[3.12] gh-104799: Move location of type_params AST fields (GH-104828) (#104974)

gh-104799: Move location of type_params AST fields (GH-104828)
(cherry picked from commit ba73473f4c18ba4cf7ab18d84d94a47d2d37a0c5)

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

1 files changed, 162 insertions, 163 deletions

diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 87906d9..030c082 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -409,29 +409,29 @@ static const char * const stmt_attributes[] = {
 static PyObject* ast2obj_stmt(struct ast_state *state, void*);
 static const char * const FunctionDef_fields[]={
     "name",
-    "type_params",
     "args",
     "body",
     "decorator_list",
     "returns",
     "type_comment",
+    "type_params",
 };
 static const char * const AsyncFunctionDef_fields[]={
     "name",
-    "type_params",
     "args",
     "body",
     "decorator_list",
     "returns",
     "type_comment",
+    "type_params",
 };
 static const char * const ClassDef_fields[]={
     "name",
-    "type_params",
     "bases",
     "keywords",
     "body",
     "decorator_list",
+    "type_params",
 };
 static const char * const Return_fields[]={
     "value",
@@ -1169,9 +1169,9 @@ init_types(struct ast_state *state)
         "FunctionType(expr* argtypes, expr returns)");
     if (!state->FunctionType_type) return 0;
     state->stmt_type = make_type(state, "stmt", state->AST_type, NULL, 0,
-        "stmt = FunctionDef(identifier name, type_param* type_params, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment)\n"
-        "     | AsyncFunctionDef(identifier name, type_param* type_params, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment)\n"
-        "     | ClassDef(identifier name, type_param* type_params, expr* bases, keyword* keywords, stmt* body, expr* decorator_list)\n"
+        "stmt = FunctionDef(identifier name, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment, type_param* type_params)\n"
+        "     | AsyncFunctionDef(identifier name, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment, type_param* type_params)\n"
+        "     | ClassDef(identifier name, expr* bases, keyword* keywords, stmt* body, expr* decorator_list, type_param* type_params)\n"
         "     | Return(expr? value)\n"
         "     | Delete(expr* targets)\n"
         "     | Assign(expr* targets, expr value, string? type_comment)\n"
@@ -1206,7 +1206,7 @@ init_types(struct ast_state *state)
         return 0;
     state->FunctionDef_type = make_type(state, "FunctionDef", state->stmt_type,
                                         FunctionDef_fields, 7,
-        "FunctionDef(identifier name, type_param* type_params, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment)");
+        "FunctionDef(identifier name, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment, type_param* type_params)");
     if (!state->FunctionDef_type) return 0;
     if (PyObject_SetAttr(state->FunctionDef_type, state->returns, Py_None) ==
         -1)
@@ -1217,7 +1217,7 @@ init_types(struct ast_state *state)
     state->AsyncFunctionDef_type = make_type(state, "AsyncFunctionDef",
                                              state->stmt_type,
                                              AsyncFunctionDef_fields, 7,
-        "AsyncFunctionDef(identifier name, type_param* type_params, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment)");
+        "AsyncFunctionDef(identifier name, arguments args, stmt* body, expr* decorator_list, expr? returns, string? type_comment, type_param* type_params)");
     if (!state->AsyncFunctionDef_type) return 0;
     if (PyObject_SetAttr(state->AsyncFunctionDef_type, state->returns, Py_None)
         == -1)
@@ -1227,7 +1227,7 @@ init_types(struct ast_state *state)
         return 0;
     state->ClassDef_type = make_type(state, "ClassDef", state->stmt_type,
                                      ClassDef_fields, 6,
-        "ClassDef(identifier name, type_param* type_params, expr* bases, keyword* keywords, stmt* body, expr* decorator_list)");
+        "ClassDef(identifier name, expr* bases, keyword* keywords, stmt* body, expr* decorator_list, type_param* type_params)");
     if (!state->ClassDef_type) return 0;
