diff -r 35a9d60145cd Modules/_dbmmodule.c
--- a/Modules/_dbmmodule.c	Fri Apr 17 04:58:45 2015 +0300
+++ b/Modules/_dbmmodule.c	Sun Apr 19 11:38:39 2015 -0700
@@ -272,7 +272,7 @@
 
     self: dbmobject
 
-    key: str(types={'str', 'robuffer'}, length=True)
+    key: str(types={str, robuffer}, length=True)
     default: object = None
     /
 
@@ -282,7 +282,7 @@
 static PyObject *
 dbm_dbm_get_impl(dbmobject *dp, const char *key, Py_ssize_clean_t key_length,
                  PyObject *default_value)
-/*[clinic end generated code: output=4f5c0e523eaf1251 input=f81478bc211895ef]*/
+/*[clinic end generated code: output=4f5c0e523eaf1251 input=c513a2930092cc9d]*/
 {
     datum dbm_key, val;
 
diff -r 35a9d60145cd Modules/_io/bufferedio.c
--- a/Modules/_io/bufferedio.c	Fri Apr 17 04:58:45 2015 +0300
+++ b/Modules/_io/bufferedio.c	Sun Apr 19 11:38:39 2015 -0700
@@ -101,26 +101,26 @@
 
 /*[clinic input]
 _io._BufferedIOBase.readinto
-    buffer: Py_buffer(types={'rwbuffer'})
+    buffer: Py_buffer(types={rwbuffer})
     /
 [clinic start generated code]*/
 
 static PyObject *
 _io__BufferedIOBase_readinto_impl(PyObject *self, Py_buffer *buffer)
-/*[clinic end generated code: output=8c8cda6684af8038 input=f8242a06c21763a0]*/
+/*[clinic end generated code: output=8c8cda6684af8038 input=076e49a36bb37af1]*/
 {
     return _bufferediobase_readinto_generic(self, buffer, 0);
 }
 
 /*[clinic input]
 _io._BufferedIOBase.readinto1
-    buffer: Py_buffer(types={'rwbuffer'})
+    buffer: Py_buffer(types={rwbuffer})
     /
 [clinic start generated code]*/
 
 static PyObject *
 _io__BufferedIOBase_readinto1_impl(PyObject *self, Py_buffer *buffer)
-/*[clinic end generated code: output=358623e4fd2b69d3 input=2003e706c730bd21]*/
+/*[clinic end generated code: output=358623e4fd2b69d3 input=8c85e1fb51fc9c99]*/
 {
     return _bufferediobase_readinto_generic(self, buffer, 1);
 }
@@ -1065,26 +1065,26 @@
 
 /*[clinic input]
 _io._Buffered.readinto
-    buffer: Py_buffer(types={'rwbuffer'})
+    buffer: Py_buffer(types={rwbuffer})
     /
 [clinic start generated code]*/
 
 static PyObject *
 _io__Buffered_readinto_impl(buffered *self, Py_buffer *buffer)
-/*[clinic end generated code: output=bcb376580b1d8170 input=962b7496eac38b3a]*/
+/*[clinic end generated code: output=bcb376580b1d8170 input=ce115d72f68e9254]*/
 {
     return _buffered_readinto_generic(self, buffer, 0);
 }
 
 /*[clinic input]
 _io._Buffered.readinto1
-    buffer: Py_buffer(types={'rwbuffer'})
+    buffer: Py_buffer(types={rwbuffer})
     /
 [clinic start generated code]*/
 
 static PyObject *
 _io__Buffered_readinto1_impl(buffered *self, Py_buffer *buffer)
-/*[clinic end generated code: output=6e5c6ac5868205d6 input=834614d93f0adeb5]*/
+/*[clinic end generated code: output=6e5c6ac5868205d6 input=45c1263f4cdfde47]*/
 {
     return _buffered_readinto_generic(self, buffer, 1);
 }
diff -r 35a9d60145cd Modules/_io/bytesio.c
--- a/Modules/_io/bytesio.c	Fri Apr 17 04:58:45 2015 +0300
+++ b/Modules/_io/bytesio.c	Sun Apr 19 11:38:39 2015 -0700
@@ -541,7 +541,7 @@
 
 /*[clinic input]
 _io.BytesIO.readinto
-    buffer: Py_buffer(types={'rwbuffer'})
+    buffer: Py_buffer(types={rwbuffer})
     /
 
