GH-100987: Don't cache references to the names and consts array in _PyEval_EvalFrameDefault. (#102640)

* Rename local variables, names and consts, from the interpeter loop. Will allow non-code objects in frames for better introspection of C builtins and extensions.

* Remove unused dummy variables.

Author: markshannon

Python/bytecodes.c

@@ -70,8 +70,6 @@ dummy_func(
     unsigned int oparg,
     _Py_atomic_int * const eval_breaker,
     _PyCFrame cframe,
-    PyObject *names,
-    PyObject *consts,
     _Py_CODEUNIT *next_instr,
     PyObject **stack_pointer,
     PyObject *kwnames,
@@ -115,7 +113,7 @@ dummy_func(
         }
 
         inst(LOAD_CONST, (-- value)) {
-            value = GETITEM(consts, oparg);
+            value = GETITEM(frame->f_code->co_consts, oparg);
             Py_INCREF(value);
         }
 
@@ -554,7 +552,7 @@ dummy_func(
         }
 
         inst(RETURN_CONST, (--)) {
-            PyObject *retval = GETITEM(consts, oparg);
+            PyObject *retval = GETITEM(frame->f_code->co_consts, oparg);
             Py_INCREF(retval);
             assert(EMPTY());
             _PyFrame_SetStackPointer(frame, stack_pointer);
@@ -844,7 +842,7 @@ dummy_func(
         }
 
         inst(STORE_NAME, (v -- )) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             PyObject *ns = LOCALS();
             int err;
             if (ns == NULL) {
@@ -862,7 +860,7 @@ dummy_func(
         }
 
         inst(DELETE_NAME, (--)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             PyObject *ns = LOCALS();
             int err;
             if (ns == NULL) {
@@ -956,7 +954,7 @@ dummy_func(
             #if ENABLE_SPECIALIZATION
             if (ADAPTIVE_COUNTER_IS_ZERO(counter)) {
                 assert(cframe.use_tracing == 0);
-                PyObject *name = GETITEM(names, oparg);
+                PyObject *name = GETITEM(frame->f_code->co_names, oparg);
                 next_instr--;
                 _Py_Specialize_StoreAttr(owner, next_instr, name);
                 DISPATCH_SAME_OPARG();
@@ -967,29 +965,29 @@ dummy_func(
             #else
             (void)counter;  // Unused.
             #endif  /* ENABLE_SPECIALIZATION */
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err = PyObject_SetAttr(owner, name, v);
             Py_DECREF(v);
             Py_DECREF(owner);
             ERROR_IF(err, error);
         }
 
         inst(DELETE_ATTR, (owner --)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err = PyObject_SetAttr(owner, name, (PyObject *)NULL);
             Py_DECREF(owner);
             ERROR_IF(err, error);
         }
 
         inst(STORE_GLOBAL, (v --)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err = PyDict_SetItem(GLOBALS(), name, v);
             Py_DECREF(v);
             ERROR_IF(err, error);
         }
 
         inst(DELETE_GLOBAL, (--)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             int err;
             err = PyDict_DelItem(GLOBALS(), name);
             // Can't use ERROR_IF here.
@@ -1003,7 +1001,7 @@ dummy_func(
         }
 
