Fix variable deallocation order in panic unwinding paths

compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs

@@ -6,6 +6,10 @@
 //!   - [`FakeRead`]
 //!   - [`Assign`] statements with a [`Fake`] borrow
 //!   - [`Coverage`] statements of kind [`BlockMarker`] or [`SpanMarker`]
+//!   - [`StorageDead`] statements in cleanup blocks (unwind paths) - these are only needed
+//!     for borrow-checking and are removed from cleanup blocks after borrowck completes.
+//!     StorageDead on normal paths may be needed by later passes (e.g., coroutine transforms)
+//!     and will be conditionally removed by RemoveStorageMarkers during optimization if enabled.
 //!
 //! [`AscribeUserType`]: rustc_middle::mir::StatementKind::AscribeUserType
 //! [`Assign`]: rustc_middle::mir::StatementKind::Assign
@@ -15,6 +19,7 @@
 //! [`Coverage`]: rustc_middle::mir::StatementKind::Coverage
 //! [`BlockMarker`]: rustc_middle::mir::coverage::CoverageKind::BlockMarker
 //! [`SpanMarker`]: rustc_middle::mir::coverage::CoverageKind::SpanMarker
+//! [`StorageDead`]: rustc_middle::mir::StatementKind::StorageDead
 
 use rustc_middle::mir::coverage::CoverageKind;
 use rustc_middle::mir::*;
@@ -28,6 +33,11 @@ impl<'tcx> crate::MirPass<'tcx> for CleanupPostBorrowck {
         // Manually invalidate CFG caches if we actually change a terminator's edges.
         let mut invalidate_cfg = false;
         for basic_block in body.basic_blocks.as_mut_preserves_cfg().iter_mut() {
+            // Only remove StorageDead from cleanup blocks (unwind paths).
+            // StorageDead on normal paths may be needed by later passes (e.g., coroutine
+            // transforms) and may be used by codegen backends. RemoveStorageMarkers will
+            // conditionally remove them during optimization if enabled (when mir_opt_level > 0
+            // and lifetime markers are not being emitted).
             for statement in basic_block.statements.iter_mut() {
                 match statement.kind {
                     StatementKind::AscribeUserType(..)
@@ -41,6 +51,11 @@ impl<'tcx> crate::MirPass<'tcx> for CleanupPostBorrowck {
                     | StatementKind::BackwardIncompatibleDropHint { .. } => {
                         statement.make_nop(true)
                     }
+                    StatementKind::StorageDead(..)
+                        if basic_block.is_cleanup && body.coroutine.is_none() =>
+                    {
+                        statement.make_nop(true)
+                    }
                     StatementKind::Assign(box (
                         _,
                         Rvalue::Cast(

src/tools/rust-analyzer/crates/hir-def/src/import_map.rs

@@ -426,11 +426,10 @@ pub fn search_dependencies(
     let import_maps: Vec<_> =
         krate.data(db).dependencies.iter().map(|dep| db.import_map(dep.crate_id)).collect();
 
-    let mut op = fst::map::OpBuilder::new();
-
     match query.search_mode {
         SearchMode::Exact => {
             let automaton = fst::automaton::Str::new(&query.lowercased);
+            let mut op = fst::map::OpBuilder::new();
 
             for map in &import_maps {
                 op = op.add(map.fst.search(&automaton));
@@ -439,6 +438,7 @@ pub fn search_dependencies(
         }
         SearchMode::Fuzzy => {
             let automaton = fst::automaton::Subsequence::new(&query.lowercased);
+            let mut op = fst::map::OpBuilder::new();
 
             for map in &import_maps {
                 op = op.add(map.fst.search(&automaton));
@@ -447,6 +447,7 @@ pub fn search_dependencies(
         }
         SearchMode::Prefix => {
             let automaton = fst::automaton::Str::new(&query.lowercased).starts_with();
+            let mut op = fst::map::OpBuilder::new();
 
             for map in &import_maps {
                 op = op.add(map.fst.search(&automaton));

src/tools/rust-analyzer/crates/ide-db/src/symbol_index.rs

@@ -569,11 +569,10 @@ impl Query {
         cb: impl FnMut(&'db FileSymbol<'db>) -> ControlFlow<T>,
     ) -> Option<T> {
         let _p = tracing::info_span!("symbol_index::Query::search").entered();
-
-        let mut op = fst::map::OpBuilder::new();
         match self.mode {
             SearchMode::Exact => {
                 let automaton = fst::automaton::Str::new(&self.lowercased);
+                let mut op = fst::map::OpBuilder::new();
 
                 for index in indices.iter() {
                     op = op.add(index.map.search(&automaton));
@@ -582,6 +581,7 @@ impl Query {
             }
             SearchMode::Fuzzy => {
                 let automaton = fst::automaton::Subsequence::new(&self.lowercased);
+                let mut op = fst::map::OpBuilder::new();
 
                 for index in indices.iter() {
                     op = op.add(index.map.search(&automaton));
@@ -590,6 +590,7 @@ impl Query {
             }
             SearchMode::Prefix => {
                 let automaton = fst::automaton::Str::new(&self.lowercased).starts_with();
+                let mut op = fst::map::OpBuilder::new();
 
                 for index in indices.iter() {
                     op = op.add(index.map.search(&automaton));

tests/mir-opt/async_drop_live_dead.a-{closure#0}.coroutine_drop_async.0.panic-unwind.mir

