re PR c++/80979 (ice in lookup_mark, at cp/tree.c:2298)

PR c++/80979
	* name-lookup.c (adl_class_only): Don't add visible friends.

From-SVN: r248922

gcc/cp/ChangeLog

@@ -1,3 +1,8 @@
+2017-06-06  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/80979
+	* name-lookup.c (adl_class_only): Don't add visible friends.
+
 2017-06-05  Volker Reichelt  <v.reichelt@netcologne.de>
 
 	* parser.c (cp_parser_base_specifier): Fix typos in error messages.

gcc/cp/name-lookup.c

@@ -801,6 +801,12 @@ name_lookup::adl_class_only (tree type)
 	  if (CP_DECL_CONTEXT (fn) != context)
 	    continue;
 
+	  /* Only interested in anticipated friends.  (Non-anticipated
+	     ones will have been inserted during the namespace
+	     adl.)  */
+	  if (!DECL_ANTICIPATED (fn))
+	    continue;
+
 	  /* Template specializations are never found by name lookup.
 	     (Templates themselves can be found, but not template
 	     specializations.)  */

gcc/testsuite/g++.dg/lookup/pr80979.C

@@ -0,0 +1,26 @@
+// pr C++/80979 ICE with late discovery of using directives during ADL
+// of a friend declaration.
+
+namespace Tiny {
+  class Handsome {};
+  void Dahl (Handsome &, Handsome &);
+
+  namespace Jack {
+    class Vladof {
+      friend void Dahl (Vladof &, Vladof &);
+    };
+    void Dahl (Vladof &, Vladof &);
+  }
+
+  struct BDonk {};
+
+  namespace Tina {
+    void Dahl (BDonk &, Jack::Vladof &);
+  }
+  using Tina::Dahl;
+}
+
+void BoomBoom (Tiny::BDonk &vault, Tiny::Jack::Vladof &hunter)
+{
+  Dahl (vault, hunter);
+}