--- gcc/gcc.c.mp	2013-07-15 04:30:13.038677937 +0200
+++ gcc/gcc.c	2013-07-15 04:42:32.257592503 +0200
@@ -591,6 +591,28 @@ proper position among the other output f
 #define LIBTSAN_EARLY_SPEC ""
 #endif
 
+#ifndef LIBUBSAN_SPEC
+#ifdef STATIC_LIBUBSAN_LIBS
+#define ADD_STATIC_LIBUBSAN_LIBS \
+  " %{static-libubsan:" STATIC_LIBUBSAN_LIBS "}"
+#else
+#define ADD_STATIC_LIBUBSAN_LIBS
+#endif
+#ifdef LIBUBSAN_EARLY_SPEC
+#define LIBUBSAN_SPEC ADD_STATIC_LIBUBSAN_LIBS
+#elif defined(HAVE_LD_STATIC_DYNAMIC)
+#define LIBUBSAN_SPEC "%{static-libubsan:" LD_STATIC_OPTION \
+		     "} -lubsan %{static-libubsan:" LD_DYNAMIC_OPTION "}" \
+		     ADD_STATIC_LIBUBSAN_LIBS
+#else
+#define LIBUBSAN_SPEC "-lubsan" ADD_STATIC_LIBUBSAN_LIBS
+#endif
+#endif
+
+#ifndef LIBUBSAN_EARLY_SPEC
+#define LIBUBSAN_EARLY_SPEC ""
+#endif
+
 /* config.h can define LIBGCC_SPEC to override how and when libgcc.a is
    included.  */
 #ifndef LIBGCC_SPEC
@@ -714,7 +736,8 @@ proper position among the other output f
 #ifndef SANITIZER_EARLY_SPEC
 #define SANITIZER_EARLY_SPEC "\
 %{!nostdlib:%{!nodefaultlibs:%{%:sanitize(address):" LIBASAN_EARLY_SPEC "} \
-    %{%:sanitize(thread):" LIBTSAN_EARLY_SPEC "}}}"
+    %{%:sanitize(thread):" LIBTSAN_EARLY_SPEC "} \
+    %{%:sanitize(undefined):" LIBUBSAN_EARLY_SPEC "}}}"
 #endif
 
 /* Linker command line options for -fsanitize= late on the command line.  */
@@ -724,7 +747,8 @@ proper position among the other output f
     %{static:%ecannot specify -static with -fsanitize=address}\
     %{%:sanitize(thread):%e-fsanitize=address is incompatible with -fsanitize=thread}}\
     %{%:sanitize(thread):" LIBTSAN_SPEC "\
-    %{!pie:%{!shared:%e-fsanitize=thread linking must be done with -pie or -shared}}}}}"
+    %{!pie:%{!shared:%e-fsanitize=thread linking must be done with -pie or -shared}}}\
+    %{%:sanitize(undefined):" LIBUBSAN_SPEC "}}}"
 #endif
 
 /* -u* was put back because both BSD and SysV seem to support it.  */
--- gcc/testsuite/lib/ubsan-dg.exp.mp	2013-07-14 20:19:05.445091076 +0200
+++ gcc/testsuite/lib/ubsan-dg.exp	2013-07-15 04:25:00.476445749 +0200
@@ -0,0 +1,104 @@
+# Copyright (C) 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+#
+# ubsan_link_flags -- compute library path and flags to find libubsan.
