[Python-checkins] gh-99845: Clean up _PyObject_VAR_SIZE() usage (#99847)
vstinner
webhook-mailer at python.org
Tue Nov 29 06:15:27 EST 2022
https://github.com/python/cpython/commit/74d5f61ebd1cb14907bf7dae1ad9c1e676707bc5
commit: 74d5f61ebd1cb14907bf7dae1ad9c1e676707bc5
branch: main
author: Victor Stinner <vstinner at python.org>
committer: vstinner <vstinner at python.org>
date: 2022-11-29T12:15:21+01:00
summary:
gh-99845: Clean up _PyObject_VAR_SIZE() usage (#99847)
* code_sizeof() now uses an unsigned type (size_t) to compute the result.
* Fix _PyObject_ComputedDictPointer(): cast _PyObject_VAR_SIZE() to
Py_ssize_t, rather than long: it's a different type on 64-bit Windows.
* Clarify that _PyObject_VAR_SIZE() uses an unsigned type (size_t).
files:
M Modules/gcmodule.c
M Objects/codeobject.c
M Objects/object.c
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index cacfad733563..6630faa6f447 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -2329,7 +2329,6 @@ _PyObject_GC_New(PyTypeObject *tp)
PyVarObject *
_PyObject_GC_NewVar(PyTypeObject *tp, Py_ssize_t nitems)
{
- size_t size;
PyVarObject *op;
if (nitems < 0) {
@@ -2337,7 +2336,7 @@ _PyObject_GC_NewVar(PyTypeObject *tp, Py_ssize_t nitems)
return NULL;
}
size_t presize = _PyType_PreHeaderSize(tp);
- size = _PyObject_VAR_SIZE(tp, nitems);
+ size_t size = _PyObject_VAR_SIZE(tp, nitems);
op = (PyVarObject *)gc_alloc(size, presize);
if (op == NULL) {
return NULL;
@@ -2351,7 +2350,7 @@ _PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems)
{
const size_t basicsize = _PyObject_VAR_SIZE(Py_TYPE(op), nitems);
_PyObject_ASSERT((PyObject *)op, !_PyObject_GC_IS_TRACKED(op));
- if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head)) {
+ if (basicsize > (size_t)PY_SSIZE_T_MAX - sizeof(PyGC_Head)) {
return (PyVarObject *)PyErr_NoMemory();
}
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index fc1db72977aa..f5d90cf65fce 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -1867,15 +1867,13 @@ static PyGetSetDef code_getsetlist[] = {
static PyObject *
code_sizeof(PyCodeObject *co, PyObject *Py_UNUSED(args))
{
- Py_ssize_t res = _PyObject_VAR_SIZE(Py_TYPE(co), Py_SIZE(co));
-
+ size_t res = _PyObject_VAR_SIZE(Py_TYPE(co), Py_SIZE(co));
_PyCodeObjectExtra *co_extra = (_PyCodeObjectExtra*) co->co_extra;
if (co_extra != NULL) {
- res += sizeof(_PyCodeObjectExtra) +
- (co_extra->ce_size-1) * sizeof(co_extra->ce_extras[0]);
+ res += sizeof(_PyCodeObjectExtra);
+ res += ((size_t)co_extra->ce_size - 1) * sizeof(co_extra->ce_extras[0]);
}
-
- return PyLong_FromSsize_t(res);
+ return PyLong_FromSize_t(res);
}
static PyObject *
diff --git a/Objects/object.c b/Objects/object.c
index a499cb32b22f..687bd36d2b4a 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1043,22 +1043,25 @@ PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)
PyObject **
_PyObject_ComputedDictPointer(PyObject *obj)
{
- Py_ssize_t dictoffset;
PyTypeObject *tp = Py_TYPE(obj);
-
assert((tp->tp_flags & Py_TPFLAGS_MANAGED_DICT) == 0);
- dictoffset = tp->tp_dictoffset;
- if (dictoffset == 0)
+
+ Py_ssize_t dictoffset = tp->tp_dictoffset;
+ if (dictoffset == 0) {
return NULL;
+ }
+
if (dictoffset < 0) {
assert(dictoffset != -1);
+
Py_ssize_t tsize = Py_SIZE(obj);
if (tsize < 0) {
tsize = -tsize;
}
size_t size = _PyObject_VAR_SIZE(tp, tsize);
+ assert(size <= (size_t)PY_SSIZE_T_MAX);
+ dictoffset += (Py_ssize_t)size;
- dictoffset += (long)size;
_PyObject_ASSERT(obj, dictoffset > 0);
_PyObject_ASSERT(obj, dictoffset % SIZEOF_VOID_P == 0);
}
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