diff --git a/Doc/lib/libctypes.tex b/Doc/lib/libctypes.tex
index 184875f..e1a1719 100755
--- a/Doc/lib/libctypes.tex
+++ b/Doc/lib/libctypes.tex
@@ -2294,6 +2294,12 @@
 an integer address, or a string.
 \end{classdesc*}
 
+\begin{classdesc*}{c_bool}
+Represent the C \code{bool} datatype (more accurately, _Bool from C99).
+Its value can be True or False, and the constructor accepts any object that
+has a truth value.
+\end{classdesc*}
+
 \begin{classdesc*}{HRESULT}
 Windows only: Represents a \class{HRESULT} value, which contains success
 or error information for a function or method call.
diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py
index ef8e892..e2a0573 100644
--- a/Lib/ctypes/__init__.py
+++ b/Lib/ctypes/__init__.py
@@ -233,6 +233,9 @@
 c_voidp = c_void_p # backwards compatibility (to a bug)
 _check_size(c_void_p)
 
+class c_bool(_SimpleCData):
+	_type_ = "t"
+
 # This cache maps types to pointers to them.
 _pointer_type_cache = {}
 
diff --git a/Lib/ctypes/test/test_numbers.py b/Lib/ctypes/test/test_numbers.py
index c22688d..5cd3c94 100644
--- a/Lib/ctypes/test/test_numbers.py
+++ b/Lib/ctypes/test/test_numbers.py
@@ -24,6 +24,8 @@
 unsigned_types = [c_ubyte, c_ushort, c_uint, c_ulong]
 signed_types = [c_byte, c_short, c_int, c_long, c_longlong]
 
+bool_types = []
+
 float_types = [c_double, c_float]
 
 try:
@@ -35,8 +37,16 @@
     unsigned_types.append(c_ulonglong)
     signed_types.append(c_longlong)
 
+try:
+    c_bool
+except NameError:
+    pass
+else:
+    bool_types.append(c_bool)
+
 unsigned_ranges = valid_ranges(*unsigned_types)
 signed_ranges = valid_ranges(*signed_types)
+bool_values = [True, False, 0, 1, -1, 5000, 'test', [], [1]]
 
 ################################################################
 
@@ -59,6 +69,11 @@
         for t, (l, h) in zip(signed_types, signed_ranges):
             self.failUnlessEqual(t(l).value, l)
             self.failUnlessEqual(t(h).value, h)
+    
+    def test_bool_values(self):
+        from operator import truth
+        for t, v in zip(bool_types, bool_values):
+            self.failUnlessEqual(t(v).value, truth(v))
 
     def test_typeerror(self):
         # Only numbers are allowed in the contructor,
@@ -82,7 +97,7 @@
 
     def test_byref(self):
         # calling byref returns also a PyCArgObject instance
-        for t in signed_types + unsigned_types + float_types:
+        for t in signed_types + unsigned_types + float_types + bool_types:
             parm = byref(t())
             self.failUnlessEqual(ArgType, type(parm))
 
@@ -101,7 +116,7 @@
             self.assertRaises(TypeError, t, 3.14)
 
     def test_sizes(self):
-        for t in signed_types + unsigned_types + float_types:
+        for t in signed_types + unsigned_types + float_types + bool_types:
             size = struct.calcsize(t._type_)
             # sizeof of the type...
             self.failUnlessEqual(sizeof(t), size)
@@ -163,6 +178,18 @@
 
         a[0] = '?'
         self.failUnlessEqual(v.value, a[0])
+    
+    # array does not support c_bool / 't'
+    # def test_bool_from_address(self):
+    #     from ctypes import c_bool
+    #     from array import array
+    #     a = array(c_bool._type_, [True])
+    #     v = t.from_address(a.buffer_info()[0])
+    #     self.failUnlessEqual(v.value, a[0])
+    #     self.failUnlessEqual(type(v) is t)
+    #     a[0] = False
+    #     self.failUnlessEqual(v.value, a[0])
+    #     self.failUnlessEqual(type(v) is t)
 
     def test_init(self):
         # c_int() can be initialized from Python's int, and c_int.
diff --git a/Lib/ctypes/test/test_repr.py b/Lib/ctypes/test/test_repr.py
index 1044f67..f6f9366 100644
--- a/Lib/ctypes/test/test_repr.py
+++ b/Lib/ctypes/test/test_repr.py
@@ -4,7 +4,7 @@
 subclasses = []
 for base in [c_byte, c_short, c_int, c_long, c_longlong,
         c_ubyte, c_ushort, c_uint, c_ulong, c_ulonglong,
-        c_float, c_double]:
+        c_float, c_double, c_bool]:
     class X(base):
         pass
     subclasses.append(X)
diff --git a/Misc/NEWS b/Misc/NEWS
index 634ada1..41db7ff 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -168,6 +168,8 @@
 Library
 -------
 
+- Patch #1649190: Adding support for _Bool to ctypes as c_bool.
+
 - Patch #1530482: add pydoc.render_doc() which returns the documentation
   for a thing instead of paging it to stdout, which pydoc.doc() does.
 
