PEP 820 draft implementation

.gitattributes

@@ -81,6 +81,7 @@ Include/internal/pycore_uop_ids.h                   generated
 Include/internal/pycore_uop_metadata.h              generated
 Include/opcode.h                                    generated
 Include/opcode_ids.h                                generated
+Include/slots_generated.h                           generated
 Include/token.h                                     generated
 Lib/_opcode_metadata.py                             generated
 Lib/idlelib/help.html                               generated
@@ -94,7 +95,6 @@ Lib/test/test_stable_abi_ctypes.py                  generated
 Lib/test/test_zoneinfo/data/*.json                  generated
 Lib/token.py                                        generated
 Misc/sbom.spdx.json                                 generated
-Objects/typeslots.inc                               generated
 PC/python3dll.c                                     generated
 Parser/parser.c                                     generated
 Parser/token.c                                      generated
@@ -104,6 +104,7 @@ Python/executor_cases.c.h                           generated
 Python/generated_cases.c.h                          generated
 Python/optimizer_cases.c.h                          generated
 Python/opcode_targets.h                             generated
+Python/slots_generated.c                            generated
 Python/stdlib_module_names.h                        generated
 Tools/peg_generator/pegen/grammar_parser.py         generated
 aclocal.m4                                          generated

Include/Python.h

@@ -83,7 +83,8 @@ __pragma(warning(disable: 4201))
 #include "object.h"
 #include "refcount.h"
 #include "objimpl.h"
-#include "typeslots.h"
+#include "slots.h"
+#include "slots_generated.h"
 #include "pyhash.h"
 #include "cpython/pydebug.h"
 #include "bytearrayobject.h"

Include/exports.h

@@ -103,7 +103,7 @@
     #define PyMODINIT_FUNC _PyINIT_FUNC_DECLSPEC PyObject*
 #endif
 #ifndef PyMODEXPORT_FUNC
-    #define PyMODEXPORT_FUNC _PyINIT_FUNC_DECLSPEC PyModuleDef_Slot*
+    #define PyMODEXPORT_FUNC _PyINIT_FUNC_DECLSPEC PySlot*
 #endif
 
 #endif /* Py_EXPORTS_H */

Include/internal/pycore_importdl.h

@@ -124,7 +124,7 @@ extern void _Py_ext_module_loader_result_apply_error(
 
 /* The module init function. */
 typedef PyObject *(*PyModInitFunction)(void);
-typedef PyModuleDef_Slot *(*PyModExportFunction)(void);
+typedef PySlot *(*PyModExportFunction)(void);
 #ifdef HAVE_DYNAMIC_LOADING
 extern int _PyImport_GetModuleExportHooks(
     struct _Py_ext_module_loader_info *info,

