bpo-45637: Store the frame pointer in the cframe (GH-29267)

* Rename 'frame' to 'current_frame'

5 files changed, 32 insertions, 31 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index bd01e81..4ac0b53 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1561,8 +1561,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
     tstate->cframe = &cframe;
 
     assert(frame->depth == 0);
-    /* push frame */
-    tstate->frame = frame;
+    /* Push frame */
+    frame->previous = prev_cframe->current_frame;
+    cframe.current_frame = frame;
 
 start_frame:
     if (_Py_EnterRecursiveCall(tstate, "")) {
@@ -1570,7 +1571,8 @@ start_frame:
         goto exit_eval_frame;
     }
 
-    assert(frame == tstate->frame);
+    assert(tstate->cframe == &cframe);
+    assert(frame == cframe.current_frame);
 
     if (cframe.use_tracing) {
         if (trace_function_entry(tstate, frame)) {
@@ -4641,8 +4643,9 @@ check_eval_breaker:
                         goto error;
                     }
                     _PyFrame_SetStackPointer(frame, stack_pointer);
+                    new_frame->previous = frame;
+                    cframe.current_frame = frame = new_frame;
                     new_frame->depth = frame->depth + 1;
-                    tstate->frame = frame = new_frame;
                     goto start_frame;
                 }
             }
@@ -4723,9 +4726,9 @@ check_eval_breaker:
             STACK_SHRINK(1);
             Py_DECREF(func);
             _PyFrame_SetStackPointer(frame, stack_pointer);
-            new_frame->previous = tstate->frame;
+            new_frame->previous = frame;
+            frame = cframe.current_frame = new_frame;
             new_frame->depth = frame->depth + 1;
-            tstate->frame = frame = new_frame;
             goto start_frame;
         }
 
@@ -5258,11 +5261,12 @@ exit_eval_frame:
     _Py_LeaveRecursiveCall(tstate);
 
     if (frame->depth) {
-        _PyFrame_StackPush(frame->previous, retval);
+        cframe.current_frame = frame->previous;
+        _PyFrame_StackPush(cframe.current_frame, retval);
         if (_PyEvalFrameClearAndPop(tstate, frame)) {
             retval = NULL;
         }
-        frame = tstate->frame;
+        frame = cframe.current_frame;
         if (retval == NULL) {
             assert(_PyErr_Occurred(tstate));
             throwflag = 1;
@@ -5270,11 +5274,11 @@ exit_eval_frame:
         retval = NULL;
         goto resume_frame;
     }
-    tstate->frame = frame->previous;
 
-    /* Restore previous cframe */
+    /* Restore previous cframe. */
     tstate->cframe = cframe.previous;
     tstate->cframe->use_tracing = cframe.use_tracing;
+    assert(tstate->cframe->current_frame == frame->previous);
     return _Py_CheckFunctionResult(tstate, NULL, retval, __func__);
 }
 
@@ -5891,8 +5895,6 @@ _PyEvalFramePushAndInit(PyThreadState *tstate, PyFrameConstructor *con,
         _PyFrame_Clear(frame, 0);
         return NULL;
     }
-    frame->previous = tstate->frame;
-    tstate->frame = frame;
     return frame;
 }
 
@@ -5906,7 +5908,6 @@ _PyEvalFrameClearAndPop(PyThreadState *tstate, InterpreterFrame * frame)
         return -1;
     }
     --tstate->recursion_depth;
-    tstate->frame = frame->previous;
     _PyThreadState_PopFrame(tstate, frame);
     return 0;
 }
@@ -6518,17 +6519,17 @@ InterpreterFrame *
 _PyEval_GetFrame(void)
 {
     PyThreadState *tstate = _PyThreadState_GET();
-    return tstate->frame;
+    return tstate->cframe->current_frame;
 }
 
 PyFrameObject *
 PyEval_GetFrame(void)
 {
     PyThreadState *tstate = _PyThreadState_GET();
-    if (tstate->frame == NULL) {
+    if (tstate->cframe->current_frame == NULL) {
         return NULL;
     }
-    PyFrameObject *f = _PyFrame_GetFrameObject(tstate->frame);
+    PyFrameObject *f = _PyFrame_GetFrameObject(tstate->cframe->current_frame);
     if (f == NULL) {
         PyErr_Clear();
     }
@@ -6538,7 +6539,7 @@ PyEval_GetFrame(void)
 PyObject *
 _PyEval_GetBuiltins(PyThreadState *tstate)
 {
-    InterpreterFrame *frame = tstate->frame;
+    InterpreterFrame *frame = tstate->cframe->current_frame;
     if (frame != NULL) {
         return frame->f_builtins;
     }
@@ -6571,7 +6572,7 @@ PyObject *
 PyEval_GetLocals(void)
 {
     PyThreadState *tstate = _PyThreadState_GET();
-     InterpreterFrame *current_frame = tstate->frame;
+     InterpreterFrame *current_frame = tstate->cframe->current_frame;
     if (current_frame == NULL) {
         _PyErr_SetString(tstate, PyExc_SystemError, "frame does not exist");
         return NULL;
@@ -6590,7 +6591,7 @@ PyObject *
 PyEval_GetGlobals(void)
 {
     PyThreadState *tstate = _PyThreadState_GET();
-    InterpreterFrame *current_frame = tstate->frame;
+    InterpreterFrame *current_frame = tstate->cframe->current_frame;
     if (current_frame == NULL) {
         return NULL;
     }
@@ -6601,7 +6602,7 @@ int
 PyEval_MergeCompilerFlags(PyCompilerFlags *cf)
 {
     PyThreadState *tstate = _PyThreadState_GET();
-    InterpreterFrame *current_frame = tstate->frame;
+    InterpreterFrame *current_frame = tstate->cframe->current_frame;
     int result = cf->cf_flags != 0;
 
