Clean up extra lifetime, add assertions

src/librustc_mir/dataflow/impls/storage_liveness.rs

@@ -33,7 +33,9 @@ fn bits_per_block(&self) -> usize {
     }
 
     fn start_block_effect(&self, _on_entry: &mut BitSet<Local>) {
-        // Nothing is live on function entry
+        // Nothing is live on function entry (generators only have a self
+        // argument, and we don't care about that)
+        assert_eq!(1, self.body.arg_count);
     }
 
     fn statement_effect(&self,
@@ -72,16 +74,16 @@ impl<'a, 'tcx> BottomValue for MaybeStorageLive<'a, 'tcx> {
 
 /// Dataflow analysis that determines whether each local requires storage at a
 /// given location; i.e. whether its storage can go away without being observed.
-pub struct RequiresStorage<'mir, 'tcx, 'b> {
+pub struct RequiresStorage<'mir, 'tcx> {
     body: &'mir Body<'tcx>,
     borrowed_locals:
-        RefCell<DataflowResultsRefCursor<'mir, 'tcx, 'b, HaveBeenBorrowedLocals<'mir, 'tcx>>>,
+        RefCell<DataflowResultsRefCursor<'mir, 'tcx, HaveBeenBorrowedLocals<'mir, 'tcx>>>,
 }
 
-impl<'mir, 'tcx: 'mir, 'b> RequiresStorage<'mir, 'tcx, 'b> {
+impl<'mir, 'tcx: 'mir> RequiresStorage<'mir, 'tcx> {
     pub fn new(
         body: &'mir Body<'tcx>,
-        borrowed_locals: &'b DataflowResults<'tcx, HaveBeenBorrowedLocals<'mir, 'tcx>>,
+        borrowed_locals: &'mir DataflowResults<'tcx, HaveBeenBorrowedLocals<'mir, 'tcx>>,
     ) -> Self {
         RequiresStorage {
             body,
@@ -94,7 +96,7 @@ pub fn body(&self) -> &Body<'tcx> {
     }
 }
 
-impl<'mir, 'tcx, 'b> BitDenotation<'tcx> for RequiresStorage<'mir, 'tcx, 'b> {
+impl<'mir, 'tcx> BitDenotation<'tcx> for RequiresStorage<'mir, 'tcx> {
     type Idx = Local;
     fn name() -> &'static str { "requires_storage" }
     fn bits_per_block(&self) -> usize {
@@ -102,7 +104,9 @@ fn bits_per_block(&self) -> usize {
     }
 
     fn start_block_effect(&self, _sets: &mut BitSet<Local>) {
-        // Nothing is live on function entry
+        // Nothing is live on function entry (generators only have a self
+        // argument, and we don't care about that)
+        assert_eq!(1, self.body.arg_count);
     }
 
     fn statement_effect(&self,
@@ -146,7 +150,7 @@ fn propagate_call_return(
     }
 }
 
-impl<'mir, 'tcx, 'b> RequiresStorage<'mir, 'tcx, 'b> {
+impl<'mir, 'tcx> RequiresStorage<'mir, 'tcx> {
     /// Kill locals that are fully moved and have not been borrowed.
     fn check_for_move(&self, sets: &mut GenKillSet<Local>, loc: Location) {
         let mut visitor = MoveVisitor {
@@ -165,18 +169,18 @@ fn check_for_borrow(&self, sets: &mut GenKillSet<Local>, loc: Location) {
     }
 }
 
-impl<'mir, 'tcx, 'b> BottomValue for RequiresStorage<'mir, 'tcx, 'b> {
+impl<'mir, 'tcx> BottomValue for RequiresStorage<'mir, 'tcx> {
     /// bottom = dead
     const BOTTOM_VALUE: bool = false;
 }
 
-struct MoveVisitor<'a, 'b, 'mir, 'tcx> {
+struct MoveVisitor<'a, 'mir, 'tcx> {
     borrowed_locals:
-        &'a RefCell<DataflowResultsRefCursor<'mir, 'tcx, 'b, HaveBeenBorrowedLocals<'mir, 'tcx>>>,
+        &'a RefCell<DataflowResultsRefCursor<'mir, 'tcx, HaveBeenBorrowedLocals<'mir, 'tcx>>>,
     sets: &'a mut GenKillSet<Local>,
 }
 
