bpo-38500: Add PyInterpreterState_SetEvalFrameFunc()

Doc/c-api/init.rst

@@ -1083,6 +1083,35 @@ All of the following functions must be called after :c:func:`Py_Initialize`.
 
    .. versionadded:: 3.8
 
+.. c:type:: PyObject* (*PyFrameEvalFunction)(PyThreadState *tstate, PyFrameObject *frame, int throwflag)
+
+   Type of a frame evaluation function.
+
+   The *throwflag* parameter is used by the ``throw()`` method of generators:
+   if non-zero, handle the current exception.
+
+   .. versionadded:: 3.8.1
+
+   .. versionchanged:: 3.8.1
+      Add *tstate* parameter.
+
+
+.. c:function:: PyFrameEvalFunction PyInterpreterState_GetEvalFrameFunc(PyInterpreterState *interp)
+
+   Get the frame evaluation function.
+
+   See the :pep:`523` "Adding a frame evaluation API to CPython".
+
+   .. versionadded:: 3.8.1
+
+.. c:function:: void PyInterpreterState_SetEvalFrameFunc(PyInterpreterState *interp, PyFrameEvalFunction eval_frame);
+
+   Set the frame evaluation function.
+
+   See the :pep:`523` "Adding a frame evaluation API to CPython".
+
+   .. versionadded:: 3.8.1
+
 
 .. c:function:: PyObject* PyThreadState_GetDict()
 

Doc/whatsnew/3.9.rst

@@ -239,6 +239,10 @@ Build and C API Changes
   removed in Python 3.3.
   (Contributed by Victor Stinner in :issue:`38896`.)
 
+* ``PyInterpreterState.eval_frame`` (:pep:`523`) now requires a new mandatory
+  *tstate* parameter (``PyThreadState*``).
+  (Contributed by Victor Stinner in :issue:`38818`.)
+
 
 Deprecated
 ==========

Include/cpython/ceval.h

@@ -21,7 +21,10 @@ PyAPI_FUNC(PyObject *) _PyEval_GetBuiltinId(_Py_Identifier *);
    flag was set, else return 0. */
 PyAPI_FUNC(int) PyEval_MergeCompilerFlags(PyCompilerFlags *cf);
 
-PyAPI_FUNC(PyObject *) _PyEval_EvalFrameDefault(struct _frame *f, int exc);
+PyAPI_FUNC(PyObject *) _PyEval_EvalFrameDefault(
+    PyThreadState *tstate,
+    struct _frame *f,
+    int exc);
 
 PyAPI_FUNC(void) _PyEval_SetSwitchInterval(unsigned long microseconds);
 PyAPI_FUNC(unsigned long) _PyEval_GetSwitchInterval(void);

Include/cpython/pystate.h

@@ -186,6 +186,16 @@ PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void);
 
 typedef struct _frame *(*PyThreadFrameGetter)(PyThreadState *self_);
 
+/* Frame evaluation API */
+
+typedef PyObject* (*PyFrameEvalFunction)(PyThreadState *tstate, struct _frame *, int);
+
+PyAPI_FUNC(PyFrameEvalFunction) PyInterpreterState_GetEvalFrameFunc(
+    PyInterpreterState *interp);
+PyAPI_FUNC(void) PyInterpreterState_SetEvalFrameFunc(
+    PyInterpreterState *interp,
+    PyFrameEvalFunction eval_frame);
+
 /* cross-interpreter data */
 
 struct _xid;

Include/internal/pycore_ceval.h

@@ -40,7 +40,7 @@ void _PyEval_Fini(void);
 static inline PyObject*
 _PyEval_EvalFrame(PyThreadState *tstate, struct _frame *f, int throwflag)
 {
-    return tstate->interp->eval_frame(f, throwflag);
+    return tstate->interp->eval_frame(tstate, f, throwflag);
 }
 
 extern PyObject *_PyEval_EvalCode(

Include/internal/pycore_pystate.h

@@ -54,8 +54,6 @@ struct _ceval_runtime_state {
 
 /* interpreter state */
 
-typedef PyObject* (*_PyFrameEvalFunction)(struct _frame *, int);
-
 // The PyInterpreterState typedef is in Include/pystate.h.
 struct _is {
 
@@ -113,7 +111,7 @@ struct _is {
     PyObject *builtins_copy;
     PyObject *import_func;
     /* Initialized to PyEval_EvalFrameDefault(). */
-    _PyFrameEvalFunction eval_frame;
+    PyFrameEvalFunction eval_frame;
 
     Py_ssize_t co_extra_user_count;
     freefunc co_extra_freefuncs[MAX_CO_EXTRA_USERS];

Misc/NEWS.d/next/C API/2019-11-16-01-12-32.bpo-38818.bUyp8O.rst

@@ -0,0 +1,2 @@
+``PyInterpreterState.eval_frame`` (:pep:`523`) now requires a new mandatory
+*tstate* parameter (``PyThreadState*``).

Misc/NEWS.d/next/C API/2019-11-22-14-06-28.bpo-38500.nPEdjH.rst

@@ -0,0 +1,3 @@
+Add a public API to get and set the frame evaluation function: add
+:c:func:`PyInterpreterState_GetEvalFrameFunc` and
+:c:func:`PyInterpreterState_SetEvalFrameFunc` C functions

Python/ceval.c

@@ -743,7 +743,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
 }
 
 PyObject* _Py_HOT_FUNCTION
-_PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
+_PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
 {
 #ifdef DXPAIRS
     int lastopcode = 0;
@@ -755,7 +755,6 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
     PyObject **fastlocals, **freevars;
     PyObject *retval = NULL;            /* Return value */
     _PyRuntimeState * const runtime = &_PyRuntime;
-    PyThreadState * const tstate = _PyRuntimeState_GetThreadState(runtime);
     struct _ceval_runtime_state * const ceval = &runtime->ceval;
     _Py_atomic_int * const eval_breaker = &ceval->eval_breaker;
     PyCodeObject *co;

Python/pystate.c

@@ -1721,6 +1721,20 @@ _register_builtins_for_crossinterpreter_data(struct _xidregistry *xidregistry)
 }
 
 
+PyFrameEvalFunction
+PyInterpreterState_GetEvalFrameFunc(PyInterpreterState *interp)
+{
+    return interp->eval_frame;
+}
+
+
+void
+PyInterpreterState_SetEvalFrameFunc(PyInterpreterState *interp,
+                                    PyFrameEvalFunction eval_frame)
+{
+    interp->eval_frame = eval_frame;
+}
+
 #ifdef __cplusplus
 }
 #endif