Make it a static type

Author: JelleZijlstra

Include/internal/pycore_global_objects.h

@@ -75,7 +75,6 @@ struct _Py_interp_cached_objects {
     PyTypeObject *paramspec_type;
     PyTypeObject *paramspecargs_type;
     PyTypeObject *paramspeckwargs_type;
-    PyTypeObject *typealias_type;
 };
 
 #define _Py_INTERP_STATIC_OBJECT(interp, NAME) \

Include/internal/pycore_typevarobject.h

@@ -16,6 +16,8 @@ extern PyObject *_Py_subscript_generic(PyThreadState *, PyObject *);
 extern int _Py_initialize_generic(PyInterpreterState *);
 extern void _Py_clear_generic_types(PyInterpreterState *);
 
+extern PyTypeObject _PyTypeAlias_Type;
+
 #ifdef __cplusplus
 }
 #endif

Lib/test/test_type_aliases.py

@@ -209,6 +209,7 @@ def test_union(self):
         self.assertEqual(get_args(union3), (list[range], Alias1))
 
     def test_module(self):
+        self.assertEqual(TypeAliasType.__module__, "typing")
         type Alias = int
         self.assertEqual(Alias.__module__, __name__)
         self.assertEqual(mod_generics_cache.Alias.__module__,

Modules/_typingmodule.c

@@ -6,6 +6,7 @@
 
 #include "Python.h"
 #include "internal/pycore_interp.h"
+#include "internal/pycore_typevarobject.h"
 #include "clinic/_typingmodule.c.h"
 
 /*[clinic input]
@@ -56,9 +57,11 @@ _typing_exec(PyObject *m)
     EXPORT_TYPE("ParamSpec", paramspec_type);
     EXPORT_TYPE("ParamSpecArgs", paramspecargs_type);
     EXPORT_TYPE("ParamSpecKwargs", paramspeckwargs_type);
-    EXPORT_TYPE("TypeAliasType", typealias_type);
     EXPORT_TYPE("Generic", generic_type);
 #undef EXPORT_TYPE
+    if (PyModule_AddObjectRef(m, "TypeAliasType", &_PyTypeAlias_Type) < 0) {
+        return -1;
+    }
     return 0;
 }
 

Objects/object.c

@@ -14,7 +14,7 @@
 #include "pycore_pymem.h"         // _PyMem_IsPtrFreed()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 #include "pycore_symtable.h"      // PySTEntry_Type
-#include "pycore_typevarobject.h" // _PyTypeVar_Type etc., _Py_initialize_generic
+#include "pycore_typevarobject.h" // _PyTypeAlias_Type, _Py_initialize_generic
 #include "pycore_typeobject.h"    // _PyBufferWrapper_Type
 #include "pycore_unionobject.h"   // _PyUnion_Type
 #include "pycore_interpreteridobject.h"  // _PyInterpreterID_Type
@@ -2112,6 +2112,7 @@ static PyTypeObject* static_types[] = {
     &_PyWeakref_CallableProxyType,
     &_PyWeakref_ProxyType,
     &_PyWeakref_RefType,
+    &_PyTypeAlias_Type,
 
     // subclasses: _PyTypes_FiniTypes() deallocates them before their base
     // class

Objects/typevarobject.c

@@ -1337,8 +1337,7 @@ static typealiasobject *
 typealias_alloc(PyObject *name, PyObject *type_params, PyObject *compute_value,
                 PyObject *value, PyObject *module)
 {
-    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.typealias_type;
-    typealiasobject *ta = PyObject_GC_New(typealiasobject, tp);
+    typealiasobject *ta = PyObject_GC_New(typealiasobject, &_PyTypeAlias_Type);
     if (ta == NULL) {
         return NULL;
     }
@@ -1439,28 +1438,32 @@ Type aliases are created through the type statement:\n\
   type Alias = int\n\
 ");
 
-static PyType_Slot typealias_slots[] = {
-    {Py_tp_doc, (void *)typealias_doc},
-    {Py_tp_members, typealias_members},
-    {Py_tp_methods, typealias_methods},
-    {Py_tp_getset, typealias_getset},
-    {Py_mp_subscript, typealias_subscript},
-    {Py_tp_dealloc, typealias_dealloc},
-    {Py_tp_alloc, PyType_GenericAlloc},
-    {Py_tp_new, typealias_new},
-    {Py_tp_free, PyObject_GC_Del},
-    {Py_tp_traverse, (traverseproc)typealias_traverse},
-    {Py_tp_clear, (inquiry)typealias_clear},
-    {Py_tp_repr, typealias_repr},
-    {Py_nb_or, _Py_union_type_or},
-    {0, 0},
+static PyNumberMethods typealias_as_number = {
+    .nb_or = _Py_union_type_or,
+};
+
+static PyMappingMethods typealias_as_mapping = {
+    .mp_subscript = typealias_subscript,
 };
 
-PyType_Spec typealias_spec = {
-    .name = "typing.TypeAliasType",
-    .basicsize = sizeof(typealiasobject),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC,
-    .slots = typealias_slots,
+PyTypeObject _PyTypeAlias_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    .tp_name = "typing.TypeAliasType",
+    .tp_basicsize = sizeof(typealiasobject),
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC,
+    .tp_doc = typealias_doc,
+    .tp_members = typealias_members,
+    .tp_methods = typealias_methods,
+    .tp_getset = typealias_getset,
+    .tp_alloc = PyType_GenericAlloc,
+    .tp_dealloc = typealias_dealloc,
+    .tp_new = typealias_new,
+    .tp_free = PyObject_GC_Del,
+    .tp_traverse = (traverseproc)typealias_traverse,
+    .tp_clear = (inquiry)typealias_clear,
+    .tp_repr = typealias_repr,
+    .tp_as_number = &typealias_as_number,
+    .tp_as_mapping = &typealias_as_mapping,
 };
 
 PyObject *
@@ -1631,7 +1634,6 @@ int _Py_initialize_generic(PyInterpreterState *interp)
     MAKE_TYPE(paramspec);
     MAKE_TYPE(paramspecargs);
     MAKE_TYPE(paramspeckwargs);
-    MAKE_TYPE(typealias);
 #undef MAKE_TYPE
     return 0;
 }
@@ -1644,5 +1646,4 @@ void _Py_clear_generic_types(PyInterpreterState *interp)
     Py_CLEAR(interp->cached_objects.paramspec_type);
     Py_CLEAR(interp->cached_objects.paramspecargs_type);
     Py_CLEAR(interp->cached_objects.paramspeckwargs_type);
-    Py_CLEAR(interp->cached_objects.typealias_type);
 }

Objects/unionobject.c

@@ -1,6 +1,7 @@
 // types.UnionType -- used to represent e.g. Union[int, str], int | str
 #include "Python.h"
 #include "pycore_object.h"  // _PyObject_GC_TRACK/UNTRACK
+#include "pycore_typevarobject.h"  // _PyTypeAlias_Type
 #include "pycore_unionobject.h"
 #include "structmember.h"
 
@@ -150,11 +151,11 @@ is_unionable(PyObject *obj)
     if (obj == Py_None ||
         PyType_Check(obj) ||
         _PyGenericAlias_Check(obj) ||
-        _PyUnion_Check(obj)) {
+        _PyUnion_Check(obj) ||
+        Py_IS_TYPE(obj, &_PyTypeAlias_Type)) {
         return 1;
     }
-    PyInterpreterState *interp = PyInterpreterState_Get();
-    return Py_IS_TYPE(obj, interp->cached_objects.typealias_type);
+    return 0;
 }
 
 PyObject *