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brijkapadiabrijkapadia
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Add _PyFrame_ClearExceptCodeAndFunction
1 parent 1fddb7f commit d7bfddf

5 files changed

Lines changed: 29 additions & 6 deletions

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‎Include/internal/pycore_interpframe.h‎

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@@ -368,6 +368,9 @@ _PyFrame_ClearLocals(_PyInterpreterFrame *frame);
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PyAPI_FUNC(void)
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_PyFrame_ClearExceptCode(_PyInterpreterFrame * frame);
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void
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_PyFrame_ClearExceptCodeAndFunction(_PyInterpreterFrame *frame);
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int
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_PyFrame_Traverse(_PyInterpreterFrame *frame, visitproc visit, void *arg);
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‎InternalDocs/generators.md‎

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@@ -53,7 +53,7 @@ the generator object.
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When a generator object is destroyed in [`gen_dealloc`](../Objects/genobject.c),
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its embedded `_PyInterpreterFrame` field may need to be preserved, if it is exposed
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to Python as part of a [`PyFrameObject`](frames.md#frame-objects). This is detected
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in [`_PyFrame_ClearExceptCode`](../Python/frame.c) by the fact that the interpreter
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in [`_PyFrame_ClearExceptCodeAndFunction`](../Python/frame.c) by the fact that the interpreter
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frame's `frame_obj` field is set, and the frame object it points to has refcount
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greater than 1. If so, the `take_ownership()` function is called to create a new
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copy of the interpreter frame and transfer ownership of it from the generator to

‎Objects/genobject.c‎

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@@ -170,7 +170,7 @@ gen_clear_frame(PyGenObject *gen)
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_PyInterpreterFrame *frame = &gen->gi_iframe;
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_PyThreadState_UpdateLastProfiledFrame(_PyThreadState_GET(), frame, frame->previous);
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frame->previous = NULL;
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_PyFrame_ClearExceptCode(frame);
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_PyFrame_ClearExceptCodeAndFunction(frame);
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_PyErr_ClearExcState(&gen->gi_exc_state);
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}
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‎Python/ceval.c‎

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@@ -1998,10 +1998,7 @@ clear_gen_frame(PyThreadState *tstate, _PyInterpreterFrame * frame)
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gen->gi_exc_state.previous_item = NULL;
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assert(frame->frame_obj == NULL || frame->frame_obj->f_frame == frame);
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frame->previous = NULL;
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if (PyGen_Check(gen)) {
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frame->f_funcobj = PyStackRef_DUP(frame->f_funcobj);
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}
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_PyFrame_ClearExceptCode(frame);
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_PyFrame_ClearExceptCodeAndFunction(frame);
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_PyErr_ClearExcState(&gen->gi_exc_state);
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// gh-143939: There must not be any escaping calls between setting
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// the generator return kind and returning from _PyEval_EvalFrame.

‎Python/frame.c‎

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@@ -123,6 +123,29 @@ _PyFrame_ClearExceptCode(_PyInterpreterFrame *frame)
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PyStackRef_CLEAR(frame->f_funcobj);
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}
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void
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_PyFrame_ClearExceptCodeAndFunction(_PyInterpreterFrame *frame)
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{
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/* It is the responsibility of the owning generator/coroutine
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* to have cleared the enclosing generator, if any. */
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assert(frame->owner != FRAME_OWNED_BY_GENERATOR ||
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FT_ATOMIC_LOAD_INT8_RELAXED(_PyGen_GetGeneratorFromFrame(frame)->gi_frame_state) == FRAME_CLEARED);
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// GH-99729: Clearing this frame can expose the stack (via finalizers). It's
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// crucial that this frame has been unlinked, and is no longer visible:
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assert(_PyThreadState_GET()->current_frame != frame);
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if (frame->frame_obj) {
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PyFrameObject *f = frame->frame_obj;
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frame->frame_obj = NULL;
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if (!_PyObject_IsUniquelyReferenced((PyObject *)f)) {
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take_ownership(f, frame);
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Py_DECREF(f);
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return;
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}
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Py_DECREF(f);
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}
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_PyFrame_ClearLocals(frame);
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}
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/* Unstable API functions */
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PyObject *

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