Rollup merge of #98766 - lcnr:mir-visit-pass_by_value, r=oli-obk

cleanup mir visitor for `rustc::pass_by_value`

by changing `& $($mutability)?` to `$(& $mutability)?`

I also did some formatting changes because I started doing them for the visit methods I changed and then couldn't get myself to stop xx, I hope that's still fairly easy to review.

Author: Dylan-DPC

Diff for: compiler/rustc_borrowck/src/borrow_set.rs

@@ -92,9 +92,9 @@ impl LocalsStateAtExit {
         struct HasStorageDead(BitSet<Local>);
 
         impl<'tcx> Visitor<'tcx> for HasStorageDead {
-            fn visit_local(&mut self, local: &Local, ctx: PlaceContext, _: Location) {
+            fn visit_local(&mut self, local: Local, ctx: PlaceContext, _: Location) {
                 if ctx == PlaceContext::NonUse(NonUseContext::StorageDead) {
-                    self.0.insert(*local);
+                    self.0.insert(local);
                 }
             }
         }
@@ -223,7 +223,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'tcx> {
         self.super_assign(assigned_place, rvalue, location)
     }
 
-    fn visit_local(&mut self, temp: &Local, context: PlaceContext, location: Location) {
+    fn visit_local(&mut self, temp: Local, context: PlaceContext, location: Location) {
         if !context.is_use() {
             return;
         }
@@ -232,7 +232,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherBorrows<'a, 'tcx> {
         // check whether we (earlier) saw a 2-phase borrow like
         //
         //     TMP = &mut place
-        if let Some(&borrow_index) = self.pending_activations.get(temp) {
+        if let Some(&borrow_index) = self.pending_activations.get(&temp) {
             let borrow_data = &mut self.location_map[borrow_index.as_usize()];
 
             // Watch out: the use of TMP in the borrow itself

Diff for: compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs

@@ -18,8 +18,8 @@ struct AllLocalUsesVisitor {
 }
 
 impl<'tcx> Visitor<'tcx> for AllLocalUsesVisitor {
-    fn visit_local(&mut self, local: &Local, _context: PlaceContext, location: Location) {
-        if *local == self.for_local {
+    fn visit_local(&mut self, local: Local, _context: PlaceContext, location: Location) {
+        if local == self.for_local {
             self.uses.insert(location);
         }
     }

Diff for: compiler/rustc_borrowck/src/diagnostics/find_use.rs

@@ -106,7 +106,7 @@ enum DefUseResult {
 }
 
 impl<'cx, 'tcx> Visitor<'tcx> for DefUseVisitor<'cx, 'tcx> {
-    fn visit_local(&mut self, &local: &Local, context: PlaceContext, _: Location) {
+    fn visit_local(&mut self, local: Local, context: PlaceContext, _: Location) {
         let local_ty = self.body.local_decls[local].ty;
 
         let mut found_it = false;

Diff for: compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs

@@ -157,7 +157,7 @@ impl LocalUseMapBuild<'_> {
 }
 
 impl Visitor<'_> for LocalUseMapBuild<'_> {
-    fn visit_local(&mut self, &local: &Local, context: PlaceContext, location: Location) {
+    fn visit_local(&mut self, local: Local, context: PlaceContext, location: Location) {
         if self.locals_with_use_data[local] {
             match def_use::categorize(context) {
                 Some(DefUse::Def) => self.insert_def(local, location),

Diff for: compiler/rustc_borrowck/src/type_check/liveness/polonius.rs

@@ -54,7 +54,7 @@ impl UseFactsExtractor<'_, '_> {
 }
 
 impl<'a, 'tcx> Visitor<'tcx> for UseFactsExtractor<'a, 'tcx> {
-    fn visit_local(&mut self, &local: &Local, context: PlaceContext, location: Location) {
+    fn visit_local(&mut self, local: Local, context: PlaceContext, location: Location) {
         match def_use::categorize(context) {
             Some(DefUse::Def) => self.insert_def(local, location),
             Some(DefUse::Use) => self.insert_use(local, location),

Diff for: compiler/rustc_borrowck/src/type_check/mod.rs

@@ -333,9 +333,9 @@ struct TypeVerifier<'a, 'b, 'tcx> {
 }
 
 impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
-    fn visit_span(&mut self, span: &Span) {
+    fn visit_span(&mut self, span: Span) {
         if !span.is_dummy() {
-            self.last_span = *span;
+            self.last_span = span;
         }
     }
 

Diff for: compiler/rustc_borrowck/src/used_muts.rs

@@ -91,8 +91,8 @@ impl<'visit, 'cx, 'tcx> Visitor<'tcx> for GatherUsedMutsVisitor<'visit, 'cx, 'tc
         self.super_statement(statement, location);
     }
 