-impl<'a, 'b, 'mir: 'a, 'tcx> Visitor<'tcx> for MoveVisitor<'a, 'b, 'mir, 'tcx> {
+impl<'a, 'mir: 'a, 'tcx> Visitor<'tcx> for MoveVisitor<'a, 'mir, 'tcx> {
     fn visit_local(&mut self, local: &Local, context: PlaceContext, loc: Location) {
         if PlaceContext::NonMutatingUse(NonMutatingUseContext::Move) == context {
             let mut borrowed_locals = self.borrowed_locals.borrow_mut();

src/librustc_mir/dataflow/mod.rs

@@ -359,8 +359,8 @@ pub struct DataflowResultsCursor<'mir, 'tcx, BD, DR = DataflowResults<'tcx, BD>>
     body: &'mir Body<'tcx>,
 }
 
-pub type DataflowResultsRefCursor<'mir, 'tcx, 'flow, BD> =
-    DataflowResultsCursor<'mir, 'tcx, BD, &'flow DataflowResults<'tcx, BD>>;
+pub type DataflowResultsRefCursor<'mir, 'tcx, BD> =
+    DataflowResultsCursor<'mir, 'tcx, BD, &'mir DataflowResults<'tcx, BD>>;
 
 impl<'mir, 'tcx, BD, DR> DataflowResultsCursor<'mir, 'tcx, BD, DR>
 where

src/librustc_mir/transform/generator.rs

@@ -62,7 +62,6 @@
 use rustc_data_structures::bit_set::{BitSet, BitMatrix};
 use std::borrow::Cow;
 use std::iter;
-use std::marker::PhantomData;
 use std::mem;
 use crate::transform::{MirPass, MirSource};
 use crate::transform::simplify;
@@ -578,8 +577,8 @@ fn compute_storage_conflicts(
     body: &'mir Body<'tcx>,
     stored_locals: &liveness::LiveVarSet,
     ignored: &StorageIgnored,
-    requires_storage: DataflowResults<'tcx, RequiresStorage<'mir, 'tcx, '_>>,
-    _requires_storage_analysis: RequiresStorage<'mir, 'tcx, '_>,
+    requires_storage: DataflowResults<'tcx, RequiresStorage<'mir, 'tcx>>,
+    _requires_storage_analysis: RequiresStorage<'mir, 'tcx>,
 ) -> BitMatrix<GeneratorSavedLocal, GeneratorSavedLocal> {
     assert_eq!(body.local_decls.len(), ignored.0.domain_size());
     assert_eq!(body.local_decls.len(), stored_locals.domain_size());
@@ -596,7 +595,6 @@ fn compute_storage_conflicts(
         body,
         stored_locals: &stored_locals,
         local_conflicts: BitMatrix::from_row_n(&ineligible_locals, body.local_decls.len()),
-        _phantom: PhantomData::default(),
     };
     let mut state = FlowAtLocation::new(requires_storage);
     visitor.analyze_results(&mut state);
@@ -628,19 +626,18 @@ fn compute_storage_conflicts(
     storage_conflicts
 }
 
-struct StorageConflictVisitor<'body: 'b, 'tcx, 's, 'b> {
+struct StorageConflictVisitor<'body, 'tcx, 's> {
     body: &'body Body<'tcx>,
     stored_locals: &'s liveness::LiveVarSet,
     // FIXME(tmandry): Consider using sparse bitsets here once we have good
     // benchmarks for generators.
     local_conflicts: BitMatrix<Local, Local>,
-    _phantom: PhantomData<&'b ()>,
 }
 
-impl<'body, 'tcx, 's, 'b> DataflowResultsConsumer<'body, 'tcx>
-    for StorageConflictVisitor<'body, 'tcx, 's, 'b>
+impl<'body, 'tcx, 's> DataflowResultsConsumer<'body, 'tcx>
+    for StorageConflictVisitor<'body, 'tcx, 's>
 {
-    type FlowState = FlowAtLocation<'tcx, RequiresStorage<'body, 'tcx, 'b>>;
+    type FlowState = FlowAtLocation<'tcx, RequiresStorage<'body, 'tcx>>;
 
     fn body(&self) -> &'body Body<'tcx> {
         self.body
@@ -668,9 +665,9 @@ fn visit_terminator_entry(&mut self,
     }
 }
 
-impl<'body, 'tcx, 's, 'b> StorageConflictVisitor<'body, 'tcx, 's, 'b> {
+impl<'body, 'tcx, 's> StorageConflictVisitor<'body, 'tcx, 's> {
     fn apply_state(&mut self,
-                   flow_state: &FlowAtLocation<'tcx, RequiresStorage<'body, 'tcx, 'b>>,
+                   flow_state: &FlowAtLocation<'tcx, RequiresStorage<'body, 'tcx>>,
                    loc: Location) {
         // Ignore unreachable blocks.
         match self.body.basic_blocks()[loc.block].terminator().kind {