gh-103763: Implement PEP 695 (#103764)

This implements PEP 695, Type Parameter Syntax. It adds support for:

- Generic functions (def func[T](): ...)
- Generic classes (class X[T](): ...)
- Type aliases (type X = ...)
- New scoping when the new syntax is used within a class body
- Compiler and interpreter changes to support the new syntax and scoping rules 

Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Co-authored-by: Eric Traut <eric@traut.com>
Co-authored-by: Larry Hastings <larry@hastings.org>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

6 files changed, 2490 insertions, 4 deletions

diff --git a/Objects/clinic/typevarobject.c.h b/Objects/clinic/typevarobject.c.h
new file mode 100644
index 0000000..54189b9
--- /dev/null
+++ b/Objects/clinic/typevarobject.c.h
@@ -0,0 +1,786 @@
+/*[clinic input]
+preserve
+[clinic start generated code]*/
+
+#if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+#  include "pycore_gc.h"            // PyGC_Head
+#  include "pycore_runtime.h"       // _Py_ID()
+#endif
+
+
+PyDoc_STRVAR(typevar_new__doc__,
+"typevar(name, *constraints, *, bound=None, covariant=False,\n"
+"        contravariant=False, infer_variance=False)\n"
+"--\n"
+"\n"
+"Create a TypeVar.");
+
+static PyObject *
+typevar_new_impl(PyTypeObject *type, PyObject *name, PyObject *constraints,
+                 PyObject *bound, int covariant, int contravariant,
+                 int infer_variance);
+
+static PyObject *
+typevar_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 5
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(name), &_Py_ID(bound), &_Py_ID(covariant), &_Py_ID(contravariant), &_Py_ID(infer_variance), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"name", "bound", "covariant", "contravariant", "infer_variance", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "typevar",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[6];
+    PyObject * const *fastargs;
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    Py_ssize_t noptargs = Py_MIN(nargs, 1) + (kwargs ? PyDict_GET_SIZE(kwargs) : 0) - 1;
+    PyObject *name;
+    PyObject *constraints = NULL;
+    PyObject *bound = Py_None;
+    int covariant = 0;
+    int contravariant = 0;
+    int infer_variance = 0;
+
+    fastargs = _PyArg_UnpackKeywordsWithVararg(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 1, 0, 1, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    if (!PyUnicode_Check(fastargs[0])) {
+        _PyArg_BadArgument("typevar", "argument 'name'", "str", fastargs[0]);
+        goto exit;
+    }
+    name = fastargs[0];
+    constraints = fastargs[1];
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    if (fastargs[2]) {
+        bound = fastargs[2];
+        if (!--noptargs) {
+            goto skip_optional_kwonly;
+        }
+    }
+    if (fastargs[3]) {
+        covariant = PyObject_IsTrue(fastargs[3]);
+        if (covariant < 0) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_kwonly;
+        }
+    }
+    if (fastargs[4]) {
+        contravariant = PyObject_IsTrue(fastargs[4]);
+        if (contravariant < 0) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_kwonly;
+        }
+    }
+    infer_variance = PyObject_IsTrue(fastargs[5]);
+    if (infer_variance < 0) {
+        goto exit;
+    }
+skip_optional_kwonly:
+    return_value = typevar_new_impl(type, name, constraints, bound, covariant, contravariant, infer_variance);
+
+exit:
+    Py_XDECREF(constraints);
+    return return_value;
+}
+
+PyDoc_STRVAR(typevar_typing_subst__doc__,
+"__typing_subst__($self, /, arg)\n"
+"--\n"
+"\n");
+
+#define TYPEVAR_TYPING_SUBST_METHODDEF    \
+    {"__typing_subst__", _PyCFunction_CAST(typevar_typing_subst), METH_FASTCALL|METH_KEYWORDS, typevar_typing_subst__doc__},
+
+static PyObject *
+typevar_typing_subst_impl(typevarobject *self, PyObject *arg);
+
+static PyObject *
+typevar_typing_subst(typevarobject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(arg), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"arg", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "__typing_subst__",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject *arg;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    arg = args[0];
+    return_value = typevar_typing_subst_impl(self, arg);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(typevar_reduce__doc__,
+"__reduce__($self, /)\n"
+"--\n"
+"\n");
+
+#define TYPEVAR_REDUCE_METHODDEF    \
+    {"__reduce__", (PyCFunction)typevar_reduce, METH_NOARGS, typevar_reduce__doc__},
+
+static PyObject *
+typevar_reduce_impl(typevarobject *self);
+
+static PyObject *
+typevar_reduce(typevarobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return typevar_reduce_impl(self);
+}
+
+PyDoc_STRVAR(paramspecargs_new__doc__,
+"paramspecargs(origin)\n"
+"--\n"
+"\n"
+"Create a ParamSpecArgs object.");
+
+static PyObject *
+paramspecargs_new_impl(PyTypeObject *type, PyObject *origin);
+
+static PyObject *
+paramspecargs_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(origin), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"origin", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "paramspecargs",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject * const *fastargs;
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    PyObject *origin;
+
+    fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 1, 0, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    origin = fastargs[0];
+    return_value = paramspecargs_new_impl(type, origin);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(paramspeckwargs_new__doc__,
+"paramspeckwargs(origin)\n"
+"--\n"
+"\n"
+"Create a ParamSpecKwargs object.");
+
+static PyObject *
+paramspeckwargs_new_impl(PyTypeObject *type, PyObject *origin);
+
+static PyObject *
+paramspeckwargs_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(origin), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"origin", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "paramspeckwargs",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject * const *fastargs;
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    PyObject *origin;
+
+    fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 1, 0, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    origin = fastargs[0];
+    return_value = paramspeckwargs_new_impl(type, origin);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(paramspec_new__doc__,
+"paramspec(name, *, bound=None, covariant=False, contravariant=False,\n"
+"          infer_variance=False)\n"
+"--\n"
+"\n"
+"Create a ParamSpec object.");
+
+static PyObject *
+paramspec_new_impl(PyTypeObject *type, PyObject *name, PyObject *bound,
+                   int covariant, int contravariant, int infer_variance);
+
+static PyObject *
+paramspec_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 5
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(name), &_Py_ID(bound), &_Py_ID(covariant), &_Py_ID(contravariant), &_Py_ID(infer_variance), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"name", "bound", "covariant", "contravariant", "infer_variance", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "paramspec",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[5];
+    PyObject * const *fastargs;
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    Py_ssize_t noptargs = nargs + (kwargs ? PyDict_GET_SIZE(kwargs) : 0) - 1;
+    PyObject *name;
+    PyObject *bound = Py_None;
+    int covariant = 0;
+    int contravariant = 0;
+    int infer_variance = 0;
+
+    fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 1, 0, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    if (!PyUnicode_Check(fastargs[0])) {
+        _PyArg_BadArgument("paramspec", "argument 'name'", "str", fastargs[0]);
+        goto exit;
+    }
+    name = fastargs[0];
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    if (fastargs[1]) {
+        bound = fastargs[1];
+        if (!--noptargs) {
+            goto skip_optional_kwonly;
+        }
+    }
+    if (fastargs[2]) {
+        covariant = PyObject_IsTrue(fastargs[2]);
+        if (covariant < 0) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_kwonly;
+        }
+    }
+    if (fastargs[3]) {
+        contravariant = PyObject_IsTrue(fastargs[3]);
+        if (contravariant < 0) {
+            goto exit;
+        }
+        if (!--noptargs) {
+            goto skip_optional_kwonly;
+        }
+    }
+    infer_variance = PyObject_IsTrue(fastargs[4]);
+    if (infer_variance < 0) {
+        goto exit;
+    }
+skip_optional_kwonly:
+    return_value = paramspec_new_impl(type, name, bound, covariant, contravariant, infer_variance);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(paramspec_typing_subst__doc__,
+"__typing_subst__($self, /, arg)\n"
+"--\n"
+"\n");
+
+#define PARAMSPEC_TYPING_SUBST_METHODDEF    \
+    {"__typing_subst__", _PyCFunction_CAST(paramspec_typing_subst), METH_FASTCALL|METH_KEYWORDS, paramspec_typing_subst__doc__},
+
+static PyObject *
+paramspec_typing_subst_impl(paramspecobject *self, PyObject *arg);
+
+static PyObject *
+paramspec_typing_subst(paramspecobject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(arg), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"arg", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "__typing_subst__",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject *arg;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    arg = args[0];
+    return_value = paramspec_typing_subst_impl(self, arg);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(paramspec_typing_prepare_subst__doc__,
+"__typing_prepare_subst__($self, /, alias, args)\n"
+"--\n"
+"\n");
+
+#define PARAMSPEC_TYPING_PREPARE_SUBST_METHODDEF    \
+    {"__typing_prepare_subst__", _PyCFunction_CAST(paramspec_typing_prepare_subst), METH_FASTCALL|METH_KEYWORDS, paramspec_typing_prepare_subst__doc__},
+
+static PyObject *
+paramspec_typing_prepare_subst_impl(paramspecobject *self, PyObject *alias,
+                                    PyObject *args);
+
+static PyObject *
+paramspec_typing_prepare_subst(paramspecobject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 2
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(alias), &_Py_ID(args), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"alias", "args", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "__typing_prepare_subst__",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[2];
+    PyObject *alias;
+    PyObject *__clinic_args;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 2, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    alias = args[0];
+    __clinic_args = args[1];
+    return_value = paramspec_typing_prepare_subst_impl(self, alias, __clinic_args);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(paramspec_reduce__doc__,
+"__reduce__($self, /)\n"
+"--\n"
+"\n");
+
+#define PARAMSPEC_REDUCE_METHODDEF    \
+    {"__reduce__", (PyCFunction)paramspec_reduce, METH_NOARGS, paramspec_reduce__doc__},
+
+static PyObject *
+paramspec_reduce_impl(paramspecobject *self);
+
+static PyObject *
+paramspec_reduce(paramspecobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return paramspec_reduce_impl(self);
+}
+
+PyDoc_STRVAR(typevartuple__doc__,
+"typevartuple(name)\n"
+"--\n"
+"\n"
+"Create a new TypeVarTuple with the given name.");
+
+static PyObject *
+typevartuple_impl(PyTypeObject *type, PyObject *name);
+
+static PyObject *
+typevartuple(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(name), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"name", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "typevartuple",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject * const *fastargs;
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    PyObject *name;
+
+    fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 1, 0, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    if (!PyUnicode_Check(fastargs[0])) {
+        _PyArg_BadArgument("typevartuple", "argument 'name'", "str", fastargs[0]);
+        goto exit;
+    }
+    name = fastargs[0];
+    return_value = typevartuple_impl(type, name);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(typevartuple_typing_subst__doc__,
+"__typing_subst__($self, /, arg)\n"
+"--\n"
+"\n");
+
+#define TYPEVARTUPLE_TYPING_SUBST_METHODDEF    \
+    {"__typing_subst__", _PyCFunction_CAST(typevartuple_typing_subst), METH_FASTCALL|METH_KEYWORDS, typevartuple_typing_subst__doc__},
+
+static PyObject *
+typevartuple_typing_subst_impl(typevartupleobject *self, PyObject *arg);
+
+static PyObject *
+typevartuple_typing_subst(typevartupleobject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(arg), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"arg", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "__typing_subst__",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    PyObject *arg;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    arg = args[0];
+    return_value = typevartuple_typing_subst_impl(self, arg);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(typevartuple_typing_prepare_subst__doc__,
+"__typing_prepare_subst__($self, /, alias, args)\n"
+"--\n"
+"\n");
+
+#define TYPEVARTUPLE_TYPING_PREPARE_SUBST_METHODDEF    \
+    {"__typing_prepare_subst__", _PyCFunction_CAST(typevartuple_typing_prepare_subst), METH_FASTCALL|METH_KEYWORDS, typevartuple_typing_prepare_subst__doc__},
+
+static PyObject *
+typevartuple_typing_prepare_subst_impl(typevartupleobject *self,
+                                       PyObject *alias, PyObject *args);
+
+static PyObject *
+typevartuple_typing_prepare_subst(typevartupleobject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 2
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(alias), &_Py_ID(args), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"alias", "args", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "__typing_prepare_subst__",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[2];
+    PyObject *alias;
+    PyObject *__clinic_args;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 2, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    alias = args[0];
+    __clinic_args = args[1];
+    return_value = typevartuple_typing_prepare_subst_impl(self, alias, __clinic_args);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(typevartuple_reduce__doc__,
+"__reduce__($self, /)\n"
+"--\n"
+"\n");
+
+#define TYPEVARTUPLE_REDUCE_METHODDEF    \
+    {"__reduce__", (PyCFunction)typevartuple_reduce, METH_NOARGS, typevartuple_reduce__doc__},
+
+static PyObject *
+typevartuple_reduce_impl(typevartupleobject *self);
+
+static PyObject *
+typevartuple_reduce(typevartupleobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return typevartuple_reduce_impl(self);
+}
+
+PyDoc_STRVAR(typealias_reduce__doc__,
+"__reduce__($self, /)\n"
+"--\n"
+"\n");
+
+#define TYPEALIAS_REDUCE_METHODDEF    \
+    {"__reduce__", (PyCFunction)typealias_reduce, METH_NOARGS, typealias_reduce__doc__},
+
+static PyObject *
+typealias_reduce_impl(typealiasobject *self);
+
+static PyObject *
+typealias_reduce(typealiasobject *self, PyObject *Py_UNUSED(ignored))
+{
+    return typealias_reduce_impl(self);
+}
+
+PyDoc_STRVAR(typealias_new__doc__,
+"typealias(name, value, *, type_params=<unrepresentable>)\n"
+"--\n"
+"\n"
+"Create a TypeAliasType.");
+
+static PyObject *
+typealias_new_impl(PyTypeObject *type, PyObject *name, PyObject *value,
+                   PyObject *type_params);
+
+static PyObject *
+typealias_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 3
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(name), &_Py_ID(value), &_Py_ID(type_params), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"name", "value", "type_params", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "typealias",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[3];
+    PyObject * const *fastargs;
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    Py_ssize_t noptargs = nargs + (kwargs ? PyDict_GET_SIZE(kwargs) : 0) - 2;
+    PyObject *name;
+    PyObject *value;
+    PyObject *type_params = NULL;
+
+    fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 2, 2, 0, argsbuf);
+    if (!fastargs) {
+        goto exit;
+    }
+    if (!PyUnicode_Check(fastargs[0])) {
+        _PyArg_BadArgument("typealias", "argument 'name'", "str", fastargs[0]);
+        goto exit;
+    }
+    name = fastargs[0];
+    value = fastargs[1];
+    if (!noptargs) {
+        goto skip_optional_kwonly;
+    }
+    type_params = fastargs[2];
+skip_optional_kwonly:
+    return_value = typealias_new_impl(type, name, value, type_params);
+
+exit:
+    return return_value;
+}
+/*[clinic end generated code: output=807bcd30ebd10ac3 input=a9049054013a1b77]*/
diff --git a/Objects/funcobject.c b/Objects/funcobject.c
index 78c1144..69898bf 100644
--- a/Objects/funcobject.c
+++ b/Objects/funcobject.c
@@ -127,6 +127,7 @@ _PyFunction_FromConstructor(PyFrameConstructor *constr)
         PyErr_Clear();
     }
     op->func_annotations = NULL;
+    op->func_typeparams = NULL;
     op->vectorcall = _PyFunction_Vectorcall;
     op->func_version = 0;
     _PyObject_GC_TRACK(op);
@@ -202,6 +203,7 @@ PyFunction_NewWithQualName(PyObject *code, PyObject *globals, PyObject *qualname
     op->func_weakreflist = NULL;
     op->func_module = module;
     op->func_annotations = NULL;
+    op->func_typeparams = NULL;
     op->vectorcall = _PyFunction_Vectorcall;
     op->func_version = 0;
     _PyObject_GC_TRACK(op);
@@ -652,6 +654,28 @@ func_set_annotations(PyFunctionObject *op, PyObject *value, void *Py_UNUSED(igno
     return 0;
 }
 
