PR c++/80856 - ICE with local extern in template

	* semantics.c (finish_call_expr): Replace a local extern overload
	set in a template with the IDENTIFIER_NODE.

From-SVN: r248699

gcc/cp/ChangeLog

+2017-05-30  Jason Merrill  <jason@redhat.com>
+
+	PR c++/80856 - ICE with local extern in template
+	* semantics.c (finish_call_expr): Replace a local extern overload
+	set in a template with the IDENTIFIER_NODE.
+
 2017-05-30  David Malcolm  <dmalcolm@redhat.com>
 
 	* call.c (perform_implicit_conversion_flags): Convert

gcc/cp/semantics.c

@@ -2316,13 +2316,23 @@ finish_call_expr (tree fn, vec<tree, va_gc> **args, bool disallow_virtual,
 
   if (processing_template_decl)
     {
+      /* If FN is a local extern declaration or set thereof, look them up
+	 again at instantiation time.  */
+      if (is_overloaded_fn (fn))
+	{
+	  tree ifn = get_first_fn (fn);
+	  if (TREE_CODE (ifn) == FUNCTION_DECL
+	      && DECL_LOCAL_FUNCTION_P (ifn))
+	    orig_fn = DECL_NAME (ifn);
+	}
+
       /* If the call expression is dependent, build a CALL_EXPR node
 	 with no type; type_dependent_expression_p recognizes
 	 expressions with no type as being dependent.  */
       if (type_dependent_expression_p (fn)
 	  || any_type_dependent_arguments_p (*args))
 	{
-	  result = build_min_nt_call_vec (fn, *args);
+	  result = build_min_nt_call_vec (orig_fn, *args);
 	  SET_EXPR_LOCATION (result, EXPR_LOC_OR_LOC (fn, input_location));
 	  KOENIG_LOOKUP_P (result) = koenig_p;
 	  if (is_overloaded_fn (fn))

gcc/testsuite/g++.dg/template/local-fn2.C

+// PR c++/80856
+// { dg-do compile { target c++11 } }
+
+template<typename T>
+inline T WrapToCycle(T degrees)
+{
+  int Wrap(int x, int lower_bound, int upper_bound);
+
+  auto p = Wrap;
+  p (1, 0, 360);
+
+  double Wrap(double x, int lower_bound, int upper_bound);
+
+  Wrap(1, 0, 360);
+  return Wrap(degrees, 0, 360);
+}
+
+void GenerateOldReportPage()
+{
+  WrapToCycle(0);
+}