Auto merge of #25318 - nrc:for-expn, r=sfackler

r? @sfackler

src/test/compile-fail/for-expn-2.rs

@@ -0,0 +1,18 @@
+// Copyright 2015 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.
+
+// Test that we get an expansion stack for `for` loops.
+
+// error-pattern:in expansion of for loop expansion
+
+fn main() {
+    for t in &foo {
+    }
+}

src/test/compile-fail/for-expn.rs

@@ -0,0 +1,19 @@
+// Copyright 2015 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.
+
+// Test that an error on a sub-expresson in a for loop has the correct span.
+
+fn main() {
+    // Odd formatting to make sure we get the right span.
+    for t in &
+      foo //~ ERROR unresolved name `foo`
+    {
+    }
+}