+static PyObject *
+func_get_type_params(PyFunctionObject *op, void *Py_UNUSED(ignored))
+{
+    if (op->func_typeparams == NULL) {
+        return PyTuple_New(0);
+    }
+
+    assert(PyTuple_Check(op->func_typeparams));
+    return Py_NewRef(op->func_typeparams);
+}
+
+PyObject *
+_Py_set_function_type_params(PyThreadState *Py_UNUSED(ignored), PyObject *func,
+                             PyObject *type_params)
+{
+    assert(PyFunction_Check(func));
+    assert(PyTuple_Check(type_params));
+    PyFunctionObject *f = (PyFunctionObject *)func;
+    Py_XSETREF(f->func_typeparams, Py_NewRef(type_params));
+    return Py_NewRef(func);
+}
+
 static PyGetSetDef func_getsetlist[] = {
     {"__code__", (getter)func_get_code, (setter)func_set_code},
     {"__defaults__", (getter)func_get_defaults,
@@ -663,6 +687,7 @@ static PyGetSetDef func_getsetlist[] = {
     {"__dict__", PyObject_GenericGetDict, PyObject_GenericSetDict},
     {"__name__", (getter)func_get_name, (setter)func_set_name},
     {"__qualname__", (getter)func_get_qualname, (setter)func_set_qualname},
+    {"__type_params__", (getter)func_get_type_params, NULL},
     {NULL} /* Sentinel */
 };
 
@@ -783,6 +808,7 @@ func_clear(PyFunctionObject *op)
     Py_CLEAR(op->func_dict);
     Py_CLEAR(op->func_closure);
     Py_CLEAR(op->func_annotations);
+    Py_CLEAR(op->func_typeparams);
     // Don't Py_CLEAR(op->func_code), since code is always required
     // to be non-NULL. Similarly, name and qualname shouldn't be NULL.
     // However, name and qualname could be str subclasses, so they
@@ -837,6 +863,7 @@ func_traverse(PyFunctionObject *f, visitproc visit, void *arg)
     Py_VISIT(f->func_dict);
     Py_VISIT(f->func_closure);
     Py_VISIT(f->func_annotations);
+    Py_VISIT(f->func_typeparams);
     Py_VISIT(f->func_qualname);
     return 0;
 }
diff --git a/Objects/object.c b/Objects/object.c
index a7c79c6..f311866 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -14,6 +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_typeobject.h"    // _PyBufferWrapper_Type
 #include "pycore_unionobject.h"   // _PyUnion_Type
 #include "pycore_interpreteridobject.h"  // _PyInterpreterID_Type
@@ -2139,6 +2140,11 @@ _PyTypes_InitTypes(PyInterpreterState *interp)
         }
     }
 
+    // Must be after static types are initialized
+    if (_Py_initialize_generic(interp) < 0) {
+        return _PyStatus_ERR("Can't initialize generic types");
+    }
+
     return _PyStatus_OK();
 }
 
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index c152532..624dc63 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -1460,6 +1460,18 @@ type_get_annotations(PyTypeObject *type, void *context)
     return annotations;
 }
 
