gh-102192: Replace PyErr_Fetch/Restore etc by more efficient alternatives

Doc/library/dataclasses.rst

@@ -389,7 +389,7 @@ Module contents
    :func:`astuple` raises :exc:`TypeError` if ``obj`` is not a dataclass
    instance.
 
-.. function:: make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False, match_args=True, kw_only=False, slots=False, weakref_slot=False)
+.. function:: make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False, match_args=True, kw_only=False, slots=False, weakref_slot=False, module=None)
 
    Creates a new dataclass with name ``cls_name``, fields as defined
    in ``fields``, base classes as given in ``bases``, and initialized
@@ -401,6 +401,10 @@ Module contents
    ``match_args``, ``kw_only``, ``slots``, and ``weakref_slot`` have
    the same meaning as they do in :func:`dataclass`.
 
+   If ``module`` is defined, the ``__module__`` attribute
+   of the dataclass is set to that value.
+   By default, it is set to the module name of the caller.
+
    This function is not strictly required, because any Python
    mechanism for creating a new class with ``__annotations__`` can
    then apply the :func:`dataclass` function to convert that class to

Doc/library/dis.rst

@@ -57,9 +57,9 @@ the following command can be used to display the disassembly of
      2           0 RESUME                   0
    <BLANKLINE>
      3           2 LOAD_GLOBAL              1 (NULL + len)
-                14 LOAD_FAST                0 (alist)
-                16 CALL                     1
-                26 RETURN_VALUE
+                12 LOAD_FAST                0 (alist)
+                14 CALL                     1
+                24 RETURN_VALUE
 
 (The "2" is a line number).
 

Doc/library/inspect.rst

@@ -1440,8 +1440,8 @@ code execution::
            pass
 
 
-Current State of Generators and Coroutines
-------------------------------------------
+Current State of Generators, Coroutines, and Asynchronous Generators
+--------------------------------------------------------------------
 
 When implementing coroutine schedulers and for other advanced uses of
 generators, it is useful to determine whether a generator is currently
@@ -1476,6 +1476,22 @@ generator to be determined easily.
 
    .. versionadded:: 3.5
 
+.. function:: getasyncgenstate(agen)
+
+   Get current state of an asynchronous generator object.  The function is
+   intended to be used with asynchronous iterator objects created by
+   :keyword:`async def` functions which use the :keyword:`yield` statement,
+   but will accept any asynchronous generator-like object that has
+   ``ag_running`` and ``ag_frame`` attributes.
+
+   Possible states are:
+    * AGEN_CREATED: Waiting to start execution.
+    * AGEN_RUNNING: Currently being executed by the interpreter.
+    * AGEN_SUSPENDED: Currently suspended at a yield expression.
+    * AGEN_CLOSED: Execution has completed.
+
+   .. versionadded:: 3.12
+
 The current internal state of the generator can also be queried. This is
 mostly useful for testing purposes, to ensure that internal state is being
 updated as expected:
@@ -1507,6 +1523,14 @@ updated as expected:
 
    .. versionadded:: 3.5
 
+.. function:: getasyncgenlocals(agen)
+
+   This function is analogous to :func:`~inspect.getgeneratorlocals`, but
+   works for asynchronous generator objects created by :keyword:`async def`
+   functions which use the :keyword:`yield` statement.
+
+   .. versionadded:: 3.12
+
 
 .. _inspect-module-co-flags:
 

Doc/whatsnew/3.12.rst

@@ -244,6 +244,10 @@ inspect
   a :term:`coroutine` for use with :func:`iscoroutinefunction`.
   (Contributed Carlton Gibson in :gh:`99247`.)
 
+* Add :func:`inspect.getasyncgenstate` and :func:`inspect.getasyncgenlocals`
+  for determining the current state of asynchronous generators.
+  (Contributed by Thomas Krennwallner in :issue:`35759`.)
+
 pathlib
 -------
 

Include/internal/pycore_code.h

@@ -20,7 +20,7 @@ extern "C" {
 typedef struct {
     uint16_t counter;
     uint16_t index;
-    uint16_t module_keys_version[2];
+    uint16_t module_keys_version;
     uint16_t builtin_keys_version;
 } _PyLoadGlobalCache;
 

Include/internal/pycore_object.h

@@ -370,6 +370,7 @@ extern void _PyObject_FreeInstanceAttributes(PyObject *obj);
 extern int _PyObject_IsInstanceDictEmpty(PyObject *);
 extern int _PyType_HasSubclasses(PyTypeObject *);
 extern PyObject* _PyType_GetSubclasses(PyTypeObject *);
+extern PyObject* _PyObject_GenericTryGetAttr(PyObject *, PyObject *);
 
 // Access macro to the members which are floating "behind" the object
 static inline PyMemberDef* _PyHeapType_GET_MEMBERS(PyHeapTypeObject *etype) {