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 38bdeee..cce16ca 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -1101,7 +1101,7 @@
 
 */
 
-static char *SIMPLE_TYPE_CHARS = "cbBhHiIlLdfuzZqQPXOv";
+static char *SIMPLE_TYPE_CHARS = "cbBhHiIlLdfuzZqQPXOvt";
 
 static PyObject *
 c_wchar_p_from_param(PyObject *type, PyObject *value)
diff --git a/Modules/_ctypes/cfield.c b/Modules/_ctypes/cfield.c
index 799b457..1a6ceaf 100644
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -725,6 +725,35 @@
 }
 #endif
 
+#ifdef HAVE_C99_BOOL
+#define BOOL_TYPE _Bool
+#else
+#define BOOL_TYPE char
+#undef SIZEOF__BOOL
+#define SIZEOF__BOOL 1
+#endif
+
+static PyObject *
+t_set(void *ptr, PyObject *value, unsigned size)
+{
+	switch (PyObject_IsTrue(value)) {
+	case -1:
+		return NULL;
+	case 0:
+		*(BOOL_TYPE *)ptr = 0;
+		_RET(value);
+	default:
+		*(BOOL_TYPE *)ptr = 1;
+		_RET(value);
+	}
+}
+
+static PyObject *
+t_get(void *ptr, unsigned size)
+{
+	return PyBool_FromLong((long)*(BOOL_TYPE *)ptr);
+}
+
 static PyObject *
 I_set(void *ptr, PyObject *value, unsigned size)
 {
@@ -1585,6 +1614,17 @@
 	{ 'X', BSTR_set, BSTR_get, &ffi_type_pointer},
 	{ 'v', vBOOL_set, vBOOL_get, &ffi_type_sshort},
 #endif
+#if SIZEOF__BOOL == 1
+	{ 't', t_set, t_get, &ffi_type_uchar}, /* Also fallback for no native _Bool support */
+#elif SIZEOF__BOOL == SIZEOF_SHORT
+	{ 't', t_set, t_get, &ffi_type_ushort},
+#elif SIZEOF__BOOL == SIZEOF_INT
+	{ 't', t_set, t_get, &ffi_type_uint, I_set_sw, I_get_sw},
+#elif SIZEOF__BOOL == SIZEOF_LONG
+	{ 't', t_set, t_get, &ffi_type_ulong, L_set_sw, L_get_sw},
+#elif SIZEOF__BOOL == SIZEOF_LONG_LONG
+	{ 't', t_set, t_get, &ffi_type_ulong, Q_set_sw, Q_get_sw},
+#endif /* SIZEOF__BOOL */
 	{ 'O', O_set, O_get, &ffi_type_pointer},
 	{ 0, NULL, NULL, NULL},
 };
diff --git a/Modules/_ctypes/libffi/configure b/Modules/_ctypes/libffi/configure
index 9808384..f65669e 100755
--- a/Modules/_ctypes/libffi/configure
+++ b/Modules/_ctypes/libffi/configure
@@ -934,7 +934,7 @@
     else
       echo "$as_me: WARNING: no configuration information is in $ac_dir" >&2
     fi
-    cd "$ac_popdir"
+    cd $ac_popdir
   done
 fi
 
@@ -1973,7 +1973,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2031,7 +2032,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2147,7 +2149,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2201,7 +2204,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2246,7 +2250,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2290,7 +2295,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2617,7 +2623,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2787,7 +2794,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -2854,7 +2862,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3038,7 +3047,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3101,7 +3111,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3279,7 +3290,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3396,7 +3408,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3569,7 +3582,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3770,7 +3784,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3833,7 +3848,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -3914,7 +3930,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4055,7 +4072,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4191,7 +4209,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4253,7 +4272,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4293,7 +4313,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4349,7 +4370,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4389,7 +4411,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4453,7 +4476,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4484,8 +4508,10 @@
 esac
 else
   if test "$cross_compiling" = yes; then
-  { { echo "$as_me:$LINENO: error: internal error: not reached in cross-compile" >&5
-echo "$as_me: error: internal error: not reached in cross-compile" >&2;}
+  { { echo "$as_me:$LINENO: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&2;}
    { (exit 1); exit 1; }; }
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -4597,7 +4623,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4659,7 +4686,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4699,7 +4727,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4755,7 +4784,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4795,7 +4825,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4859,7 +4890,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -4890,8 +4922,10 @@
 esac
 else
   if test "$cross_compiling" = yes; then
-  { { echo "$as_me:$LINENO: error: internal error: not reached in cross-compile" >&5
-echo "$as_me: error: internal error: not reached in cross-compile" >&2;}
+  { { echo "$as_me:$LINENO: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&2;}
    { (exit 1); exit 1; }; }
 else
   cat >conftest.$ac_ext <<_ACEOF
@@ -4986,6 +5020,479 @@
 fi
 