     state->Return_type = make_type(state, "Return", state->stmt_type,
                                    Return_fields, 1,
@@ -2032,11 +2032,11 @@ _PyAST_FunctionType(asdl_expr_seq * argtypes, expr_ty returns, PyArena *arena)
 }
 
 stmt_ty
-_PyAST_FunctionDef(identifier name, asdl_type_param_seq * type_params,
-                   arguments_ty args, asdl_stmt_seq * body, asdl_expr_seq *
-                   decorator_list, expr_ty returns, string type_comment, int
-                   lineno, int col_offset, int end_lineno, int end_col_offset,
-                   PyArena *arena)
+_PyAST_FunctionDef(identifier name, arguments_ty args, asdl_stmt_seq * body,
+                   asdl_expr_seq * decorator_list, expr_ty returns, string
+                   type_comment, asdl_type_param_seq * type_params, int lineno,
+                   int col_offset, int end_lineno, int end_col_offset, PyArena
+                   *arena)
 {
     stmt_ty p;
     if (!name) {
@@ -2054,12 +2054,12 @@ _PyAST_FunctionDef(identifier name, asdl_type_param_seq * type_params,
         return NULL;
     p->kind = FunctionDef_kind;
     p->v.FunctionDef.name = name;
-    p->v.FunctionDef.type_params = type_params;
     p->v.FunctionDef.args = args;
     p->v.FunctionDef.body = body;
     p->v.FunctionDef.decorator_list = decorator_list;
     p->v.FunctionDef.returns = returns;
     p->v.FunctionDef.type_comment = type_comment;
+    p->v.FunctionDef.type_params = type_params;
     p->lineno = lineno;
     p->col_offset = col_offset;
     p->end_lineno = end_lineno;
@@ -2068,9 +2068,9 @@ _PyAST_FunctionDef(identifier name, asdl_type_param_seq * type_params,
 }
 
 stmt_ty
-_PyAST_AsyncFunctionDef(identifier name, asdl_type_param_seq * type_params,
-                        arguments_ty args, asdl_stmt_seq * body, asdl_expr_seq
-                        * decorator_list, expr_ty returns, string type_comment,
+_PyAST_AsyncFunctionDef(identifier name, arguments_ty args, asdl_stmt_seq *
+                        body, asdl_expr_seq * decorator_list, expr_ty returns,
+                        string type_comment, asdl_type_param_seq * type_params,
                         int lineno, int col_offset, int end_lineno, int
                         end_col_offset, PyArena *arena)
 {
@@ -2090,12 +2090,12 @@ _PyAST_AsyncFunctionDef(identifier name, asdl_type_param_seq * type_params,
         return NULL;
     p->kind = AsyncFunctionDef_kind;
     p->v.AsyncFunctionDef.name = name;
-    p->v.AsyncFunctionDef.type_params = type_params;
     p->v.AsyncFunctionDef.args = args;
     p->v.AsyncFunctionDef.body = body;
     p->v.AsyncFunctionDef.decorator_list = decorator_list;
     p->v.AsyncFunctionDef.returns = returns;
     p->v.AsyncFunctionDef.type_comment = type_comment;
+    p->v.AsyncFunctionDef.type_params = type_params;
     p->lineno = lineno;
     p->col_offset = col_offset;
     p->end_lineno = end_lineno;
@@ -2104,11 +2104,10 @@ _PyAST_AsyncFunctionDef(identifier name, asdl_type_param_seq * type_params,
 }
 
 stmt_ty
-_PyAST_ClassDef(identifier name, asdl_type_param_seq * type_params,
-                asdl_expr_seq * bases, asdl_keyword_seq * keywords,
-                asdl_stmt_seq * body, asdl_expr_seq * decorator_list, int
-                lineno, int col_offset, int end_lineno, int end_col_offset,
-                PyArena *arena)
+_PyAST_ClassDef(identifier name, asdl_expr_seq * bases, asdl_keyword_seq *
+                keywords, asdl_stmt_seq * body, asdl_expr_seq * decorator_list,
+                asdl_type_param_seq * type_params, int lineno, int col_offset,
+                int end_lineno, int end_col_offset, PyArena *arena)
 {
     stmt_ty p;
     if (!name) {
@@ -2121,11 +2120,11 @@ _PyAST_ClassDef(identifier name, asdl_type_param_seq * type_params,
         return NULL;
     p->kind = ClassDef_kind;
     p->v.ClassDef.name = name;
-    p->v.ClassDef.type_params = type_params;
     p->v.ClassDef.bases = bases;
     p->v.ClassDef.keywords = keywords;
     p->v.ClassDef.body = body;
     p->v.ClassDef.decorator_list = decorator_list;
+    p->v.ClassDef.type_params = type_params;
     p->lineno = lineno;
     p->col_offset = col_offset;
     p->end_lineno = end_lineno;
