Improve diagnostic when passing arg to closure and missing borrow.

[rust.git] / compiler / rustc_trait_selection / src / traits / object_safety.rs

diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index 9f531e03f06ad7e3245efff61f98e56fdc56c45f..a45749fe48cd48a5d625deb3d7e146ec942984e8 100644 (file)
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -17,11 +17,10 @@
 use rustc_errors::{DelayDm, FatalError, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
-use rustc_middle::ty::abstract_const::{walk_abstract_const, AbstractConst};
+use rustc_middle::ty::subst::{GenericArg, InternalSubsts};
 use rustc_middle::ty::{
     self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
-use rustc_middle::ty::{GenericArg, InternalSubsts};
 use rustc_middle::ty::{Predicate, ToPredicate};
 use rustc_session::lint::builtin::WHERE_CLAUSES_OBJECT_SAFETY;
 use rustc_span::symbol::Symbol;
@@ -837,23 +836,9 @@ fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
         }
 
         fn visit_const(&mut self, ct: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {
-            // Constants can only influence object safety if they reference `Self`.
+            // Constants can only influence object safety if they are generic and reference `Self`.
             // This is only possible for unevaluated constants, so we walk these here.
-            //
-            // If `AbstractConst::from_const` returned an error we already failed compilation
-            // so we don't have to emit an additional error here.
-            use rustc_middle::ty::abstract_const::Node;
-            if let Ok(Some(ct)) = AbstractConst::from_const(self.tcx, ct) {
-                walk_abstract_const(self.tcx, ct, |node| match node.root(self.tcx) {
-                    Node::Leaf(leaf) => self.visit_const(leaf),
-                    Node::Cast(_, _, ty) => self.visit_ty(ty),
-                    Node::Binop(..) | Node::UnaryOp(..) | Node::FunctionCall(_, _) => {
-                        ControlFlow::CONTINUE
-                    }
-                })
-            } else {
-                ct.super_visit_with(self)
-            }
+            self.tcx.expand_abstract_consts(ct).super_visit_with(self)
         }
     }