Include/internal/pycore_slots.h

@@ -0,0 +1,132 @@
+#ifndef _Py_PYCORE_SLOTS_H
+#define _Py_PYCORE_SLOTS_H
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+#include <stdbool.h>
+
+typedef enum _PySlot_DTYPE {
+    _PySlot_DTYPE_VOID,
+    _PySlot_DTYPE_FUNC,
+    _PySlot_DTYPE_PTR,
+    _PySlot_DTYPE_SIZE,
+    _PySlot_DTYPE_INT64,
+    _PySlot_DTYPE_UINT64,
+}_PySlot_DTYPE;
+
+typedef enum _PySlot_KIND {
+    _PySlot_KIND_TYPE,
+    _PySlot_KIND_MOD,
+    _PySlot_KIND_COMPAT,
+    _PySlot_KIND_SLOT,
+} _PySlot_KIND;
+
+typedef enum _PySlot_PROBLEM_HANDLING {
+    _PySlot_PROBLEM_ALLOW = 0,
+    _PySlot_PROBLEM_DEPRECATED,
+    _PySlot_PROBLEM_REJECT,
+} _PySlot_PROBLEM_HANDLING;
+
+PyAPI_DATA(char *) _PySlot_names[];
+
+#define _PySlot_MAX_NESTING 5
+
+/* State for one nesting level of a slots iterator */
+typedef struct _PySlotIterator_state {
+    union {
+        // tagged by slot_struct_kind:
+        const PySlot *slot;               // with _PySlot_KIND_SLOT
+        const PyType_Slot *tp_slot;       // with _PySlot_KIND_TYPE
+        const PyModuleDef_Slot *mod_slot; // with _PySlot_KIND_MOD
+        const void *any_slot;
+    };
+    _PySlot_KIND slot_struct_kind;
+    bool ignoring_fallbacks :1;
+} _PySlotIterator_state;
+
+/* State for a slots iterator */
+typedef struct {
+    _PySlotIterator_state *state;
+    _PySlotIterator_state states[_PySlot_MAX_NESTING];
+    _PySlot_KIND kind;
+    uint8_t recursion_level;
+    unsigned int seen[_Py_slot_COUNT / sizeof(unsigned int) + 1];
+    bool is_at_end :1;
+    bool is_first_run :1;
+
+    // Name of the object (type/module) being defined, NULL if unknown.
+    // Must be set by the callers as soon as it's known.
+    const char *name;
+
+    /* Output information: */
+
+    // The slot. Always a copy; may be modified by caller of the iterator.
+    PySlot current;
+
+} _PySlotIterator;
+
+/* Initialize an iterator using a Py_Slot array */
+PyAPI_FUNC(void)
+_PySlotIterator_Init(_PySlotIterator *it, const PySlot *slots,
+                     _PySlot_KIND result_kind);
+
+/* Initialize an iterator using a legacy slot array */
+PyAPI_FUNC(void)
+_PySlotIterator_InitLegacy(_PySlotIterator *it, const void *slots,
+                           _PySlot_KIND kind);
+
+/* Reset a *successfully exhausted* iterator to the beginning.
+ * The *slots* must be the same as for the previous
+ * `_PySlotIterator_InitWithKind` call.
+ * (Subsequent iterations skip some validation.)
+ */
+PyAPI_FUNC(void) _PySlotIterator_Rewind(_PySlotIterator *it, const void *slots);
+
+/* Iteration function.
+ *
+ * Return false at the end (when successfully exhausted).
+ * Otherwise (even on error), fill output information in `it` and return true.
+ *
+ * On error, set an exception and set `it->current.sl_id` to `Py_slot_invalid`.
+ */
+PyAPI_FUNC(bool) _PySlotIterator_Next(_PySlotIterator *it);
+
+/* Return 1 if given slot was "seen" by an earlier _PySlotIterator_Next call.
+ * (This state is not reset by rewinding.)
+ */
+PyAPI_FUNC(bool) _PySlotIterator_SawSlot(_PySlotIterator *, int);
+
+static inline const char *
+_PySlot_GetName(uint16_t id)
+{
+    if (id >= _Py_slot_COUNT) {
+        return "<unknown_slot>";
+    }
+    if (id == Py_slot_invalid) {
+        return "Py_slot_invalid";
+    }
+    return _PySlot_names[id];
+}
+
+static inline void
+_PySlot_err_bad_slot(char *kind, uint16_t id)
+{
+    if (id < _Py_slot_COUNT) {
+        PyErr_Format(PyExc_SystemError, "invalid %s slot %d (%s)",
+                    kind, (unsigned int)id, _PySlot_names[id]);
+    }
+    else if (id == Py_slot_invalid) {
+        PyErr_Format(PyExc_SystemError, "invalid slot (Py_slot_invalid, %u)",
+                     (unsigned int)id);
+    }
+    else {
+        PyErr_Format(PyExc_SystemError, "unknown %s slot ID %u",
+                     kind, (unsigned int)id);
+    }
+}
+
+#include "internal/pycore_slots_generated.h"
+
+#endif // _Py_PYCORE_SLOTS_H