re PR c++/59315 (g++.dg/warn/Wunused-3.C FAILs with -fno-use-cxa-atexit)

	PR c++/59315
	* decl.c (cxx_maybe_build_cleanup): Call mark_used.

From-SVN: r207236

gcc/cp/ChangeLog

+2014-01-29  Jason Merrill  <jason@redhat.com>
+
+	PR c++/59315
+	* decl.c (cxx_maybe_build_cleanup): Call mark_used.
+
 2014-01-29  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/58702

gcc/cp/decl.c

@@ -14353,6 +14353,13 @@ cxx_maybe_build_cleanup (tree decl, tsubst_flags_t complain)
      destructor call instead.  */
   if (cleanup != NULL && EXPR_P (cleanup))
     SET_EXPR_LOCATION (cleanup, UNKNOWN_LOCATION);
+
+  if (cleanup
+      && !lookup_attribute ("warn_unused", TYPE_ATTRIBUTES (TREE_TYPE (decl))))
+    /* Treat objects with destructors as used; the destructor may do
+       something substantive.  */
+    mark_used (decl);
+
   return cleanup;
 }
 

gcc/testsuite/g++.dg/warn/Wunused-3.C

 // { dg-do compile }
-// { dg-options "-Wunused -O" }
+// { dg-options "-Wunused -O -fno-use-cxa-atexit" }
 
 void do_cleanups();