@@ -3883,12 +3882,6 @@ ast2obj_stmt(struct ast_state *state, void* _o)
         if (PyObject_SetAttr(result, state->name, value) == -1)
             goto failed;
         Py_DECREF(value);
-        value = ast2obj_list(state, (asdl_seq*)o->v.FunctionDef.type_params,
-                             ast2obj_type_param);
-        if (!value) goto failed;
-        if (PyObject_SetAttr(result, state->type_params, value) == -1)
-            goto failed;
-        Py_DECREF(value);
         value = ast2obj_arguments(state, o->v.FunctionDef.args);
         if (!value) goto failed;
         if (PyObject_SetAttr(result, state->args, value) == -1)
@@ -3916,6 +3909,12 @@ ast2obj_stmt(struct ast_state *state, void* _o)
         if (PyObject_SetAttr(result, state->type_comment, value) == -1)
             goto failed;
         Py_DECREF(value);
+        value = ast2obj_list(state, (asdl_seq*)o->v.FunctionDef.type_params,
+                             ast2obj_type_param);
+        if (!value) goto failed;
+        if (PyObject_SetAttr(result, state->type_params, value) == -1)
+            goto failed;
+        Py_DECREF(value);
         break;
     case AsyncFunctionDef_kind:
         tp = (PyTypeObject *)state->AsyncFunctionDef_type;
@@ -3926,13 +3925,6 @@ ast2obj_stmt(struct ast_state *state, void* _o)
         if (PyObject_SetAttr(result, state->name, value) == -1)
             goto failed;
         Py_DECREF(value);
-        value = ast2obj_list(state,
-                             (asdl_seq*)o->v.AsyncFunctionDef.type_params,
-                             ast2obj_type_param);
-        if (!value) goto failed;
-        if (PyObject_SetAttr(result, state->type_params, value) == -1)
-            goto failed;
-        Py_DECREF(value);
         value = ast2obj_arguments(state, o->v.AsyncFunctionDef.args);
         if (!value) goto failed;
         if (PyObject_SetAttr(result, state->args, value) == -1)
@@ -3961,6 +3953,13 @@ ast2obj_stmt(struct ast_state *state, void* _o)
         if (PyObject_SetAttr(result, state->type_comment, value) == -1)
             goto failed;
         Py_DECREF(value);
+        value = ast2obj_list(state,
+                             (asdl_seq*)o->v.AsyncFunctionDef.type_params,
+                             ast2obj_type_param);
+        if (!value) goto failed;
+        if (PyObject_SetAttr(result, state->type_params, value) == -1)
+            goto failed;
+        Py_DECREF(value);
         break;
     case ClassDef_kind:
         tp = (PyTypeObject *)state->ClassDef_type;
@@ -3971,12 +3970,6 @@ ast2obj_stmt(struct ast_state *state, void* _o)
         if (PyObject_SetAttr(result, state->name, value) == -1)
             goto failed;
         Py_DECREF(value);
-        value = ast2obj_list(state, (asdl_seq*)o->v.ClassDef.type_params,
-                             ast2obj_type_param);
-        if (!value) goto failed;
-        if (PyObject_SetAttr(result, state->type_params, value) == -1)
-            goto failed;
-        Py_DECREF(value);
         value = ast2obj_list(state, (asdl_seq*)o->v.ClassDef.bases,
                              ast2obj_expr);
         if (!value) goto failed;
@@ -4001,6 +3994,12 @@ ast2obj_stmt(struct ast_state *state, void* _o)
         if (PyObject_SetAttr(result, state->decorator_list, value) == -1)
             goto failed;
         Py_DECREF(value);
+        value = ast2obj_list(state, (asdl_seq*)o->v.ClassDef.type_params,
+                             ast2obj_type_param);
+        if (!value) goto failed;
+        if (PyObject_SetAttr(result, state->type_params, value) == -1)
+            goto failed;
+        Py_DECREF(value);
         break;
     case Return_kind:
         tp = (PyTypeObject *)state->Return_type;
@@ -6075,12 +6074,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
     }
     if (isinstance) {
         identifier name;
-        asdl_type_param_seq* type_params;
         arguments_ty args;
         asdl_stmt_seq* body;
         asdl_expr_seq* decorator_list;
         expr_ty returns;
         string type_comment;
+        asdl_type_param_seq* type_params;
 
         if (_PyObject_LookupAttr(obj, state->name, &tmp) < 0) {
             return 1;
@@ -6099,42 +6098,6 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             if (res != 0) goto failed;
