Check proc_macro on stmt

Author: csmoe

src/librustc/hir/check_attr.rs

@@ -269,7 +269,11 @@ impl<'a, 'tcx> CheckAttrVisitor<'a, 'tcx> {
                 if attr.check_name("inline") {
                     self.check_inline(attr, &stmt.span, Target::Statement);
                 }
-                if attr.check_name("repr") {
+                if attr.check_name("repr")
+                    || attr.check_name("proc_macro")
+                    || attr.check_name("proc_macro_attribute")
+                    || attr.check_name("proc_macro_derive")
+                {
                     self.emit_repr_error(
                         attr.span,
                         stmt.span,

src/test/compile-fail-fulldeps/proc-macro/issue-52329.rs

@@ -0,0 +1,20 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(proc_macro)]
+
+fn main() {
+    #[proc_macro] //~ ERROR: attribute should not be applied to a statement
+    let x = 10;
+    #[proc_macro_attribute] //~ ERROR: attribute should not be applied to a statement
+    let x = 11;
+    #[proc_macro_derive]  //~ ERROR: attribute should not be applied to a statement
+    let x = 12;
+}