add the lint back to the list, and fix tests

Author: RalfJung

src/librustc_lint/builtin.rs

@@ -1607,17 +1607,6 @@ fn check_const(cx: &LateContext, body_id: hir::BodyId) {
     let _ = cx.tcx.const_eval(param_env.and(cid));
 }
 
-struct UnusedBrokenConstVisitor<'a, 'tcx: 'a>(&'a LateContext<'a, 'tcx>);
-
-impl<'a, 'tcx, 'v> hir::intravisit::Visitor<'v> for UnusedBrokenConstVisitor<'a, 'tcx> {
-    fn visit_nested_body(&mut self, id: hir::BodyId) {
-        check_const(self.0, id);
-    }
-    fn nested_visit_map<'this>(&'this mut self) -> hir::intravisit::NestedVisitorMap<'this, 'v> {
-        hir::intravisit::NestedVisitorMap::None
-    }
-}
-
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedBrokenConst {
     fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
         match it.node {
@@ -1627,10 +1616,6 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedBrokenConst {
             hir::ItemKind::Static(_, _, body_id) => {
                 check_const(cx, body_id);
             },
-            hir::ItemKind::Ty(ref ty, _) => hir::intravisit::walk_ty(
-                &mut UnusedBrokenConstVisitor(cx),
-                ty
-            ),
             _ => {},
         }
     }

src/librustc_lint/lib.rs

@@ -152,6 +152,7 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
         UnreachablePub: UnreachablePub,
         UnnameableTestItems: UnnameableTestItems::new(),
         TypeAliasBounds: TypeAliasBounds,
+        UnusedBrokenConst: UnusedBrokenConst,
         TrivialConstraints: TrivialConstraints,
         TypeLimits: TypeLimits::new(),
         MissingDoc: MissingDoc::new(),

src/test/ui/array_const_index-0.rs

@@ -14,5 +14,5 @@ const B: i32 = (&A)[1];
 //~| ERROR any use of this value will cause an error
 
 fn main() {
-    let _ = B; //~ ERROR erroneous constant used
+    let _ = B;
 }

src/test/ui/array_const_index-0.stderr

@@ -8,12 +8,5 @@ LL | const B: i32 = (&A)[1];
    |
    = note: #[deny(const_err)] on by default
 
-error[E0080]: erroneous constant used
-  --> $DIR/array_const_index-0.rs:17:13
-   |
-LL |     let _ = B; //~ ERROR erroneous constant used
-   |             ^ referenced constant has errors
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0080`.

src/test/ui/array_const_index-1.rs

@@ -14,5 +14,5 @@ const B: i32 = A[1];
 //~| ERROR any use of this value will cause an error
 
 fn main() {
-    let _ = B; //~ ERROR erroneous constant used
+    let _ = B;
 }

src/test/ui/array_const_index-1.stderr

@@ -8,12 +8,5 @@ LL | const B: i32 = A[1];
    |
    = note: #[deny(const_err)] on by default
 
-error[E0080]: erroneous constant used
-  --> $DIR/array_const_index-1.rs:17:13
-   |
-LL |     let _ = B; //~ ERROR erroneous constant used
-   |             ^ referenced constant has errors
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0080`.

src/test/ui/consts/const-err-early.rs

@@ -17,10 +17,10 @@ pub const D: u8 = 42u8 - (42u8 + 1); //~ ERROR const_err
 pub const E: u8 = [5u8][1]; //~ ERROR const_err
 
 fn main() {
-    let _a = A; //~ ERROR erroneous constant used
-    let _b = B; //~ ERROR erroneous constant used
-    let _c = C; //~ ERROR erroneous constant used
-    let _d = D; //~ ERROR erroneous constant used
-    let _e = E; //~ ERROR erroneous constant used
-    let _e = [6u8][1]; //~ ERROR index out of bounds
+    let _a = A;
+    let _b = B;
+    let _c = C;
+    let _d = D;
+    let _e = E;
+    let _e = [6u8][1];
 }

src/test/ui/consts/const-err-early.stderr

@@ -44,42 +44,5 @@ LL | pub const E: u8 = [5u8][1]; //~ ERROR const_err
    |                   |
    |                   index out of bounds: the len is 1 but the index is 1
 
-error[E0080]: erroneous constant used
-  --> $DIR/const-err-early.rs:20:14
-   |
-LL |     let _a = A; //~ ERROR erroneous constant used
-   |              ^ referenced constant has errors
-
-error[E0080]: erroneous constant used
-  --> $DIR/const-err-early.rs:21:14
-   |
-LL |     let _b = B; //~ ERROR erroneous constant used
-   |              ^ referenced constant has errors
-
-error[E0080]: erroneous constant used
-  --> $DIR/const-err-early.rs:22:14
-   |
-LL |     let _c = C; //~ ERROR erroneous constant used
-   |              ^ referenced constant has errors
-
-error[E0080]: erroneous constant used
-  --> $DIR/const-err-early.rs:23:14
-   |
-LL |     let _d = D; //~ ERROR erroneous constant used
-   |              ^ referenced constant has errors
-
-error[E0080]: erroneous constant used
-  --> $DIR/const-err-early.rs:24:14
-   |
-LL |     let _e = E; //~ ERROR erroneous constant used
-   |              ^ referenced constant has errors
-
-error: index out of bounds: the len is 1 but the index is 1
-  --> $DIR/const-err-early.rs:25:14
-   |
-LL |     let _e = [6u8][1]; //~ ERROR index out of bounds
-   |              ^^^^^^^^
-
-error: aborting due to 11 previous errors
+error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0080`.

src/test/ui/consts/const-err-multi.rs

@@ -21,5 +21,4 @@ pub const D: i8 = 50 - A;
 
 fn main() {
     let _ = (A, B, C, D);
-    //~^ ERROR erroneous constant used
 }

src/test/ui/consts/const-err-multi.stderr

@@ -36,12 +36,5 @@ LL | pub const D: i8 = 50 - A;
    |                   |
    |                   referenced constant has errors
 
-error[E0080]: erroneous constant used
-  --> $DIR/const-err-multi.rs:23:13
-   |
-LL |     let _ = (A, B, C, D);
-   |             ^^^^^^^^^^^^ referenced constant has errors
-
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
 
-For more information about this error, try `rustc --explain E0080`.