[C API] PyThreadState_GetFrame() and PyFrame_GetCode() should return a strong refrence

[vstinner]

BPO	40429
Nosy	@vstinner
PRs	bpo-40429: PyFrame_GetCode() result cannot be NULL #19772 bpo-40429: PyFrame_GetCode() now returns a strong reference #19773 bpo-40429: Refactor super_init() #19776 bpo-40429: PyThreadState_GetFrame() returns a strong ref #19781

^{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 = None
closed_at = <Date 2020-05-14.01:19:36.786>
created_at = <Date 2020-04-28.21:55:17.533>
labels = ['expert-C-API', '3.9']
title = '[C API] PyThreadState_GetFrame() and PyFrame_GetCode() should return a strong refrence'
updated_at = <Date 2020-05-14.01:19:36.785>
user = 'https://github.com/vstinner'

bugs.python.org fields:

activity = <Date 2020-05-14.01:19:36.785>
actor = 'vstinner'
assignee = 'none'
closed = True
closed_date = <Date 2020-05-14.01:19:36.786>
closer = 'vstinner'
components = ['C API']
creation = <Date 2020-04-28.21:55:17.533>
creator = 'vstinner'
dependencies = []
files = []
hgrepos = []
issue_num = 40429
keywords = ['patch']
message_count = 5.0
messages = ['367570', '367572', '367574', '367594', '367601']
nosy_count = 1.0
nosy_names = ['vstinner']
pr_nums = ['19772', '19773', '19776', '19781']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue40429'
versions = ['Python 3.9']

[vstinner]

I recently added PyThreadState_GetFrame() and PyFrame_GetCode() functions to the C API of Python 3.9.

Currently, these functions return borrowed references.

I asked on capi-sig and Brett confirms that borrowed refrences should be avoided:
https://mail.python.org/archives/list/capi-sig@python.org/thread/LHESBBB3IYTXMBUKQ3WZI5CWB4WUH5YZ/

Borrowed references should be avoidedd!
https://github.com/vstinner/misc/blob/master/cpython/pep-opaque-c-api.rst#borrowed-references

I will work on a PR to modify these functions to return a strong reference instead.

[vstinner]

New changeset 6d86a23 by Victor Stinner in branch 'master':
bpo-40429: PyFrame_GetCode() result cannot be NULL (GH-19772)
6d86a23

[vstinner]

New changeset 8852ad4 by Victor Stinner in branch 'master':
bpo-40429: PyFrame_GetCode() now returns a strong reference (GH-19773)
8852ad4

[vstinner]

New changeset cc0dc7e by Victor Stinner in branch 'master':
bpo-40429: Refactor super_init() (GH-19776)
cc0dc7e

[vstinner]

New changeset 4386b90 by Victor Stinner in branch 'master':
bpo-40429: PyThreadState_GetFrame() returns a strong ref (GH-19781)
4386b90