tighten return type declarations of some C-API functions

Cython/Includes/cpython/dict.pxd

@@ -25,7 +25,7 @@ cdef extern from "Python.h":
     # Return true if p is a dict object, but not an instance of a
     # subtype of the dict type.
 
-    object PyDict_New()
+    dict PyDict_New()
     # Return value: New reference.
     # Return a new empty dictionary, or NULL on failure.
 
@@ -43,7 +43,7 @@ cdef extern from "Python.h":
     # matches key, return 1, otherwise return 0. On error, return
     # -1. This is equivalent to the Python expression "key in p".
 
-    object PyDict_Copy(object p)
+    dict PyDict_Copy(object p)
     # Return value: New reference.
     # Return a new dictionary that contains the same key-value pairs as p.
 
@@ -77,19 +77,19 @@ cdef extern from "Python.h":
     # This is the same as PyDict_GetItem(), but key is specified as a
     # char*, rather than a PyObject*.
 
-    object PyDict_Items(object p)
+    list PyDict_Items(object p)
     # Return value: New reference.
     # Return a PyListObject containing all the items from the
     # dictionary, as in the dictionary method items() (see the Python
     # Library Reference).
 
-    object PyDict_Keys(object p)
+    list PyDict_Keys(object p)
     # Return value: New reference.
     # Return a PyListObject containing all the keys from the
     # dictionary, as in the dictionary method keys() (see the Python
     # Library Reference).
 
-    object PyDict_Values(object p)
+    list PyDict_Values(object p)
     # Return value: New reference.
     # Return a PyListObject containing all the values from the
     # dictionary p, as in the dictionary method values() (see the

Cython/Includes/cpython/list.pxd

@@ -5,7 +5,7 @@ cdef extern from "Python.h":
     ############################################################################
     # Lists
     ############################################################################
-    object PyList_New(Py_ssize_t len)
+    list PyList_New(Py_ssize_t len)
     # Return a new list of length len on success, or NULL on failure.
     #
     # Note: If length is greater than zero, the returned list object's
@@ -64,7 +64,7 @@ cdef extern from "Python.h":
     # successful; return -1 and set an exception if
     # unsuccessful. Analogous to list.append(item).
 
-    object PyList_GetSlice(object list, Py_ssize_t low, Py_ssize_t high)
+    list PyList_GetSlice(object list, Py_ssize_t low, Py_ssize_t high)
     # Return value: New reference.
     # Return a list of the objects in list containing the objects
     # between low and high. Return NULL and set an exception if
@@ -84,7 +84,7 @@ cdef extern from "Python.h":
     # Reverse the items of list in place. Return 0 on success, -1 on
     # failure. This is the equivalent of "list.reverse()".
 
-    object PyList_AsTuple(object list)
+    tuple PyList_AsTuple(object list)
     # Return value: New reference.
     # Return a new tuple object containing the contents of list;
     # equivalent to "tuple(list)".

Cython/Includes/cpython/unicode.pxd

@@ -87,14 +87,14 @@ cdef extern from *:
     # not NULL, the return value might be a shared object. Therefore,
     # modification of the resulting Unicode object is only allowed
     # when u is NULL.
-    object PyUnicode_FromUnicode(Py_UNICODE *u, Py_ssize_t size)
+    unicode PyUnicode_FromUnicode(Py_UNICODE *u, Py_ssize_t size)
 
     # Create a Unicode Object from the given Unicode code point ordinal.
     #
     # The ordinal must be in range(0x10000) on narrow Python builds
     # (UCS2), and range(0x110000) on wide builds (UCS4). A ValueError
     # is raised in case it is not.
-    object PyUnicode_FromOrdinal(int ordinal)
+    unicode PyUnicode_FromOrdinal(int ordinal)
 
     # Return a read-only pointer to the Unicode object's internal
     # Py_UNICODE buffer, NULL if unicode is not a Unicode object.