         inst(LOAD_NAME, ( -- v)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             PyObject *locals = LOCALS();
             if (locals == NULL) {
                 _PyErr_Format(tstate, PyExc_SystemError,
@@ -1074,15 +1072,15 @@ dummy_func(
             _PyLoadGlobalCache *cache = (_PyLoadGlobalCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
                 assert(cframe.use_tracing == 0);
-                PyObject *name = GETITEM(names, oparg>>1);
+                PyObject *name = GETITEM(frame->f_code->co_names, oparg>>1);
                 next_instr--;
                 _Py_Specialize_LoadGlobal(GLOBALS(), BUILTINS(), next_instr, name);
                 DISPATCH_SAME_OPARG();
             }
             STAT_INC(LOAD_GLOBAL, deferred);
             DECREMENT_ADAPTIVE_COUNTER(cache->counter);
             #endif  /* ENABLE_SPECIALIZATION */
-            PyObject *name = GETITEM(names, oparg>>1);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg>>1);
             if (PyDict_CheckExact(GLOBALS())
                 && PyDict_CheckExact(BUILTINS()))
             {
@@ -1436,15 +1434,15 @@ dummy_func(
             _PyAttrCache *cache = (_PyAttrCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
                 assert(cframe.use_tracing == 0);
-                PyObject *name = GETITEM(names, oparg>>1);
+                PyObject *name = GETITEM(frame->f_code->co_names, oparg>>1);
                 next_instr--;
                 _Py_Specialize_LoadAttr(owner, next_instr, name);
                 DISPATCH_SAME_OPARG();
             }
             STAT_INC(LOAD_ATTR, deferred);
             DECREMENT_ADAPTIVE_COUNTER(cache->counter);
             #endif  /* ENABLE_SPECIALIZATION */
-            PyObject *name = GETITEM(names, oparg >> 1);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg >> 1);
             if (oparg & 1) {
                 /* Designed to work in tandem with CALL, pushes two values. */
                 PyObject* meth = NULL;
@@ -1525,7 +1523,7 @@ dummy_func(
             PyDictObject *dict = (PyDictObject *)_PyDictOrValues_GetDict(dorv);
             DEOPT_IF(dict == NULL, LOAD_ATTR);
             assert(PyDict_CheckExact((PyObject *)dict));
-            PyObject *name = GETITEM(names, oparg>>1);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg>>1);
             uint16_t hint = index;
             DEOPT_IF(hint >= (size_t)dict->ma_keys->dk_nentries, LOAD_ATTR);
             if (DK_IS_UNICODE(dict->ma_keys)) {
@@ -1616,7 +1614,7 @@ dummy_func(
             DEOPT_IF(!_PyThreadState_HasStackSpace(tstate, code->co_framesize), LOAD_ATTR);
             STAT_INC(LOAD_ATTR, hit);
 
-            PyObject *name = GETITEM(names, oparg >> 1);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg >> 1);
             Py_INCREF(f);
             _PyInterpreterFrame *new_frame = _PyFrame_PushUnchecked(tstate, f, 2);
             // Manipulate stack directly because we exit with DISPATCH_INLINED().
@@ -1661,7 +1659,7 @@ dummy_func(
             PyDictObject *dict = (PyDictObject *)_PyDictOrValues_GetDict(dorv);
             DEOPT_IF(dict == NULL, STORE_ATTR);
             assert(PyDict_CheckExact((PyObject *)dict));
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             DEOPT_IF(hint >= (size_t)dict->ma_keys->dk_nentries, STORE_ATTR);
             PyObject *old_value;
             uint64_t new_version;
@@ -1855,14 +1853,14 @@ dummy_func(
         }
 
          inst(IMPORT_NAME, (level, fromlist -- res)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             res = import_name(tstate, frame, name, fromlist, level);
             DECREF_INPUTS();
             ERROR_IF(res == NULL, error);
         }
 
         inst(IMPORT_FROM, (from -- from, res)) {
-            PyObject *name = GETITEM(names, oparg);
+            PyObject *name = GETITEM(frame->f_code->co_names, oparg);
             res = import_from(tstate, from, name);
             ERROR_IF(res == NULL, error);
         }
@@ -2360,8 +2358,8 @@ dummy_func(
 
         inst(KW_NAMES, (--)) {
             assert(kwnames == NULL);
-            assert(oparg < PyTuple_GET_SIZE(consts));
-            kwnames = GETITEM(consts, oparg);
+            assert(oparg < PyTuple_GET_SIZE(frame->f_code->co_consts));
+            kwnames = GETITEM(frame->f_code->co_consts, oparg);
         }
 
         // Cache layout: counter/1, func_version/2, min_args/1

Python/ceval.c

@@ -773,18 +773,11 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     /* Local "register" variables.
      * These are cached values from the frame and code object.  */
 
-    PyObject *names;
-    PyObject *consts;
     _Py_CODEUNIT *next_instr;
     PyObject **stack_pointer;
 
 /* Sets the above local variables from the frame */
 #define SET_LOCALS_FROM_FRAME() \
-    { \
-        PyCodeObject *co = frame->f_code; \
-        names = co->co_names; \
-        consts = co->co_consts; \
-    } \
     assert(_PyInterpreterFrame_LASTI(frame) >= -1); \
     /* Jump back to the last instruction executed... */ \
     next_instr = frame->prev_instr + 1; \