---

yaml
---
r: 225371
b: refs/heads/stable
c: 57c75b6
h: refs/heads/master
i:
  225369: e5336ed
  225367: 1dafaae
v: v3

Author: nikomatsakis

[refs]

@@ -29,6 +29,6 @@ refs/heads/tmp: e5d90d98402475b6e154ce216f9efcb80da1a747
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f
 refs/tags/homu-tmp: 1fe32ca12c51afcd761d9962f51a74ff0d07a591
 refs/tags/1.0.0-beta: 8cbb92b53468ee2b0c2d3eeb8567005953d40828
-refs/heads/stable: 710270d9c0b9b9e65e606e1c6109329c93499837
+refs/heads/stable: 57c75b6b10c329ed1c9c1957e98a990dd04608f2
 refs/tags/1.0.0: 55bd4f8ff2b323f317ae89e254ce87162d52a375
 refs/tags/1.1.0: bc3c16f09287e5545c1d3f76b7abd54f2eca868b

branches/stable/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"));