             Py_CLEAR(tmp);
         }
-        if (_PyObject_LookupAttr(obj, state->type_params, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from FunctionDef");
-            return 1;
-        }
-        else {
-            int res;
-            Py_ssize_t len;
-            Py_ssize_t i;
-            if (!PyList_Check(tmp)) {
-                PyErr_Format(PyExc_TypeError, "FunctionDef field \"type_params\" must be a list, not a %.200s", _PyType_Name(Py_TYPE(tmp)));
-                goto failed;
-            }
-            len = PyList_GET_SIZE(tmp);
-            type_params = _Py_asdl_type_param_seq_new(len, arena);
-            if (type_params == NULL) goto failed;
-            for (i = 0; i < len; i++) {
-                type_param_ty val;
-                PyObject *tmp2 = Py_NewRef(PyList_GET_ITEM(tmp, i));
-                if (_Py_EnterRecursiveCall(" while traversing 'FunctionDef' node")) {
-                    goto failed;
-                }
-                res = obj2ast_type_param(state, tmp2, &val, arena);
-                _Py_LeaveRecursiveCall();
-                Py_DECREF(tmp2);
-                if (res != 0) goto failed;
-                if (len != PyList_GET_SIZE(tmp)) {
-                    PyErr_SetString(PyExc_RuntimeError, "FunctionDef field \"type_params\" changed size during iteration");
-                    goto failed;
-                }
-                asdl_seq_SET(type_params, i, val);
-            }
-            Py_CLEAR(tmp);
-        }
         if (_PyObject_LookupAttr(obj, state->args, &tmp) < 0) {
             return 1;
         }
@@ -6258,10 +6221,46 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             if (res != 0) goto failed;
             Py_CLEAR(tmp);
         }
-        *out = _PyAST_FunctionDef(name, type_params, args, body,
-                                  decorator_list, returns, type_comment,
-                                  lineno, col_offset, end_lineno,
-                                  end_col_offset, arena);
+        if (_PyObject_LookupAttr(obj, state->type_params, &tmp) < 0) {
+            return 1;
+        }
+        if (tmp == NULL) {
+            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from FunctionDef");
+            return 1;
+        }
+        else {
+            int res;
+            Py_ssize_t len;
+            Py_ssize_t i;
+            if (!PyList_Check(tmp)) {
+                PyErr_Format(PyExc_TypeError, "FunctionDef field \"type_params\" must be a list, not a %.200s", _PyType_Name(Py_TYPE(tmp)));
+                goto failed;
+            }
+            len = PyList_GET_SIZE(tmp);
+            type_params = _Py_asdl_type_param_seq_new(len, arena);
+            if (type_params == NULL) goto failed;
+            for (i = 0; i < len; i++) {
+                type_param_ty val;
+                PyObject *tmp2 = Py_NewRef(PyList_GET_ITEM(tmp, i));
+                if (_Py_EnterRecursiveCall(" while traversing 'FunctionDef' node")) {
+                    goto failed;
+                }
+                res = obj2ast_type_param(state, tmp2, &val, arena);
+                _Py_LeaveRecursiveCall();
+                Py_DECREF(tmp2);
+                if (res != 0) goto failed;
+                if (len != PyList_GET_SIZE(tmp)) {
+                    PyErr_SetString(PyExc_RuntimeError, "FunctionDef field \"type_params\" changed size during iteration");
+                    goto failed;
+                }
+                asdl_seq_SET(type_params, i, val);
+            }
+            Py_CLEAR(tmp);
+        }
+        *out = _PyAST_FunctionDef(name, args, body, decorator_list, returns,
+                                  type_comment, type_params, lineno,
+                                  col_offset, end_lineno, end_col_offset,
+                                  arena);
         if (*out == NULL) goto failed;
         return 0;
     }
@@ -6272,12 +6271,12 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
     }
     if (isinstance) {
         identifier name;
-        asdl_type_param_seq* type_params;
         arguments_ty args;
         asdl_stmt_seq* body;
         asdl_expr_seq* decorator_list;
         expr_ty returns;