+static PyObject *
+type_get_type_params(PyTypeObject *type, void *context)
+{
+    PyObject *params = PyDict_GetItem(lookup_tp_dict(type), &_Py_ID(__type_params__));
+
+    if (params) {
+        return Py_NewRef(params);
+    }
+
+    return PyTuple_New(0);
+}
+
 static int
 type_set_annotations(PyTypeObject *type, PyObject *value, void *context)
 {
@@ -1536,6 +1548,7 @@ static PyGetSetDef type_getsets[] = {
     {"__doc__", (getter)type_get_doc, (setter)type_set_doc, NULL},
     {"__text_signature__", (getter)type_get_text_signature, NULL, NULL},
     {"__annotations__", (getter)type_get_annotations, (setter)type_set_annotations, NULL},
+    {"__type_params__", (getter)type_get_type_params, NULL, NULL},
     {0}
 };
 
@@ -3130,11 +3143,12 @@ type_new_copy_slots(type_new_ctx *ctx, PyObject *dict)
             goto error;
         }
         if (r > 0) {
-            /* CPython inserts __qualname__ and __classcell__ (when needed)
+            /* CPython inserts these names (when needed)
                into the namespace when creating a class.  They will be deleted
                below so won't act as class variables. */
             if (!_PyUnicode_Equal(slot, &_Py_ID(__qualname__)) &&
-                !_PyUnicode_Equal(slot, &_Py_ID(__classcell__)))
+                !_PyUnicode_Equal(slot, &_Py_ID(__classcell__)) &&
+                !_PyUnicode_Equal(slot, &_Py_ID(__classdictcell__)))
             {
                 PyErr_Format(PyExc_ValueError,
                              "%R in __slots__ conflicts with class variable",
@@ -3585,6 +3599,32 @@ type_new_set_classcell(PyTypeObject *type)
     return 0;
 }
 
+static int
+type_new_set_classdictcell(PyTypeObject *type)
+{
+    PyObject *dict = lookup_tp_dict(type);
+    PyObject *cell = PyDict_GetItemWithError(dict, &_Py_ID(__classdictcell__));
+    if (cell == NULL) {
+        if (PyErr_Occurred()) {
+            return -1;
+        }
+        return 0;
+    }
+
+    /* At least one method requires a reference to the dict of its defining class */
+    if (!PyCell_Check(cell)) {
+        PyErr_Format(PyExc_TypeError,
+                     "__classdictcell__ must be a nonlocal cell, not %.200R",
+                     Py_TYPE(cell));
+        return -1;
+    }
+
+    (void)PyCell_Set(cell, (PyObject *)dict);
+    if (PyDict_DelItem(dict, &_Py_ID(__classdictcell__)) < 0) {
+        return -1;
+    }
+    return 0;
+}
 
 static int
 type_new_set_attrs(const type_new_ctx *ctx, PyTypeObject *type)
@@ -3629,6 +3669,9 @@ type_new_set_attrs(const type_new_ctx *ctx, PyTypeObject *type)
     if (type_new_set_classcell(type) < 0) {
         return -1;
     }
+    if (type_new_set_classdictcell(type) < 0) {
+        return -1;
+    }
     return 0;
 }
 
