Address review

Author: Fidget-Spinner

Include/internal/pycore_stackref.h

@@ -374,7 +374,6 @@ PyStackRef_FromPyObjectBorrow(PyObject *obj)
 }
 #define PyStackRef_FromPyObjectBorrow(obj) PyStackRef_FromPyObjectBorrow(_PyObject_CAST(obj))
 
-
 #define PyStackRef_CLOSE(REF)                                        \
         do {                                                            \
             _PyStackRef _close_tmp = (REF);                             \

Python/optimizer_cases.c.h

@@ -170,11 +170,10 @@ _Py_uop_sym_is_safe_const(JitOptContext *ctx, JitOptSymbol *sym)
     }
     PyTypeObject *typ = Py_TYPE(const_val);
     return (typ == &PyLong_Type) ||
-        (typ == &PyUnicode_Type) ||
-        (typ == &PyFloat_Type) ||
-        (typ == &PyDict_Type) ||
-        (typ == &PyTuple_Type) ||
-        (typ == &PyList_Type);
+           (typ == &PyUnicode_Type) ||
+           (typ == &PyFloat_Type) ||
+           (typ == &PyDict_Type) ||
+           (typ == &PyTuple_Type);
 }
 
 void
@@ -438,6 +437,10 @@ _Py_uop_sym_new_const_steal(JitOptContext *ctx, PyObject *const_val)
 {
     assert(const_val != NULL);
     JitOptSymbol *res = _Py_uop_sym_new_const(ctx, const_val);
+    // Decref once because sym_new_const increfs it.
+    Py_DECREF(const_val);
+    // Decref it another time, because we are a steal operation.
+    // (Ownership now belongs to the symbol).
     Py_DECREF(const_val);
     return res;
 }

Python/optimizer_symbols.c

@@ -217,7 +217,7 @@ def write_uop_pure_evaluation_region_header(
         # All new stackrefs are created from new references.
         # That's how the stackref contract works.
         if not outp.peek:
-            emitter.emit(f"{outp.name} = sym_new_const_steal(ctx, PyStackRef_AsPyObjectBorrow({outp.name}_stackref));\n")
+            emitter.emit(f"{outp.name} = sym_new_const_steal(ctx, PyStackRef_AsPyObjectSteal({outp.name}_stackref));\n")
         else:
             emitter.emit(f"{outp.name} = sym_new_const(ctx, PyStackRef_AsPyObjectBorrow({outp.name}_stackref));\n")
     storage.flush(out)