re PR lto/53808 (Undefined symbol when building a library with lto)

	PR lto/53808
	* class.c (clone_function_decl): Call note_vague_linkage_fn for
	defaulted virtual dtor.

From-SVN: r208153

gcc/cp/ChangeLog

 2014-02-25  Jason Merrill  <jason@redhat.com>
 
+	PR lto/53808
+	* class.c (clone_function_decl): Call note_vague_linkage_fn for
+	defaulted virtual dtor.
+
 	DR 1286
 	PR c++/60328
 	* pt.c (get_underlying_template): Fix equivalence calculation.

gcc/cp/class.c

@@ -4582,6 +4582,10 @@ clone_function_decl (tree fn, int update_method_vec_p)
 	 destructor.  */
       if (DECL_VIRTUAL_P (fn))
 	{
+	  if (DECL_DEFAULTED_FN (fn) && flag_devirtualize)
+	    /* Make sure the destructor gets synthesized so that it can be
+	       inlined after devirtualization.  */
+	    note_vague_linkage_fn (fn);
 	  clone = build_clone (fn, deleting_dtor_identifier);
 	  if (update_method_vec_p)
 	    add_method (DECL_CONTEXT (clone), clone, NULL_TREE);

gcc/testsuite/g++.dg/opt/devirt4.C

+// PR lto/53808
+// Devirtualization + inlining should produce a non-virtual
+// call to ~foo.
+// { dg-options "-O -fdevirtualize" }
+// { dg-final { scan-assembler "_ZN3fooD2Ev" } }
+
+struct foo {
+ virtual ~foo();
+};
+struct bar : public foo {
+ virtual void zed();
+};
+void f() {
+ foo *x(new bar);
+ delete x;
+}