 Read up to len(buffer) bytes into buffer.
@@ -552,7 +552,7 @@
 
 static PyObject *
 _io_BytesIO_readinto_impl(bytesio *self, Py_buffer *buffer)
-/*[clinic end generated code: output=a5d407217dcf0639 input=d289da851c7c4159]*/
+/*[clinic end generated code: output=a5d407217dcf0639 input=cdca8e493d75ad72]*/
 {
     Py_ssize_t len, n;
 
diff -r 35a9d60145cd Modules/_io/fileio.c
--- a/Modules/_io/fileio.c	Fri Apr 17 04:58:45 2015 +0300
+++ b/Modules/_io/fileio.c	Sun Apr 19 11:38:39 2015 -0700
@@ -604,7 +604,7 @@
 
 /*[clinic input]
 _io.FileIO.readinto
-    buffer: Py_buffer(types={'rwbuffer'})
+    buffer: Py_buffer(types={rwbuffer})
     /
 
 Same as RawIOBase.readinto().
@@ -612,7 +612,7 @@
 
 static PyObject *
 _io_FileIO_readinto_impl(fileio *self, Py_buffer *buffer)
-/*[clinic end generated code: output=b01a5a22c8415cb4 input=5edd8327498d468c]*/
+/*[clinic end generated code: output=b01a5a22c8415cb4 input=045b19325ec5dcf8]*/
 {
     Py_ssize_t n;
     int err;
diff -r 35a9d60145cd Modules/arraymodule.c
--- a/Modules/arraymodule.c	Fri Apr 17 04:58:45 2015 +0300
+++ b/Modules/arraymodule.c	Sun Apr 19 11:38:39 2015 -0700
@@ -1600,7 +1600,7 @@
 /*[clinic input]
 array.array.fromstring
 
-    buffer: Py_buffer(types={'str', 'buffer'})
+    buffer: Py_buffer(types={str, buffer})
     /
 
 Appends items from the string, interpreting it as an array of machine values, as if it had been read from a file using the fromfile() method).
@@ -1610,7 +1610,7 @@
 
 static PyObject *
 array_array_fromstring_impl(arrayobject *self, Py_buffer *buffer)
-/*[clinic end generated code: output=31c4baa779df84ce input=fdde1a56cbe2b05b]*/
+/*[clinic end generated code: output=31c4baa779df84ce input=1303b97380a50a03]*/
 {
     if (PyErr_WarnEx(PyExc_DeprecationWarning,
             "fromstring() is deprecated. Use frombytes() instead.", 2) != 0)
@@ -1929,7 +1929,7 @@
 array._array_reconstructor
 
     arraytype: object(type="PyTypeObject *")
-    typecode: int(types={'str'})
+    typecode: int(types={str})
     mformat_code: int(type="enum machine_format_code")
     items: object
     /
@@ -1942,7 +1942,7 @@
                                 int typecode,
                                 enum machine_format_code mformat_code,
                                 PyObject *items)
-/*[clinic end generated code: output=6ecbf0e8e4d92ab9 input=a9ae223306d7b262]*/
+/*[clinic end generated code: output=6ecbf0e8e4d92ab9 input=eeae27b3cf2d7c16]*/
 {
     PyObject *converted_items;
     PyObject *result;
diff -r 35a9d60145cd Tools/clinic/clinic.py
--- a/Tools/clinic/clinic.py	Fri Apr 17 04:58:45 2015 +0300
+++ b/Tools/clinic/clinic.py	Sun Apr 19 11:38:39 2015 -0700
@@ -26,8 +26,12 @@
 import tempfile
 import textwrap
 import traceback
+import types
 import uuid
 
+from types import *
+NoneType = type(None)
+
 # TODO:
 #
 # soon:
@@ -2531,17 +2535,17 @@
         if not bitwise:
             fail("Unsigned shorts must be bitwise (for now).")
 
-@add_legacy_c_converter('C', types={'str'})
+@add_legacy_c_converter('C', types={str})
 class int_converter(CConverter):
     type = 'int'
     default_type = int
     format_unit = 'i'
     c_ignored_default = "0"
 
-    def converter_init(self, *, types={'int'}, type=None):
-        if types == {'str'}:
+    def converter_init(self, *, types={int}, type=None):
+        if types == {str}:
             self.format_unit = 'C'
-        elif types != {'int'}:
+        elif types != {int}:
             fail("int_converter: illegal 'types' argument " + repr(types))
         if type != None:
             self.type = type
@@ -2634,17 +2638,22 @@
 