diff --git a/Objects/typevarobject.c b/Objects/typevarobject.c
new file mode 100644
index 0000000..b057875
--- /dev/null
+++ b/Objects/typevarobject.c
@@ -0,0 +1,1620 @@
+// TypeVar, TypeVarTuple, and ParamSpec
+#include "Python.h"
+#include "pycore_object.h"  // _PyObject_GC_TRACK/UNTRACK
+#include "pycore_typevarobject.h"
+#include "pycore_unionobject.h"   // _Py_union_type_or
+#include "structmember.h"
+
+/*[clinic input]
+class typevar "typevarobject *" "&_PyTypeVar_Type"
+class paramspec "paramspecobject *" "&_PyParamSpec_Type"
+class paramspecargs "paramspecattrobject *" "&_PyParamSpecArgs_Type"
+class paramspeckwargs "paramspecattrobject *" "&_PyParamSpecKwargs_Type"
+class typevartuple "typevartupleobject *" "&_PyTypeVarTuple_Type"
+class typealias "typealiasobject *" "&_PyTypeAlias_Type"
+class Generic "PyObject *" "&PyGeneric_Type"
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=aa86741931a0f55c]*/
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *name;
+    PyObject *bound;
+    PyObject *evaluate_bound;
+    PyObject *constraints;
+    PyObject *evaluate_constraints;
+    bool covariant;
+    bool contravariant;
+    bool infer_variance;
+} typevarobject;
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *name;
+} typevartupleobject;
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *name;
+    PyObject *bound;
+    bool covariant;
+    bool contravariant;
+    bool infer_variance;
+} paramspecobject;
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *name;
+    PyObject *type_params;
+    PyObject *compute_value;
+    PyObject *value;
+} typealiasobject;
+
+#include "clinic/typevarobject.c.h"
+
+static PyObject *
+call_typing_func_object(const char *name, PyObject **args, size_t nargs)
+{
+    PyObject *typing = PyImport_ImportModule("typing");
+    if (typing == NULL) {
+        return NULL;
+    }
+    PyObject *func = PyObject_GetAttrString(typing, name);
+    if (func == NULL) {
+        Py_DECREF(typing);
+        return NULL;
+    }
+    PyObject *result = PyObject_Vectorcall(func, args, nargs, NULL);
+    Py_DECREF(func);
+    Py_DECREF(typing);
+    return result;
+}
+
+static PyObject *
+type_check(PyObject *arg, const char *msg)
+{
+    // Calling typing.py here leads to bootstrapping problems
+    if (Py_IsNone(arg)) {
+        return Py_NewRef(Py_TYPE(arg));
+    }
+    PyObject *message_str = PyUnicode_FromString(msg);
+    if (message_str == NULL) {
+        return NULL;
+    }
+    PyObject *args[2] = {arg, message_str};
+    PyObject *result = call_typing_func_object("_type_check", args, 2);
+    Py_DECREF(message_str);
+    return result;
+}
+
+/*
+ * Return a typing.Union. This is used as the nb_or (|) operator for
+ * TypeVar and ParamSpec. We use this rather than _Py_union_type_or
+ * (which would produce a types.Union) because historically TypeVar
+ * supported unions with string forward references, and we want to
+ * preserve that behavior. _Py_union_type_or only allows a small set
+ * of types.
+ */
+static PyObject *
+make_union(PyObject *self, PyObject *other)
+{
+    PyObject *args[2] = {self, other};
+    PyObject *result = call_typing_func_object("_make_union", args, 2);
+    return result;
+}
+
+static PyObject *
+caller(void)
+{
+    _PyInterpreterFrame *f = _PyThreadState_GET()->cframe->current_frame;
+    if (f == NULL) {
+        Py_RETURN_NONE;
+    }
+    if (f == NULL || f->f_funcobj == NULL) {
+        Py_RETURN_NONE;
+    }
+    PyObject *r = PyFunction_GetModule(f->f_funcobj);
+    if (!r) {
+        PyErr_Clear();
+        Py_RETURN_NONE;
+    }
+    return Py_NewRef(r);
+}
+
+static PyObject *
+typevartuple_unpack(PyObject *tvt)
+{
+    PyObject *typing = PyImport_ImportModule("typing");
+    if (typing == NULL) {
+        return NULL;
+    }
+    PyObject *unpack = PyObject_GetAttrString(typing, "Unpack");
+    if (unpack == NULL) {
+        Py_DECREF(typing);
+        return NULL;
+    }
+    PyObject *unpacked = PyObject_GetItem(unpack, tvt);
+    Py_DECREF(typing);
+    Py_DECREF(unpack);
+    return unpacked;
+}
+
+static int
+contains_typevartuple(PyTupleObject *params)
+{
+    Py_ssize_t n = PyTuple_GET_SIZE(params);
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.typevartuple_type;
+    for (Py_ssize_t i = 0; i < n; i++) {
+        PyObject *param = PyTuple_GET_ITEM(params, i);
+        if (Py_IS_TYPE(param, tp)) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static PyObject *
+unpack_typevartuples(PyObject *params)
+{
+    assert(PyTuple_Check(params));
+    // TypeVarTuple must be unpacked when passed to Generic, so we do that here.
+    if (contains_typevartuple((PyTupleObject *)params)) {
+        Py_ssize_t n = PyTuple_GET_SIZE(params);
+        PyObject *new_params = PyTuple_New(n);
+        if (new_params == NULL) {
+            return NULL;
+        }
+        PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.typevartuple_type;
+        for (Py_ssize_t i = 0; i < n; i++) {
+            PyObject *param = PyTuple_GET_ITEM(params, i);
+            if (Py_IS_TYPE(param, tp)) {
+                PyObject *unpacked = typevartuple_unpack(param);
+                if (unpacked == NULL) {
+                    Py_DECREF(new_params);
+                    return NULL;
+                }
+                PyTuple_SET_ITEM(new_params, i, unpacked);
+            }
+            else {
+                PyTuple_SET_ITEM(new_params, i, Py_NewRef(param));
+            }
+        }
+        return new_params;
+    }
+    else {
+        return Py_NewRef(params);
+    }
+}
+
+static void
+typevar_dealloc(PyObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    typevarobject *tv = (typevarobject *)self;
+
+    _PyObject_GC_UNTRACK(self);
+
+    Py_DECREF(tv->name);
+    Py_XDECREF(tv->bound);
+    Py_XDECREF(tv->evaluate_bound);
+    Py_XDECREF(tv->constraints);
+    Py_XDECREF(tv->evaluate_constraints);
+    _PyObject_ClearManagedDict(self);
+
+    Py_TYPE(self)->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static int
+typevar_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    Py_VISIT(Py_TYPE(self));
+    typevarobject *tv = (typevarobject *)self;
+    Py_VISIT(tv->bound);
+    Py_VISIT(tv->evaluate_bound);
+    Py_VISIT(tv->constraints);
+    Py_VISIT(tv->evaluate_constraints);
+    _PyObject_VisitManagedDict(self, visit, arg);
+    return 0;
+}
+
+static int
+typevar_clear(typevarobject *self)
+{
+    Py_CLEAR(self->bound);
+    Py_CLEAR(self->evaluate_bound);
+    Py_CLEAR(self->constraints);
+    Py_CLEAR(self->evaluate_constraints);
+    _PyObject_ClearManagedDict((PyObject *)self);
+    return 0;
+}
+
+static PyObject *
+typevar_repr(PyObject *self)
+{
+    typevarobject *tv = (typevarobject *)self;
+
+    if (tv->infer_variance) {
+        return Py_NewRef(tv->name);
+    }
+
+    char variance = tv->covariant ? '+' : tv->contravariant ? '-' : '~';
+    return PyUnicode_FromFormat("%c%U", variance, tv->name);
+}
+
+static PyMemberDef typevar_members[] = {
+    {"__name__", T_OBJECT, offsetof(typevarobject, name), READONLY},
+    {"__covariant__", T_BOOL, offsetof(typevarobject, covariant), READONLY},
+    {"__contravariant__", T_BOOL, offsetof(typevarobject, contravariant), READONLY},
+    {"__infer_variance__", T_BOOL, offsetof(typevarobject, infer_variance), READONLY},
+    {0}
+};
+
+static PyObject *
+typevar_bound(typevarobject *self, void *Py_UNUSED(ignored))
+{
+    if (self->bound != NULL) {
+        return Py_NewRef(self->bound);
+    }
+    if (self->evaluate_bound == NULL) {
+        Py_RETURN_NONE;
+    }
+    PyObject *bound = PyObject_CallNoArgs(self->evaluate_bound);
+    self->bound = Py_XNewRef(bound);
+    return bound;
+}
+
+static PyObject *
+typevar_constraints(typevarobject *self, void *Py_UNUSED(ignored))
+{
+    if (self->constraints != NULL) {
+        return Py_NewRef(self->constraints);
+    }
+    if (self->evaluate_constraints == NULL) {
+        Py_RETURN_NONE;
+    }
+    PyObject *constraints = PyObject_CallNoArgs(self->evaluate_constraints);
+    self->constraints = Py_XNewRef(constraints);
+    return constraints;
+}
+
+static PyGetSetDef typevar_getset[] = {
+    {"__bound__", (getter)typevar_bound, NULL, NULL, NULL},
+    {"__constraints__", (getter)typevar_constraints, NULL, NULL, NULL},
+    {0}
+};
+
+static typevarobject *
+typevar_alloc(PyObject *name, PyObject *bound, PyObject *evaluate_bound,
+              PyObject *constraints, PyObject *evaluate_constraints,
+              bool covariant, bool contravariant, bool infer_variance,
+              PyObject *module)
+{
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.typevar_type;
+    assert(tp != NULL);
+    typevarobject *tv = PyObject_GC_New(typevarobject, tp);
+    if (tv == NULL) {
+        return NULL;
+    }
+
+    tv->name = Py_NewRef(name);
+
+    tv->bound = Py_XNewRef(bound);
+    tv->evaluate_bound = Py_XNewRef(evaluate_bound);
+    tv->constraints = Py_XNewRef(constraints);
+    tv->evaluate_constraints = Py_XNewRef(evaluate_constraints);
+
+    tv->covariant = covariant;
+    tv->contravariant = contravariant;
+    tv->infer_variance = infer_variance;
+    _PyObject_GC_TRACK(tv);
+
+    if (module != NULL) {
+        if (PyObject_SetAttrString((PyObject *)tv, "__module__", module) < 0) {
+            Py_DECREF(tv);
+            return NULL;
+        }
+    }
+
+    return tv;
+}
+
+/*[clinic input]
+@classmethod
+typevar.__new__ as typevar_new
+