@@ -44,7 +44,6 @@ fn a::{closure#0}(_1: Pin<&mut {async fn body of a<T>()}>, _2: &mut Context<'_>)
     }
 
     bb3 (cleanup): {
-        nop;
         nop;
         goto -> bb5;
     }

tests/mir-opt/basic_assignment.main.SimplifyCfg-initial.after.mir

@@ -73,14 +73,19 @@ fn main() -> () {
     }
 
     bb6 (cleanup): {
+        StorageDead(_6);
         drop(_5) -> [return: bb7, unwind terminate(cleanup)];
     }
 
     bb7 (cleanup): {
+        StorageDead(_5);
         drop(_4) -> [return: bb8, unwind terminate(cleanup)];
     }
 
     bb8 (cleanup): {
+        StorageDead(_4);
+        StorageDead(_2);
+        StorageDead(_1);
         resume;
     }
 }

tests/mir-opt/building/logical_or_in_conditional.test_complex.built.after.mir

@@ -19,7 +19,7 @@ fn test_complex() -> () {
     bb0: {
         StorageLive(_1);
         StorageLive(_2);
-        _2 = E::f() -> [return: bb1, unwind: bb35];
+        _2 = E::f() -> [return: bb1, unwind: bb38];
     }
 
     bb1: {
@@ -42,7 +42,7 @@ fn test_complex() -> () {
 
     bb5: {
         StorageLive(_4);
-        _4 = always_true() -> [return: bb6, unwind: bb35];
+        _4 = always_true() -> [return: bb6, unwind: bb38];
     }
 
     bb6: {
@@ -64,7 +64,7 @@ fn test_complex() -> () {
     }
 
     bb9: {
-        drop(_7) -> [return: bb11, unwind: bb35];
+        drop(_7) -> [return: bb11, unwind: bb37];
     }
 
     bb10: {
@@ -78,7 +78,7 @@ fn test_complex() -> () {
     }
 
     bb12: {
-        drop(_7) -> [return: bb13, unwind: bb35];
+        drop(_7) -> [return: bb13, unwind: bb37];
     }
 
     bb13: {
@@ -98,7 +98,7 @@ fn test_complex() -> () {
     }
 
     bb15: {
-        drop(_10) -> [return: bb17, unwind: bb35];
+        drop(_10) -> [return: bb17, unwind: bb36];
     }
 
     bb16: {
@@ -139,7 +139,7 @@ fn test_complex() -> () {
         StorageDead(_4);
         StorageDead(_1);
         StorageLive(_11);
-        _11 = always_true() -> [return: bb23, unwind: bb35];
+        _11 = always_true() -> [return: bb23, unwind: bb38];
     }
 
     bb23: {
@@ -156,7 +156,7 @@ fn test_complex() -> () {
 
     bb26: {
         StorageLive(_12);
-        _12 = E::f() -> [return: bb27, unwind: bb35];
+        _12 = E::f() -> [return: bb27, unwind: bb38];
     }
 
     bb27: {
@@ -199,6 +199,25 @@ fn test_complex() -> () {
     }
 
     bb35 (cleanup): {
+        StorageDead(_10);
+        StorageDead(_9);
+        StorageDead(_2);
+        goto -> bb38;
+    }
+
+    bb36 (cleanup): {
+        StorageDead(_10);
+        StorageDead(_9);
+        goto -> bb38;
+    }
+
+    bb37 (cleanup): {
+        StorageDead(_7);
+        StorageDead(_6);
+        goto -> bb38;
+    }
+
+    bb38 (cleanup): {
         resume;
     }
 }

tests/mir-opt/building/logical_or_in_conditional.test_or.built.after.mir

@@ -20,7 +20,7 @@ fn test_or() -> () {
     }
 
     bb1: {
-        drop(_3) -> [return: bb3, unwind: bb13];
+        drop(_3) -> [return: bb3, unwind: bb14];
     }
 
     bb2: {
@@ -34,7 +34,7 @@ fn test_or() -> () {
     }
 
     bb4: {
-        drop(_3) -> [return: bb5, unwind: bb13];
+        drop(_3) -> [return: bb5, unwind: bb14];
     }
 
     bb5: {
@@ -86,6 +86,19 @@ fn test_or() -> () {
     }
 
     bb13 (cleanup): {
+        StorageDead(_6);
+        StorageDead(_5);
+        goto -> bb15;
+    }
+
+    bb14 (cleanup): {
+        StorageDead(_3);
+        StorageDead(_2);
+        goto -> bb15;
+    }
+
+    bb15 (cleanup): {
+        StorageDead(_1);
         resume;
     }
 }