`hir`: Add `Become` expression kind

3 files changed, 10 insertions, 2 deletions

diff --git a/compiler/rustc_passes/src/hir_stats.rs b/compiler/rustc_passes/src/hir_stats.rs
index 90809270118..6c748147abe 100644
--- a/compiler/rustc_passes/src/hir_stats.rs
+++ b/compiler/rustc_passes/src/hir_stats.rs
@@ -302,8 +302,8 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
             [
                 ConstBlock, Array, Call, MethodCall, Tup, Binary, Unary, Lit, Cast, Type,
                 DropTemps, Let, If, Loop, Match, Closure, Block, Assign, AssignOp, Field, Index,
-                Path, AddrOf, Break, Continue, Ret, InlineAsm, OffsetOf, Struct, Repeat, Yield,
-                Err
+                Path, AddrOf, Break, Continue, Ret, Become, InlineAsm, OffsetOf, Struct, Repeat,
+                Yield, Err
             ]
         );
         hir_visit::walk_expr(self, e)
diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index 63b1578d43f..803ca05b202 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -463,6 +463,7 @@ impl<'tcx> Visitor<'tcx> for IrMaps<'tcx> {
             | hir::ExprKind::Lit(_)
             | hir::ExprKind::ConstBlock(..)
             | hir::ExprKind::Ret(..)
+            | hir::ExprKind::Become(..)
             | hir::ExprKind::Block(..)
             | hir::ExprKind::Assign(..)
             | hir::ExprKind::AssignOp(..)
@@ -967,6 +968,11 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 self.propagate_through_opt_expr(o_e.as_deref(), self.exit_ln)
             }
 
+            hir::ExprKind::Become(ref e) => {
+                // Ignore succ and subst exit_ln.
+                self.propagate_through_expr(e, self.exit_ln)
+            }
+
             hir::ExprKind::Break(label, ref opt_expr) => {
                 // Find which label this break jumps to
                 let target = match label.target_id {
@@ -1408,6 +1414,7 @@ fn check_expr<'tcx>(this: &mut Liveness<'_, 'tcx>, expr: &'tcx Expr<'tcx>) {
         | hir::ExprKind::DropTemps(..)
         | hir::ExprKind::Unary(..)
         | hir::ExprKind::Ret(..)
+        | hir::ExprKind::Become(..)
         | hir::ExprKind::Break(..)
         | hir::ExprKind::Continue(..)
         | hir::ExprKind::Lit(_)
diff --git a/compiler/rustc_passes/src/naked_functions.rs b/compiler/rustc_passes/src/naked_functions.rs
index a849d61edfe..769b389009b 100644
--- a/compiler/rustc_passes/src/naked_functions.rs
+++ b/compiler/rustc_passes/src/naked_functions.rs
@@ -204,6 +204,7 @@ impl<'tcx> CheckInlineAssembly<'tcx> {
             | ExprKind::Continue(..)
             | ExprKind::Ret(..)
             | ExprKind::OffsetOf(..)
+            | ExprKind::Become(..)
             | ExprKind::Struct(..)
             | ExprKind::Repeat(..)
             | ExprKind::Yield(..) => {