---

yaml
---
r: 218791
b: refs/heads/snap-stage3
c: 57c75b6
h: refs/heads/master
i:
  218789: 71fa876
  218787: f464f5b
  218783: c0caa23
v: v3

Author: nikomatsakis

[refs]

@@ -1,6 +1,6 @@
 ---
 refs/heads/master: c044791d80ea0dc5c4b57b6030a67b69f8510239
-refs/heads/snap-stage3: 710270d9c0b9b9e65e606e1c6109329c93499837
+refs/heads/snap-stage3: 57c75b6b10c329ed1c9c1957e98a990dd04608f2
 refs/heads/try: b53c0f93eedcdedd4fd89bccc5a3a09d1c5cd23e
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596

branches/snap-stage3/src/librustc/middle/check_const.rs

@@ -205,7 +205,16 @@ impl<'a, 'tcx> CheckCrateVisitor<'a, 'tcx> {
                             ret_ty: Ty<'tcx>)
                             -> bool {
         if let Some(fn_like) = const_eval::lookup_const_fn_by_id(self.tcx, def_id) {
-            if self.mode != Mode::Var && !self.tcx.sess.features.borrow().const_fn {
+            if
+                // we are in a static/const initializer
+                self.mode != Mode::Var &&
+
+                // feature-gate is not enabled
+                !self.tcx.sess.features.borrow().const_fn &&
+
+                // this doesn't come from a macro that has #[allow_internal_unstable]
+                !self.tcx.sess.codemap().span_allows_unstable(expr.span)
+            {
                 self.tcx.sess.span_err(
                     expr.span,
                     &format!("const fns are an unstable feature"));