Support tail-calling

Author: markshannon

Python/ceval.c

@@ -1039,7 +1039,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
         monitor_throw(tstate, frame, next_instr);
         stack_pointer = _PyFrame_GetStackPointer(frame);
 #if Py_TAIL_CALL_INTERP
-        return _TAIL_CALL_error(frame, stack_pointer, tstate, next_instr, 0);
+        return _TAIL_CALL_error(frame, stack_pointer, tstate, next_instr, 0, PyStackRef_NULL);
 #else
         goto error;
 #endif
@@ -1052,7 +1052,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 #endif
     _PyStackRef _tos = PyStackRef_NULL;
 #if Py_TAIL_CALL_INTERP
-    return _TAIL_CALL_start_frame(frame, NULL, tstate, NULL, 0);
+    return _TAIL_CALL_start_frame(frame, NULL, tstate, NULL, 0, _tos);
 #else
     goto start_frame;
 #   include "generated_cases.c.h"

Python/ceval_macros.h

@@ -70,8 +70,8 @@
 #define INSTRUCTION_STATS(op) ((void)0)
 #endif
 
-#define TAIL_CALL_PARAMS _PyInterpreterFrame *frame, _PyStackRef *stack_pointer, PyThreadState *tstate, _Py_CODEUNIT *next_instr, int oparg
-#define TAIL_CALL_ARGS frame, stack_pointer, tstate, next_instr, oparg
+#define TAIL_CALL_PARAMS _PyInterpreterFrame *frame, _PyStackRef *stack_pointer, PyThreadState *tstate, _Py_CODEUNIT *next_instr, int oparg, _PyStackRef _tos
+#define TAIL_CALL_ARGS frame, stack_pointer, tstate, next_instr, oparg, _tos
 
 #if Py_TAIL_CALL_INTERP
     // Note: [[clang::musttail]] works for GCC 15, but not __attribute__((musttail)) at the moment.
@@ -90,7 +90,7 @@
         } while (0)
 #   define JUMP_TO_PREDICTED(name) \
         do { \
-            Py_MUSTTAIL return (_TAIL_CALL_##name)(frame, stack_pointer, tstate, this_instr, oparg); \
+            Py_MUSTTAIL return (_TAIL_CALL_##name)(frame, stack_pointer, tstate, this_instr, oparg, _tos); \
         } while (0)
 #    define LABEL(name) TARGET(name)
 #elif USE_COMPUTED_GOTOS