gh-86682: Adds sys._getframemodulename as a lightweight alternative to _getframe

Doc/library/sys.rst

@@ -808,6 +808,22 @@ always available.
       It is not guaranteed to exist in all implementations of Python.
 
 
+.. function:: _getframemodulename([depth])
+
+   Return the name of a module from the call stack.  If optional integer *depth*
+   is given, return the module that many calls below the top of the stack.  If
+   that is deeper than the call stack, or if the module is unidentifiable,
+   ``None`` is returned.  The default for *depth* is zero, returning the
+   module at the top of the call stack.
+
+   .. audit-event:: sys._getframemodulename depth sys._getframemodulename
+
+   .. impl-detail::
+
+      This function should be used for internal and specialized purposes only.
+      It is not guaranteed to exist in all implementations of Python.
+
+
 .. function:: getprofile()
 
    .. index::

Lib/_pydecimal.py

@@ -159,7 +159,7 @@
 
 try:
     from collections import namedtuple as _namedtuple
-    DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent')
+    DecimalTuple = _namedtuple('DecimalTuple', 'sign digits exponent', module='decimal')
 except ImportError:
     DecimalTuple = lambda *args: args
 

Lib/collections/__init__.py

@@ -507,9 +507,12 @@ def __getnewargs__(self):
     # specified a particular module.
     if module is None:
         try:
-            module = _sys._getframe(1).f_globals.get('__name__', '__main__')
-        except (AttributeError, ValueError):
-            pass
+            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:
         result.__module__ = module
 

Lib/doctest.py

@@ -207,7 +207,13 @@ def _normalize_module(module, depth=2):
     elif isinstance(module, str):
         return __import__(module, globals(), locals(), ["*"])
     elif module is None:
-        return sys.modules[sys._getframe(depth).f_globals['__name__']]
+        try:
+            try:
+                return sys.modules[sys._getframemodulename(depth)]
+            except AttributeError:
+                return sys.modules[sys._getframe(depth).f_globals['__name__']]
+        except KeyError:
+            pass
     else:
         raise TypeError("Expected a module, string, or None")
 

Lib/enum.py

@@ -862,13 +862,15 @@ def _create_(cls, class_name, names, *, module=None, qualname=None, type=None, s
                 member_name, member_value = item
             classdict[member_name] = member_value
 
-        # TODO: replace the frame hack if a blessed way to know the calling
-        # module is ever developed
         if module is None:
             try:
-                module = sys._getframe(2).f_globals['__name__']
-            except (AttributeError, ValueError, KeyError):
-                pass
+                module = sys._getframemodulename(2)
+            except AttributeError:
+                # Fall back on _getframe if _getframemodulename is missing
+                try:
+                    module = sys._getframe(2).f_globals['__name__']
+                except (AttributeError, ValueError, KeyError):
+                    pass
         if module is None:
             _make_class_unpicklable(classdict)
         else:

Lib/test/audit-tests.py

@@ -419,6 +419,17 @@ def hook(event, args):
     sys._getframe()
 
 
+def test_sys_getframemodulename():
+    import sys
+
+    def hook(event, args):
+        if event.startswith("sys."):
+            print(event, *args)
+
+    sys.addaudithook(hook)
+    sys._getframemodulename()
+
+
 def test_threading():
     import _thread
 

Lib/test/test_audit.py

@@ -186,6 +186,18 @@ def test_sys_getframe(self):
 
         self.assertEqual(actual, expected)
 
+    def test_sys_getframemodulename(self):
+        returncode, events, stderr = self.run_python("test_sys_getframemodulename")
+        if returncode:
+            self.fail(stderr)
+
+        if support.verbose:
+            print(*events, sep='\n')
+        actual = [(ev[0], ev[2]) for ev in events]
+        expected = [("sys._getframemodulename", "0")]
+
+        self.assertEqual(actual, expected)
+
 
     def test_threading(self):
         returncode, events, stderr = self.run_python("test_threading")

Lib/test/test_sys.py

@@ -399,6 +399,26 @@ def test_getframe(self):
             is sys._getframe().f_code
         )
 
