add inheritance hierarchy and other tests for ctypes base types

python · erlend-aasland · Jan 9, 2024 · Jan 4, 2024 · Jan 5, 2024 · Jan 5, 2024
commit 1d95bbcf95489cb3db0cac0018f3cbb3db024372
diff --git a/Lib/test/test_ctypes/test_arrays.py b/Lib/test/test_ctypes/test_arrays.py
@@ -14,6 +14,10 @@
 formats = c_byte, c_ubyte, c_short, c_ushort, c_int, c_uint, \
           c_long, c_ulonglong, c_float, c_double, c_longdouble
 
+ArrayType = type(Array)
+# _CData is not exported to Python, so we have to access it from __base__.
+_CData = Structure.__base__
+
 
 def ARRAY(*args):
     # ignore DeprecationWarning in tests
@@ -23,6 +27,25 @@ def ARRAY(*args):
 
 
 class ArrayTestCase(unittest.TestCase):
+    def test_inheritance_hierarchy(self):
+        self.assertEqual(_CData.__name__, "_CData")
+        self.assertEqual(Array.mro(), [Array, _CData, object])
+
+        self.assertEqual(ArrayType.__name__, "PyCArrayType")
+        self.assertEqual(type(ArrayType), type)
+
+    def test_instantiation(self):
+        with self.assertRaisesRegex(TypeError, "abstract class"):
+            Array()
+
+        ArrayType("Foo", (Array,), {"_length_": 1, "_type_": c_int})
+
+    def test_immutability(self):
+        for t in [Array, ArrayType]:
+            msg = "cannot set 'foo' attribute of immutable type"
+            with self.assertRaisesRegex(TypeError, msg):
+                t.foo = "bar"
+
     def test_simple(self):
         # create classes holding simple numeric types, and check
         # various properties.

diff --git a/Lib/test/test_ctypes/test_pointers.py b/Lib/test/test_ctypes/test_pointers.py
@@ -17,8 +17,31 @@
 python_types = [int, int, int, int, int, int,
                 int, int, int, int, float, float]
 
+PointerType = type(_Pointer)
+# _CData is not exported to Python, so we have to access it from __base__.
+_CData = Structure.__base__
+
 
 class PointersTestCase(unittest.TestCase):
+    def test_inheritance_hierarchy(self):
+        self.assertEqual(_CData.__name__, "_CData")
+        self.assertEqual(_Pointer.mro(), [_Pointer, _CData, object])
+
+        self.assertEqual(PointerType.__name__, "PyCPointerType")
+        self.assertEqual(type(PointerType), type)
+
+    def test_abstract_class(self):
+        with self.assertRaisesRegex(TypeError, "Cannot create instance: has no _type"):
+            _Pointer()
+
+        PointerType("Foo", (_Pointer,), {})
+
+    def test_immutability(self):
+        for t in [_Pointer, PointerType]:
+            msg = "cannot set 'foo' attribute of immutable type"
+            with self.assertRaisesRegex(TypeError, msg):
+                t.foo = "bar"
+
     def test_pointer_crash(self):
 
         class A(POINTER(c_ulong)):

diff --git a/Lib/test/test_ctypes/test_simplesubclasses.py b/Lib/test/test_ctypes/test_simplesubclasses.py
@@ -1,5 +1,10 @@
 import unittest
-from ctypes import Structure, CFUNCTYPE, c_int
+from ctypes import Structure, CFUNCTYPE, c_int, _SimpleCData
+
+
+SimpleType = type(_SimpleCData)
+# _CData is not exported to Python, so we have to access it from __base__.
+_CData = Structure.__base__
 
 
 class MyInt(c_int):
@@ -10,6 +15,27 @@ def __eq__(self, other):
 
 
 class Test(unittest.TestCase):
+    def test_inheritance_hierarchy(self):
+        self.assertEqual(_CData.__name__, "_CData")
+        self.assertEqual(_SimpleCData.mro(), [_SimpleCData, _CData, object])
+
+        self.assertEqual(SimpleType.__name__, "PyCSimpleType")
+        self.assertEqual(type(SimpleType), type)
+
+        self.assertEqual(c_int.mro(), [c_int, _SimpleCData, _CData, object])
+
+    def test_abstract_class(self):
+        with self.assertRaisesRegex(TypeError, "abstract class"):
+            _SimpleCData()
+
+        SimpleType("Foo", (_SimpleCData,), {"_type_": "i"})
+
+    def test_immutability(self):
+        for t in [_SimpleCData, SimpleType]:
+            msg = "cannot set 'foo' attribute of immutable type"
+            with self.assertRaisesRegex(TypeError, msg):
+                t.foo = "bar"
+
 
     def test_compare(self):
         self.assertEqual(MyInt(3), MyInt(3))

diff --git a/Lib/test/test_ctypes/test_structures.py b/Lib/test/test_ctypes/test_structures.py
@@ -13,6 +13,10 @@
 from collections import namedtuple
 from test import support
 
+StructureType = type(Structure)
+# _CData is not exported to Python, so we have to access it from __base__.
+_CData = Array.__base__
+

 class SubclassesTest(unittest.TestCase):
     def test_subclass(self):
@@ -70,6 +74,25 @@ class StructureTestCase(unittest.TestCase):
                "d": c_double,
                }
 
+    def test_inheritance_hierarchy(self):
+        self.assertEqual(_CData.__name__, "_CData")
+        self.assertEqual(Structure.mro(), [Structure, _CData, object])
+
+        self.assertEqual(StructureType.__name__, "PyCStructType")
+        self.assertEqual(type(StructureType), type)
+
+    def test_instantiation(self):
+        with self.assertRaisesRegex(TypeError, "abstract class"):
+            Structure()
+
+        StructureType("Foo", (Structure,), {})
+
+    def test_immutability(self):
+        for t in [Structure, StructureType]:
+            msg = "cannot set 'foo' attribute of immutable type"
+            with self.assertRaisesRegex(TypeError, msg):
+                t.foo = "bar"
+
     def test_simple_structs(self):
         for code, tp in self.formats.items():
             class X(Structure):

diff --git a/Lib/test/test_ctypes/test_unions.py b/Lib/test/test_ctypes/test_unions.py
@@ -0,0 +1,32 @@
+import ctypes
+import sys
+import unittest
+import warnings
+from ctypes import Union
+
+
+UnionType = type(Union)
+# _CData is not exported to Python, so we have to access it from __base__.
+_CData = Union.__base__
+
+
+class ArrayTestCase(unittest.TestCase):
+    def test_inheritance_hierarchy(self):
+        self.assertEqual(_CData.__name__, "_CData")
+        self.assertEqual(Union.mro(), [Union, _CData, object])
+
+        self.assertEqual(UnionType.__name__, "UnionType")
+        self.assertEqual(type(UnionType), type)
+
+    def test_instantiation(self):
+        with self.assertRaisesRegex(TypeError, "abstract class"):
+            Union()
+
+        UnionType("Foo", (Union,), {})
+
+    def test_immutability(self):
+        Union.foo = "bar"
+
+        msg = "cannot set 'foo' attribute of immutable type"
+        with self.assertRaisesRegex(TypeError, msg):
+            UnionType.foo = "bar"