Auto merge of #142707 - ashivaram23:drop_wildcard, r=dianqk

Apply effects to `otherwise` edge in dataflow analysis

This allows `ElaborateDrops` to remove drops when a `match` wildcard arm covers multiple no-Drop enum variants. It modifies dataflow analysis to update the `MaybeUninitializedPlaces` and `MaybeInitializedPlaces` data for a block reached through an `otherwise` edge.

Fixes rust-lang/rust#142705.

2 files changed, 3 insertions, 0 deletions

diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs
index 42c8cb0b906..b4fa2be1d00 100644
--- a/compiler/rustc_mir_transform/src/elaborate_drops.rs
+++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs
@@ -62,12 +62,14 @@ impl<'tcx> crate::MirPass<'tcx> for ElaborateDrops {
             let env = MoveDataTypingEnv { move_data, typing_env };
 
             let mut inits = MaybeInitializedPlaces::new(tcx, body, &env.move_data)
+                .exclude_inactive_in_otherwise()
                 .skipping_unreachable_unwind()
                 .iterate_to_fixpoint(tcx, body, Some("elaborate_drops"))
                 .into_results_cursor(body);
             let dead_unwinds = compute_dead_unwinds(body, &mut inits);
 
             let uninits = MaybeUninitializedPlaces::new(tcx, body, &env.move_data)
+                .include_inactive_in_otherwise()
                 .mark_inactive_variants_as_uninit()
                 .skipping_unreachable_unwind(dead_unwinds)
                 .iterate_to_fixpoint(tcx, body, Some("elaborate_drops"))
diff --git a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs
index 9044a88295c..25d6fa1bab9 100644
--- a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs
+++ b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs
@@ -22,6 +22,7 @@ impl<'tcx> crate::MirPass<'tcx> for RemoveUninitDrops {
         let move_data = MoveData::gather_moves(body, tcx, |ty| ty.needs_drop(tcx, typing_env));
 
         let mut maybe_inits = MaybeInitializedPlaces::new(tcx, body, &move_data)
+            .exclude_inactive_in_otherwise()
             .iterate_to_fixpoint(tcx, body, Some("remove_uninit_drops"))
             .into_results_cursor(body);