Allow access to long/int internals

Cython/Compiler/Code.py

@@ -54,6 +54,16 @@ non_portable_builtins_map = {
     'raw_input'     : ('PY_MAJOR_VERSION >= 3', 'input'),
 }
 
+ctypedef_builtins_map = {
+    # types of builtins in "ctypedef class" statements which we don't
+    # import either because the names conflict with C types or because
+    # the type simply is not exposed.
+    'py_int'             : '&PyInt_Type',
+    'py_long'            : '&PyLong_Type',
+    'py_float'           : '&PyFloat_Type',
+    'wrapper_descriptor' : '&PyWrapperDescr_Type',
+}
+
 basicsize_builtins_map = {
     # builtins whose type has a different tp_basicsize than sizeof(...)
     'PyTypeObject': 'PyHeapTypeObject',

Cython/Compiler/ModuleNode.py

@@ -2995,6 +2995,11 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         condition = replacement = None
         if module_name not in ('__builtin__', 'builtins'):
             module_name = '"%s"' % module_name
+        elif type.name in Code.ctypedef_builtins_map:
+            # Fast path for special builtins, don't actually import
+            ctypename = Code.ctypedef_builtins_map[type.name]
+            code.putln('%s = %s;' % (type.typeptr_cname, ctypename))
+            return
         else:
             module_name = '__Pyx_BUILTIN_MODULE_NAME'
             if type.name in Code.non_portable_builtins_map:

Cython/Includes/cpython/longintrepr.pxd

@@ -2,14 +2,13 @@
 # This is not part of Python's published API.
 
 cdef extern from "longintrepr.h":
-    # Add explicit cast to avoid compiler warnings
-    cdef _PyLong_New "(PyObject*)_PyLong_New"(Py_ssize_t s)
-
     ctypedef unsigned int digit
     ctypedef int sdigit  # Python >= 2.7 only
 
-    ctypedef struct PyLongObject:
-        digit* ob_digit
+    ctypedef class __builtin__.py_long [object PyLongObject]:
+        cdef digit* ob_digit
+
+    cdef py_long _PyLong_New(Py_ssize_t s)
 
     cdef long PyLong_SHIFT
     cdef digit PyLong_BASE

tests/run/longintrepr.pyx

@@ -48,15 +48,15 @@ def lshift(long a, unsigned long n):
 
     if high == 0:
         ret = _PyLong_New(index + 1)
-        (<PyLongObject*>ret).ob_digit[index] = low
+        ret.ob_digit[index] = low
     else:
         ret = _PyLong_New(index + 2)
-        (<PyLongObject*>ret).ob_digit[index] = low
-        (<PyLongObject*>ret).ob_digit[index + 1] = high
+        ret.ob_digit[index] = low
+        ret.ob_digit[index + 1] = high
 
     while index >= 1:
         index -= 1
-        (<PyLongObject*>ret).ob_digit[index] = 0
+        ret.ob_digit[index] = 0
 
     if a < 0:
         Py_SIZE_PTR(ret)[0] *= -1