re PR c++/68508 (Internal compiler error with parentheses around return value in…

re PR c++/68508 (Internal compiler error with parentheses around return value in C++14 with ASan enabled)

	PR c++/68508
	* cp-tree.h (cp_ubsan_maybe_instrument_downcast): Add INTYPE argument.
	* cp-ubsan.c (cp_ubsan_maybe_instrument_downcast): Likewise.  Use
	it instead of or in addition to TREE_TYPE (op).  Use
	is_properly_derived_from, return NULL_TREE if TREE_TYPE (intype) and
	TREE_TYPE (type) are the same type minus qualifiers.
	* typeck.c (build_static_cast_1): Adjust callers.

	* g++.dg/ubsan/pr68508.C: New test.

From-SVN: r230928

gcc/cp/ChangeLog

+2015-11-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/68508
+	* cp-tree.h (cp_ubsan_maybe_instrument_downcast): Add INTYPE argument.
+	* cp-ubsan.c (cp_ubsan_maybe_instrument_downcast): Likewise.  Use
+	it instead of or in addition to TREE_TYPE (op).  Use
+	is_properly_derived_from, return NULL_TREE if TREE_TYPE (intype) and
+	TREE_TYPE (type) are the same type minus qualifiers.
+	* typeck.c (build_static_cast_1): Adjust callers.
+
 2015-11-25  Martin Sebor  <msebor@redhat.com>
 
 	PR c++/67876

gcc/cp/cp-tree.h

@@ -6854,7 +6854,7 @@ extern bool cilk_valid_spawn                    (tree);
 /* In cp-ubsan.c */
 extern void cp_ubsan_maybe_instrument_member_call (tree);
 extern void cp_ubsan_instrument_member_accesses (tree *);
-extern tree cp_ubsan_maybe_instrument_downcast	(location_t, tree, tree);
+extern tree cp_ubsan_maybe_instrument_downcast	(location_t, tree, tree, tree);
 extern tree cp_ubsan_maybe_instrument_cast_to_vbase (location_t, tree, tree);
 
 /* -- end of C++ */

gcc/cp/cp-ubsan.c

@@ -243,13 +243,14 @@ cp_ubsan_instrument_member_accesses (tree *t_p)
 /* Instrument downcast.  */
 
 tree
-cp_ubsan_maybe_instrument_downcast (location_t loc, tree type, tree op)
+cp_ubsan_maybe_instrument_downcast (location_t loc, tree type,
+				    tree intype, tree op)
 {
   if (!POINTER_TYPE_P (type)
+      || !POINTER_TYPE_P (intype)
       || !POINTER_TYPE_P (TREE_TYPE (op))
-      || !CLASS_TYPE_P (TREE_TYPE (type))
       || !CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (op)))
-      || !DERIVED_FROM_P (TREE_TYPE (TREE_TYPE (op)), TREE_TYPE (type)))
+      || !is_properly_derived_from (TREE_TYPE (type), TREE_TYPE (intype)))
     return NULL_TREE;
 
   return cp_ubsan_maybe_instrument_vptr (loc, op, TREE_TYPE (type), true,

gcc/cp/typeck.c

@@ -6590,7 +6590,8 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
       if (flag_sanitize & SANITIZE_VPTR)
 	{
 	  tree ubsan_check
-	    = cp_ubsan_maybe_instrument_downcast (input_location, type, expr);
+	    = cp_ubsan_maybe_instrument_downcast (input_location, type,
+						  intype, expr);
 	  if (ubsan_check)
 	    expr = ubsan_check;
 	}
@@ -6737,7 +6738,8 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
       if (flag_sanitize & SANITIZE_VPTR)
 	{
 	  tree ubsan_check
-	    = cp_ubsan_maybe_instrument_downcast (input_location, type, expr);
+	    = cp_ubsan_maybe_instrument_downcast (input_location, type,
+						  intype, expr);
 	  if (ubsan_check)
 	    expr = ubsan_check;
 	}

gcc/testsuite/ChangeLog

+2015-11-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/68508
+	* g++.dg/ubsan/pr68508.C: New test.
+
 2015-11-25  Martin Sebor  <msebor@redhat.com>
 
 	PR c++/67876

gcc/testsuite/g++.dg/ubsan/pr68508.C

+// PR c++/68508
+// { dg-do compile }
+// { dg-options "-std=c++14 -fsanitize=vptr" }
+
+struct A
+{
+  virtual int foo () { return 0; }
+};
+
+const A &
+bar ()
+{
+  static A x = A ();
+  return (x);
+}