Lib/dataclasses.py

@@ -616,21 +616,19 @@ def _repr_fn(fields, globals):
 def _frozen_get_del_attr(cls, fields, globals):
     locals = {'cls': cls,
               'FrozenInstanceError': FrozenInstanceError}
+    condition = 'type(self) is cls'
     if fields:
-        fields_str = '(' + ','.join(repr(f.name) for f in fields) + ',)'
-    else:
-        # Special case for the zero-length tuple.
-        fields_str = '()'
+        condition += ' or name in {' + ', '.join(repr(f.name) for f in fields) + '}'
     return (_create_fn('__setattr__',
                       ('self', 'name', 'value'),
-                      (f'if type(self) is cls or name in {fields_str}:',
+                      (f'if {condition}:',
                         ' raise FrozenInstanceError(f"cannot assign to field {name!r}")',
                        f'super(cls, self).__setattr__(name, value)'),
                        locals=locals,
                        globals=globals),
             _create_fn('__delattr__',
                       ('self', 'name'),
-                      (f'if type(self) is cls or name in {fields_str}:',
+                      (f'if {condition}:',
                         ' raise FrozenInstanceError(f"cannot delete field {name!r}")',
                        f'super(cls, self).__delattr__(name)'),
                        locals=locals,
@@ -1283,7 +1281,7 @@ class C:
     If given, 'dict_factory' will be used instead of built-in dict.
     The function applies recursively to field values that are
     dataclass instances. This will also look into built-in containers:
-    tuples, lists, and dicts.
+    tuples, lists, and dicts. Other objects are copied with 'copy.deepcopy()'.
     """
     if not _is_dataclass_instance(obj):
         raise TypeError("asdict() should be called on dataclass instances")
@@ -1355,7 +1353,7 @@ class C:
     If given, 'tuple_factory' will be used instead of built-in tuple.
     The function applies recursively to field values that are
     dataclass instances. This will also look into built-in containers:
-    tuples, lists, and dicts.
+    tuples, lists, and dicts. Other objects are copied with 'copy.deepcopy()'.
     """
 
     if not _is_dataclass_instance(obj):
@@ -1393,7 +1391,7 @@ def _astuple_inner(obj, tuple_factory):
 def make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True,
                    repr=True, eq=True, order=False, unsafe_hash=False,
                    frozen=False, match_args=True, kw_only=False, slots=False,
-                   weakref_slot=False):
+                   weakref_slot=False, module=None):
     """Return a new dynamically created dataclass.
 
     The dataclass name will be 'cls_name'.  'fields' is an iterable
@@ -1457,6 +1455,19 @@ def exec_body_callback(ns):
     # of generic dataclasses.
     cls = types.new_class(cls_name, bases, {}, exec_body_callback)
 
+    # For pickling to work, the __module__ variable needs to be set to the frame
+    # where the dataclass is created.
+    if module is None:
+        try:
+            module = sys._getframemodulename(1) or '__main__'
+        except AttributeError:
+            try:
+                module = sys._getframe(1).f_globals.get('__name__', '__main__')
+            except (AttributeError, ValueError):
+                pass
+    if module is not None:
+        cls.__module__ = module
+
     # Apply the normal decorator.
     return dataclass(cls, init=init, repr=repr, eq=eq, order=order,
                      unsafe_hash=unsafe_hash, frozen=frozen,

Lib/importlib/_bootstrap_external.py

@@ -431,12 +431,17 @@ def _write_atomic(path, data, mode=0o666):
 #     Python 3.12a5 3515 (Embed jump mask in COMPARE_OP oparg)
 #     Python 3.12a5 3516 (Add COMPARE_AND_BRANCH instruction)
 #     Python 3.12a5 3517 (Change YIELD_VALUE oparg to exception block depth)
-#     Python 3.12a5 3518 (Add RETURN_CONST instruction)
-#     Python 3.12a5 3519 (Modify SEND instruction)
-#     Python 3.12a5 3520 (Remove PREP_RERAISE_STAR, add CALL_INTRINSIC_2)
+#     Python 3.12a6 3518 (Add RETURN_CONST instruction)
+#     Python 3.12a6 3519 (Modify SEND instruction)
+#     Python 3.12a6 3520 (Remove PREP_RERAISE_STAR, add CALL_INTRINSIC_2)
+#     Python 3.12a7 3521 (Shrink the LOAD_GLOBAL caches)
 
 #     Python 3.13 will start with 3550
 
+#     Please don't copy-paste the same pre-release tag for new entries above!!!
+#     You should always use the *upcoming* tag. For example, if 3.12a6 came out
+#     a week ago, I should put "Python 3.12a7" next to my new magic number.
+
 # MAGIC must change whenever the bytecode emitted by the compiler may no
 # longer be understood by older implementations of the eval loop (usually
 # due to the addition of new opcodes).
@@ -446,7 +451,7 @@ def _write_atomic(path, data, mode=0o666):
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3520).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3521).to_bytes(2, 'little') + b'\r\n'
 