 
 #
-# We define three string conventions for buffer types in the 'types' argument:
-#  'buffer' : any object supporting the buffer interface
-#  'rwbuffer': any object supporting the buffer interface, but must be writeable
-#  'robuffer': any object supporting the buffer interface, but must not be writeable
+# We define three conventions for buffer types in the 'types' argument:
 #
-
-@add_legacy_c_converter('s#', types={"str", "robuffer"}, length=True)
-@add_legacy_c_converter('y', types={"robuffer"})
-@add_legacy_c_converter('y#', types={"robuffer"}, length=True)
+#  buffer  : any object supporting the buffer interface
+#  rwbuffer: any object supporting the buffer interface, but must be writeable
+#  robuffer: any object supporting the buffer interface, but must not be writeable
+#
+
+class buffer: pass
+class rwbuffer: pass
+class robuffer: pass
+
+@add_legacy_c_converter('s#', types={str, robuffer}, length=True)
+@add_legacy_c_converter('y', types={robuffer})
+@add_legacy_c_converter('y#', types={robuffer}, length=True)
 @add_legacy_c_converter('z', nullable=True)
-@add_legacy_c_converter('z#', types={"str", "robuffer"}, nullable=True, length=True)
+@add_legacy_c_converter('z#', types={str, robuffer}, nullable=True, length=True)
 # add_legacy_c_converter not supported for es, es#, et, et#
 # because of their extra encoding argument
 class str_converter(CConverter):
@@ -2652,15 +2661,15 @@
     default_type = (str, Null, NoneType)
     format_unit = 's'
 
-    def converter_init(self, *, encoding=None, types={"str"},
+    def converter_init(self, *, encoding=None, types={str},
         length=False, nullable=False, zeroes=False):
 
         self.length = bool(length)
 
-        is_b_or_ba = types == {"bytes", "bytearray"}
-        is_str = types == {"str"}
-        is_robuffer = types == {"robuffer"}
-        is_str_or_robuffer = types == {"str", "robuffer"}
+        is_b_or_ba = types == {bytes, bytearray}
+        is_str = types == {str}
+        is_robuffer = types == {robuffer}
+        is_str_or_robuffer = types == {str, robuffer}
 
         format_unit = None
 
@@ -2728,29 +2737,29 @@
             self.length = True
         self.format_unit = format_unit
 
-@add_legacy_c_converter('s*', types={'str', 'buffer'})
-@add_legacy_c_converter('z*', types={'str', 'buffer'}, nullable=True)
-@add_legacy_c_converter('w*', types={'rwbuffer'})
+@add_legacy_c_converter('s*', types={str, buffer})
+@add_legacy_c_converter('z*', types={str, buffer}, nullable=True)
+@add_legacy_c_converter('w*', types={rwbuffer})
 class Py_buffer_converter(CConverter):
     type = 'Py_buffer'
     format_unit = 'y*'
     impl_by_reference = True
     c_ignored_default = "{NULL, NULL}"
 
-    def converter_init(self, *, types={'buffer'}, nullable=False):
+    def converter_init(self, *, types={buffer}, nullable=False):
         if self.default not in (unspecified, None):
             fail("The only legal default value for Py_buffer is None.")
         self.c_default = self.c_ignored_default
 
         format_unit = None
-        if types == {'str', 'buffer'}:
+        if types == {str, buffer}:
             format_unit = 's*' if not nullable else 'z*'
         else:
             if nullable:
                 fail('Py_buffer_converter: illegal combination of arguments (nullable=True)')
-            elif types == {'buffer'}:
+            elif types == {buffer}:
                 format_unit = 'y*'
-            elif types == {'rwbuffer'}:
+            elif types == {rwbuffer}:
                 format_unit = 'w*'
         if not format_unit:
             fail("Py_buffer_converter: illegal combination of arguments")
@@ -3035,6 +3044,27 @@
             'return_value = PyUnicode_DecodeFSDefault(_return_value);\n')
 
 
+def eval_ast_expr(node, symbols=None, *, filename='-'):
+    """
+    Takes an ast.Expr node.  Compiles and evaluates it.
+    Returns the result of the expression.
+
+    symbols represents the globals dict the expression
+    should see.  (There's no equivalent for "locals" here.)
+    """
+
+    if isinstance(node, ast.Expr):
+        node = node.value
+
+    if symbols == None:
+        symbols = globals()
+
+    node = ast.Expression(node)
+    co = compile(node, filename, 'eval')
+    fn = types.FunctionType(co, symbols)
+    return fn()
+
+
 class IndentStack:
     def __init__(self):
         self.indents = []
@@ -3795,7 +3825,9 @@
             fail("Annotations must be either a name, a function call, or a string.")
 
         name = annotation.func.id
-        kwargs = {node.arg: ast.literal_eval(node.value) for node in annotation.keywords}
+        symbols = globals()
+
+        kwargs = {node.arg: eval_ast_expr(node.value, symbols) for node in annotation.keywords}
         return name, False, kwargs
 
     def parse_special_symbol(self, symbol):