Assorted fixups

Author: markshannon

Include/cpython/frameobject.h

@@ -28,6 +28,15 @@ PyAPI_FUNC(int) _PyFrame_IsEntryFrame(PyFrameObject *frame);
 PyAPI_FUNC(int) PyFrame_FastToLocalsWithError(PyFrameObject *f);
 PyAPI_FUNC(void) PyFrame_FastToLocals(PyFrameObject *);
 
+typedef struct PyExtensionFrame {
+    void *opaque[4];
+} PyExtensionFrame;
+
+PyAPI_FUNC(int) Py_PushExtensionFrame(PyThreadState *tstate, PyExtensionFrame *frame, PyObject *codelike);
+
+/* Returns a new reference to the codelike object */
+PyAPI_FUNC(void) Py_PopExtensionFrame(PyThreadState *tstate, PyExtensionFrame *frame);
+
 
 typedef struct {
     PyObject_HEAD

Include/internal/pycore_frame.h

@@ -58,7 +58,8 @@ enum _frameowner {
     FRAME_OWNED_BY_GENERATOR = 1,
     FRAME_OWNED_BY_FRAME_OBJECT = 2,
     FRAME_OWNED_BY_INTERPRETER = 3,
-    FRAME_OWNED_BY_CSTACK = 4,
+    FRAME_OWNED_BY_EXTENSION = 4,
+    FRAME_OWNED_BY_CSTACK = 5,
 };
 
 struct _PyFrameCore {
@@ -93,10 +94,18 @@ typedef struct _PyInterpreterFrame {
     _PyStackRef localsplus[1];
 } _PyInterpreterFrame;
 
+typedef struct _PyExtensionFrame {
+    _PyStackRef f_executable; /* A "code like" object */
+    union _PyVMFrame *previous;
+    char owner;
+    void *extension_data;
+} _PyExtensionFrame;
+
 
 typedef union _PyVMFrame {
     struct _PyFrameCore core;
     _PyInterpreterFrame iframe;
+    _PyExtensionFrame eframe;
 } _PyVMFrame;
 
 #define _PyInterpreterFrame_LASTI(IF) \
@@ -366,6 +375,24 @@ _PyThreadState_HasStackSpace(PyThreadState *tstate, int size)
         size < tstate->datastack_limit - tstate->datastack_top;
 }
 
+static inline void
+_Py_PushNonPythonFrame(PyThreadState *tstate, struct _PyFrameCore *frame, PyObject *callable, enum _frameowner owner)
+{
+    frame->owner = owner;
+    frame->f_executable = PyStackRef_FromPyObjectNew(callable);
+    frame->previous = tstate->current_frame;
+    tstate->current_frame = (_PyVMFrame *)frame;
+}
+
+static inline void
+_Py_PopNonPythonFrame(PyThreadState *tstate, struct _PyFrameCore *frame)
+{
+    assert(tstate->current_frame == (_PyVMFrame *)frame);
+    _PyStackRef codelike = frame->f_executable;
+    tstate->current_frame = frame->previous;
+    PyStackRef_CLOSE(codelike);
+}
+
 extern _PyInterpreterFrame *
 _PyThreadState_PushFrame(PyThreadState *tstate, size_t size);
 

Modules/_testexternalinspection.c

@@ -1265,8 +1265,8 @@ parse_async_frame_object(
         return -1;
     }
 
-    if (owner == FRAME_OWNED_BY_CSTACK || owner == FRAME_OWNED_BY_INTERPRETER) {
-        return 0;  // C frame
+    if (owner >= FRAME_OWNED_BY_INTERPRETER) {
+        return 0;  // Non-Python frame
     }
 
     if (owner != FRAME_OWNED_BY_GENERATOR

Objects/genobject.c

@@ -962,11 +962,11 @@ _Py_MakeCoro(PyFunctionObject *func)
     if (origin_depth == 0) {
         ((PyCoroObject *)coro)->cr_origin_or_finalizer = NULL;
     } else {
-        _PyInterpreterFrame *frame = tstate->current_frame;
+        _PyVMFrame *frame = tstate->current_frame;
         assert(frame);
-        assert(_PyFrame_IsIncomplete(frame));
-        frame = _PyFrame_GetFirstComplete(frame->previous);
-        PyObject *cr_origin = compute_cr_origin(origin_depth, frame);
+        assert(_PyVMFrame_IsIncomplete(frame));
+        _PyInterpreterFrame *iframe = _PyFrame_GetFirstComplete(frame->core.previous);
+        PyObject *cr_origin = compute_cr_origin(origin_depth, iframe);
         ((PyCoroObject *)coro)->cr_origin_or_finalizer = cr_origin;
         if (!cr_origin) {
             Py_DECREF(coro);

Objects/typevarobject.c

@@ -384,14 +384,15 @@ make_union(PyObject *self, PyObject *other)
 static PyObject *
 caller(void)
 {
-    _PyInterpreterFrame *f = _PyThreadState_GET()->current_frame;
+    _PyVMFrame *f = _PyThreadState_GET()->current_frame;
     if (f == NULL) {
         Py_RETURN_NONE;
     }
-    if (f == NULL || PyStackRef_IsNull(f->f_funcobj)) {
+    _PyInterpreterFrame *frame = _PyFrame_GetFirstComplete(f);
+    if (frame == NULL || PyStackRef_IsNull(frame->f_funcobj)) {
         Py_RETURN_NONE;
     }
-    PyObject *r = PyFunction_GetModule(PyStackRef_AsPyObjectBorrow(f->f_funcobj));
+    PyObject *r = PyFunction_GetModule(PyStackRef_AsPyObjectBorrow(frame->f_funcobj));
     if (!r) {
         PyErr_Clear();
         Py_RETURN_NONE;

Python/frame.c

@@ -110,7 +110,7 @@ _PyFrame_ClearExceptCode(_PyInterpreterFrame *frame)
         _PyGen_GetGeneratorFromFrame(frame)->gi_frame_state == FRAME_CLEARED);
     // GH-99729: Clearing this frame can expose the stack (via finalizers). It's
     // crucial that this frame has been unlinked, and is no longer visible:
-    assert(_PyThreadState_GET()->current_frame != frame);
+    assert(_PyThreadState_GET()->current_frame != (_PyVMFrame *)frame);
     if (frame->frame_obj) {
         PyFrameObject *f = frame->frame_obj;
         frame->frame_obj = NULL;
@@ -153,3 +153,18 @@ const PyTypeObject *const PyUnstable_ExecutableKinds[PyUnstable_EXECUTABLE_KINDS
     [PyUnstable_EXECUTABLE_KIND_METHOD_DESCRIPTOR] = &PyMethodDescr_Type,
     [PyUnstable_EXECUTABLE_KINDS] = NULL,
 };
+
+int
+Py_PushExtensionFrame(PyThreadState *tstate, PyExtensionFrame *frame, PyObject *codelike)
+{
+    assert(sizeof(PyExtensionFrame) >= sizeof(struct _PyFrameCore));
+    _Py_PushNonPythonFrame(tstate, (struct _PyFrameCore *)frame, codelike, FRAME_OWNED_BY_EXTENSION);
+    return 0;
+}
+
+void
+Py_PopExtensionFrame(PyThreadState *tstate, PyExtensionFrame *frame)
+{
+    assert(((struct _PyFrameCore *)frame)->owner == FRAME_OWNED_BY_EXTENSION);
+    _Py_PopNonPythonFrame(tstate, (struct _PyFrameCore *)frame);
+}