Stop ICE when using foreign statics in statics

Only change is to stop an ICE when a foreign static are referenced in
consts and statics.

See: #16538, #16479, #14227, #13325

Author: whataloadofwhat

src/librustc/middle/check_static_recursion.rs

@@ -96,10 +96,20 @@ impl<'a, 'ast, 'v> Visitor<'v> for CheckItemRecursionVisitor<'a, 'ast> {
         match e.node {
             ast::ExprPath(..) => {
                 match self.def_map.borrow().find(&e.id) {
-                    Some(&DefStatic(def_id, _)) |
-                    Some(&DefConst(def_id)) if
+                    Some(&DefStatic(def_id, _)) | Some(&DefConst(def_id)) if
                             ast_util::is_local(def_id) => {
-                        self.visit_item(&*self.ast_map.expect_item(def_id.node));
+                        match self.ast_map.find(def_id.node) {
+                            Some(ast_map::NodeItem(item)) => {
+                                self.visit_item(item);
+                            }
+                            Some(ast_map::NodeForeignItem(item)) => {
+                                //External statics don't have values so it
+                                //won't be recursive.
+                                self.visit_foreign_item(item);
+                            }
+                            _ => fail!("expected item or foreign item, got {}",
+                                      self.ast_map.node_to_string(def_id.node))
+                        }
                     }
                     _ => ()
                 }

src/test/run-pass/static-reference-foreign-static.rs

@@ -0,0 +1,17 @@
+// Copyright 2014 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.
+
+extern {
+    static x: i32;
+}
+
+static X: &'static i32 = &x;
+
+fn main() { }