+    name: object(subclass_of="&PyUnicode_Type")
+    *constraints: object
+    *
+    bound: object = None
+    covariant: bool = False
+    contravariant: bool = False
+    infer_variance: bool = False
+
+Create a TypeVar.
+[clinic start generated code]*/
+
+static PyObject *
+typevar_new_impl(PyTypeObject *type, PyObject *name, PyObject *constraints,
+                 PyObject *bound, int covariant, int contravariant,
+                 int infer_variance)
+/*[clinic end generated code: output=1d200450ee99226d input=2c07ab87c94f462b]*/
+{
+    if (covariant && contravariant) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Bivariant types are not supported.");
+        return NULL;
+    }
+
+    if (infer_variance && (covariant || contravariant)) {
+        PyErr_SetString(PyExc_ValueError,
+                        "Variance cannot be specified with infer_variance.");
+        return NULL;
+    }
+
+    if (Py_IsNone(bound)) {
+        bound = NULL;
+    }
+    if (bound != NULL) {
+        bound = type_check(bound, "Bound must be a type.");
+        if (bound == NULL) {
+            return NULL;
+        }
+    }
+
+    if (!PyTuple_CheckExact(constraints)) {
+        PyErr_SetString(PyExc_TypeError,
+                        "constraints must be a tuple");
+        return NULL;
+    }
+    Py_ssize_t n_constraints = PyTuple_GET_SIZE(constraints);
+    if (n_constraints == 1) {
+        PyErr_SetString(PyExc_TypeError,
+                        "A single constraint is not allowed");
+        Py_XDECREF(bound);
+        return NULL;
+    } else if (n_constraints == 0) {
+        constraints = NULL;
+    } else if (bound != NULL) {
+        PyErr_SetString(PyExc_TypeError,
+                        "Constraints cannot be combined with bound=...");
+        Py_XDECREF(bound);
+        return NULL;
+    }
+    PyObject *module = caller();
+    if (module == NULL) {
+        Py_XDECREF(bound);
+        return NULL;
+    }
+
+    PyObject *tv = (PyObject *)typevar_alloc(name, bound, NULL,
+                                             constraints, NULL,
+                                             covariant, contravariant,
+                                             infer_variance, module);
+    Py_XDECREF(bound);
+    Py_XDECREF(module);
+    return tv;
+}
+
+/*[clinic input]
+typevar.__typing_subst__ as typevar_typing_subst
+
+    arg: object
+
+[clinic start generated code]*/
+
+static PyObject *
+typevar_typing_subst_impl(typevarobject *self, PyObject *arg)
+/*[clinic end generated code: output=c76ced134ed8f4e1 input=6b70a4bb2da838de]*/
+{
+    PyObject *args[2] = {(PyObject *)self, arg};
+    PyObject *result = call_typing_func_object("_typevar_subst", args, 2);
+    return result;
+}
+
+/*[clinic input]
+typevar.__reduce__ as typevar_reduce
+
+[clinic start generated code]*/
+
+static PyObject *
+typevar_reduce_impl(typevarobject *self)
+/*[clinic end generated code: output=02e5c55d7cf8a08f input=de76bc95f04fb9ff]*/
+{
+    return Py_NewRef(self->name);
+}
+
+static PyObject *
+typevar_mro_entries(PyObject *self, PyObject *args)
+{
+    PyErr_SetString(PyExc_TypeError,
+                    "Cannot subclass an instance of TypeVar");
+    return NULL;
+}
+
+static PyMethodDef typevar_methods[] = {
+    TYPEVAR_TYPING_SUBST_METHODDEF
+    TYPEVAR_REDUCE_METHODDEF
+    {"__mro_entries__", typevar_mro_entries, METH_O},
+    {0}
+};
+
+PyDoc_STRVAR(typevar_doc,
+"Type variable.\n\
+\n\
+Usage::\n\
+\n\
+  T = TypeVar('T')  # Can be anything\n\
+  A = TypeVar('A', str, bytes)  # Must be str or bytes\n\
+\n\
+Type variables exist primarily for the benefit of static type\n\
+checkers.  They serve as the parameters for generic types as well\n\
+as for generic function definitions.  See class Generic for more\n\
+information on generic types.  Generic functions work as follows:\n\
+\n\
+  def repeat(x: T, n: int) -> List[T]:\n\
+      '''Return a list containing n references to x.'''\n\
+      return [x]*n\n\
+\n\
+  def longest(x: A, y: A) -> A:\n\
+      '''Return the longest of two strings.'''\n\
+      return x if len(x) >= len(y) else y\n\
+\n\
+The latter example's signature is essentially the overloading\n\
+of (str, str) -> str and (bytes, bytes) -> bytes.  Also note\n\
+that if the arguments are instances of some subclass of str,\n\
+the return type is still plain str.\n\
+\n\
+At runtime, isinstance(x, T) and issubclass(C, T) will raise TypeError.\n\
+\n\
+Type variables defined with covariant=True or contravariant=True\n\
+can be used to declare covariant or contravariant generic types.\n\
+See PEP 484 for more details. By default generic types are invariant\n\
+in all type variables.\n\
+\n\
+Type variables can be introspected. e.g.:\n\
+\n\
+  T.__name__ == 'T'\n\
+  T.__constraints__ == ()\n\
+  T.__covariant__ == False\n\
+  T.__contravariant__ = False\n\
+  A.__constraints__ == (str, bytes)\n\
+\n\
+Note that only type variables defined in global scope can be pickled.\n\
+");
+
+static PyType_Slot typevar_slots[] = {
+    {Py_tp_doc, (void *)typevar_doc},
+    {Py_tp_methods, typevar_methods},
+    {Py_nb_or, make_union},
+    {Py_tp_new, typevar_new},
+    {Py_tp_dealloc, typevar_dealloc},
+    {Py_tp_alloc, PyType_GenericAlloc},
+    {Py_tp_free, PyObject_GC_Del},
+    {Py_tp_traverse, typevar_traverse},
+    {Py_tp_clear, typevar_clear},
+    {Py_tp_repr, typevar_repr},
+    {Py_tp_members, typevar_members},
+    {Py_tp_getset, typevar_getset},
+    {0, NULL},
+};
+
+PyType_Spec typevar_spec = {
+    .name = "typing.TypeVar",
+    .basicsize = sizeof(typevarobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE
+        | Py_TPFLAGS_MANAGED_DICT,
+    .slots = typevar_slots,
+};
+
+typedef struct {
+    PyObject_HEAD
+    PyObject *__origin__;
+} paramspecattrobject;
+
+static void
+paramspecattr_dealloc(PyObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    paramspecattrobject *psa = (paramspecattrobject *)self;
+
+    _PyObject_GC_UNTRACK(self);
+
+    Py_XDECREF(psa->__origin__);
+
+    Py_TYPE(self)->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static int
+paramspecattr_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    paramspecattrobject *psa = (paramspecattrobject *)self;
+    Py_VISIT(psa->__origin__);
+    return 0;
+}
+
+static int
+paramspecattr_clear(paramspecattrobject *self)
+{
+    Py_CLEAR(self->__origin__);
+    return 0;
+}
+
+static PyObject *
+paramspecattr_richcompare(PyObject *a, PyObject *b, int op)
+{
+    if (!Py_IS_TYPE(a, Py_TYPE(b))) {
+        Py_RETURN_NOTIMPLEMENTED;
+    }
+    if (op != Py_EQ && op != Py_NE) {
+        Py_RETURN_NOTIMPLEMENTED;
+    }
+    return PyObject_RichCompare(
+        ((paramspecattrobject *)a)->__origin__,
+        ((paramspecattrobject *)b)->__origin__,
+        op
+    );
+}
+
+static PyMemberDef paramspecattr_members[] = {
+    {"__origin__", T_OBJECT, offsetof(paramspecattrobject, __origin__), READONLY},
+    {0}
+};
+
+static paramspecattrobject *
+paramspecattr_new(PyTypeObject *tp, PyObject *origin)
+{
+    paramspecattrobject *psa = PyObject_GC_New(paramspecattrobject, tp);
+    if (psa == NULL) {
+        return NULL;
+    }
+    psa->__origin__ = Py_NewRef(origin);
+    _PyObject_GC_TRACK(psa);
+    return psa;
+}
+
+static PyObject *
+paramspecargs_repr(PyObject *self)
+{
+    paramspecattrobject *psa = (paramspecattrobject *)self;
+
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.paramspec_type;
+    if (Py_IS_TYPE(psa->__origin__, tp)) {
+        return PyUnicode_FromFormat("%U.args",
+            ((paramspecobject *)psa->__origin__)->name);
+    }
+    return PyUnicode_FromFormat("%R.args", psa->__origin__);
+}
+
+
+/*[clinic input]
+@classmethod
+paramspecargs.__new__ as paramspecargs_new
+
+    origin: object
+
+Create a ParamSpecArgs object.
+[clinic start generated code]*/
+
+static PyObject *
+paramspecargs_new_impl(PyTypeObject *type, PyObject *origin)
+/*[clinic end generated code: output=9a1463dc8942fe4e input=3596a0bb6183c208]*/
+{
+    return (PyObject *)paramspecattr_new(type, origin);
+}
+
+static PyObject *
+paramspecargs_mro_entries(PyObject *self, PyObject *args)
+{
+    PyErr_SetString(PyExc_TypeError,
+                    "Cannot subclass an instance of ParamSpecArgs");
+    return NULL;
+}
+
+static PyMethodDef paramspecargs_methods[] = {
+    {"__mro_entries__", paramspecargs_mro_entries, METH_O},
+    {0}
+};
+
+PyDoc_STRVAR(paramspecargs_doc,
+"The args for a ParamSpec object.\n\
+\n\
+Given a ParamSpec object P, P.args is an instance of ParamSpecArgs.\n\
+\n\
+ParamSpecArgs objects have a reference back to their ParamSpec:\n\
+\n\
+    P.args.__origin__ is P\n\
+\n\
+This type is meant for runtime introspection and has no special meaning to\n\
+static type checkers.\n\
+");
+
+static PyType_Slot paramspecargs_slots[] = {
+    {Py_tp_doc, (void *)paramspecargs_doc},
+    {Py_tp_methods, paramspecargs_methods},
+    {Py_tp_new, paramspecargs_new},
+    {Py_tp_dealloc, paramspecattr_dealloc},
+    {Py_tp_alloc, PyType_GenericAlloc},
+    {Py_tp_free, PyObject_GC_Del},
+    {Py_tp_traverse, paramspecattr_traverse},
+    {Py_tp_clear, (inquiry)paramspecattr_clear},
+    {Py_tp_repr, paramspecargs_repr},
+    {Py_tp_members, paramspecattr_members},
+    {Py_tp_richcompare, paramspecattr_richcompare},
+    {0, NULL},
+};
+
+PyType_Spec paramspecargs_spec = {
+    .name = "typing.ParamSpecArgs",
