Add defaults for Analysis::apply_{call_return_effect,terminator_effect}.

To avoid some low-value boilerplate code.

Author: nnethercote

compiler/rustc_borrowck/src/dataflow.rs

@@ -1,9 +1,7 @@
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::graph;
 use rustc_index::bit_set::BitSet;
-use rustc_middle::mir::{
-    self, BasicBlock, Body, CallReturnPlaces, Location, Place, TerminatorEdges,
-};
+use rustc_middle::mir::{self, BasicBlock, Body, Location, Place, TerminatorEdges};
 use rustc_middle::ty::{RegionVid, TyCtxt};
 use rustc_mir_dataflow::fmt::DebugWithContext;
 use rustc_mir_dataflow::impls::{EverInitializedPlaces, MaybeUninitializedPlaces};
@@ -595,14 +593,6 @@ impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
         }
         terminator.edges()
     }
-
-    fn apply_call_return_effect(
-        &mut self,
-        _trans: &mut Self::Domain,
-        _block: mir::BasicBlock,
-        _return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-    }
 }
 
 impl<C> DebugWithContext<C> for BorrowIndex {}

compiler/rustc_mir_dataflow/src/framework/mod.rs

@@ -161,10 +161,12 @@ pub trait Analysis<'tcx> {
     /// initialized here.
     fn apply_terminator_effect<'mir>(
         &mut self,
-        state: &mut Self::Domain,
+        _state: &mut Self::Domain,
         terminator: &'mir mir::Terminator<'tcx>,
-        location: Location,
-    ) -> TerminatorEdges<'mir, 'tcx>;
+        _location: Location,
+    ) -> TerminatorEdges<'mir, 'tcx> {
+        terminator.edges()
+    }
 
     /// Updates the current dataflow state with an effect that occurs immediately *before* the
     /// given terminator.
@@ -189,10 +191,11 @@ pub trait Analysis<'tcx> {
     /// edges.
     fn apply_call_return_effect(
         &mut self,
-        state: &mut Self::Domain,
-        block: BasicBlock,
-        return_places: CallReturnPlaces<'_, 'tcx>,
-    );
+        _state: &mut Self::Domain,
+        _block: BasicBlock,
+        _return_places: CallReturnPlaces<'_, 'tcx>,
+    ) {
+    }
 
     /// Updates the current dataflow state with the effect of taking a particular branch in a
     /// `SwitchInt` terminator.

compiler/rustc_mir_dataflow/src/framework/tests.rs

@@ -208,14 +208,6 @@ impl<'tcx, D: Direction> Analysis<'tcx> for MockAnalysis<'tcx, D> {
         let idx = self.effect(Effect::Before.at_index(location.statement_index));
         assert!(state.insert(idx));
     }
-
-    fn apply_call_return_effect(
-        &mut self,
-        _state: &mut Self::Domain,
-        _block: BasicBlock,
-        _return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-    }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]

compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs

@@ -51,14 +51,6 @@ impl<'tcx> Analysis<'tcx> for MaybeBorrowedLocals {
         self.transfer_function(trans).visit_terminator(terminator, location);
         terminator.edges()
     }
-
-    fn apply_call_return_effect(
-        &mut self,
-        _trans: &mut Self::Domain,
-        _block: BasicBlock,
-        _return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-    }
 }
 
 /// A `Visitor` that defines the transfer function for `MaybeBorrowedLocals`.

compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs

@@ -50,25 +50,6 @@ impl<'a, 'tcx> Analysis<'tcx> for MaybeStorageLive<'a> {
             _ => (),
         }
     }
-
-    fn apply_terminator_effect<'mir>(
-        &mut self,
-        _trans: &mut Self::Domain,
-        terminator: &'mir Terminator<'tcx>,
-        _: Location,
-    ) -> TerminatorEdges<'mir, 'tcx> {
-        // Terminators have no effect
-        terminator.edges()
-    }
-
-    fn apply_call_return_effect(
-        &mut self,
-        _trans: &mut Self::Domain,
-        _block: BasicBlock,
-        _return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-        // Nothing to do when a call returns successfully
-    }
 }
 
 pub struct MaybeStorageDead<'a> {
@@ -113,25 +94,6 @@ impl<'a, 'tcx> Analysis<'tcx> for MaybeStorageDead<'a> {
             _ => (),
         }
     }
-
-    fn apply_terminator_effect<'mir>(
-        &mut self,
-        _: &mut Self::Domain,
-        terminator: &'mir Terminator<'tcx>,
-        _: Location,
-    ) -> TerminatorEdges<'mir, 'tcx> {
-        // Terminators have no effect
-        terminator.edges()
-    }
-
-    fn apply_call_return_effect(
-        &mut self,
-        _trans: &mut Self::Domain,
-        _block: BasicBlock,
-        _return_places: CallReturnPlaces<'_, 'tcx>,
-    ) {
-        // Nothing to do when a call returns successfully
-    }
 }
 
 type BorrowedLocalsResults<'mir, 'tcx> = ResultsCursor<'mir, 'tcx, MaybeBorrowedLocals>;