4 files changed, 31 insertions, 13 deletions
diff --git a/compiler/rustc_ast_pretty/src/pprust/mod.rs b/compiler/rustc_ast_pretty/src/pprust/mod.rs
index ac9e7d06c..83b7e1390 100644
--- a/compiler/rustc_ast_pretty/src/pprust/mod.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/mod.rs
@@ -32,6 +32,10 @@ pub fn bounds_to_string(bounds: &[ast::GenericBound]) -> String {
     State::new().bounds_to_string(bounds)
 }
 
+pub fn where_bound_predicate_to_string(where_bound_predicate: &ast::WhereBoundPredicate) -> String {
+    State::new().where_bound_predicate_to_string(where_bound_predicate)
+}
+
 pub fn pat_to_string(pat: &ast::Pat) -> String {
     State::new().pat_to_string(pat)
 }
diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
index 3f80728a2..59239b49e 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -824,6 +824,13 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         Self::to_string(|s| s.print_type_bounds(bounds))
     }
 
+    fn where_bound_predicate_to_string(
+        &self,
+        where_bound_predicate: &ast::WhereBoundPredicate,
+    ) -> String {
+        Self::to_string(|s| s.print_where_bound_predicate(where_bound_predicate))
+    }
+
     fn pat_to_string(&self, pat: &ast::Pat) -> String {
         Self::to_string(|s| s.print_pat(pat))
     }
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
index 87c32ffce..609920180 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
@@ -537,6 +537,11 @@ impl<'a> State<'a> {
                     self.print_expr_maybe_paren(expr, parser::PREC_JUMP);
                 }
             }
+            ast::ExprKind::Become(result) => {
+                self.word("become");
+                self.word(" ");
+                self.print_expr_maybe_paren(result, parser::PREC_JUMP);
+            }
             ast::ExprKind::InlineAsm(a) => {
                 // FIXME: This should have its own syntax, distinct from a macro invocation.
                 self.word("asm!");
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/item.rs b/compiler/rustc_ast_pretty/src/pprust/state/item.rs
index c465f8c94..5c01b7ea7 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state/item.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state/item.rs
@@ -623,19 +623,8 @@ impl<'a> State<'a> {
 
     pub fn print_where_predicate(&mut self, predicate: &ast::WherePredicate) {
         match predicate {
-            ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
-                bound_generic_params,
-                bounded_ty,
-                bounds,
-                ..
-            }) => {
-                self.print_formal_generic_params(bound_generic_params);
-                self.print_type(bounded_ty);
-                self.word(":");
-                if !bounds.is_empty() {
-                    self.nbsp();
-                    self.print_type_bounds(bounds);
-                }
+            ast::WherePredicate::BoundPredicate(where_bound_predicate) => {
+                self.print_where_bound_predicate(where_bound_predicate);
             }
             ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
                 lifetime,
@@ -658,6 +647,19 @@ impl<'a> State<'a> {
         }
     }
 
+    pub fn print_where_bound_predicate(
+        &mut self,
+        where_bound_predicate: &ast::WhereBoundPredicate,
+    ) {
+        self.print_formal_generic_params(&where_bound_predicate.bound_generic_params);
+        self.print_type(&where_bound_predicate.bounded_ty);
+        self.word(":");
+        if !where_bound_predicate.bounds.is_empty() {
+            self.nbsp();
+            self.print_type_bounds(&where_bound_predicate.bounds);
+        }
+    }
+
     fn print_use_tree(&mut self, tree: &ast::UseTree) {
         match &tree.kind {
             ast::UseTreeKind::Simple(rename) => {