-    fn visit_local(&mut self, local: &Local, place_context: PlaceContext, location: Location) {
-        if place_context.is_place_assignment() && self.temporary_used_locals.contains(local) {
+    fn visit_local(&mut self, local: Local, place_context: PlaceContext, location: Location) {
+        if place_context.is_place_assignment() && self.temporary_used_locals.contains(&local) {
             // Propagate the Local assigned at this Location as a used mutable local variable
             for moi in &self.mbcx.move_data.loc_map[location] {
                 let mpi = &self.mbcx.move_data.moves[*moi].path;

Diff for: compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -143,13 +143,13 @@ impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> LocalAnalyzer<'mir, 'a, 'tcx,
             // now that we have moved to the "slice of projections" representation.
             if let mir::ProjectionElem::Index(local) = elem {
                 self.visit_local(
-                    &local,
+                    local,
                     PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
                     location,
                 );
             }
         } else {
-            self.visit_local(&place_ref.local, context, location);
+            self.visit_local(place_ref.local, context, location);
         }
     }
 }
@@ -185,7 +185,7 @@ impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
         self.process_place(&place.as_ref(), context, location);
     }
 
-    fn visit_local(&mut self, &local: &mir::Local, context: PlaceContext, location: Location) {
+    fn visit_local(&mut self, local: mir::Local, context: PlaceContext, location: Location) {
         match context {
             PlaceContext::MutatingUse(MutatingUseContext::Call)
             | PlaceContext::MutatingUse(MutatingUseContext::Yield) => {

Diff for: compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -418,7 +418,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                             PlaceContext::MutatingUse(MutatingUseContext::Borrow)
                         }
                     };
-                    self.visit_local(&reborrowed_place_ref.local, ctx, location);
+                    self.visit_local(reborrowed_place_ref.local, ctx, location);
                     self.visit_projection(reborrowed_place_ref, ctx, location);
                     return;
                 }
@@ -431,7 +431,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                         }
                         Mutability::Mut => PlaceContext::MutatingUse(MutatingUseContext::AddressOf),
                     };
-                    self.visit_local(&reborrowed_place_ref.local, ctx, location);
+                    self.visit_local(reborrowed_place_ref.local, ctx, location);
                     self.visit_projection(reborrowed_place_ref, ctx, location);
                     return;
                 }

Diff for: compiler/rustc_const_eval/src/transform/promote_consts.rs

@@ -106,7 +106,7 @@ struct Collector<'a, 'tcx> {
 }
 
 impl<'tcx> Visitor<'tcx> for Collector<'_, 'tcx> {
-    fn visit_local(&mut self, &index: &Local, context: PlaceContext, location: Location) {
+    fn visit_local(&mut self, index: Local, context: PlaceContext, location: Location) {
         debug!("visit_local: index={:?} context={:?} location={:?}", index, context, location);
         // We're only interested in temporaries and the return place
         match self.ccx.body.local_kind(index) {

Diff for: compiler/rustc_const_eval/src/transform/validate.rs

@@ -196,8 +196,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
-    fn visit_local(&mut self, local: &Local, context: PlaceContext, location: Location) {
-        if self.body.local_decls.get(*local).is_none() {
+    fn visit_local(&mut self, local: Local, context: PlaceContext, location: Location) {
+        if self.body.local_decls.get(local).is_none() {
             self.fail(
                 location,
                 format!("local {:?} has no corresponding declaration in `body.local_decls`", local),
@@ -208,7 +208,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             // Uses of locals must occur while the local's storage is allocated.
             self.storage_liveness.seek_after_primary_effect(location);
             let locals_with_storage = self.storage_liveness.get();
-            if !locals_with_storage.contains(*local) {
+            if !locals_with_storage.contains(local) {
                 self.fail(location, format!("use of local {:?}, which has no storage here", local));
             }
         }
@@ -823,8 +823,8 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
         self.super_terminator(terminator, location);
     }
 
-    fn visit_source_scope(&mut self, scope: &SourceScope) {
-        if self.body.source_scopes.get(*scope).is_none() {
+    fn visit_source_scope(&mut self, scope: SourceScope) {
+        if self.body.source_scopes.get(scope).is_none() {
             self.tcx.sess.diagnostic().delay_span_bug(
                 self.body.span,
                 &format!(

Diff for: compiler/rustc_const_eval/src/util/collect_writes.rs

@@ -24,8 +24,8 @@ struct FindLocalAssignmentVisitor {
 }
 
 impl<'tcx> Visitor<'tcx> for FindLocalAssignmentVisitor {
-    fn visit_local(&mut self, local: &Local, place_context: PlaceContext, location: Location) {
-        if self.needle != *local {
+    fn visit_local(&mut self, local: Local, place_context: PlaceContext, location: Location) {
+        if self.needle != local {
             return;
         }