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 

Lib/inspect.py

@@ -34,6 +34,10 @@
               'Yury Selivanov <yselivanov@sprymix.com>')
 
 __all__ = [
+    "AGEN_CLOSED",
+    "AGEN_CREATED",
+    "AGEN_RUNNING",
+    "AGEN_SUSPENDED",
     "ArgInfo",
     "Arguments",
     "Attribute",
@@ -77,6 +81,8 @@
     "getabsfile",
     "getargs",
     "getargvalues",
+    "getasyncgenlocals",
+    "getasyncgenstate",
     "getattr_static",
     "getblock",
     "getcallargs",
@@ -1935,6 +1941,50 @@ def getcoroutinelocals(coroutine):
         return {}
 
 
+# ----------------------------------- asynchronous generator introspection
+
+AGEN_CREATED = 'AGEN_CREATED'
+AGEN_RUNNING = 'AGEN_RUNNING'
+AGEN_SUSPENDED = 'AGEN_SUSPENDED'
+AGEN_CLOSED = 'AGEN_CLOSED'
+
+
+def getasyncgenstate(agen):
+    """Get current state of an asynchronous generator object.
+
+    Possible states are:
+      AGEN_CREATED: Waiting to start execution.
+      AGEN_RUNNING: Currently being executed by the interpreter.
+      AGEN_SUSPENDED: Currently suspended at a yield expression.
+      AGEN_CLOSED: Execution has completed.
+    """
+    if agen.ag_running:
+        return AGEN_RUNNING
+    if agen.ag_suspended:
+        return AGEN_SUSPENDED
+    if agen.ag_frame is None:
+        return AGEN_CLOSED
+    return AGEN_CREATED
+
+
+def getasyncgenlocals(agen):
+    """
+    Get the mapping of asynchronous generator local variables to their current
+    values.
+
+    A dict is returned, with the keys the local variable names and values the
+    bound values."""
+
+    if not isasyncgen(agen):
+        raise TypeError(f"{agen!r} is not a Python async generator")
+
+    frame = getattr(agen, "ag_frame", None)
+    if frame is not None:
+        return agen.ag_frame.f_locals
+    else:
+        return {}
+
+
 ###############################################################################
 ### Function Signature Object (PEP 362)
 ###############################################################################

Lib/opcode.py

@@ -390,7 +390,7 @@ def pseudo_op(name, op, real_ops):
     "LOAD_GLOBAL": {
         "counter": 1,
         "index": 1,
-        "module_keys_version": 2,
+        "module_keys_version": 1,
         "builtin_keys_version": 1,
     },
     "BINARY_OP": {

Lib/pathlib.py

@@ -320,8 +320,9 @@ def _from_parsed_parts(cls, drv, root, parts):
     def _format_parsed_parts(cls, drv, root, parts):
         if drv or root:
             return drv + root + cls._flavour.sep.join(parts[1:])
-        else:
-            return cls._flavour.sep.join(parts)
+        elif parts and cls._flavour.splitdrive(parts[0])[0]:
+            parts = ['.'] + parts
+        return cls._flavour.sep.join(parts)
 
     def __str__(self):
         """Return the string representation of the path, suitable for
@@ -1188,7 +1189,8 @@ def expanduser(self):
             homedir = self._flavour.expanduser(self._parts[0])
             if homedir[:1] == "~":
                 raise RuntimeError("Could not determine home directory.")
-            return self._from_parts([homedir] + self._parts[1:])
+            drv, root, parts = self._parse_parts((homedir,))
+            return self._from_parsed_parts(drv, root, parts + self._parts[1:])
 
         return self
 

Lib/test/test_ast.py

@@ -11,6 +11,7 @@
 from textwrap import dedent
 
 from test import support
+from test.support import os_helper, script_helper
 from test.support.ast_helper import ASTTestMixin
 
 def to_tuple(t):
@@ -2564,6 +2565,25 @@ def test_subinterpreter(self):
         self.assertEqual(res, 0)
 
 
+class ASTMainTests(unittest.TestCase):
+    # Tests `ast.main()` function.
+
+    def test_cli_file_input(self):
+        code = "print(1, 2, 3)"
+        expected = ast.dump(ast.parse(code), indent=3)
+
+        with os_helper.temp_dir() as tmp_dir:
+            filename = os.path.join(tmp_dir, "test_module.py")
+            with open(filename, 'w', encoding='utf-8') as f:
+                f.write(code)
+            res, _ = script_helper.run_python_until_end("-m", "ast", filename)
+
+        self.assertEqual(res.err, b"")
+        self.assertEqual(expected.splitlines(),
+                         res.out.decode("utf8").splitlines())
+        self.assertEqual(res.rc, 0)
+
+
 def main():
     if __name__ != '__main__':
         return