+# (originally from g++.exp)
+#
+
+proc ubsan_link_flags { paths } {
+    global srcdir
+    global ld_library_path
+    global shlib_ext
+
+    set gccpath ${paths}
+    set flags ""
+
+    set shlib_ext [get_shlib_extension]
+
+    if { $gccpath != "" } {
+      if { [file exists "${gccpath}/libsanitizer/ubsan/.libs/libubsan.a"]
+	   || [file exists "${gccpath}/libsanitizer/ubsan/.libs/libubsan.${shlib_ext}"] } {
+	  append flags " -B${gccpath}/libsanitizer/ubsan/ "
+	  append flags " -L${gccpath}/libsanitizer/ubsan/.libs"
+	  append ld_library_path ":${gccpath}/libsanitizer/ubsan/.libs"
+      }
+    } else {
+      global tool_root_dir
+
+      set libubsan [lookfor_file ${tool_root_dir} libubsan]
+      if { $libubsan != "" } {
+	  append flags "-L${libubsan} "
+	  append ld_library_path ":${libubsan}"
+      }
+    }
+
+    set_ld_library_path_env_vars
+
+    return "$flags"
+}
+
+#
+# ubsan_init -- called at the start of each subdir of tests
+#
+
+proc ubsan_init { args } {
+    global TEST_ALWAYS_FLAGS
+    global ALWAYS_CXXFLAGS
+    global TOOL_OPTIONS
+    global ubsan_saved_TEST_ALWAYS_FLAGS
+
+    set link_flags ""
+    if ![is_remote host] {
+	if [info exists TOOL_OPTIONS] {
+	    set link_flags "[ubsan_link_flags [get_multilibs ${TOOL_OPTIONS}]]"
+	} else {
+	    set link_flags "[ubsan_link_flags [get_multilibs]]"
+	}
+    }
+
+    if [info exists TEST_ALWAYS_FLAGS] {
+	set ubsan_saved_TEST_ALWAYS_FLAGS $TEST_ALWAYS_FLAGS
+    }
+    if [info exists ALWAYS_CXXFLAGS] {
+	set ALWAYS_CXXFLAGS [concat "{ldflags=$link_flags}" $ALWAYS_CXXFLAGS]
+    } else {
+	if [info exists TEST_ALWAYS_FLAGS] {
+	    set TEST_ALWAYS_FLAGS "$link_flags $TEST_ALWAYS_FLAGS"
+	} else {
+	    set TEST_ALWAYS_FLAGS "$link_flags"
+	}
+    }
+    if { $link_flags != "" } {
+	return 1
+    }
+    return 0
+}
+
+#
+# ubsan_finish -- called at the start of each subdir of tests
+#
+
+proc ubsan_finish { args } {
+    global TEST_ALWAYS_FLAGS
+    global ubsan_saved_TEST_ALWAYS_FLAGS
+
+    if [info exists ubsan_saved_TEST_ALWAYS_FLAGS] {
+	set TEST_ALWAYS_FLAGS $ubsan_saved_TEST_ALWAYS_FLAGS
+    } else {
+	unset TEST_ALWAYS_FLAGS
+    }
+}
--- gcc/testsuite/g++.dg/ubsan/ubsan.exp.mp	2013-07-15 04:23:57.350195021 +0200
+++ gcc/testsuite/g++.dg/ubsan/ubsan.exp	2013-07-15 04:25:41.662610652 +0200
@@ -0,0 +1,34 @@
+# Copyright (C) 2013 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Load support procs.
+load_lib g++-dg.exp
+load_lib ubsan-dg.exp
+
+# Initialize `dg'.
+dg-init
+if [ubsan_init] {
+
+# Main loop.
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.C $srcdir/c-c++-common/ubsan/*.c]] ""
+
+}
+
+# All done.
+ubsan_finish
+dg-finish
--- gcc/testsuite/g++.dg/ubsan/cxx11-shift-1.C.mp	2013-07-15 08:50:26.786626970 +0200
+++ gcc/testsuite/g++.dg/ubsan/cxx11-shift-1.C	2013-07-15 08:50:42.852684617 +0200
@@ -0,0 +1,9 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w -std=c++11" } */
+
+int
+main (void)
+{
+  int a = 1;
+  a <<= 31;
+}
--- gcc/testsuite/g++.dg/ubsan/cxx11-shift-2.C.mp	2013-07-15 08:58:40.648302392 +0200
+++ gcc/testsuite/g++.dg/ubsan/cxx11-shift-2.C	2013-07-15 09:00:08.169601202 +0200
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w -std=c++11" } */
+
+int
+main (void)
+{
+  int a = -42;
+  a <<= 1;
+}
+/* { dg-output "left shift of negative value -42" } */
--- gcc/testsuite/c-c++-common/ubsan/div-by-zero-3.c.mp	2013-07-15 05:06:26.069422162 +0200
+++ gcc/testsuite/c-c++-common/ubsan/div-by-zero-3.c	2013-07-15 08:00:25.517263218 +0200
@@ -0,0 +1,12 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=integer-divide-by-zero -Wno-overflow" } */
+
+#include <limits.h>
+
+int
+main (void)
+{
+  INT_MIN / -1;
+  return 0;
+}
+ /* { dg-output "division of -2147483648 by -1 cannot be represented in type int" } */
--- gcc/testsuite/c-c++-common/ubsan/div-by-zero-1.c.mp	2013-07-15 04:56:34.640124598 +0200