+    .basicsize = sizeof(paramspecattrobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE,
+    .slots = paramspecargs_slots,
+};
+
+static PyObject *
+paramspeckwargs_repr(PyObject *self)
+{
+    paramspecattrobject *psk = (paramspecattrobject *)self;
+
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.paramspec_type;
+    if (Py_IS_TYPE(psk->__origin__, tp)) {
+        return PyUnicode_FromFormat("%U.kwargs",
+            ((paramspecobject *)psk->__origin__)->name);
+    }
+    return PyUnicode_FromFormat("%R.kwargs", psk->__origin__);
+}
+
+/*[clinic input]
+@classmethod
+paramspeckwargs.__new__ as paramspeckwargs_new
+
+    origin: object
+
+Create a ParamSpecKwargs object.
+[clinic start generated code]*/
+
+static PyObject *
+paramspeckwargs_new_impl(PyTypeObject *type, PyObject *origin)
+/*[clinic end generated code: output=277b11967ebaf4ab input=981bca9b0cf9e40a]*/
+{
+    return (PyObject *)paramspecattr_new(type, origin);
+}
+
+static PyObject *
+paramspeckwargs_mro_entries(PyObject *self, PyObject *args)
+{
+    PyErr_SetString(PyExc_TypeError,
+                    "Cannot subclass an instance of ParamSpecKwargs");
+    return NULL;
+}
+
+static PyMethodDef paramspeckwargs_methods[] = {
+    {"__mro_entries__", paramspeckwargs_mro_entries, METH_O},
+    {0}
+};
+
+PyDoc_STRVAR(paramspeckwargs_doc,
+"The kwargs for a ParamSpec object.\n\
+\n\
+Given a ParamSpec object P, P.kwargs is an instance of ParamSpecKwargs.\n\
+\n\
+ParamSpecKwargs objects have a reference back to their ParamSpec:\n\
+\n\
+    P.kwargs.__origin__ is P\n\
+\n\
+This type is meant for runtime introspection and has no special meaning to\n\
+static type checkers.\n\
+");
+
+static PyType_Slot paramspeckwargs_slots[] = {
+    {Py_tp_doc, (void *)paramspeckwargs_doc},
+    {Py_tp_methods, paramspeckwargs_methods},
+    {Py_tp_new, paramspeckwargs_new},
+    {Py_tp_dealloc, paramspecattr_dealloc},
+    {Py_tp_alloc, PyType_GenericAlloc},
+    {Py_tp_free, PyObject_GC_Del},
+    {Py_tp_traverse, paramspecattr_traverse},
+    {Py_tp_clear, (inquiry)paramspecattr_clear},
+    {Py_tp_repr, paramspeckwargs_repr},
+    {Py_tp_members, paramspecattr_members},
+    {Py_tp_richcompare, paramspecattr_richcompare},
+    {0, NULL},
+};
+
+PyType_Spec paramspeckwargs_spec = {
+    .name = "typing.ParamSpecKwargs",
+    .basicsize = sizeof(paramspecattrobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE,
+    .slots = paramspeckwargs_slots,
+};
+
+static void
+paramspec_dealloc(PyObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    paramspecobject *ps = (paramspecobject *)self;
+
+    _PyObject_GC_UNTRACK(self);
+
+    Py_DECREF(ps->name);
+    Py_XDECREF(ps->bound);
+    _PyObject_ClearManagedDict(self);
+
+    Py_TYPE(self)->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static int
+paramspec_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    Py_VISIT(Py_TYPE(self));
+    paramspecobject *ps = (paramspecobject *)self;
+    Py_VISIT(ps->bound);
+    _PyObject_VisitManagedDict(self, visit, arg);
+    return 0;
+}
+
+static int
+paramspec_clear(paramspecobject *self)
+{
+    Py_CLEAR(self->bound);
+    _PyObject_ClearManagedDict((PyObject *)self);
+    return 0;
+}
+
+static PyObject *
+paramspec_repr(PyObject *self)
+{
+    paramspecobject *ps = (paramspecobject *)self;
+
+    if (ps->infer_variance) {
+        return Py_NewRef(ps->name);
+    }
+
+    char variance = ps->covariant ? '+' : ps->contravariant ? '-' : '~';
+    return PyUnicode_FromFormat("%c%U", variance, ps->name);
+}
+
+static PyMemberDef paramspec_members[] = {
+    {"__name__", T_OBJECT, offsetof(paramspecobject, name), READONLY},
+    {"__bound__", T_OBJECT, offsetof(paramspecobject, bound), READONLY},
+    {"__covariant__", T_BOOL, offsetof(paramspecobject, covariant), READONLY},
+    {"__contravariant__", T_BOOL, offsetof(paramspecobject, contravariant), READONLY},
+    {"__infer_variance__", T_BOOL, offsetof(paramspecobject, infer_variance), READONLY},
+    {0}
+};
+
+static PyObject *
+paramspec_args(PyObject *self, void *unused)
+{
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.paramspecargs_type;
+    return (PyObject *)paramspecattr_new(tp, self);
+}
+
+static PyObject *
+paramspec_kwargs(PyObject *self, void *unused)
+{
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.paramspeckwargs_type;
+    return (PyObject *)paramspecattr_new(tp, self);
+}
+
+static PyGetSetDef paramspec_getset[] = {
+    {"args", (getter)paramspec_args, NULL, "Represents positional arguments.", NULL},
+    {"kwargs", (getter)paramspec_kwargs, NULL, "Represents keyword arguments.", NULL},
+    {0},
+};
+
+static paramspecobject *
+paramspec_alloc(PyObject *name, PyObject *bound, bool covariant,
+                bool contravariant, bool infer_variance, PyObject *module)
+{
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.paramspec_type;
+    paramspecobject *ps = PyObject_GC_New(paramspecobject, tp);
+    if (ps == NULL) {
+        return NULL;
+    }
+    ps->name = Py_NewRef(name);
+    ps->bound = Py_XNewRef(bound);
+    ps->covariant = covariant;
+    ps->contravariant = contravariant;
+    ps->infer_variance = infer_variance;
+    _PyObject_GC_TRACK(ps);
+    if (module != NULL) {
+        if (PyObject_SetAttrString((PyObject *)ps, "__module__", module) < 0) {
+            Py_DECREF(ps);
+            return NULL;
+        }
+    }
+    return ps;
+}
+
+/*[clinic input]
+@classmethod
+paramspec.__new__ as paramspec_new
+
+    name: object(subclass_of="&PyUnicode_Type")
+    *
+    bound: object = None
+    covariant: bool = False
+    contravariant: bool = False
+    infer_variance: bool = False
+
+Create a ParamSpec object.
+[clinic start generated code]*/
+
+static PyObject *
+paramspec_new_impl(PyTypeObject *type, PyObject *name, PyObject *bound,
+                   int covariant, int contravariant, int infer_variance)
+/*[clinic end generated code: output=fd2daab79cba62da input=57c49c581979b952]*/
+{
+    if (covariant && contravariant) {
+        PyErr_SetString(PyExc_ValueError, "Bivariant types are not supported.");
+        return NULL;
+    }
+    if (infer_variance && (covariant || contravariant)) {
+        PyErr_SetString(PyExc_ValueError, "Variance cannot be specified with infer_variance.");
+        return NULL;
+    }
+    if (bound != NULL) {
+        bound = type_check(bound, "Bound must be a type.");
+        if (bound == NULL) {
+            return NULL;
+        }
+    }
+    PyObject *module = caller();
+    if (module == NULL) {
+        Py_XDECREF(bound);
+        return NULL;
+    }
+    PyObject *ps = (PyObject *)paramspec_alloc(
+        name, bound, covariant, contravariant, infer_variance, module);
+    Py_XDECREF(bound);
+    Py_DECREF(module);
+    return ps;
+}
+
+
+/*[clinic input]
+paramspec.__typing_subst__ as paramspec_typing_subst
+
+    arg: object
+
+[clinic start generated code]*/
+
+static PyObject *
+paramspec_typing_subst_impl(paramspecobject *self, PyObject *arg)
+/*[clinic end generated code: output=803e1ade3f13b57d input=4e0005d24023e896]*/
+{
+    PyObject *args[2] = {(PyObject *)self, arg};
+    PyObject *result = call_typing_func_object("_paramspec_subst", args, 2);
+    return result;
+}
+
+/*[clinic input]
+paramspec.__typing_prepare_subst__ as paramspec_typing_prepare_subst
+
+    alias: object
+    args: object
+
+[clinic start generated code]*/
+
+static PyObject *
+paramspec_typing_prepare_subst_impl(paramspecobject *self, PyObject *alias,
+                                    PyObject *args)
+/*[clinic end generated code: output=95449d630a2adb9a input=4375e2ffcb2ad635]*/
+{
+    PyObject *args_array[3] = {(PyObject *)self, alias, args};
+    PyObject *result = call_typing_func_object(
+        "_paramspec_prepare_subst", args_array, 3);
+    return result;
+}
+
+/*[clinic input]
+paramspec.__reduce__ as paramspec_reduce
+
+[clinic start generated code]*/
+
+static PyObject *
+paramspec_reduce_impl(paramspecobject *self)
+/*[clinic end generated code: output=b83398674416db27 input=5bf349f0d5dd426c]*/
+{
+    return Py_NewRef(self->name);
+}
+
+static PyObject *
+paramspec_mro_entries(PyObject *self, PyObject *args)
+{
+    PyErr_SetString(PyExc_TypeError,
+                    "Cannot subclass an instance of ParamSpec");
+    return NULL;
+}
+
+static PyMethodDef paramspec_methods[] = {
+    PARAMSPEC_TYPING_SUBST_METHODDEF
+    PARAMSPEC_TYPING_PREPARE_SUBST_METHODDEF
+    PARAMSPEC_REDUCE_METHODDEF
+    {"__mro_entries__", paramspec_mro_entries, METH_O},
+    {0}
+};
+
+PyDoc_STRVAR(paramspec_doc,
+"Parameter specification variable.\n\
+\n\
+Usage::\n\
+\n\
+    P = ParamSpec('P')\n\
+\n\
+Parameter specification variables exist primarily for the benefit of static\n\
+type checkers.  They are used to forward the parameter types of one\n\
+callable to another callable, a pattern commonly found in higher order\n\
+functions and decorators.  They are only valid when used in ``Concatenate``,\n\
+or as the first argument to ``Callable``, or as parameters for user-defined\n\
+Generics.  See class Generic for more information on generic types.  An\n\
+example for annotating a decorator::\n\
+\n\
+    T = TypeVar('T')\n\
+    P = ParamSpec('P')\n\
+\n\
+    def add_logging(f: Callable[P, T]) -> Callable[P, T]:\n\
+        '''A type-safe decorator to add logging to a function.'''\n\
+        def inner(*args: P.args, **kwargs: P.kwargs) -> T:\n\
+            logging.info(f'{f.__name__} was called')\n\
