re PR c++/38392 (Template friend function injection)

	PR c++/38392
	* pt.c (tsubst_friend_function): Instatiate a friend that has already
	been used.

From-SVN: r158073

gcc/cp/ChangeLog

 2010-04-07  Jason Merrill  <jason@redhat.com>
 
+	PR c++/38392
+	* pt.c (tsubst_friend_function): Instatiate a friend that has already
+	been used.
+
 	* pt.c (print_template_statistics): New.
 	* cp-tree.h: Declare it.
 	* tree.c (cxx_print_statistics): Call it.

gcc/cp/pt.c

@@ -7330,11 +7330,18 @@ tsubst_friend_function (tree decl, tree args)
 	      DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
 
 	      if (TREE_CODE (old_decl) != TEMPLATE_DECL)
-		/* We should have called reregister_specialization in
-		   duplicate_decls.  */
-		gcc_assert (retrieve_specialization (new_template,
-						     new_args, 0)
-			    == old_decl);
+		{
+		  /* We should have called reregister_specialization in
+		     duplicate_decls.  */
+		  gcc_assert (retrieve_specialization (new_template,
+						       new_args, 0)
+			      == old_decl);
+
+		  /* Instantiate it if the global has already been used.  */
+		  if (DECL_ODR_USED (old_decl))
+		    instantiate_decl (old_decl, /*defer_ok=*/true,
+				      /*expl_inst_class_mem_p=*/false);
+		}
 	      else
 		{
 		  tree t;

gcc/testsuite/ChangeLog

 2010-04-07  Jason Merrill  <jason@redhat.com>
 
+	PR c++/38392
+	* g++.dg/template/friend51.C: New test.
+
 	PR c++/41970
 	* g++.old-deja/g++.other/linkage1.C: Adjust.
 

gcc/testsuite/g++.dg/template/friend51.C

+// PR c++/38392
+// { dg-do link }
+
+void Function();
+
+int main()
+{
+  Function();
+}
+
+template <typename T>
+struct Test
+{
+  friend void Function() { }
+};
+
+template class Test<int>;