Raise SystemError on programmical errors in PyArg_Parse*()

[serhiy-storchaka]

BPO	26312
Nosy	@vstinner, @vadmium, @JimJJewett, @serhiy-storchaka
Files	pyarg_parse_error.patch

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = 'https://github.com/serhiy-storchaka'
closed_at = <Date 2016-02-11.11:33:18.682>
created_at = <Date 2016-02-08.19:39:33.798>
labels = ['interpreter-core', 'type-feature']
title = 'Raise SystemError on programmical errors in PyArg_Parse*()'
updated_at = <Date 2016-02-11.11:33:18.681>
user = 'https://github.com/serhiy-storchaka'

bugs.python.org fields:

activity = <Date 2016-02-11.11:33:18.681>
actor = 'serhiy.storchaka'
assignee = 'serhiy.storchaka'
closed = True
closed_date = <Date 2016-02-11.11:33:18.682>
closer = 'serhiy.storchaka'
components = ['Interpreter Core']
creation = <Date 2016-02-08.19:39:33.798>
creator = 'serhiy.storchaka'
dependencies = []
files = ['41859']
hgrepos = []
issue_num = 26312
keywords = ['patch']
message_count = 8.0
messages = ['259877', '259916', '260049', '260059', '260064', '260083', '260084', '260090']
nosy_count = 5.0
nosy_names = ['vstinner', 'python-dev', 'martin.panter', 'Jim.Jewett', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue26312'
versions = ['Python 3.6']

[serhiy-storchaka]

For now programmical errors with the use of PyArg_ParseTuple() cause raising SystemError. But some programmical errors with the use of PyArg_ParseTupleAndKeywords() cause raising RuntimeError. I think that SystemError is the correct exception type.

Proposed patch replaces RuntimeError with SystemError in PyArg_ParseTupleAndKeywords(). This change shouldn't break any code (except CPython tests for PyArg_ParseTupleAndKeywords()), because this exception never raised if PyArg_Parse*() functions are used correctly.

[vadmium]

Seems like a reasonable change and patch to me.

[vstinner]

Yeah, I also expect SystemError from C functions (of the Python C API) badly used.

RuntimeError is more used in programming bugs at Python level.

pyarg_parse_error.patch LGTM.

[jimjjewett]

It feels a bit odd to say that I've performed a triage review given the three people already involved -- but I did, and I think it is ready to commit.

I believe it is a bug fix, but too subtle a bug to justify backporting.

The only question is whether there should be a "What's New?" entry for the change.

[vstinner]

The only question is whether there should be a "What's New?" entry for the change.

I don't think so. It's low level and nobody should see this exception anyway :-) It's an obvious bug in a C extension.

[serhiy-storchaka]

SystemError is not new exception. It could be raised on other programming bugs. In any case I doesn't expect that anybody catches such exceptions.

[python-dev]

New changeset c7eff18f3840 by Serhiy Storchaka in branch 'default':
Issue bpo-26312: SystemError is now raised in all programming bugs with using
https://hg.python.org/cpython/rev/c7eff18f3840

[serhiy-storchaka]

Thanks for your review.