[Python-checkins] gh-99537: Use Py_SETREF() function in C code (#99656)
vstinner
webhook-mailer at python.org
Tue Nov 22 08:22:31 EST 2022
https://github.com/python/cpython/commit/7e3f09cad9b783d8968aa79ff6a8ee57beb8b83e
commit: 7e3f09cad9b783d8968aa79ff6a8ee57beb8b83e
branch: main
author: Victor Stinner <vstinner at python.org>
committer: vstinner <vstinner at python.org>
date: 2022-11-22T14:22:22+01:00
summary:
gh-99537: Use Py_SETREF() function in C code (#99656)
Fix potential race condition in code patterns:
* Replace "Py_DECREF(var); var = new;" with "Py_SETREF(var, new);"
* Replace "Py_XDECREF(var); var = new;" with "Py_XSETREF(var, new);"
* Replace "Py_CLEAR(var); var = new;" with "Py_XSETREF(var, new);"
Other changes:
* Replace "old = var; var = new; Py_DECREF(var)"
with "Py_SETREF(var, new);"
* Replace "old = var; var = new; Py_XDECREF(var)"
with "Py_XSETREF(var, new);"
* And remove the "old" variable.
files:
M Doc/includes/custom2.c
M Doc/includes/custom3.c
M Doc/includes/custom4.c
M Modules/_collectionsmodule.c
M Modules/_datetimemodule.c
M Modules/_elementtree.c
M Modules/_functoolsmodule.c
M Modules/_io/stringio.c
M Modules/_io/textio.c
M Modules/_json.c
M Modules/_pickle.c
M Modules/_sqlite/cursor.c
M Modules/_testinternalcapi.c
M Modules/_tkinter.c
M Modules/_zoneinfo.c
M Modules/audioop.c
M Modules/cjkcodecs/multibytecodec.c
M Modules/itertoolsmodule.c
M Modules/mathmodule.c
M Modules/posixmodule.c
diff --git a/Doc/includes/custom2.c b/Doc/includes/custom2.c
index 6638b9fbc1d7..a3b2d6ab78d3 100644
--- a/Doc/includes/custom2.c
+++ b/Doc/includes/custom2.c
@@ -42,7 +42,7 @@ static int
Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
{
static char *kwlist[] = {"first", "last", "number", NULL};
- PyObject *first = NULL, *last = NULL, *tmp;
+ PyObject *first = NULL, *last = NULL;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist,
&first, &last,
@@ -50,14 +50,10 @@ Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
return -1;
if (first) {
- tmp = self->first;
- self->first = Py_NewRef(first);
- Py_XDECREF(tmp);
+ Py_XSETREF(self->first, Py_NewRef(first));
}
if (last) {
- tmp = self->last;
- self->last = Py_NewRef(last);
- Py_XDECREF(tmp);
+ Py_XSETREF(self->last, Py_NewRef(last));
}
return 0;
}
diff --git a/Doc/includes/custom3.c b/Doc/includes/custom3.c
index 0faf2bd4be17..1a68bc4be8c3 100644
--- a/Doc/includes/custom3.c
+++ b/Doc/includes/custom3.c
@@ -42,7 +42,7 @@ static int
Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
{
static char *kwlist[] = {"first", "last", "number", NULL};
- PyObject *first = NULL, *last = NULL, *tmp;
+ PyObject *first = NULL, *last = NULL;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist,
&first, &last,
@@ -50,14 +50,10 @@ Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
return -1;
if (first) {
- tmp = self->first;
- self->first = Py_NewRef(first);
- Py_DECREF(tmp);
+ Py_SETREF(self->first, Py_NewRef(first));
}
if (last) {
- tmp = self->last;
- self->last = Py_NewRef(last);
- Py_DECREF(tmp);
+ Py_SETREF(self->last, Py_NewRef(last));
}
return 0;
}
@@ -77,7 +73,6 @@ Custom_getfirst(CustomObject *self, void *closure)
static int
Custom_setfirst(CustomObject *self, PyObject *value, void *closure)
{
- PyObject *tmp;
if (value == NULL) {
PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute");
return -1;
@@ -87,9 +82,7 @@ Custom_setfirst(CustomObject *self, PyObject *value, void *closure)
"The first attribute value must be a string");
return -1;
}
- tmp = self->first;
- self->first = Py_NewRef(value);
- Py_DECREF(tmp);
+ Py_SETREF(self->first, Py_NewRef(value));
return 0;
}
@@ -102,7 +95,6 @@ Custom_getlast(CustomObject *self, void *closure)
static int
Custom_setlast(CustomObject *self, PyObject *value, void *closure)
{
- PyObject *tmp;
if (value == NULL) {
PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute");
return -1;
@@ -112,9 +104,7 @@ Custom_setlast(CustomObject *self, PyObject *value, void *closure)
"The last attribute value must be a string");
return -1;
}
- tmp = self->last;
- self->last = Py_NewRef(value);
- Py_DECREF(tmp);
