
-            })
+            on_all_children_bits(move_data, mpi, |mpi| callback(mpi, DropFlagState::Absent))
         }
     }
 
     debug!("drop_flag_effects: assignment for location({:?})", loc);
 
-    for_location_inits(tcx, body, move_data, loc, |mpi| callback(mpi, DropFlagState::Present));
+    for_location_inits(move_data, loc, |mpi| callback(mpi, DropFlagState::Present));
 }
 
-fn for_location_inits<'tcx, F>(
-    tcx: TyCtxt<'tcx>,
-    body: &Body<'tcx>,
-    move_data: &MoveData<'tcx>,
-    loc: Location,
-    mut callback: F,
-) where
+fn for_location_inits<'tcx, F>(move_data: &MoveData<'tcx>, loc: Location, mut callback: F)
+where
     F: FnMut(MovePathIndex),
 {
     for ii in &move_data.init_loc_map[loc] {
@@ -143,7 +127,7 @@ fn for_location_inits<'tcx, F>(
             InitKind::Deep => {
                 let path = init.path;
 
-                on_all_children_bits(tcx, body, move_data, path, &mut callback)
+                on_all_children_bits(move_data, path, &mut callback)
             }
             InitKind::Shallow => {
                 let mpi = init.path;
@@ -160,8 +144,6 @@ fn for_location_inits<'tcx, F>(
 /// NOTE: If there are no move paths corresponding to an inactive variant,
 /// `handle_inactive_variant` will not be called for that variant.
 pub(crate) fn on_all_inactive_variants<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    body: &mir::Body<'tcx>,
     move_data: &MoveData<'tcx>,
     enum_place: mir::Place<'tcx>,
     active_variant: VariantIdx,
@@ -184,9 +166,7 @@ pub(crate) fn on_all_inactive_variants<'tcx>(
         };
 
         if variant_idx != active_variant {
-            on_all_children_bits(tcx, body, move_data, variant_mpi, |mpi| {
-                handle_inactive_variant(mpi)
-            });
+            on_all_children_bits(move_data, variant_mpi, |mpi| handle_inactive_variant(mpi));
         }
     }
 }

compiler/rustc_mir_dataflow/src/impls/initialized.rs

@@ -72,7 +72,7 @@ impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
     ) -> bool {
         if let LookupResult::Exact(path) = self.move_data().rev_lookup.find(place.as_ref()) {
             let mut maybe_live = false;
-            on_all_children_bits(self.tcx, self.body, self.move_data(), path, |child| {
+            on_all_children_bits(self.move_data(), path, |child| {
                 maybe_live |= state.contains(child);
             });
             !maybe_live
@@ -203,14 +203,13 @@ impl<'a, 'tcx> HasMoveData<'tcx> for MaybeUninitializedPlaces<'a, 'tcx> {
 /// 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 }
+    pub fn new(body: &'a Body<'tcx>, mdpe: &'a MoveDataParamEnv<'tcx>) -> Self {
+        DefinitelyInitializedPlaces { body, mdpe }
     }
 }
 
@@ -317,7 +316,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
     fn initialize_start_block(&self, _: &mir::Body<'tcx>, state: &mut Self::Domain) {
         *state =
             MaybeReachable::Reachable(ChunkedBitSet::new_empty(self.move_data().move_paths.len()));
-        drop_flag_effects_for_function_entry(self.tcx, self.body, self.mdpe, |path, s| {
+        drop_flag_effects_for_function_entry(self.body, self.mdpe, |path, s| {
             assert!(s == DropFlagState::Present);
             state.gen(path);
         });
@@ -337,7 +336,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
         statement: &mir::Statement<'tcx>,
         location: Location,
     ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
+        drop_flag_effects_for_location(self.body, self.mdpe, location, |path, s| {
             Self::update_bits(trans, path, s)
         });
 
@@ -349,7 +348,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
                 | mir::Rvalue::AddressOf(_, place) = rvalue
             && let LookupResult::Exact(mpi) = self.move_data().rev_lookup.find(place.as_ref())
         {
-            on_all_children_bits(self.tcx, self.body, self.move_data(), mpi, |child| {
+            on_all_children_bits(self.move_data(), mpi, |child| {
                 trans.gen(child);
             })
         }
@@ -369,7 +368,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
         {
             edges = TerminatorEdges::Single(target);
         }
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
+        drop_flag_effects_for_location(self.body, self.mdpe, location, |path, s| {
             Self::update_bits(state, path, s)
         });
         edges
@@ -385,8 +384,6 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
             // 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| {
@@ -430,8 +427,6 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
             // 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,
@@ -456,7 +451,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
         // 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| {
+        drop_flag_effects_for_function_entry(self.body, self.mdpe, |path, s| {
             assert!(s == DropFlagState::Present);
             state.remove(path);
         });
@@ -476,7 +471,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
         _statement: &mir::Statement<'tcx>,
         location: Location,
     ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
+        drop_flag_effects_for_location(self.body, self.mdpe, location, |path, s| {
             Self::update_bits(trans, path, s)
         });
 
@@ -490,7 +485,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
         terminator: &'mir mir::Terminator<'tcx>,
         location: Location,
     ) -> TerminatorEdges<'mir, 'tcx> {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
+        drop_flag_effects_for_location(self.body, self.mdpe, location, |path, s| {
             Self::update_bits(trans, path, s)
         });
         if self.skip_unreachable_unwind.contains(location.block) {
@@ -512,8 +507,6 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
             // 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| {
@@ -561,8 +554,6 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
             // 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,
@@ -587,7 +578,7 @@ impl<'a, 'tcx> AnalysisDomain<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
     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| {
+        drop_flag_effects_for_function_entry(self.body, self.mdpe, |path, s| {
             assert!(s == DropFlagState::Present);
             state.0.insert(path);
         });
@@ -607,7 +598,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> {
         _statement: &mir::Statement<'tcx>,
         location: Location,
     ) {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
+        drop_flag_effects_for_location(self.body, self.mdpe, location, |path, s| {
             Self::update_bits(trans, path, s)
         })
     }
@@ -618,7 +609,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> {
         terminator: &'mir mir::Terminator<'tcx>,
         location: Location,
     ) -> TerminatorEdges<'mir, 'tcx> {
-        drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| {
+        drop_flag_effects_for_location(self.body, self.mdpe, location, |path, s| {
             Self::update_bits(trans, path, s)
         });
         terminator.edges()
@@ -634,8 +625,6 @@ impl<'tcx> GenKillAnalysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> {
             // 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| {

compiler/rustc_mir_dataflow/src/rustc_peek.rs

@@ -66,7 +66,7 @@ impl<'tcx> MirPass<'tcx> for SanityCheck {
         }
 
         if has_rustc_mir_with(tcx, def_id, sym::rustc_peek_definite_init).is_some() {
-            let flow_def_inits = DefinitelyInitializedPlaces::new(tcx, body, &mdpe)
+            let flow_def_inits = DefinitelyInitializedPlaces::new(body, &mdpe)
                 .into_engine(tcx, body)
                 .iterate_to_fixpoint();