From 22c4ee365c3b921859e0a325a559b3d41f49c4bb Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishsmail@gmail.com>
Date: Tue, 30 May 2017 14:23:02 -0700
Subject: Improve error message for const extern fn

---
 src/libsyntax/parse/parser.rs | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'src/libsyntax/parse')

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 8d7c8c5248b..d0b6a8b9fed 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -5981,6 +5981,10 @@ impl<'a> Parser<'a> {
             return Ok(Some(self.parse_item_foreign_fn(visibility, lo, attrs)?));
         }
 
+        if self.check_keyword(keywords::Const) {
+            return Err(self.span_fatal(self.span, "extern items cannot be `const`"));
+        }
+
         // FIXME #5668: this will occur for a macro invocation:
         match self.parse_macro_use_or_failure(attrs, true, false, lo, visibility)? {
             Some(item) => {
-- 
cgit 1.4.1-3-g733a5