+ Py_SETREF(self->last, Py_NewRef(value));
return 0;
}
diff --git a/Doc/includes/custom4.c b/Doc/includes/custom4.c
index b725bc0b6fae..b932d159d26e 100644
--- a/Doc/includes/custom4.c
+++ b/Doc/includes/custom4.c
@@ -58,7 +58,7 @@ static int
Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
{
static char *kwlist[] = {"first", "last", "number", NULL};
- PyObject *first = NULL, *last = NULL, *tmp;
+ PyObject *first = NULL, *last = NULL;
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist,
&first, &last,
@@ -66,14 +66,10 @@ Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
return -1;
if (first) {
- tmp = self->first;
- self->first = Py_NewRef(first);
- Py_DECREF(tmp);
+ Py_SETREF(self->first, Py_NewRef(first));
}
if (last) {
- tmp = self->last;
- self->last = Py_NewRef(last);
- Py_DECREF(tmp);
+ Py_SETREF(self->last, Py_NewRef(last));
}
return 0;
}
@@ -102,9 +98,7 @@ Custom_setfirst(CustomObject *self, PyObject *value, void *closure)
"The first attribute value must be a string");
return -1;
}
- Py_INCREF(value);
- Py_CLEAR(self->first);
- self->first = value;
+ Py_XSETREF(self->first, Py_NewRef(value));
return 0;
}
@@ -126,9 +120,7 @@ Custom_setlast(CustomObject *self, PyObject *value, void *closure)
"The last attribute value must be a string");
return -1;
}
- Py_INCREF(value);
- Py_CLEAR(self->last);
- self->last = value;
+ Py_XSETREF(self->last, Py_NewRef(value));
return 0;
}
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index f1fd271f6d21..5fa583821889 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -1256,7 +1256,6 @@ deque_remove(dequeobject *deque, PyObject *value)
static int
deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v)
{
- PyObject *old_value;
block *b;
Py_ssize_t n, len=Py_SIZE(deque), halflen=(len+1)>>1, index=i;
@@ -1282,9 +1281,7 @@ deque_ass_item(dequeobject *deque, Py_ssize_t i, PyObject *v)
while (--n >= 0)
b = b->leftlink;
}
- old_value = b->data[i];
- b->data[i] = Py_NewRef(v);
- Py_DECREF(old_value);
+ Py_SETREF(b->data[i], Py_NewRef(v));
return 0;
}
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index 20e8516fcde7..712abc3346fa 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -6247,13 +6247,10 @@ datetime_astimezone(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
}
else {
/* Result is already aware - just replace tzinfo. */
- temp = result->tzinfo;
- result->tzinfo = Py_NewRef(PyDateTime_TimeZone_UTC);
- Py_DECREF(temp);
+ Py_SETREF(result->tzinfo, Py_NewRef(PyDateTime_TimeZone_UTC));
}
/* Attach new tzinfo and let fromutc() do the rest. */
- temp = result->tzinfo;
if (tzinfo == Py_None) {
tzinfo = local_timezone(result);
if (tzinfo == NULL) {
@@ -6263,8 +6260,7 @@ datetime_astimezone(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
}
else
Py_INCREF(tzinfo);
- result->tzinfo = tzinfo;
- Py_DECREF(temp);
+ Py_SETREF(result->tzinfo, tzinfo);
temp = (PyObject *)result;
result = (PyDateTime_DateTime *)
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index 7b0977931f2a..3df93651654a 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -537,8 +537,7 @@ element_get_text(ElementObject* self)
if (!tmp)
return NULL;
self->text = tmp;
- Py_DECREF(res);
- res = tmp;
+ Py_SETREF(res, tmp);
}
}
@@ -559,8 +558,7 @@ element_get_tail(ElementObject* self)
if (!tmp)
return NULL;
self->tail = tmp;
- Py_DECREF(res);
- res = tmp;
+ Py_SETREF(res, tmp);
}
}
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
index 9b30f41ec699..4032ba79374f 100644
--- a/Modules/_functoolsmodule.c
+++ b/Modules/_functoolsmodule.c
@@ -1243,8 +1243,7 @@ lru_cache_clear_list(lru_list_elem *link)
{
while (link != NULL) {
lru_list_elem *next = link->next;
- Py_DECREF(link);
- link = next;
+ Py_SETREF(link, next);
}
}
diff --git a/Modules/_io/stringio.c b/Modules/_io/stringio.c
index 5c3bf353680e..ae6c3125a2d9 100644
--- a/Modules/_io/stringio.c
+++ b/Modules/_io/stringio.c
@@ -193,8 +193,7 @@ write_str(stringio *self, PyObject *obj)
if (self->writenl) {
PyObject *translated = PyUnicode_Replace(
decoded, &_Py_STR(newline), self->writenl, -1);
- Py_DECREF(decoded);
- decoded = translated;
