re PR sanitizer/64717 (-fsanitize=vptr leads to warning: ‘<anonymous>’ may be…

re PR sanitizer/64717 (-fsanitize=vptr leads to warning: ‘<anonymous>’ may be used uninitialized in this function [-Wmaybe-uninitialized])

	PR c++/64717
	* cp-ubsan.c (cp_ubsan_instrument_vptr): Don't wrap vptr
	into SAVE_EXPR.

	* g++.dg/ubsan/pr64717-1.C: New test.
	* g++.dg/ubsan/pr64717-2.C: New test.

From-SVN: r220262

gcc/cp/ChangeLog

+2015-01-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/64717
+	* cp-ubsan.c (cp_ubsan_instrument_vptr): Don't wrap vptr
+	into SAVE_EXPR.
+
 2015-01-29  Jason Merrill  <jason@redhat.com>
 
 	PR c++/49508

gcc/cp/cp-ubsan.c

@@ -107,7 +107,6 @@ cp_ubsan_instrument_vptr (location_t loc, tree op, tree type, bool is_addr,
 			fold_build2 (NE_EXPR, boolean_type_node, op,
 				     build_zero_cst (TREE_TYPE (op))),
 			vptr, build_int_cst (uint64_type_node, 0));
-  vptr = build1_loc (loc, SAVE_EXPR, uint64_type_node, vptr);
   tree ti_decl = get_tinfo_decl (type);
   mark_used (ti_decl);
   tree ptype = build_pointer_type (type);

gcc/testsuite/ChangeLog

-2015-22-01  Uros Bizjak  <ubizjak@gmail.com>
+2015-01-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/64717
+	* g++.dg/ubsan/pr64717-1.C: New test.
+	* g++.dg/ubsan/pr64717-2.C: New test.
+
+2015-01-29  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.dg/tree-ssa/pr64801.c: Fix scan-tree-dump-not directive.
 

gcc/testsuite/g++.dg/ubsan/pr64717-1.C

+// PR c++/64717
+// { dg-do compile }
+// { dg-options "-O2 -Wuninitialized -fsanitize=vptr" }
+
+class Foo {};
+Foo make_foo ();
+
+struct Handle { virtual ~Handle (); };
+Handle open (Foo);
+
+void
+bar ()
+{
+  Handle file (open (make_foo ())); // { dg-bogus "is used uninitialized" }
+}

gcc/testsuite/g++.dg/ubsan/pr64717-2.C

+// PR c++/64717
+// { dg-do compile }
+// { dg-options "-O2 -Wuninitialized -fsanitize=vptr" }
+
+class ios {};
+
+struct stringstream : virtual ios {
+  stringstream (char *);
+  ~stringstream ();
+};
+
+struct string { char *c_str (); };
+
+string make_str ();
+
+void
+bar ()
+{
+  stringstream param (make_str ().c_str ()); // { dg-bogus "is used uninitialized" }
+}