+            return f(*args, **kwargs)\n\
+        return inner\n\
+\n\
+    @add_logging\n\
+    def add_two(x: float, y: float) -> float:\n\
+        '''Add two numbers together.'''\n\
+        return x + y\n\
+\n\
+Parameter specification variables defined with covariant=True or\n\
+contravariant=True can be used to declare covariant or contravariant\n\
+generic types.  These keyword arguments are valid, but their actual semantics\n\
+are yet to be decided.  See PEP 612 for details.\n\
+\n\
+Parameter specification variables can be introspected. e.g.:\n\
+\n\
+    P.__name__ == 'P'\n\
+    P.__bound__ == None\n\
+    P.__covariant__ == False\n\
+    P.__contravariant__ == False\n\
+\n\
+Note that only parameter specification variables defined in global scope can\n\
+be pickled.\n\
+");
+
+static PyType_Slot paramspec_slots[] = {
+    {Py_tp_doc, (void *)paramspec_doc},
+    {Py_tp_members, paramspec_members},
+    {Py_tp_methods, paramspec_methods},
+    {Py_tp_getset, paramspec_getset},
+    // Unions of ParamSpecs have no defined meaning, but they were allowed
+    // by the Python implementation, so we allow them here too.
+    {Py_nb_or, make_union},
+    {Py_tp_new, paramspec_new},
+    {Py_tp_dealloc, paramspec_dealloc},
+    {Py_tp_alloc, PyType_GenericAlloc},
+    {Py_tp_free, PyObject_GC_Del},
+    {Py_tp_traverse, paramspec_traverse},
+    {Py_tp_clear, paramspec_clear},
+    {Py_tp_repr, paramspec_repr},
+    {0, 0},
+};
+
+PyType_Spec paramspec_spec = {
+    .name = "typing.ParamSpec",
+    .basicsize = sizeof(paramspecobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE
+        | Py_TPFLAGS_MANAGED_DICT,
+    .slots = paramspec_slots,
+};
+
+static void
+typevartuple_dealloc(PyObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    _PyObject_GC_UNTRACK(self);
+    typevartupleobject *tvt = (typevartupleobject *)self;
+
+    Py_DECREF(tvt->name);
+    _PyObject_ClearManagedDict(self);
+
+    Py_TYPE(self)->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static PyObject *
+typevartuple_iter(PyObject *self)
+{
+    PyObject *unpacked = typevartuple_unpack(self);
+    if (unpacked == NULL) {
+        return NULL;
+    }
+    PyObject *tuple = PyTuple_Pack(1, unpacked);
+    if (tuple == NULL) {
+        Py_DECREF(unpacked);
+        return NULL;
+    }
+    PyObject *result = PyObject_GetIter(tuple);
+    Py_DECREF(unpacked);
+    Py_DECREF(tuple);
+    return result;
+}
+
+static PyObject *
+typevartuple_repr(PyObject *self)
+{
+    typevartupleobject *tvt = (typevartupleobject *)self;
+
+    return Py_NewRef(tvt->name);
+}
+
+static PyMemberDef typevartuple_members[] = {
+    {"__name__", T_OBJECT, offsetof(typevartupleobject, name), READONLY},
+    {0}
+};
+
+static typevartupleobject *
+typevartuple_alloc(PyObject *name, PyObject *module)
+{
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.typevartuple_type;
+    typevartupleobject *tvt = PyObject_GC_New(typevartupleobject, tp);
+    if (tvt == NULL) {
+        return NULL;
+    }
+    tvt->name = Py_NewRef(name);
+    _PyObject_GC_TRACK(tvt);
+    if (module != NULL) {
+        if (PyObject_SetAttrString((PyObject *)tvt, "__module__", module) < 0) {
+            Py_DECREF(tvt);
+            return NULL;
+        }
+    }
+    return tvt;
+}
+
+/*[clinic input]
+@classmethod
+typevartuple.__new__
+
+    name: object(subclass_of="&PyUnicode_Type")
+
+Create a new TypeVarTuple with the given name.
+[clinic start generated code]*/
+
+static PyObject *
+typevartuple_impl(PyTypeObject *type, PyObject *name)
+/*[clinic end generated code: output=09d417a28f976202 input=00d28abcf1fc96bb]*/
+{
+    PyObject *module = caller();
+    if (module == NULL) {
+        return NULL;
+    }
+    PyObject *result = (PyObject *)typevartuple_alloc(name, module);
+    Py_DECREF(module);
+    return result;
+}
+
+/*[clinic input]
+typevartuple.__typing_subst__ as typevartuple_typing_subst
+
+    arg: object
+
+[clinic start generated code]*/
+
+static PyObject *
+typevartuple_typing_subst_impl(typevartupleobject *self, PyObject *arg)
+/*[clinic end generated code: output=814316519441cd76 input=670c4e0a36e5d8c0]*/
+{
+    PyErr_SetString(PyExc_TypeError, "Substitution of bare TypeVarTuple is not supported");
+    return NULL;
+}
+
+/*[clinic input]
+typevartuple.__typing_prepare_subst__ as typevartuple_typing_prepare_subst
+
+    alias: object
+    args: object
+
+[clinic start generated code]*/
+
+static PyObject *
+typevartuple_typing_prepare_subst_impl(typevartupleobject *self,
+                                       PyObject *alias, PyObject *args)
+/*[clinic end generated code: output=ff999bc5b02036c1 input=a211b05f2eeb4306]*/
+{
+    PyObject *args_array[3] = {(PyObject *)self, alias, args};
+    PyObject *result = call_typing_func_object(
+        "_typevartuple_prepare_subst", args_array, 3);
+    return result;
+}
+
+/*[clinic input]
+typevartuple.__reduce__ as typevartuple_reduce
+
+[clinic start generated code]*/
+
+static PyObject *
+typevartuple_reduce_impl(typevartupleobject *self)
+/*[clinic end generated code: output=3215bc0477913d20 input=3018a4d66147e807]*/
+{
+    return Py_NewRef(self->name);
+}
+
+static PyObject *
+typevartuple_mro_entries(PyObject *self, PyObject *args)
+{
+    PyErr_SetString(PyExc_TypeError,
+                    "Cannot subclass an instance of TypeVarTuple");
+    return NULL;
+}
+
+static int
+typevartuple_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    Py_VISIT(Py_TYPE(self));
+    _PyObject_VisitManagedDict(self, visit, arg);
+    return 0;
+}
+
+static int
+typevartuple_clear(PyObject *self)
+{
+    _PyObject_ClearManagedDict(self);
+    return 0;
+}
+
+static PyMethodDef typevartuple_methods[] = {
+    TYPEVARTUPLE_TYPING_SUBST_METHODDEF
+    TYPEVARTUPLE_TYPING_PREPARE_SUBST_METHODDEF
+    TYPEVARTUPLE_REDUCE_METHODDEF
+    {"__mro_entries__", typevartuple_mro_entries, METH_O},
+    {0}
+};
+
+PyDoc_STRVAR(typevartuple_doc,
+"Type variable tuple.\n\
+\n\
+Usage:\n\
+\n\
+  Ts = TypeVarTuple('Ts')  # Can be given any name\n\
+\n\
+Just as a TypeVar (type variable) is a placeholder for a single type,\n\
+a TypeVarTuple is a placeholder for an *arbitrary* number of types. For\n\
+example, if we define a generic class using a TypeVarTuple:\n\
+\n\
+  class C(Generic[*Ts]): ...\n\
+\n\
+Then we can parameterize that class with an arbitrary number of type\n\
+arguments:\n\
+\n\
+  C[int]       # Fine\n\
+  C[int, str]  # Also fine\n\
+  C[()]        # Even this is fine\n\
+\n\
+For more details, see PEP 646.\n\
+\n\
+Note that only TypeVarTuples defined in global scope can be pickled.\n\
+");
+
+PyType_Slot typevartuple_slots[] = {
+    {Py_tp_doc, (void *)typevartuple_doc},
+    {Py_tp_members, typevartuple_members},
+    {Py_tp_methods, typevartuple_methods},
+    {Py_tp_new, typevartuple},
+    {Py_tp_iter, typevartuple_iter},
+    {Py_tp_repr, typevartuple_repr},
+    {Py_tp_dealloc, typevartuple_dealloc},
+    {Py_tp_alloc, PyType_GenericAlloc},
+    {Py_tp_free, PyObject_GC_Del},
+    {Py_tp_traverse, typevartuple_traverse},
+    {Py_tp_clear, typevartuple_clear},
+    {0, 0},
+};
+
+PyType_Spec typevartuple_spec = {
+    .name = "typing.TypeVarTuple",
+    .basicsize = sizeof(typevartupleobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_MANAGED_DICT
+        | Py_TPFLAGS_HAVE_GC,
+    .slots = typevartuple_slots,
+};
+
+PyObject *
+_Py_make_typevar(PyObject *name, PyObject *evaluate_bound, PyObject *evaluate_constraints)
+{
+    return (PyObject *)typevar_alloc(name, NULL, evaluate_bound, NULL, evaluate_constraints,
+                                     false, false, true, NULL);
+}
+
+PyObject *
+_Py_make_paramspec(PyThreadState *Py_UNUSED(ignored), PyObject *v)
+{
+    assert(PyUnicode_Check(v));
+    return (PyObject *)paramspec_alloc(v, NULL, false, false, true, NULL);
+}
+
+PyObject *
+_Py_make_typevartuple(PyThreadState *Py_UNUSED(ignored), PyObject *v)
+{
+    assert(PyUnicode_Check(v));
+    return (PyObject *)typevartuple_alloc(v, NULL);
+}
+
+static void
+typealias_dealloc(PyObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    _PyObject_GC_UNTRACK(self);
+    typealiasobject *ta = (typealiasobject *)self;
+    Py_DECREF(ta->name);
+    Py_XDECREF(ta->type_params);
+    Py_XDECREF(ta->compute_value);
+    Py_XDECREF(ta->value);
+    Py_TYPE(self)->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static PyObject *
+typealias_get_value(typealiasobject *ta)
+{
+    if (ta->value != NULL) {
+        return Py_NewRef(ta->value);
+    }
+    PyObject *result = PyObject_CallNoArgs(ta->compute_value);
+    if (result == NULL) {
+        return NULL;
+    }
+    ta->value = Py_NewRef(result);
+    return result;
+}
+
+static PyObject *
+typealias_repr(PyObject *self)
+{
+    typealiasobject *ta = (typealiasobject *)self;
+    return Py_NewRef(ta->name);
+}
+
+static PyMemberDef typealias_members[] = {
+    {"__name__", T_OBJECT, offsetof(typealiasobject, name), READONLY},
+    {0}
+};
+
+static PyObject *
+typealias_value(PyObject *self, void *unused)
+{
+    typealiasobject *ta = (typealiasobject *)self;
+    return typealias_get_value(ta);
+}
+
+static PyObject *
+typealias_parameters(PyObject *self, void *unused)
+{
+    typealiasobject *ta = (typealiasobject *)self;
+    if (ta->type_params == NULL) {
+        return PyTuple_New(0);
+    }
+    return unpack_typevartuples(ta->type_params);
+}
+
+static PyObject *
