Turn ICE on type arguments on variables into an error

Author: oli-obk

src/librustc_typeck/check/mod.rs

@@ -5195,7 +5195,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
         &self,
         res: Res,
         span: Span,
-    ) -> Result<(DefKind, DefId, Ty<'tcx>), ErrorReported> {
+    ) -> Result<Res, ErrorReported> {
         let tcx = self.tcx;
         if let Res::SelfCtor(impl_def_id) = res {
             let ty = self.impl_self_ty(span, impl_def_id).ty;
@@ -5205,11 +5205,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 Some(adt_def) if adt_def.has_ctor() => {
                     let variant = adt_def.non_enum_variant();
                     let ctor_def_id = variant.ctor_def_id.unwrap();
-                    Ok((
-                        DefKind::Ctor(CtorOf::Struct, variant.ctor_kind),
-                        ctor_def_id,
-                        tcx.type_of(ctor_def_id),
-                    ))
+                    Ok(Res::Def(DefKind::Ctor(CtorOf::Struct, variant.ctor_kind), ctor_def_id))
                 }
                 _ => {
                     let mut err = tcx.sess.struct_span_err(span,
@@ -5236,15 +5232,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 }
             }
         } else {
-            match res {
-                Res::Def(kind, def_id) => {
-                    // The things we are substituting into the type should not contain
-                    // escaping late-bound regions, and nor should the base type scheme.
-                    let ty = tcx.type_of(def_id);
-                    Ok((kind, def_id, ty))
-                }
-                _ => span_bug!(span, "unexpected res in rewrite_self_ctor: {:?}", res),
-            }
+            Ok(res)
         }
     }
 
@@ -5267,27 +5255,21 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
 
         let tcx = self.tcx;
 
-        match res {
-            Res::Local(hid) | Res::Upvar(hid, ..) => {
-                let ty = self.local_ty(span, hid).decl_ty;
-                let ty = self.normalize_associated_types_in(span, &ty);
-                self.write_ty(hir_id, ty);
-                return (ty, res);
-            }
-            _ => {}
-        }
-
-        let (kind, def_id, ty) = match self.rewrite_self_ctor(res, span) {
-            Ok(result) => result,
+        let res = match self.rewrite_self_ctor(res, span) {
+            Ok(res) => res,
             Err(ErrorReported) => return (tcx.types.err, res),
         };
-        let path_segs =
-            AstConv::def_ids_for_value_path_segments(self, segments, self_ty, kind, def_id);
+        let path_segs = match res {
+            Res::Local(_) | Res::Upvar(..) => Vec::new(),
+            Res::Def(kind, def_id) =>
+                AstConv::def_ids_for_value_path_segments(self, segments, self_ty, kind, def_id),
+            _ => bug!("instantiate_value_path on {:?}", res),
+        };
 
         let mut user_self_ty = None;
         let mut is_alias_variant_ctor = false;
-        match kind {
-            DefKind::Ctor(CtorOf::Variant, _) => {
+        match res {
+            Res::Def(DefKind::Ctor(CtorOf::Variant, _), _) => {
                 if let Some(self_ty) = self_ty {
                     let adt_def = self_ty.ty_adt_def().unwrap();
                     user_self_ty = Some(UserSelfTy {
@@ -5297,8 +5279,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                     is_alias_variant_ctor = true;
                 }
             }
-            DefKind::Method
-            | DefKind::AssociatedConst => {
+            Res::Def(DefKind::Method, def_id)
+            | Res::Def(DefKind::AssociatedConst, def_id) => {
                 let container = tcx.associated_item(def_id).container;
                 debug!("instantiate_value_path: def_id={:?} container={:?}", def_id, container);
                 match container {
@@ -5338,6 +5320,17 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 None
             }
         }));
+
+        match res {
+            Res::Local(hid) | Res::Upvar(hid, ..) => {
+                let ty = self.local_ty(span, hid).decl_ty;
+                let ty = self.normalize_associated_types_in(span, &ty);
+                self.write_ty(hir_id, ty);
+                return (ty, res);
+            }
+            _ => {}
+        }
+
         if generics_has_err {
             // Don't try to infer type parameters when prohibited generic arguments were given.
             user_self_ty = None;
@@ -5375,6 +5368,12 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             tcx.generics_of(*def_id).has_self
         }).unwrap_or(false);
 
+        let def_id = res.def_id();
+
+        // The things we are substituting into the type should not contain
+        // escaping late-bound regions, and nor should the base type scheme.
+        let ty = tcx.type_of(def_id);
+
         let substs = AstConv::create_substs_for_generic_args(
             tcx,
             def_id,
@@ -5491,7 +5490,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                ty_substituted);
         self.write_substs(hir_id, substs);
 
-        (ty_substituted, Res::Def(kind, def_id))
+        (ty_substituted, res)
     }
 
     fn check_rustc_args_require_const(&self,

src/test/ui/issues/issue-60989.rs

@@ -0,0 +1,18 @@
+struct A {}
+struct B {}
+
+impl From<A> for B {
+    fn from(a: A) -> B {
+        B{}
+    }
+}
+
+fn main() {
+    let c1 = ();
+    c1::<()>;
+    //~^ ERROR type arguments are not allowed for this type
+
+    let c1 = A {};
+    c1::<Into<B>>;
+    //~^ ERROR type arguments are not allowed for this type
+}

src/test/ui/issues/issue-60989.stderr

@@ -0,0 +1,15 @@
+error[E0109]: type arguments are not allowed for this type
+  --> $DIR/issue-60989.rs:12:10
+   |
+LL |     c1::<()>;
+   |          ^^ type argument not allowed
+
+error[E0109]: type arguments are not allowed for this type
+  --> $DIR/issue-60989.rs:16:10
+   |
+LL |     c1::<Into<B>>;
+   |          ^^^^^^^ type argument not allowed
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0109`.