         string type_comment;
+        asdl_type_param_seq* type_params;
 
         if (_PyObject_LookupAttr(obj, state->name, &tmp) < 0) {
             return 1;
@@ -6296,42 +6295,6 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             if (res != 0) goto failed;
             Py_CLEAR(tmp);
         }
-        if (_PyObject_LookupAttr(obj, state->type_params, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from AsyncFunctionDef");
-            return 1;
-        }
-        else {
-            int res;
-            Py_ssize_t len;
-            Py_ssize_t i;
-            if (!PyList_Check(tmp)) {
-                PyErr_Format(PyExc_TypeError, "AsyncFunctionDef field \"type_params\" must be a list, not a %.200s", _PyType_Name(Py_TYPE(tmp)));
-                goto failed;
-            }
-            len = PyList_GET_SIZE(tmp);
-            type_params = _Py_asdl_type_param_seq_new(len, arena);
-            if (type_params == NULL) goto failed;
-            for (i = 0; i < len; i++) {
-                type_param_ty val;
-                PyObject *tmp2 = Py_NewRef(PyList_GET_ITEM(tmp, i));
-                if (_Py_EnterRecursiveCall(" while traversing 'AsyncFunctionDef' node")) {
-                    goto failed;
-                }
-                res = obj2ast_type_param(state, tmp2, &val, arena);
-                _Py_LeaveRecursiveCall();
-                Py_DECREF(tmp2);
-                if (res != 0) goto failed;
-                if (len != PyList_GET_SIZE(tmp)) {
-                    PyErr_SetString(PyExc_RuntimeError, "AsyncFunctionDef field \"type_params\" changed size during iteration");
-                    goto failed;
-                }
-                asdl_seq_SET(type_params, i, val);
-            }
-            Py_CLEAR(tmp);
-        }
         if (_PyObject_LookupAttr(obj, state->args, &tmp) < 0) {
             return 1;
         }
@@ -6455,8 +6418,44 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             if (res != 0) goto failed;
             Py_CLEAR(tmp);
         }
-        *out = _PyAST_AsyncFunctionDef(name, type_params, args, body,
-                                       decorator_list, returns, type_comment,
+        if (_PyObject_LookupAttr(obj, state->type_params, &tmp) < 0) {
+            return 1;
+        }
+        if (tmp == NULL) {
+            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from AsyncFunctionDef");
+            return 1;
+        }
+        else {
+            int res;
+            Py_ssize_t len;
+            Py_ssize_t i;
+            if (!PyList_Check(tmp)) {
+                PyErr_Format(PyExc_TypeError, "AsyncFunctionDef field \"type_params\" must be a list, not a %.200s", _PyType_Name(Py_TYPE(tmp)));
+                goto failed;
+            }
+            len = PyList_GET_SIZE(tmp);
+            type_params = _Py_asdl_type_param_seq_new(len, arena);
+            if (type_params == NULL) goto failed;
+            for (i = 0; i < len; i++) {
+                type_param_ty val;
+                PyObject *tmp2 = Py_NewRef(PyList_GET_ITEM(tmp, i));
+                if (_Py_EnterRecursiveCall(" while traversing 'AsyncFunctionDef' node")) {
+                    goto failed;
+                }
+                res = obj2ast_type_param(state, tmp2, &val, arena);
+                _Py_LeaveRecursiveCall();
+                Py_DECREF(tmp2);
+                if (res != 0) goto failed;
+                if (len != PyList_GET_SIZE(tmp)) {
+                    PyErr_SetString(PyExc_RuntimeError, "AsyncFunctionDef field \"type_params\" changed size during iteration");
+                    goto failed;
+                }
+                asdl_seq_SET(type_params, i, val);
+            }
+            Py_CLEAR(tmp);
+        }
+        *out = _PyAST_AsyncFunctionDef(name, args, body, decorator_list,
+                                       returns, type_comment, type_params,
                                        lineno, col_offset, end_lineno,
                                        end_col_offset, arena);
         if (*out == NULL) goto failed;
@@ -6469,11 +6468,11 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
     }
     if (isinstance) {
         identifier name;