+    def test_getframemodulename(self):
+        # Default depth gets ourselves
+        self.assertEqual(__name__, sys._getframemodulename())
+        self.assertEqual("unittest.case", sys._getframemodulename(1))
+        i = 0
+        f = sys._getframe(i)
+        while f:
+            self.assertEqual(
+                f.f_globals['__name__'],
+                sys._getframemodulename(i) or '__main__'
+            )
+            i += 1
+            f2 = f.f_back
+            try:
+                f = sys._getframe(i)
+            except ValueError:
+                break
+            self.assertIs(f, f2)
+        self.assertIsNone(sys._getframemodulename(i))
+
     # sys._current_frames() is a CPython-only gimmick.
     @threading_helper.reap_threads
     @threading_helper.requires_working_threading()

Lib/typing.py

@@ -1939,11 +1939,15 @@ def _no_init_or_replace_init(self, *args, **kwargs):
 
 
 def _caller(depth=1, default='__main__'):
+    try:
+        return sys._getframemodulename(depth + 1) or default
+    except AttributeError:  # For platforms without _getframemodulename()
+        pass
     try:
         return sys._getframe(depth + 1).f_globals.get('__name__', default)
     except (AttributeError, ValueError):  # For platforms without _getframe()
-        return None
-
+        pass
+    return None
 
 def _allow_reckless_class_checks(depth=3):
     """Allow instance and class checks for special stdlib modules.

Misc/NEWS.d/next/Library/2022-11-15-23-30-39.gh-issue-86682.gK9i1N.rst

@@ -0,0 +1,2 @@
+Ensure runtime-created collections have the correct module name using
+the newly added (internal) :func:`sys._getframemodulename`.

Objects/funcobject.c

@@ -93,7 +93,10 @@ _PyFunction_FromConstructor(PyFrameConstructor *constr)
     op->func_doc = Py_NewRef(Py_None);
     op->func_dict = NULL;
     op->func_weakreflist = NULL;
-    op->func_module = NULL;
+    op->func_module = Py_XNewRef(PyDict_GetItem(op->func_globals, &_Py_ID(__name__)));
+    if (!op->func_module) {
+        PyErr_Clear();
+    }
     op->func_annotations = NULL;
     op->vectorcall = _PyFunction_Vectorcall;
     op->func_version = 0;

Python/sysmodule.c

@@ -2172,6 +2172,43 @@ sys_is_stack_trampoline_active_impl(PyObject *module)
 }
 
 
+/*[clinic input]
+sys._getframemodulename
+
+    depth: int = 0
+
+Return the name of the module for a calling frame.
+
+The default depth returns the module containing the call to this API.
+A more typical use in a library will pass a depth of 1 to get the user's
+module rather than the library module.
+
+If no frame, module, or name can be found, returns None.
+[clinic start generated code]*/
+
+static PyObject *
+sys__getframemodulename_impl(PyObject *module, int depth)
+/*[clinic end generated code: output=1d70ef691f09d2db input=d4f1a8ed43b8fb46]*/
+{
+    if (PySys_Audit("sys._getframemodulename", "i", depth) < 0) {
+        return NULL;
+    }
+    _PyInterpreterFrame *f = _PyThreadState_GET()->cframe->current_frame;
+    while (f && (_PyFrame_IsIncomplete(f) || depth-- > 0)) {
+        f = f->previous;
+    }
+    if (f == NULL || f->f_funcobj == NULL) {
+        Py_RETURN_NONE;
+    }
+    PyObject *r = PyFunction_GetModule(f->f_funcobj);
+    if (!r) {
+        PyErr_Clear();
+        r = Py_None;
+    }
+    return Py_NewRef(r);
+}
+
+
 static PyMethodDef sys_methods[] = {
     /* Might as well keep this in alphabetic order */
     SYS_ADDAUDITHOOK_METHODDEF
@@ -2200,6 +2237,7 @@ static PyMethodDef sys_methods[] = {
     {"getsizeof", _PyCFunction_CAST(sys_getsizeof),
      METH_VARARGS | METH_KEYWORDS, getsizeof_doc},
     SYS__GETFRAME_METHODDEF
+    SYS__GETFRAMEMODULENAME_METHODDEF
     SYS_GETWINDOWSVERSION_METHODDEF
     SYS__ENABLELEGACYWINDOWSFSENCODING_METHODDEF
     SYS_INTERN_METHODDEF