Improve `implicit_return`

[rust.git] / clippy_utils / src / visitors.rs

diff --git a/clippy_utils/src/visitors.rs b/clippy_utils/src/visitors.rs
index 5a8c629e3338c41683de26a237968a33bb1cda8b..d431bdf34eeeea2c62f0662f8ca562df16e35ac2 100644 (file)
--- a/clippy_utils/src/visitors.rs
+++ b/clippy_utils/src/visitors.rs
@@ -1,7 +1,7 @@
 use crate::path_to_local_id;
 use rustc_hir as hir;
-use rustc_hir::intravisit::{self, walk_expr, NestedVisitorMap, Visitor};
-use rustc_hir::{Arm, Body, Expr, HirId, Stmt};
+use rustc_hir::intravisit::{self, walk_expr, ErasedMap, NestedVisitorMap, Visitor};
+use rustc_hir::{Arm, Block, Body, Destination, Expr, ExprKind, HirId, Stmt};
 use rustc_lint::LateContext;
 use rustc_middle::hir::map::Map;
 
@@ -188,3 +188,54 @@ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
         NestedVisitorMap::OnlyBodies(self.hir)
     }
 }
+
+pub trait Visitable<'tcx> {
+    fn visit<V: Visitor<'tcx>>(self, v: &mut V);
+}
+impl Visitable<'tcx> for &'tcx Expr<'tcx> {
+    fn visit<V: Visitor<'tcx>>(self, v: &mut V) {
+        v.visit_expr(self)
+    }
+}
+impl Visitable<'tcx> for &'tcx Block<'tcx> {
+    fn visit<V: Visitor<'tcx>>(self, v: &mut V) {
+        v.visit_block(self)
+    }
+}
+impl<'tcx> Visitable<'tcx> for &'tcx Stmt<'tcx> {
+    fn visit<V: Visitor<'tcx>>(self, v: &mut V) {
+        v.visit_stmt(self)
+    }
+}
+impl<'tcx> Visitable<'tcx> for &'tcx Body<'tcx> {
+    fn visit<V: Visitor<'tcx>>(self, v: &mut V) {
+        v.visit_body(self)
+    }
+}
+impl<'tcx> Visitable<'tcx> for &'tcx Arm<'tcx> {
+    fn visit<V: Visitor<'tcx>>(self, v: &mut V) {
+        v.visit_arm(self)
+    }
+}
+
+pub fn visit_break_exprs<'tcx>(
+    node: impl Visitable<'tcx>,
+    f: impl FnMut(&'tcx Expr<'tcx>, Destination, Option<&'tcx Expr<'tcx>>),
+) {
+    struct V<F>(F);
+    impl<'tcx, F: FnMut(&'tcx Expr<'tcx>, Destination, Option<&'tcx Expr<'tcx>>)> Visitor<'tcx> for V<F> {
+        type Map = ErasedMap<'tcx>;
+        fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+            NestedVisitorMap::None
+        }
+
+        fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+            if let ExprKind::Break(dest, sub_expr) = e.kind {
+                self.0(e, dest, sub_expr)
+            }
+            walk_expr(self, e);
+        }
+    }
+
+    node.visit(&mut V(f));
+}