+typealias_type_params(PyObject *self, void *unused)
+{
+    typealiasobject *ta = (typealiasobject *)self;
+    if (ta->type_params == NULL) {
+        return PyTuple_New(0);
+    }
+    return Py_NewRef(ta->type_params);
+}
+
+static PyGetSetDef typealias_getset[] = {
+    {"__parameters__", typealias_parameters, (setter)NULL, NULL, NULL},
+    {"__type_params__", typealias_type_params, (setter)NULL, NULL, NULL},
+    {"__value__", typealias_value, (setter)NULL, NULL, NULL},
+    {0}
+};
+
+static typealiasobject *
+typealias_alloc(PyObject *name, PyObject *type_params, PyObject *compute_value,
+                PyObject *value)
+{
+    PyTypeObject *tp = PyInterpreterState_Get()->cached_objects.typealias_type;
+    typealiasobject *ta = PyObject_GC_New(typealiasobject, tp);
+    if (ta == NULL) {
+        return NULL;
+    }
+    ta->name = Py_NewRef(name);
+    ta->type_params = Py_IsNone(type_params) ? NULL : Py_XNewRef(type_params);
+    ta->compute_value = Py_XNewRef(compute_value);
+    ta->value = Py_XNewRef(value);
+    _PyObject_GC_TRACK(ta);
+    return ta;
+}
+
+static int
+typealias_traverse(typealiasobject *self, visitproc visit, void *arg)
+{
+    Py_VISIT(self->type_params);
+    Py_VISIT(self->compute_value);
+    Py_VISIT(self->value);
+    return 0;
+}
+
+static int
+typealias_clear(typealiasobject *self)
+{
+    Py_CLEAR(self->type_params);
+    Py_CLEAR(self->compute_value);
+    Py_CLEAR(self->value);
+    return 0;
+}
+
+/*[clinic input]
+typealias.__reduce__ as typealias_reduce
+
+[clinic start generated code]*/
+
+static PyObject *
+typealias_reduce_impl(typealiasobject *self)
+/*[clinic end generated code: output=913724f92ad3b39b input=4f06fbd9472ec0f1]*/
+{
+    return Py_NewRef(self->name);
+}
+
+static PyObject *
+typealias_subscript(PyObject *self, PyObject *args)
+{
+    if (((typealiasobject *)self)->type_params == NULL) {
+        PyErr_SetString(PyExc_TypeError,
+                        "Only generic type aliases are subscriptable");
+        return NULL;
+    }
+    return Py_GenericAlias(self, args);
+}
+
+static PyMethodDef typealias_methods[] = {
+    TYPEALIAS_REDUCE_METHODDEF
+    {0}
+};
+
+
+/*[clinic input]
+@classmethod
+typealias.__new__ as typealias_new
+
+    name: object(subclass_of="&PyUnicode_Type")
+    value: object
+    *
+    type_params: object = NULL
+
+Create a TypeAliasType.
+[clinic start generated code]*/
+
+static PyObject *
+typealias_new_impl(PyTypeObject *type, PyObject *name, PyObject *value,
+                   PyObject *type_params)
+/*[clinic end generated code: output=8920ce6bdff86f00 input=df163c34e17e1a35]*/
+{
+    if (type_params != NULL && !PyTuple_Check(type_params)) {
+        PyErr_SetString(PyExc_TypeError, "type_params must be a tuple");
+        return NULL;
+    }
+    return (PyObject *)typealias_alloc(name, type_params, NULL, value);
+}
+
+PyDoc_STRVAR(typealias_doc,
+"Type alias.\n\
+\n\
+Type aliases are created through the type statement:\n\
+\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},
+};
+
+PyType_Spec typealias_spec = {
+    .name = "typing.TypeAliasType",
+    .basicsize = sizeof(typealiasobject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC,
+    .slots = typealias_slots,
+};
+
+PyObject *
+_Py_make_typealias(PyThreadState* unused, PyObject *args)
+{
+    assert(PyTuple_Check(args));
+    assert(PyTuple_GET_SIZE(args) == 3);
+    PyObject *name = PyTuple_GET_ITEM(args, 0);
+    assert(PyUnicode_Check(name));
+    PyObject *type_params = PyTuple_GET_ITEM(args, 1);
+    PyObject *compute_value = PyTuple_GET_ITEM(args, 2);
+    return (PyObject *)typealias_alloc(name, type_params, compute_value, NULL);
+}
+
+PyDoc_STRVAR(generic_doc,
+"Abstract base class for generic types.\n\
+\n\
+A generic type is typically declared by inheriting from\n\
+this class parameterized with one or more type variables.\n\
+For example, a generic mapping type might be defined as::\n\
+\n\
+    class Mapping(Generic[KT, VT]):\n\
+        def __getitem__(self, key: KT) -> VT:\n\
+            ...\n\
+        # Etc.\n\
+\n\
+This class can then be used as follows::\n\
+\n\
+    def lookup_name(mapping: Mapping[KT, VT], key: KT, default: VT) -> VT:\n\
+        try:\n\
+            return mapping[key]\n\
+        except KeyError:\n\
+            return default\n\
+");
+
+PyDoc_STRVAR(generic_class_getitem_doc,
+"Parameterizes a generic class.\n\
+\n\
+At least, parameterizing a generic class is the *main* thing this method\n\
+does. For example, for some generic class `Foo`, this is called when we\n\
+do `Foo[int]` - there, with `cls=Foo` and `params=int`.\n\
+\n\
+However, note that this method is also called when defining generic\n\
+classes in the first place with `class Foo(Generic[T]): ...`.\n\
+");
+
+static PyObject *
+call_typing_args_kwargs(const char *name, PyTypeObject *cls, PyObject *args, PyObject *kwargs)
+{
+    PyObject *typing = NULL, *func = NULL, *new_args = NULL;
+    typing = PyImport_ImportModule("typing");
+    if (typing == NULL) {
+        goto error;
+    }
+    func = PyObject_GetAttrString(typing, name);
+    if (func == NULL) {
+        goto error;
+    }
+    assert(PyTuple_Check(args));
+    Py_ssize_t nargs = PyTuple_GET_SIZE(args);
+    new_args = PyTuple_New(nargs + 1);
+    if (new_args == NULL) {
+        goto error;
+    }
+    PyTuple_SET_ITEM(new_args, 0, Py_NewRef((PyObject *)cls));
+    for (Py_ssize_t i = 0; i < nargs; i++) {
+        PyObject *arg = PyTuple_GET_ITEM(args, i);
+        PyTuple_SET_ITEM(new_args, i + 1, Py_NewRef(arg));
+    }
+    PyObject *result = PyObject_Call(func, new_args, kwargs);
+    Py_DECREF(typing);
+    Py_DECREF(func);
+    Py_DECREF(new_args);
+    return result;
+error:
+    Py_XDECREF(typing);
+    Py_XDECREF(func);
+    Py_XDECREF(new_args);
+    return NULL;
+}
+
+static PyObject *
+generic_init_subclass(PyTypeObject *cls, PyObject *args, PyObject *kwargs)
+{
+    return call_typing_args_kwargs("_generic_init_subclass", cls, args, kwargs);
+}
+
+static PyObject *
+generic_class_getitem(PyTypeObject *cls, PyObject *args, PyObject *kwargs)
+{
+    return call_typing_args_kwargs("_generic_class_getitem", cls, args, kwargs);
+}
+
+PyObject *
+_Py_subscript_generic(PyThreadState* unused, PyObject *params)
+{
+    params = unpack_typevartuples(params);
+
+    PyInterpreterState *interp = PyInterpreterState_Get();
+    if (interp->cached_objects.generic_type == NULL) {
+        PyErr_SetString(PyExc_SystemError, "Cannot find Generic type");
+        return NULL;
+    }
+    PyObject *args[2] = {(PyObject *)interp->cached_objects.generic_type, params};
+    PyObject *result = call_typing_func_object("_GenericAlias", args, 2);
+    Py_DECREF(params);
+    return result;
+}
+
+static PyMethodDef generic_methods[] = {
+    {"__class_getitem__", (PyCFunction)(void (*)(void))generic_class_getitem,
+     METH_VARARGS | METH_KEYWORDS | METH_CLASS,
+     generic_class_getitem_doc},
+    {"__init_subclass__", (PyCFunction)(void (*)(void))generic_init_subclass,
+     METH_VARARGS | METH_KEYWORDS | METH_CLASS,
+     PyDoc_STR("Function to initialize subclasses.")},
+    {NULL} /* Sentinel */
+};
+
+static void
+generic_dealloc(PyObject *self)
+{
+    PyTypeObject *tp = Py_TYPE(self);
+    _PyObject_GC_UNTRACK(self);
+    Py_TYPE(self)->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static int
+generic_traverse(PyObject *self, visitproc visit, void *arg)
+{
+    Py_VISIT(Py_TYPE(self));
+    return 0;
+}
+
+static PyType_Slot generic_slots[] = {
+    {Py_tp_doc, (void *)generic_doc},
+    {Py_tp_methods, generic_methods},
+    {Py_tp_dealloc, generic_dealloc},
+    {Py_tp_alloc, PyType_GenericAlloc},
+    {Py_tp_free, PyObject_GC_Del},
+    {Py_tp_traverse, generic_traverse},
+    {0, NULL},
+};
+
+PyType_Spec generic_spec = {
+    .name = "typing.Generic",
+    .basicsize = sizeof(PyObject),
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
+    .slots = generic_slots,
+};
+
+int _Py_initialize_generic(PyInterpreterState *interp)
+{
+#define MAKE_TYPE(name) \
+    do { \
+        PyTypeObject *name ## _type = (PyTypeObject *)PyType_FromSpec(&name ## _spec); \
+        if (name ## _type == NULL) { \
+            return -1; \
+        } \
+        interp->cached_objects.name ## _type = name ## _type; \
+    } while(0)
+
+    MAKE_TYPE(generic);
+    MAKE_TYPE(typevar);
+    MAKE_TYPE(typevartuple);
+    MAKE_TYPE(paramspec);
+    MAKE_TYPE(paramspecargs);
+    MAKE_TYPE(paramspeckwargs);
+    MAKE_TYPE(typealias);
+#undef MAKE_TYPE
+    return 0;
+}
+
+void _Py_clear_generic_types(PyInterpreterState *interp)
+{
+    Py_CLEAR(interp->cached_objects.generic_type);
+    Py_CLEAR(interp->cached_objects.typevar_type);
+    Py_CLEAR(interp->cached_objects.typevartuple_type);
+    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);
+}
diff --git a/Objects/unionobject.c b/Objects/unionobject.c
index f273f7d..9806678 100644
--- a/Objects/unionobject.c
+++ b/Objects/unionobject.c
@@ -147,10 +147,14 @@ get_types(PyObject **obj, Py_ssize_t *size)
 static int
 is_unionable(PyObject *obj)
 {
-    return (obj == Py_None ||
+    if (obj == Py_None ||
         PyType_Check(obj) ||
         _PyGenericAlias_Check(obj) ||
-        _PyUnion_Check(obj));
+        _PyUnion_Check(obj)) {
+        return 1;
+    }
+    PyInterpreterState *interp = PyInterpreterState_Get();
+    return Py_IS_TYPE(obj, interp->cached_objects.typealias_type);
 }
 
 PyObject *