+
+struct FindPanicUnwrap<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ panic_span: Option<Span>,
+ typeck_results: &'tcx ty::TypeckResults<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if self.panic_span.is_some() {
+ return;
+ }
+
+ // check for `begin_panic`
+ if_chain! {
+ if let ExprKind::Call(ref func_expr, _) = expr.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path)) = func_expr.kind;
+ if let Some(path_def_id) = path.res.opt_def_id();
+ if match_panic_def_id(self.cx, path_def_id);
+ if is_expn_of(expr.span, "unreachable").is_none();
+ then {
+ self.panic_span = Some(expr.span);
+ }
+ }
+
+ // check for `unwrap`
+ if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
+ let reciever_ty = self.typeck_results.expr_ty(&arglists[0][0]).peel_refs();
+ if is_type_diagnostic_item(self.cx, reciever_ty, sym::option_type)
+ || is_type_diagnostic_item(self.cx, reciever_ty, sym::result_type)
+ {
+ self.panic_span = Some(expr.span);
+ }
+ }
+
+ // and check sub-expressions
+ intravisit::walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+ NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
+ }
+}