Don't just check params

compiler/rustc_typeck/src/check/wfcheck.rs

@@ -301,7 +301,6 @@ fn check_gat_where_clauses(
         sig.output().visit_with(&mut visitor);
         let mut wf_tys = FxHashSet::default();
         wf_tys.extend(sig.inputs());
-        // FIXME: normalize and add normalized inputs?
 
         for (region, region_idx) in &visitor.regions {
             for (ty, ty_idx) in &visitor.types {
@@ -423,12 +422,9 @@ impl<'tcx> TypeVisitor<'tcx> for GATSubstCollector<'tcx> {
                         GenericArgKind::Lifetime(lt) => {
                             self.regions.insert((lt, idx));
                         }
-                        GenericArgKind::Type(t) => match t.kind() {
+                        GenericArgKind::Type(t) => {
-                            ty::Param(_) => {
+                            self.types.insert((t, idx));
-                                self.types.insert((t, idx));
+                        }
-                            }
-                            _ => {}
-                        },
                         _ => {}
                     }
                 }

src/test/ui/generic-associated-types/self-outlives-lint.rs

@@ -54,10 +54,10 @@ trait Deserializer4 {
 
 struct Wrap<T>(T);
 
-// Even though we might theoretically want `D: 'x`, because we pass `Wrap<T>` and
+// We pass `Wrap<T>` and we see `&'z Wrap<T>`, so we require `D: 'x`
-// we see `&'z Wrap<T>`, we are conservative and only add bounds for direct params
 trait Des {
     type Out<'x, D>;
+    //~^ Missing required bounds
     fn des<'z, T>(&self, data: &'z Wrap<T>) -> Self::Out<'z, Wrap<T>>;
 }
 /*

src/test/ui/generic-associated-types/self-outlives-lint.stderr

@@ -30,6 +30,14 @@ LL |     type Out<'x, 'y>;
    |                     |
    |                     help: add the required where clauses: `where U: 'y, T: 'x`
 
+error: Missing required bounds on Out
+  --> $DIR/self-outlives-lint.rs:59:5
+   |
+LL |     type Out<'x, D>;
+   |     ^^^^^^^^^^^^^^^-
+   |                    |
+   |                    help: add the required where clauses: `where D: 'x`
+
 error: Missing required bounds on Out
   --> $DIR/self-outlives-lint.rs:75:5
    |
@@ -46,5 +54,5 @@ LL |     type Out<'x, D>;
    |                    |
    |                    help: add the required where clauses: `where D: 'x`
 
-error: aborting due to 6 previous errors
+error: aborting due to 7 previous errors