+ Py_SETREF(decoded, translated);
}
if (decoded == NULL)
return -1;
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 8b5d00fe4aaf..ff903e9341de 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -320,8 +320,7 @@ _PyIncrementalNewlineDecoder_decode(PyObject *myself,
out = PyUnicode_DATA(modified);
PyUnicode_WRITE(kind, out, 0, '\r');
memcpy(out + kind, PyUnicode_DATA(output), kind * output_len);
- Py_DECREF(output);
- output = modified; /* output remains ready */
+ Py_SETREF(output, modified); /* output remains ready */
self->pendingcr = 0;
output_len++;
}
@@ -336,8 +335,7 @@ _PyIncrementalNewlineDecoder_decode(PyObject *myself,
PyObject *modified = PyUnicode_Substring(output, 0, output_len -1);
if (modified == NULL)
goto error;
- Py_DECREF(output);
- output = modified;
+ Py_SETREF(output, modified);
self->pendingcr = 1;
}
}
@@ -865,8 +863,7 @@ _textiowrapper_set_decoder(textio *self, PyObject *codec_info,
self->decoder, self->readtranslate ? Py_True : Py_False, NULL);
if (incrementalDecoder == NULL)
return -1;
- Py_CLEAR(self->decoder);
- self->decoder = incrementalDecoder;
+ Py_XSETREF(self->decoder, incrementalDecoder);
}
return 0;
diff --git a/Modules/_json.c b/Modules/_json.c
index 06f232f7d7de..81431aa1041c 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -709,9 +709,7 @@ _parse_object_unicode(PyScannerObject *s, PyObject *pystr, Py_ssize_t idx, Py_ss
if (memokey == NULL) {
goto bail;
}
- Py_INCREF(memokey);
- Py_DECREF(key);
- key = memokey;
+ Py_SETREF(key, Py_NewRef(memokey));
idx = next_idx;
/* skip whitespace between key and : delimiter, read :, skip whitespace */
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index db62094c5a5a..1e118e9cd10b 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1829,8 +1829,7 @@ get_deep_attribute(PyObject *obj, PyObject *names, PyObject **pparent)
n = PyList_GET_SIZE(names);
for (i = 0; i < n; i++) {
PyObject *name = PyList_GET_ITEM(names, i);
- Py_XDECREF(parent);
- parent = obj;
+ Py_XSETREF(parent, obj);
(void)_PyObject_LookupAttr(parent, name, &obj);
if (obj == NULL) {
Py_DECREF(parent);
@@ -3717,9 +3716,7 @@ save_global(PicklerObject *self, PyObject *obj, PyObject *name)
else {
gen_global:
if (parent == module) {
- Py_INCREF(lastname);
- Py_DECREF(global_name);
- global_name = lastname;
+ Py_SETREF(global_name, Py_NewRef(lastname));
}
if (self->proto >= 4) {
const char stack_global_op = STACK_GLOBAL;
diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
index 7844b6e26cdb..a4e22bb4a2b5 100644
--- a/Modules/_sqlite/cursor.c
+++ b/Modules/_sqlite/cursor.c
@@ -1123,8 +1123,7 @@ pysqlite_cursor_iternext(pysqlite_Cursor *self)
PyObject *factory = self->row_factory;
PyObject *args[] = { (PyObject *)self, row, };
PyObject *new_row = PyObject_Vectorcall(factory, args, 2, NULL);
- Py_DECREF(row);
- row = new_row;
+ Py_SETREF(row, new_row);
}
return row;
}
diff --git a/Modules/_testinternalcapi.c b/Modules/_testinternalcapi.c
index cec114cb5919..b14b8ac3c740 100644
--- a/Modules/_testinternalcapi.c
+++ b/Modules/_testinternalcapi.c
@@ -523,8 +523,7 @@ set_eval_frame_record(PyObject *self, PyObject *list)
PyErr_SetString(PyExc_TypeError, "argument must be a list");
return NULL;
}
- Py_CLEAR(record_list);
- record_list = Py_NewRef(list);
+ Py_XSETREF(record_list, Py_NewRef(list));
_PyInterpreterState_SetEvalFrameFunc(PyInterpreterState_Get(), record_eval);
Py_RETURN_NONE;
}
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index a5d5428eaf50..6ff7d2bfced2 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -1105,8 +1105,7 @@ fromBignumObj(TkappObject *tkapp, Tcl_Obj *value)
PyMem_Free(bytes);
if (res != NULL && bigValue.sign == MP_NEG) {
PyObject *res2 = PyNumber_Negative(res);
- Py_DECREF(res);
- res = res2;
+ Py_SETREF(res, res2);
}
mp_clear(&bigValue);
return res;
diff --git a/Modules/_zoneinfo.c b/Modules/_zoneinfo.c
index 34f5abd343ec..c0fef13ba17d 100644
--- a/Modules/_zoneinfo.c
+++ b/Modules/_zoneinfo.c
@@ -1074,8 +1074,7 @@ load_data(PyZoneInfo_ZoneInfo *self, PyObject *file_obj)
// that the dstoff is set correctly in that case.
