diff options
Diffstat (limited to 'Objects/structseq.c')
| -rw-r--r-- | Objects/structseq.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/Objects/structseq.c b/Objects/structseq.c index d8289f2..94f09b3 100644 --- a/Objects/structseq.c +++ b/Objects/structseq.c @@ -41,12 +41,20 @@ get_type_attr_as_size(PyTypeObject *tp, PyObject *name) get_type_attr_as_size(tp, &_Py_ID(n_sequence_fields)) #define REAL_SIZE_TP(tp) \ get_type_attr_as_size(tp, &_Py_ID(n_fields)) -#define REAL_SIZE(op) REAL_SIZE_TP(Py_TYPE(op)) +#define REAL_SIZE(op) get_real_size((PyObject *)op) #define UNNAMED_FIELDS_TP(tp) \ get_type_attr_as_size(tp, &_Py_ID(n_unnamed_fields)) #define UNNAMED_FIELDS(op) UNNAMED_FIELDS_TP(Py_TYPE(op)) +static Py_ssize_t +get_real_size(PyObject *op) +{ + // Compute the real size from the visible size (i.e., Py_SIZE()) and the + // number of non-sequence fields accounted for in tp_basicsize. + Py_ssize_t hidden = Py_TYPE(op)->tp_basicsize - offsetof(PyStructSequence, ob_item); + return Py_SIZE(op) + hidden / sizeof(PyObject *); +} PyObject * PyStructSequence_New(PyTypeObject *type) @@ -120,6 +128,9 @@ structseq_dealloc(PyStructSequence *obj) PyObject_GC_UnTrack(obj); PyTypeObject *tp = Py_TYPE(obj); + // gh-122527: We can't use REAL_SIZE_TP() or any macros that access the + // type's dictionary here, because the dictionary may have already been + // cleared by the garbage collector. size = REAL_SIZE(obj); for (i = 0; i < size; ++i) { Py_XDECREF(obj->ob_item[i]); @@ -565,10 +576,14 @@ initialize_members(PyStructSequence_Desc *desc, static void initialize_static_fields(PyTypeObject *type, PyStructSequence_Desc *desc, - PyMemberDef *tp_members, unsigned long tp_flags) + PyMemberDef *tp_members, Py_ssize_t n_members, + unsigned long tp_flags) { type->tp_name = desc->name; - type->tp_basicsize = sizeof(PyStructSequence) - sizeof(PyObject *); + // Account for hidden members in tp_basicsize because they are not + // included in the variable size. + Py_ssize_t n_hidden = n_members - desc->n_in_sequence; + type->tp_basicsize = sizeof(PyStructSequence) + (n_hidden - 1) * sizeof(PyObject *); type->tp_itemsize = sizeof(PyObject *); type->tp_dealloc = (destructor)structseq_dealloc; type->tp_repr = (reprfunc)structseq_repr; @@ -621,7 +636,7 @@ _PyStructSequence_InitBuiltinWithFlags(PyInterpreterState *interp, if (members == NULL) { goto error; } - initialize_static_fields(type, desc, members, tp_flags); + initialize_static_fields(type, desc, members, n_members, tp_flags); _Py_SetImmortal((PyObject *)type); } @@ -684,7 +699,7 @@ PyStructSequence_InitType2(PyTypeObject *type, PyStructSequence_Desc *desc) if (members == NULL) { return -1; } - initialize_static_fields(type, desc, members, 0); + initialize_static_fields(type, desc, members, n_members, 0); if (initialize_static_type(type, desc, n_members, n_unnamed_members) < 0) { PyMem_Free(members); return -1; @@ -760,7 +775,8 @@ _PyStructSequence_NewType(PyStructSequence_Desc *desc, unsigned long tp_flags) /* The name in this PyType_Spec is statically allocated so it is */ /* expected that it'll outlive the PyType_Spec */ spec.name = desc->name; - spec.basicsize = sizeof(PyStructSequence) - sizeof(PyObject *); + Py_ssize_t hidden = n_members - desc->n_in_sequence; + spec.basicsize = (int)(sizeof(PyStructSequence) + (hidden - 1) * sizeof(PyObject *)); spec.itemsize = sizeof(PyObject *); spec.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | tp_flags; spec.slots = slots; |