Check no pointee attribute pos

compiler/rustc_passes/src/check_attr.rs

@@ -158,6 +158,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     self.check_rustc_std_internal_symbol(attr, span, target)
                 }
                 [sym::naked] => self.check_naked(hir_id, attr, span, target, attrs),
+                [sym::pointee] => self.check_applied_to_fn_or_method(hir_id, attr, span, target),
                 [sym::rustc_never_returns_null_ptr] => {
                     self.check_applied_to_fn_or_method(hir_id, attr, span, target)
                 }

tests/ui/attributes/pointee.rs

@@ -0,0 +1,35 @@
+#![feature(pointee)]
+#![feature(stmt_expr_attributes)]
+#![feature(derive_smart_pointer)]
+#![deny(unused_attributes)]
+#![allow(dead_code)]
+
+fn invalid() {
+    #[pointee] //~ ERROR attribute should be applied to a function definition
+    {
+        1
+    };
+}
+
+#[pointee] //~ ERROR attribute should be applied to a function definition
+type InvalidTy = ();
+
+#[pointee] //~ ERROR attribute should be applied to a function definition
+mod invalid_module {}
+
+fn main() {
+    let _ = #[pointee] //~ ERROR attribute should be applied to a function definition
+    (|| 1);
+}
+
+#[pointee] //~ ERROR attribute should be applied to a function definition
+struct F;
+
+#[pointee] //~ ERROR attribute should be applied to a function definition
+impl F {
+    #[pointee]
+    fn valid(&self) {}
+}
+
+#[pointee]
+fn valid() {}

tests/ui/attributes/pointee.stderr

@@ -0,0 +1,54 @@
+error: attribute should be applied to a function definition
+  --> $DIR/pointee.rs:8:5
+   |
+LL |       #[pointee]
+   |       ^^^^^^^^^^
+LL | /     {
+LL | |         1
+LL | |     };
+   | |_____- not a function definition
+
+error: attribute should be applied to a function definition
+  --> $DIR/pointee.rs:14:1
+   |
+LL | #[pointee]
+   | ^^^^^^^^^^
+LL | type InvalidTy = ();
+   | -------------------- not a function definition
+
+error: attribute should be applied to a function definition
+  --> $DIR/pointee.rs:17:1
+   |
+LL | #[pointee]
+   | ^^^^^^^^^^
+LL | mod invalid_module {}
+   | --------------------- not a function definition
+
+error: attribute should be applied to a function definition
+  --> $DIR/pointee.rs:21:13
+   |
+LL |     let _ = #[pointee]
+   |             ^^^^^^^^^^
+LL |     (|| 1);
+   |     ------ not a function definition
+
+error: attribute should be applied to a function definition
+  --> $DIR/pointee.rs:25:1
+   |
+LL | #[pointee]
+   | ^^^^^^^^^^
+LL | struct F;
+   | --------- not a function definition
+
+error: attribute should be applied to a function definition
+  --> $DIR/pointee.rs:28:1
+   |
+LL |   #[pointee]
+   |   ^^^^^^^^^^
+LL | / impl F {
+LL | |     #[pointee]
+LL | |     fn valid(&self) {}
+LL | | }
+   | |_- not a function definition
+
+error: aborting due to 6 previous errors