 
+echo "$as_me:$LINENO: checking for _Bool support" >&5
+echo $ECHO_N "checking for _Bool support... $ECHO_C" >&6
+have_c99_bool=no
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+_Bool x; x = (_Bool)0;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_C99_BOOL 1
+_ACEOF
+
+  have_c99_bool=yes
+
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+echo "$as_me:$LINENO: result: $have_c99_bool" >&5
+echo "${ECHO_T}$have_c99_bool" >&6
+if test "$have_c99_bool" = yes ; then
+echo "$as_me:$LINENO: checking for _Bool" >&5
+echo $ECHO_N "checking for _Bool... $ECHO_C" >&6
+if test "${ac_cv_type__Bool+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+if ((_Bool *) 0)
+  return 0;
+if (sizeof (_Bool))
+  return 0;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_type__Bool=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_cv_type__Bool=no
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+echo "$as_me:$LINENO: result: $ac_cv_type__Bool" >&5
+echo "${ECHO_T}$ac_cv_type__Bool" >&6
+
+echo "$as_me:$LINENO: checking size of _Bool" >&5
+echo $ECHO_N "checking size of _Bool... $ECHO_C" >&6
+if test "${ac_cv_sizeof__Bool+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  if test "$ac_cv_type__Bool" = yes; then
+  # The cast to unsigned long works around a bug in the HP C Compiler
+  # version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+  # declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+  # This bug is HP SR number 8606223364.
+  if test "$cross_compiling" = yes; then
+  # Depending upon the size, compute the lo and hi bounds.
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(((long) (sizeof (_Bool))) >= 0)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_lo=0 ac_mid=0
+  while :; do
+    cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(((long) (sizeof (_Bool))) <= $ac_mid)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_hi=$ac_mid; break
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_lo=`expr $ac_mid + 1`
+		    if test $ac_lo -le $ac_mid; then
+		      ac_lo= ac_hi=
+		      break
+		    fi
+		    ac_mid=`expr 2 '*' $ac_mid + 1`
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+  done
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(((long) (sizeof (_Bool))) < 0)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_hi=-1 ac_mid=-1
+  while :; do
+    cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(((long) (sizeof (_Bool))) >= $ac_mid)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_lo=$ac_mid; break
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_hi=`expr '(' $ac_mid ')' - 1`
+		       if test $ac_mid -le $ac_hi; then
+			 ac_lo= ac_hi=
+			 break
+		       fi
+		       ac_mid=`expr 2 '*' $ac_mid`
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+  done
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_lo= ac_hi=
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+# Binary search between lo and hi bounds.
+while test "x$ac_lo" != "x$ac_hi"; do
+  ac_mid=`expr '(' $ac_hi - $ac_lo ')' / 2 + $ac_lo`
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+int
+main ()
+{
+static int test_array [1 - 2 * !(((long) (sizeof (_Bool))) <= $ac_mid)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_hi=$ac_mid
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_lo=`expr '(' $ac_mid ')' + 1`
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext
+done
+case $ac_lo in
+?*) ac_cv_sizeof__Bool=$ac_lo;;
+'') { { echo "$as_me:$LINENO: error: cannot compute sizeof (_Bool), 77
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot compute sizeof (_Bool), 77
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; } ;;
+esac
+else
+  if test "$cross_compiling" = yes; then
+  { { echo "$as_me:$LINENO: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot run test program while cross compiling
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; }
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+$ac_includes_default
+long longval () { return (long) (sizeof (_Bool)); }
+unsigned long ulongval () { return (long) (sizeof (_Bool)); }
+#include <stdio.h>
+#include <stdlib.h>
+int
+main ()
+{
+
+  FILE *f = fopen ("conftest.val", "w");
+  if (! f)
+    exit (1);
+  if (((long) (sizeof (_Bool))) < 0)
+    {
+      long i = longval ();
+      if (i != ((long) (sizeof (_Bool))))
+	exit (1);
+      fprintf (f, "%ld\n", i);
+    }
+  else
+    {
+      unsigned long i = ulongval ();
+      if (i != ((long) (sizeof (_Bool))))
+	exit (1);
+      fprintf (f, "%lu\n", i);
+    }
+  exit (ferror (f) || fclose (f) != 0);
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_sizeof__Bool=`cat conftest.val`
+else
+  echo "$as_me: program exited with status $ac_status" >&5
+echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+( exit $ac_status )
+{ { echo "$as_me:$LINENO: error: cannot compute sizeof (_Bool), 77
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot compute sizeof (_Bool), 77
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+rm -f core *.core gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
+fi
+fi
+rm -f conftest.val
+else
+  ac_cv_sizeof__Bool=0
+fi
+fi
+echo "$as_me:$LINENO: result: $ac_cv_sizeof__Bool" >&5
+echo "${ECHO_T}$ac_cv_sizeof__Bool" >&6
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF__BOOL $ac_cv_sizeof__Bool
+_ACEOF
+
+
+fi
+
 echo "$as_me:$LINENO: checking whether byte ordering is bigendian" >&5
 echo $ECHO_N "checking whether byte ordering is bigendian... $ECHO_C" >&6
 if test "${ac_cv_c_bigendian+set}" = set; then
@@ -5021,7 +5528,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -5063,7 +5571,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -5120,7 +5629,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -5252,7 +5762,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -5318,7 +5829,8 @@
   cat conftest.err >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -6277,6 +6789,11 @@
 
