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Argument Clinic: Unsafe code generation with defining_class and no slash #117613
Description
Bug report
Bug description:
When using the Argument Clinic to implement a function with METH_METHOD calling convention, the generated code can cause a crash if defining_class is used without slashing. For example, datetime.now() in Modules/_datetimemodule.c produces:
/*[clinic input]
@classmethod
datetime.datetime.now
+ cls: defining_class
tz: object = None
Timezone object.
Returns new datetime object representing current time local to tz.
If no tz is specified, uses local timezone.
[clinic start generated code]*/
static PyObject *
datetime_datetime_now_impl(PyTypeObject *type, ...>python -m test test_datetime -m test_tzinfo_now
Running Debug|x64 interpreter...
Using random seed: 389474023
0:00:00 Run 1 test sequentially
0:00:00 [1/1] test_datetime
Windows fatal exception: access violation
Thread 0x00001298 (most recent call first):
File "C:\cp\Lib\test\libregrtest\win_utils.py", line 47 in _update_load
No crash if NUM_KEYWORDS below is 1 in _datetimemodule.c.h:
static PyObject *
datetime_datetime_now(PyTypeObject *type, PyTypeObject *cls, ...
{
...
#define NUM_KEYWORDS 2CPython versions tested on:
3.13, CPython main branch
Operating systems tested on:
Windows
Linked PRs
- gh-117613: Argument Clinic: ensure that
defining_classparams are positional-only #117781 - gh-117613: Enhance test_clinic @defining_class tests #117896
- [3.12] gh-117613: Argument Clinic: ensure that
defining_classparams are positional-only #117939 - gh-117613: Argument Clinic: disallow
defining_classparameter at module level #117950
Activity
erlend-aasland commentedon Apr 8, 2024
Yes, Argument Clinic should explicitly check that
defining_classis a positional parameter.erlend-aasland commentedon Apr 8, 2024
Hm, we should already be checking that. So, perhaps that check is malfunctioning.
pythongh-117613: Enhance test_clinic @defining_class tests
gh-117613: Enhance test_clinic @defining_class tests (#117896)
gh-117613: Argument Clinic: ensure that 'defining_class' params are p…
pythongh-117613: Enhance test_clinic @defining_class tests (python#11…
pythongh-117613: Argument Clinic: ensure that 'defining_class' params…
gh-117613: Argument Clinic: disallow defining class parameter at modu…
[3.12] gh-117613: Argument Clinic: ensure that defining class params …
neonene commentedon Apr 18, 2024
Closing. Thanks, @erlend-aasland, @vstinner.