re PR sanitizer/81111 (Cannot build libstdc++ with -fsanitize=undefined)

	PR sanitizer/81111
	* ubsan.c (ubsan_encode_value): If current_function_decl is NULL,
	use create_tmp_var_raw instead of create_tmp_var, mark it addressable
	just by setting TREE_ADDRESSABLE on the result and use a TARGET_EXPR.

	* g++.dg/ubsan/pr81111.C: New test.

From-SVN: r249375

gcc/ChangeLog

+2017-06-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/81111
+	* ubsan.c (ubsan_encode_value): If current_function_decl is NULL,
+	use create_tmp_var_raw instead of create_tmp_var, mark it addressable
+	just by setting TREE_ADDRESSABLE on the result and use a TARGET_EXPR.
+
 2017-06-19  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/81118

gcc/testsuite/ChangeLog

+2017-06-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/81111
+	* g++.dg/ubsan/pr81111.C: New test.
+
 2017-06-19  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/81118

gcc/testsuite/g++.dg/ubsan/pr81111.C

+// PR sanitizer/81111
+// { dg-do compile }
+// { dg-options "-fsanitize=shift" }
+
+template <typename V>
+struct N
+{
+  static const V m = (((V)(-1) < 0)
+		      ? (V)1 << (sizeof(V) * __CHAR_BIT__ - ((V)(-1) < 0))
+		      : (V) 0);
+};
+
+template<typename V>
+const V N<V>::m;
+
+template <typename V>
+struct O
+{
+  static const V m = (V)1 << sizeof(V) * __CHAR_BIT__;
+};
+
+template<typename V>
+const V O<V>::m;
+
+void
+foo ()
+{
+  N<long long>::m;
+  N<unsigned long long>::m;
+#ifdef __SIZEOF_INT128__
+  N<__int128>::m;
+  N<unsigned __int128>::m;
+#endif
+}
+
+void
+bar ()
+{
+  O<long long>::m;
+  O<unsigned long long>::m;
+#ifdef __SIZEOF_INT128__
+  O<__int128>::m;
+  O<unsigned __int128>::m;
+#endif
+}

gcc/ubsan.c

@@ -143,9 +143,17 @@ ubsan_encode_value (tree t, bool in_expand_p)
 	{
 	  /* The reason for this is that we don't want to pessimize
 	     code by making vars unnecessarily addressable.  */
-	  tree var = create_tmp_var (type);
-	  tree tem = build2 (MODIFY_EXPR, void_type_node, var, t);
-	  mark_addressable (var);
+	  tree var;
+	  if (current_function_decl)
+	    {
+	      var = create_tmp_var (type);
+	      mark_addressable (var);
+	    }
+	  else
+	    {
+	      var = create_tmp_var_raw (type);
+	      TREE_ADDRESSABLE (var) = 1;
+	    }
 	  if (in_expand_p)
 	    {
 	      rtx mem
@@ -156,8 +164,17 @@ ubsan_encode_value (tree t, bool in_expand_p)
 	      expand_assignment (var, t, false);
 	      return build_fold_addr_expr (var);
 	    }
-	  t = build_fold_addr_expr (var);
-	  return build2 (COMPOUND_EXPR, TREE_TYPE (t), tem, t);
+	  if (current_function_decl)
+	    {
+	      tree tem = build2 (MODIFY_EXPR, void_type_node, var, t);
+	      t = build_fold_addr_expr (var);
+	      return build2 (COMPOUND_EXPR, TREE_TYPE (t), tem, t);
+	    }
+	  else
+	    {
+	      var = build4 (TARGET_EXPR, type, var, t, NULL_TREE, NULL_TREE);
+	      return build_fold_addr_expr (var);
+	    }
 	}
       else
 	return build_fold_addr_expr (t);