 
 
+  if test x"$ac_file" != x-; then
+    { echo "$as_me:$LINENO: creating $ac_file" >&5
+echo "$as_me: creating $ac_file" >&6;}
+    rm -f "$ac_file"
+  fi
   # Let's still pretend it is `configure' which instantiates (i.e., don't
   # use $as_me), people would be surprised to read:
   #    /* config.h.  Generated by config.status.  */
@@ -6315,12 +6832,6 @@
 	 fi;;
       esac
     done` || { (exit 1); exit 1; }
-
-  if test x"$ac_file" != x-; then
-    { echo "$as_me:$LINENO: creating $ac_file" >&5
-echo "$as_me: creating $ac_file" >&6;}
-    rm -f "$ac_file"
-  fi
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF
   sed "$ac_vpsub
diff --git a/Modules/_ctypes/libffi/configure.ac b/Modules/_ctypes/libffi/configure.ac
index 1308034..8870fcb 100644
--- a/Modules/_ctypes/libffi/configure.ac
+++ b/Modules/_ctypes/libffi/configure.ac
@@ -106,6 +106,17 @@
 fi
 AC_SUBST(HAVE_LONG_DOUBLE)
 
+AC_MSG_CHECKING(for _Bool support)
+have_c99_bool=no
+AC_TRY_COMPILE([], [_Bool x; x = (_Bool)0;], [
+  AC_DEFINE(HAVE_C99_BOOL, 1, [Define this if you have the type _Bool.]) 
+  have_c99_bool=yes
+])
+AC_MSG_RESULT($have_c99_bool)
+if test "$have_c99_bool" = yes ; then
+AC_CHECK_SIZEOF(_Bool, 1)
+fi
+
 AC_C_BIGENDIAN
 AH_VERBATIM([WORDS_BIGENDIAN],
 [
diff --git a/Modules/_ctypes/libffi/fficonfig.h.in b/Modules/_ctypes/libffi/fficonfig.h.in
index bcc5a58..ad2be4e 100644
--- a/Modules/_ctypes/libffi/fficonfig.h.in
+++ b/Modules/_ctypes/libffi/fficonfig.h.in
@@ -28,6 +28,9 @@
    */
 #undef HAVE_AS_SPARC_UA_PCREL
 
+/* Define this if you have the type _Bool. */
+#undef HAVE_C99_BOOL
+
 /* Define if __attribute__((visibility("hidden"))) is supported. */
 #undef HAVE_HIDDEN_VISIBILITY_ATTRIBUTE
 
@@ -103,6 +106,9 @@
 /* The size of a `long double', as computed by sizeof. */
 #undef SIZEOF_LONG_DOUBLE
 
+/* The size of a `_Bool', as computed by sizeof. */
+#undef SIZEOF__BOOL
+
 /* If using the C implementation of alloca, define if you know the
    direction of stack growth for your system; otherwise it will be
    automatically deduced at run-time.