if (PyObject_IsTrue(tti->dstoff)) {
_ttinfo *tti_after = &(self->tzrule_after.std);
- Py_DECREF(tti_after->dstoff);
- tti_after->dstoff = Py_NewRef(tti->dstoff);
+ Py_SETREF(tti_after->dstoff, Py_NewRef(tti->dstoff));
}
}
diff --git a/Modules/audioop.c b/Modules/audioop.c
index 6d484e8bba3e..9325f82f9a17 100644
--- a/Modules/audioop.c
+++ b/Modules/audioop.c
@@ -1471,8 +1471,7 @@ audioop_ratecv_impl(PyObject *module, Py_buffer *fragment, int width,
len = (Py_ssize_t)(ncp - PyBytes_AsString(str));
rv = PyBytes_FromStringAndSize
(PyBytes_AsString(str), len);
- Py_DECREF(str);
- str = rv;
+ Py_SETREF(str, rv);
if (str == NULL)
goto exit;
rv = Py_BuildValue("(O(iO))", str, d, samps);
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 6d67fce1da03..8b6232695d4c 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -980,8 +980,7 @@ _multibytecodec_MultibyteIncrementalEncoder_setstate_impl(MultibyteIncrementalEn
goto errorexit;
}
- Py_CLEAR(self->pending);
- self->pending = pending;
+ Py_XSETREF(self->pending, pending);
memcpy(self->state.c, statebytes+1+statebytes[0],
sizeof(self->state.c));
@@ -1438,8 +1437,7 @@ mbstreamreader_iread(MultibyteStreamReaderObject *self,
memcpy(ctrdata + self->pendingsize,
PyBytes_AS_STRING(cres),
PyBytes_GET_SIZE(cres));
- Py_DECREF(cres);
- cres = ctr;
+ Py_SETREF(cres, ctr);
self->pendingsize = 0;
}
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 65d014250522..4b0a4d88c435 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -834,8 +834,7 @@ teedataobject_safe_decref(PyObject *obj)
Py_REFCNT(obj) == 1) {
PyObject *nextlink = ((teedataobject *)obj)->nextlink;
((teedataobject *)obj)->nextlink = NULL;
- Py_DECREF(obj);
- obj = nextlink;
+ Py_SETREF(obj, nextlink);
}
Py_XDECREF(obj);
}
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 16a2f45c8b84..83eb338be9b8 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -2069,8 +2069,7 @@ factorial_odd_part(unsigned long n)
Py_DECREF(partial);
if (tmp == NULL)
goto error;
- Py_DECREF(inner);
- inner = tmp;
+ Py_SETREF(inner, tmp);
/* Now inner is the product of all odd integers j in the range (0,
n/2**i], giving the inner product in the formula above. */
@@ -2078,8 +2077,7 @@ factorial_odd_part(unsigned long n)
tmp = PyNumber_Multiply(outer, inner);
if (tmp == NULL)
goto error;
- Py_DECREF(outer);
- outer = tmp;
+ Py_SETREF(outer, tmp);
}
Py_DECREF(inner);
return outer;
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 6d65ae97c9e3..98fc264aff6b 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -1202,8 +1202,7 @@ path_converter(PyObject *o, void *p)
}
/* still owns a reference to the original object */
- Py_DECREF(o);
- o = res;
+ Py_SETREF(o, res);
}
if (is_unicode) {
More information about the Python-checkins
mailing list