-        asdl_type_param_seq* type_params;
         asdl_expr_seq* bases;
         asdl_keyword_seq* keywords;
         asdl_stmt_seq* body;
         asdl_expr_seq* decorator_list;
+        asdl_type_param_seq* type_params;
 
         if (_PyObject_LookupAttr(obj, state->name, &tmp) < 0) {
             return 1;
@@ -6492,42 +6491,6 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             if (res != 0) goto failed;
             Py_CLEAR(tmp);
         }
-        if (_PyObject_LookupAttr(obj, state->type_params, &tmp) < 0) {
-            return 1;
-        }
-        if (tmp == NULL) {
-            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from ClassDef");
-            return 1;
-        }
-        else {
-            int res;
-            Py_ssize_t len;
-            Py_ssize_t i;
-            if (!PyList_Check(tmp)) {
-                PyErr_Format(PyExc_TypeError, "ClassDef field \"type_params\" must be a list, not a %.200s", _PyType_Name(Py_TYPE(tmp)));
-                goto failed;
-            }
-            len = PyList_GET_SIZE(tmp);
-            type_params = _Py_asdl_type_param_seq_new(len, arena);
-            if (type_params == NULL) goto failed;
-            for (i = 0; i < len; i++) {
-                type_param_ty val;
-                PyObject *tmp2 = Py_NewRef(PyList_GET_ITEM(tmp, i));
-                if (_Py_EnterRecursiveCall(" while traversing 'ClassDef' node")) {
-                    goto failed;
-                }
-                res = obj2ast_type_param(state, tmp2, &val, arena);
-                _Py_LeaveRecursiveCall();
-                Py_DECREF(tmp2);
-                if (res != 0) goto failed;
-                if (len != PyList_GET_SIZE(tmp)) {
-                    PyErr_SetString(PyExc_RuntimeError, "ClassDef field \"type_params\" changed size during iteration");
-                    goto failed;
-                }
-                asdl_seq_SET(type_params, i, val);
-            }
-            Py_CLEAR(tmp);
-        }
         if (_PyObject_LookupAttr(obj, state->bases, &tmp) < 0) {
             return 1;
         }
@@ -6672,8 +6635,44 @@ obj2ast_stmt(struct ast_state *state, PyObject* obj, stmt_ty* out, PyArena*
             }
             Py_CLEAR(tmp);
         }
-        *out = _PyAST_ClassDef(name, type_params, bases, keywords, body,
-                               decorator_list, lineno, col_offset, end_lineno,
+        if (_PyObject_LookupAttr(obj, state->type_params, &tmp) < 0) {
+            return 1;
+        }
+        if (tmp == NULL) {
+            PyErr_SetString(PyExc_TypeError, "required field \"type_params\" missing from ClassDef");
+            return 1;
+        }
+        else {
+            int res;
+            Py_ssize_t len;
+            Py_ssize_t i;
+            if (!PyList_Check(tmp)) {
+                PyErr_Format(PyExc_TypeError, "ClassDef field \"type_params\" must be a list, not a %.200s", _PyType_Name(Py_TYPE(tmp)));
+                goto failed;
+            }
+            len = PyList_GET_SIZE(tmp);
+            type_params = _Py_asdl_type_param_seq_new(len, arena);
+            if (type_params == NULL) goto failed;
+            for (i = 0; i < len; i++) {
+                type_param_ty val;
+                PyObject *tmp2 = Py_NewRef(PyList_GET_ITEM(tmp, i));
+                if (_Py_EnterRecursiveCall(" while traversing 'ClassDef' node")) {
+                    goto failed;
+                }
+                res = obj2ast_type_param(state, tmp2, &val, arena);
+                _Py_LeaveRecursiveCall();
+                Py_DECREF(tmp2);
+                if (res != 0) goto failed;
+                if (len != PyList_GET_SIZE(tmp)) {
+                    PyErr_SetString(PyExc_RuntimeError, "ClassDef field \"type_params\" changed size during iteration");
+                    goto failed;
+                }
+                asdl_seq_SET(type_params, i, val);
+            }
+            Py_CLEAR(tmp);
+        }
+        *out = _PyAST_ClassDef(name, bases, keywords, body, decorator_list,
+                               type_params, lineno, col_offset, end_lineno,
                                end_col_offset, arena);
         if (*out == NULL) goto failed;
         return 0;