+++ gcc/testsuite/c-c++-common/ubsan/div-by-zero-1.c	2013-07-15 07:59:58.713250028 +0200
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=integer-divide-by-zero -Wno-div-by-zero" } */
+
+int
+main (void)
+{
+  0 / 0;
+  return 0;
+}
+ /* { dg-output "division by zero" } */
--- gcc/testsuite/c-c++-common/ubsan/div-by-zero-4.c.mp	2013-07-15 05:06:32.331446996 +0200
+++ gcc/testsuite/c-c++-common/ubsan/div-by-zero-4.c	2013-07-15 05:26:00.450043589 +0200
@@ -0,0 +1,11 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=integer-divide-by-zero -Wno-overflow" } */
+
+#include <limits.h>
+
+int
+main (void)
+{
+  /* This should not fail.  */
+  return (unsigned int) INT_MIN / -1;
+}
--- gcc/testsuite/c-c++-common/ubsan/shift-3.c.mp	2013-07-15 08:55:51.786698656 +0200
+++ gcc/testsuite/c-c++-common/ubsan/shift-3.c	2013-07-15 09:06:12.325948616 +0200
@@ -0,0 +1,11 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w" } */
+
+int
+main (void)
+{
+  unsigned int a = 1;
+  a <<= 31;
+  a <<= 1;
+  return 0;
+}
--- gcc/testsuite/c-c++-common/ubsan/unreachable-1.c.mp	2013-07-15 04:23:03.799985724 +0200
+++ gcc/testsuite/c-c++-common/ubsan/unreachable-1.c	2013-07-15 08:08:26.949168293 +0200
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=unreachable" } */
+/* { dg-shouldfail "ubsan" } */
+
+int
+main (void)
+{
+  __builtin_unreachable ();
+}
+ /* { dg-output "execution reached a __builtin_unreachable\\(\\) call" } */
--- gcc/testsuite/c-c++-common/ubsan/shift-1.c.mp	2013-07-15 05:30:50.662201212 +0200
+++ gcc/testsuite/c-c++-common/ubsan/shift-1.c	2013-07-15 08:55:12.915542820 +0200
@@ -0,0 +1,11 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w" } */
+
+int
+main (void)
+{
+  int a = 1;
+  a <<= 152;
+  return 0;
+}
+/* { dg-output "shift exponent 152 is too large for \[^\n\r]*-bit type int" } */
--- gcc/testsuite/c-c++-common/ubsan/shift-2.c.mp	2013-07-15 06:36:50.754358414 +0200
+++ gcc/testsuite/c-c++-common/ubsan/shift-2.c	2013-07-15 07:59:13.770070848 +0200
@@ -0,0 +1,11 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w" } */
+
+int
+main (void)
+{
+  int a = 1;
+  a <<= -3;
+  return 0;
+}
+/* { dg-output "shift exponent -3 is negative" } */
--- gcc/testsuite/c-c++-common/ubsan/div-by-zero-2.c.mp	2013-07-15 05:02:33.252507624 +0200
+++ gcc/testsuite/c-c++-common/ubsan/div-by-zero-2.c	2013-07-15 08:00:10.452296766 +0200
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=integer-divide-by-zero -Wno-div-by-zero" } */
+
+int
+main (void)
+{
+  1UL / 0;
+  return 0;
+}
+ /* { dg-output "division by zero" } */
--- gcc/testsuite/gcc.dg/ubsan/c99-shift-2.c.mp	2013-07-15 08:47:01.177890666 +0200
+++ gcc/testsuite/gcc.dg/ubsan/c99-shift-2.c	2013-07-15 08:48:39.085243951 +0200
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w -std=c99" } */
+
+int
+main (void)
+{
+  int a = 1;
+  a <<= 31;
+}
+/* { dg-output "left shift of 1 by 31 places cannot be represented in type int" } */
--- gcc/testsuite/gcc.dg/ubsan/ubsan.exp.mp	2013-07-14 20:17:20.856743632 +0200
+++ gcc/testsuite/gcc.dg/ubsan/ubsan.exp	2013-07-15 01:44:18.316194533 +0200
@@ -0,0 +1,36 @@
+# Copyright (C) 2013 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# GCC testsuite that uses the `dg.exp' driver.
+
+# Load support procs.
+load_lib gcc-dg.exp
+load_lib ubsan-dg.exp
+
+# Initialize `dg'.
+dg-init
+if [ubsan_init] {
+
+# Main loop.
+gcc-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.c $srcdir/c-c++-common/ubsan/*.c]] ""
+
+}
+
+# All done.
+ubsan_finish
+dg-finish
--- gcc/testsuite/gcc.dg/ubsan/c99-shift-1.c.mp	2013-07-15 08:42:03.829843562 +0200
+++ gcc/testsuite/gcc.dg/ubsan/c99-shift-1.c	2013-07-15 08:43:20.769105362 +0200
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=shift -w -std=c99" } */
+
+int
+main (void)
+{
+  int a = -42;
+  a << 1;
+}
+/* { dg-output "left shift of negative value -42" } */