     if (current_frame != NULL) {
@@ -6651,7 +6652,7 @@ PyEval_GetFuncDesc(PyObject *func)
 #define C_TRACE(x, call) \
 if (use_tracing && tstate->c_profilefunc) { \
     if (call_trace(tstate->c_profilefunc, tstate->c_profileobj, \
-        tstate, tstate->frame, \
+        tstate, tstate->cframe->current_frame, \
         PyTrace_C_CALL, func)) { \
         x = NULL; \
     } \
@@ -6661,13 +6662,13 @@ if (use_tracing && tstate->c_profilefunc) { \
             if (x == NULL) { \
                 call_trace_protected(tstate->c_profilefunc, \
                     tstate->c_profileobj, \
-                    tstate, tstate->frame, \
+                    tstate, tstate->cframe->current_frame, \
                     PyTrace_C_EXCEPTION, func); \
                 /* XXX should pass (type, value, tb) */ \
             } else { \
                 if (call_trace(tstate->c_profilefunc, \
                     tstate->c_profileobj, \
-                    tstate, tstate->frame, \
+                    tstate, tstate->cframe->current_frame, \
                     PyTrace_C_RETURN, func)) { \
                     Py_DECREF(x); \
                     x = NULL; \
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 9ce845c..3ccf32a 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -2031,7 +2031,7 @@ Py_EndInterpreter(PyThreadState *tstate)
     if (tstate != _PyThreadState_GET()) {
         Py_FatalError("thread is not current");
     }
-    if (tstate->frame != NULL) {
+    if (tstate->cframe->current_frame != NULL) {
         Py_FatalError("thread still has a frame");
     }
     interp->finalizing = 1;
diff --git a/Python/pystate.c b/Python/pystate.c
index 7804e17..114f915 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -636,12 +636,12 @@ new_threadstate(PyInterpreterState *interp, int init)
 
     tstate->interp = interp;
 
-    tstate->frame = NULL;
     tstate->recursion_depth = 0;
     tstate->recursion_headroom = 0;
     tstate->stackcheck_counter = 0;
     tstate->tracing = 0;
     tstate->root_cframe.use_tracing = 0;
+    tstate->root_cframe.current_frame = NULL;
     tstate->cframe = &tstate->root_cframe;
     tstate->gilstate_counter = 0;
     tstate->async_exc = NULL;
@@ -861,7 +861,7 @@ PyThreadState_Clear(PyThreadState *tstate)
 {
     int verbose = _PyInterpreterState_GetConfig(tstate->interp)->verbose;
 
-    if (verbose && tstate->frame != NULL) {
+    if (verbose && tstate->cframe->current_frame != NULL) {
         /* bpo-20526: After the main thread calls
            _PyRuntimeState_SetFinalizing() in Py_FinalizeEx(), threads must
            exit when trying to take the GIL. If a thread exit in the middle of
@@ -1134,10 +1134,10 @@ PyFrameObject*
 PyThreadState_GetFrame(PyThreadState *tstate)
 {
     assert(tstate != NULL);
-    if (tstate->frame == NULL) {
+    if (tstate->cframe->current_frame == NULL) {
         return NULL;
     }
-    PyFrameObject *frame = _PyFrame_GetFrameObject(tstate->frame);
+    PyFrameObject *frame = _PyFrame_GetFrameObject(tstate->cframe->current_frame);
     if (frame == NULL) {
         PyErr_Clear();
     }
@@ -1277,7 +1277,7 @@ _PyThread_CurrentFrames(void)
     for (i = runtime->interpreters.head; i != NULL; i = i->next) {
         PyThreadState *t;
         for (t = i->tstate_head; t != NULL; t = t->next) {
-            InterpreterFrame *frame = t->frame;
+            InterpreterFrame *frame = t->cframe->current_frame;
             if (frame == NULL) {
                 continue;
             }
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 5e663c1..27937a0 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1813,7 +1813,7 @@ sys__getframe_impl(PyObject *module, int depth)
 /*[clinic end generated code: output=d438776c04d59804 input=c1be8a6464b11ee5]*/
 {
     PyThreadState *tstate = _PyThreadState_GET();
-    InterpreterFrame *frame = tstate->frame;
+    InterpreterFrame *frame = tstate->cframe->current_frame;
 
     if (_PySys_Audit(tstate, "sys._getframe", NULL) < 0) {
         return NULL;
diff --git a/Python/traceback.c b/Python/traceback.c
index b18cbb9..22a0922 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -1082,7 +1082,7 @@ dump_traceback(int fd, PyThreadState *tstate, int write_header)
         PUTS(fd, "Stack (most recent call first):\n");
     }
 
-    frame = tstate->frame;
+    frame = tstate->cframe->current_frame;
     if (frame == NULL) {
         PUTS(fd, "  <no Python frame>\n");
         return;